Merge Redis Functions PR (#9780)

# Redis Function
This PR added the Redis Functions capabilities that were suggested on #8693.
The PR also introduce a big refactoring to the current Lua implementation
(i.e `scripting.c`). The main purpose of the refactoring is to have better
code sharing between the Lua implementation that exists today on Redis
(`scripting.c`) and the new Lua engine that is introduced on this PR.
The refactoring includes code movements and file name changes as well as some
logic changes that need to be carefully reviewed. To make the review easier,
the PR was split into multiple commits. Each commit is deeply described later on
but the main concept is that some commits are just moving code around without
making any logical changes, those commits are less likely to cause any issues
or regressions and can be reviewed fast. Other commits, which perform code and
logic changes, need to be reviewed carefully, but those commits were created
after the code movements so it's pretty easy to see what was changed. To sum up,
it is highly recommended to review this PR commit by commit as it will be easier
to see the changes, it is also recommended to read each commit description
(written below) to understand what was changed on the commit and whether or not
it's just a huge code movement or a logic changes.

## Terminology
Currently, the terminology in Redis is not clearly defined. Scripts refer to Lua
scripts and eval also refers only to Lua. Introducing Redis Function requires
redefining those terms to be able to clearly understand what is been discussed
on each context.
* eval - legacy Lua script implementation.
* Function - new scripting implementation (currently implemented in Lua but in
  the future, it might be other languages like javascript).
* Engine - the component that is responsible for executing functions.
* Script - Function or legacy Lua (executed with `eval` or `evalsha`)

## Refactoring New Structure
Today, the entire scripting logic is located on `scripting.c`. This logic can
be split into 3 main groups:
1. Script management - responsible for storing the scripts that were sent to
   Redis and retrieving them when they need to be run (base on the script sha
   on the current implementation).
2. Script invocation - invoke the script given on `eval` or `evalsha` command
   (this part includes finding the relevant script, preparing the arguments, ..)
3. Interact back with Redis (command invocation)

Those 3 groups are tightly coupled on `scripting.c`. Redis Functions also need
to use those groups logics, for example,  to interact back with Redis or to
execute Lua code. The refactoring attempts to split those 3 groups and define
APIs so that we can reuse the code both on legacy Lua scripts and Redis Functions.

In order to do so we define the following units:
1. script.c: responsible for interaction with Redis from within a script.
2. script_lua.c: responsible to execute Lua code, uses `script.c` to interact
   with Redis from within the Lua code.
3. function_lua.c: contains the Lua engine implementation, uses `script_lua.c`
   to execute the Lua code.
4. functions.c: Contains Redis Functions implementation (`FUNCTION` command,),
   uses `functions_lua.c` if the function it wants to invoke needs the Lua
   engine.
4. eval.c: the original `scripting.c` contains the Lua legacy implementation and
   was refactored to use `script_lua.c` to invoke the Lua code.

## Commits breakdown
Notice: Some small commits are omitted from this list as they are small and
insignificant (for example build fixes)

### First commit - code movements
This commit rename `scripting.c` -> `eval.c` and introduce the new `script_lua.c`
unit. The commit moves relevant code from `eval.c` (`scripting.c`) to
`script_lua.c`, the purpose of moving the code is so that later we will be able
to re-use the code on the Lua engine (`function_lua.c`). The commit only moves
the code without modifying even a single line, so there is a very low risk of
breaking anything and it also makes it much easier to see the changes on the
following commits.
Because the commit does not change the code (only moves it), it does not compile.
But we do not care about it as the only purpose here is to make the review
processes simpler.

### Second commit - move legacy Lua variables into `eval.c`
Today, all Lua-related variables are located on the server struct. The commit
attempt to identify those variable and take them out from the server struct,
leaving only script related variables (variables that later need to be used
also by engines)
The following variable where renamed and left on the server struct:
   * lua_caller 			-> script_caller
   * lua_time_limit 		-> script_time_limit
   * lua_timedout 		-> script_timedout
   * lua_oom 			-> script_oom
   * lua_disable_deny_script 	-> script_disable_deny_script
   * in_eval			-> in_script

The following variables where moved to lctx under eval.c
   * lua
   * lua_client
   * lua_cur_script
   * lua_scripts
   * lua_scripts_mem
   * lua_replicate_commands
   * lua_write_dirty
   * lua_random_dirty
   * lua_multi_emitted
   * lua_repl
   * lua_kill
   * lua_time_start
   * lua_time_snapshot

This commit is in a low risk of introducing any issues and it is just moving
variables around and not changing any logic.

### Third commit - introducing script unit
This commit introduces the `script.c` unit. Its purpose (as described above) is
to provide an API for scripts to interact with Redis. Interaction includes
mostly executing commands, but also other functionalities. The interaction is
done using a `ScriptRunCtx` object that needs to be created by the user and
initialized using `scriptPrepareForRun`. A detailed list of functionalities
expose by the unit:
1. Calling commands (including all the validation checks such as
   acl, cluster, read only run, ...)
2. Set Resp
3. Set Replication method (AOF/REPLICATION/NONE)
4. Call Redis back on long-running scripts to allow Redis to reply to clients
   and perform script kill

The commit introduces the new unit and uses it on eval commands to interact with
Redis.

### Fourth commit - Moved functionality of invoke Lua code to `script_lua.c`
This commit moves the logic of invoking the Lua code into `script_lua.c` so
later it can be used also by Lua engine (`function_lua.c`). The code is located
on `callFunction` function and assumes the Lua function already located on the
top of the Lua stack. This commit also change `eval.c` to use the new
functionality to invoke Lua code.

### Fith commit - Added Redis Functions unit (`functions.c`) and Lua engine
(`function_lua.c`)
Added Redis Functions unit under `functions.c`, included:
1. FUNCTION command:
     * FUNCTION CREATE
     * FUNCTION CALL
     * FUNCTION DELETE
     * FUNCTION KILL
     * FUNCTION INFO
     * FUNCTION STATS
2. Register engines

In addition, this commit introduces the first engine that uses the Redis
Functions capabilities, the Lua engine (`function_lua.c`)

## API Changes
### `lua-time-limit`
configuration was renamed to `script-time-limit` (keep `lua-time-limit` as alias
for backward compatibility).

### Error log changes
When integrating with Redis from within a Lua script, the `Lua` term was removed
from all the error messages and instead we write only `script`. For example:
`Wrong number of args calling Redis command From Lua script` -> `Wrong number
of args calling Redis command From script`

### `info memory` changes:
Before stating all the changes made to memory stats we will try to explain the
reason behind them and what we want to see on those metrics:
* memory metrics should show both totals (for all scripting frameworks), as well
  as a breakdown per framework / vm.
* The totals metrics should have "human" metrics while the breakdown shouldn't.
* We did try to maintain backward compatibility in some way, that said we did
  make some repurpose to existing metrics where it looks reasonable.
* We separate between memory used by the script framework (part of redis's
  used_memory), and memory used by the VM (not part of redis's used_memory)

A full breakdown of `info memory` changes:
* `used_memory_lua` and `used_memory_lua_human` was deprecated,
  `used_memory_vm_eval` has the same meaning as `used_memory_lua`
* `used_memory_scripts` was renamed to `used_memory_scripts_eval`
* `used_memory_scripts` and `used_memory_scripts_human` were repurposed and now
  return the total memory used by functions and eval (not including vm memory,
  only code cache, and structs).
* `used_memory_vm_function` was added and represents the total memory used by
  functions vm's
* `used_memory_functions` was added and represents the total memory by functions
  (not including vm memory, only code cache, and structs)
* `used_memory_vm_total` and `used_memory_vm_total_human` was added and
  represents the total memory used by vm's (functions and eval combined)

### `functions.caches`
`functions.caches` field was added to `memory stats`, representing the memory
used by engines that are not functions (this memory includes data structures
like dictionaries, arrays, ...)

## New API
### FUNCTION CREATE

Usage: FUNCTION CREATE `ENGINE` `NAME` `[REPLACE]` `[DESC <DESCRIPTION>]` `<CODE>`

* `ENGINE` - The name of the engine to use to create the script.
* `NAME` - the name of the function that can be used later to call the function
  using `FUNCTION CALL` command.
* `REPLACE` - if given, replace the given function with the existing function
  (if exists).
* `DESCRIPTION` - optional argument describing the function and what it does
* `CODE` - function code.

The command will return `OK` if created successfully or error in the following
cases:
* The given engine name does not exist
* The function name is already taken and `REPLACE` was not used.
* The given function failed on the compilation.

### FCALL and FCALL_RO

Usage: FCALL/FCALL_RO `NAME` `NUM_KEYS key1 key2` … ` arg1 arg2`

Call and execute the function specified by `NAME`. The function will receive
all arguments given after `NUM_KEYS`. The return value from the function will
be returned to the user as a result.

* `NAME` - Name of the function to run.
* The rest is as today with EVALSHA command.

The command will return an error in the following cases:
* `NAME` does not exist
* The function itself returned an error.

The `FCALL_RO` is equivalent to `EVAL_RO` and allows only read-only commands to
be invoked from the script.

### FUNCTION DELETE

Usage: FUNCTION DELETE `NAME`

Delete a function identified by `NAME`. Return `OK` on success or error on one
of the following:
* The given function does not exist

### FUNCTION INFO

Usage: FUNCTION INFO `NAME` [WITHCODE]

Return information about a function by function name:
* Function name
* Engine name
* Description
* Raw code (only if WITHCODE argument is given)

### FUNCTION LIST

Usage: FUNCTION LIST

Return general information about all the functions:
* Function name
* Engine name
* Description

### FUNCTION STATS

Usage: FUNCTION STATS

Return information about the current running function:
* Function name
* Command that was used to invoke the function
* Duration in MS that the function is already running

If no function is currently running, this section is just a RESP nil.

Additionally, return a list of all the available engines.

### FUNCTION KILL

Usage: `FUNCTION KILL`

Kill the currently executing function. The command will fail if the function
already initiated a write command.

## Notes
Note: Function creation/deletion is replicated to AOF but AOFRW is not
implemented sense its going to be removed: #9794

README.md

@@ -443,6 +443,16 @@ This file also implements both the `SYNC` and `PSYNC` commands that are
 used in order to perform the first synchronization between masters and
 replicas, or to continue the replication after a disconnection.
 
+Script
+---
+The script unit is compose of 3 units
+* `script.c` - integration of scripts with Redis (commands execution, set replication/resp, ..)
+* `script_lua.c` - responsible to execute Lua code, uses script.c to interact with Redis from within the Lua code.
+* `function_lua.c` - contains the Lua engine implementation, uses script_lua.c to execute the Lua code.
+* `functions.c` - Contains Redis Functions implementation (FUNCTION command), uses functions_lua.c if the function it wants to invoke needs the Lua engine.
+* `eval.c` - Contains the `eval` implementation using `script_lua.c` to invoke the Lua code.
+
+
 Other C files
 ---
 
@@ -451,7 +461,6 @@ Other C files
 * `sds.c` is the Redis string library, check https://github.com/antirez/sds for more information.
 * `anet.c` is a library to use POSIX networking in a simpler way compared to the raw interface exposed by the kernel.
 * `dict.c` is an implementation of a non-blocking hash table which rehashes incrementally.
-* `scripting.c` implements Lua scripting. It is completely self-contained and isolated from the rest of the Redis implementation and is simple enough to understand if you are familiar with the Lua API.
 * `cluster.c` implements the Redis Cluster. Probably a good read only after being very familiar with the rest of the Redis code base. If you want to read `cluster.c` make sure to read the [Redis Cluster specification][4].
 
 [4]: https://redis.io/topics/cluster-spec

src/Makefile

@@ -309,7 +309,7 @@ endif
 
 REDIS_SERVER_NAME=redis-server$(PROG_SUFFIX)
 REDIS_SENTINEL_NAME=redis-sentinel$(PROG_SUFFIX)
-REDIS_SERVER_OBJ=adlist.o quicklist.o ae.o anet.o dict.o server.o sds.o zmalloc.o lzf_c.o lzf_d.o pqsort.o zipmap.o sha1.o ziplist.o release.o networking.o util.o object.o db.o replication.o rdb.o t_string.o t_list.o t_set.o t_zset.o t_hash.o config.o aof.o pubsub.o multi.o debug.o sort.o intset.o syncio.o cluster.o crc16.o endianconv.o slowlog.o scripting.o bio.o rio.o rand.o memtest.o crcspeed.o crc64.o bitops.o sentinel.o notify.o setproctitle.o blocked.o hyperloglog.o latency.o sparkline.o redis-check-rdb.o redis-check-aof.o geo.o lazyfree.o module.o evict.o expire.o geohash.o geohash_helper.o childinfo.o defrag.o siphash.o rax.o t_stream.o listpack.o localtime.o lolwut.o lolwut5.o lolwut6.o acl.o tracking.o connection.o tls.o sha256.o timeout.o setcpuaffinity.o monotonic.o mt19937-64.o resp_parser.o call_reply.o
+REDIS_SERVER_OBJ=adlist.o quicklist.o ae.o anet.o dict.o server.o sds.o zmalloc.o lzf_c.o lzf_d.o pqsort.o zipmap.o sha1.o ziplist.o release.o networking.o util.o object.o db.o replication.o rdb.o t_string.o t_list.o t_set.o t_zset.o t_hash.o config.o aof.o pubsub.o multi.o debug.o sort.o intset.o syncio.o cluster.o crc16.o endianconv.o slowlog.o eval.o bio.o rio.o rand.o memtest.o crcspeed.o crc64.o bitops.o sentinel.o notify.o setproctitle.o blocked.o hyperloglog.o latency.o sparkline.o redis-check-rdb.o redis-check-aof.o geo.o lazyfree.o module.o evict.o expire.o geohash.o geohash_helper.o childinfo.o defrag.o siphash.o rax.o t_stream.o listpack.o localtime.o lolwut.o lolwut5.o lolwut6.o acl.o tracking.o connection.o tls.o sha256.o timeout.o setcpuaffinity.o monotonic.o mt19937-64.o resp_parser.o call_reply.o script_lua.o script.o functions.o function_lua.o
 REDIS_CLI_NAME=redis-cli$(PROG_SUFFIX)
 REDIS_CLI_OBJ=anet.o adlist.o dict.o redis-cli.o zmalloc.o release.o ae.o redisassert.o crcspeed.o crc64.o siphash.o crc16.o monotonic.o cli_common.o mt19937-64.o
 REDIS_BENCHMARK_NAME=redis-benchmark$(PROG_SUFFIX)

src/acl.c

@@ -1897,7 +1897,7 @@ void addACLLogEntry(client *c, int reason, int context, int argpos, sds username
     }
 
     client *realclient = c;
-    if (realclient->flags & CLIENT_LUA) realclient = server.lua_caller;
+    if (realclient->flags & CLIENT_SCRIPT) realclient = server.script_caller;
 
     le->cinfo = catClientInfoString(sdsempty(),realclient);
     le->context = context;

src/aof.c

@@ -30,6 +30,7 @@
 #include "server.h"
 #include "bio.h"
 #include "rio.h"
+#include "functions.h"
 
 #include <signal.h>
 #include <fcntl.h>
@@ -754,7 +755,8 @@ int loadAppendOnlyFile(char *filename) {
         serverLog(LL_NOTICE,"Reading RDB preamble from AOF file...");
         if (fseek(fp,0,SEEK_SET) == -1) goto readerr;
         rioInitWithFile(&rdb,fp);
-        if (rdbLoadRio(&rdb,RDBFLAGS_AOF_PREAMBLE,NULL,server.db) != C_OK) {
+
+        if (rdbLoadRio(&rdb,RDBFLAGS_AOF_PREAMBLE,NULL) != C_OK) {
             serverLog(LL_WARNING,"Error reading the RDB preamble of the AOF file, AOF loading aborted");
             goto readerr;
         } else {

src/config.c

@@ -2650,7 +2650,7 @@ standardConfig configs[] = {
     createULongConfig("acllog-max-len", NULL, MODIFIABLE_CONFIG, 0, LONG_MAX, server.acllog_max_len, 128, INTEGER_CONFIG, NULL, NULL),
 
     /* Long Long configs */
-    createLongLongConfig("lua-time-limit", NULL, MODIFIABLE_CONFIG, 0, LONG_MAX, server.lua_time_limit, 5000, INTEGER_CONFIG, NULL, NULL),/* milliseconds */
+    createLongLongConfig("script-time-limit", "lua-time-limit", MODIFIABLE_CONFIG, 0, LONG_MAX, server.script_time_limit, 5000, INTEGER_CONFIG, NULL, NULL),/* milliseconds */
     createLongLongConfig("cluster-node-timeout", NULL, MODIFIABLE_CONFIG, 0, LLONG_MAX, server.cluster_node_timeout, 15000, INTEGER_CONFIG, NULL, NULL),
     createLongLongConfig("slowlog-log-slower-than", NULL, MODIFIABLE_CONFIG, -1, LLONG_MAX, server.slowlog_log_slower_than, 10000, INTEGER_CONFIG, NULL, NULL),
     createLongLongConfig("latency-monitor-threshold", NULL, MODIFIABLE_CONFIG, 0, LLONG_MAX, server.latency_monitor_threshold, 0, INTEGER_CONFIG, NULL, NULL),

src/db.c

@@ -31,6 +31,7 @@
 #include "cluster.h"
 #include "atomicvar.h"
 #include "latency.h"
+#include "script.h"
 
 #include <signal.h>
 #include <ctype.h>
@@ -88,7 +89,7 @@ robj *lookupKey(redisDb *db, robj *key, int flags) {
              * commands is to make writable replicas behave consistently. It
              * shall not be used in readonly commands. Modules are accepted so
              * that we don't break old modules. */
-            client *c = server.in_eval ? server.lua_client : server.current_client;
+            client *c = server.in_script ? scriptGetClient() : server.current_client;
             serverAssert(!c || !c->cmd || (c->cmd->flags & (CMD_WRITE|CMD_MODULE)));
         }
         if (expireIfNeeded(db, key, force_delete_expired)) {
@@ -1501,8 +1502,8 @@ int keyIsExpired(redisDb *db, robj *key) {
      * only the first time it is accessed and not in the middle of the
      * script execution, making propagation to slaves / AOF consistent.
      * See issue #1525 on Github for more information. */
-    if (server.lua_caller) {
-        now = server.lua_time_snapshot;
+    if (server.script_caller) {
+        now = evalTimeSnapshot();
     }
     /* If we are in the middle of a command execution, we still want to use
      * a reference time that does not change: in that case we just use the
@@ -1743,6 +1744,11 @@ int evalGetKeys(struct redisCommand *cmd, robj **argv, int argc, getKeysResult *
     return genericGetKeys(0, 2, 3, 1, argv, argc, result);
 }
 
+int functionGetKeys(struct redisCommand *cmd, robj **argv, int argc, getKeysResult *result) {
+    UNUSED(cmd);
+    return genericGetKeys(0, 2, 3, 1, argv, argc, result);
+}
+
 int lmpopGetKeys(struct redisCommand *cmd, robj **argv, int argc, getKeysResult *result) {
     UNUSED(cmd);
     return genericGetKeys(0, 1, 2, 1, argv, argc, result);

src/debug.c

@@ -919,7 +919,7 @@ NULL
         addReplyStatus(c,"Apparently Redis did not crash: test passed");
     } else if (!strcasecmp(c->argv[1]->ptr,"set-disable-deny-scripts") && c->argc == 3)
     {
-        server.lua_disable_deny_script = atoi(c->argv[2]->ptr);;
+        server.script_disable_deny_script = atoi(c->argv[2]->ptr);;
         addReply(c,shared.ok);
     } else if (!strcasecmp(c->argv[1]->ptr,"config-rewrite-force-all") && c->argc == 2)
     {

src/defrag.c

@@ -939,7 +939,7 @@ long defragOtherGlobals() {
     /* there are many more pointers to defrag (e.g. client argv, output / aof buffers, etc.
      * but we assume most of these are short lived, we only need to defrag allocations
      * that remain static for a long time */
-    defragged += activeDefragSdsDict(server.lua_scripts, DEFRAG_SDS_DICT_VAL_IS_STROB);
+    defragged += activeDefragSdsDict(evalScriptsDict(), DEFRAG_SDS_DICT_VAL_IS_STROB);
     defragged += activeDefragSdsListAndDict(server.repl_scriptcache_fifo, server.repl_scriptcache_dict, DEFRAG_SDS_DICT_NO_VAL);
     defragged += moduleDefragGlobals();
     return defragged;

src/evict.c

@@ -33,6 +33,7 @@
 #include "server.h"
 #include "bio.h"
 #include "atomicvar.h"
+#include "script.h"
 #include <math.h>
 
 /* ----------------------------------------------------------------------------
@@ -472,7 +473,7 @@ static int evictionTimeProc(
 static int isSafeToPerformEvictions(void) {
     /* - There must be no script in timeout condition.
      * - Nor we are loading data right now.  */
-    if (server.lua_timedout || server.loading) return 0;
+    if (scriptIsTimedout() || server.loading) return 0;
 
     /* By default replicas should ignore maxmemory
      * and just be masters exact copies. */

src/function_lua.c

@@ -0,0 +1,183 @@
+/*
+ * Copyright (c) 2021, Redis Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * function_lua.c unit provides the Lua engine functionality.
+ * Including registering the engine and implementing the engine
+ * callbacks:
+ * * Create a function from blob (usually text)
+ * * Invoke a function
+ * * Free function memory
+ * * Get memory usage
+ *
+ * Uses script_lua.c to run the Lua code.
+ */
+
+#include "functions.h"
+#include "script_lua.h"
+#include <lua.h>
+#include <lauxlib.h>
+#include <lualib.h>
+
+#define LUA_ENGINE_NAME "LUA"
+#define REGISTRY_ENGINE_CTX_NAME "__ENGINE_CTX__"
+#define REGISTRY_ERROR_HANDLER_NAME "__ERROR_HANDLER__"
+
+/* Lua engine ctx */
+typedef struct luaEngineCtx {
+    lua_State *lua;
+} luaEngineCtx;
+
+/* Lua function ctx */
+typedef struct luaFunctionCtx {
+    /* Special ID that allows getting the Lua function object from the Lua registry */
+    int lua_function_ref;
+} luaFunctionCtx;
+
+/*
+ * Compile a given blob and save it on the registry.
+ * Return a function ctx with Lua ref that allows to later retrieve the
+ * function from the registry.
+ *
+ * Return NULL on compilation error and set the error to the err variable
+ */
+static void* luaEngineCreate(void *engine_ctx, sds blob, sds *err) {
+    luaEngineCtx *lua_engine_ctx = engine_ctx;
+    lua_State *lua = lua_engine_ctx->lua;
+    if (luaL_loadbuffer(lua, blob, sdslen(blob), "@user_function")) {
+        *err = sdsempty();
+        *err = sdscatprintf(*err, "Error compiling function: %s",
+                lua_tostring(lua, -1));
+        lua_pop(lua, 1);
+        return NULL;
+    }
+
+    serverAssert(lua_isfunction(lua, -1));
+
+    int lua_function_ref = luaL_ref(lua, LUA_REGISTRYINDEX);
+
+    luaFunctionCtx *f_ctx = zmalloc(sizeof(*f_ctx));
+    *f_ctx = (luaFunctionCtx ) { .lua_function_ref = lua_function_ref, };
+
+    return f_ctx;
+}
+
+/*
+ * Invole the give function with the given keys and args
+ */
+static void luaEngineCall(scriptRunCtx *run_ctx,
+                          void *engine_ctx,
+                          void *compiled_function,
+                          robj **keys,
+                          size_t nkeys,
+                          robj **args,
+                          size_t nargs)
+{
+    luaEngineCtx *lua_engine_ctx = engine_ctx;
+    lua_State *lua = lua_engine_ctx->lua;
+    luaFunctionCtx *f_ctx = compiled_function;
+
+    /* Push error handler */
+    lua_pushstring(lua, REGISTRY_ERROR_HANDLER_NAME);
+    lua_gettable(lua, LUA_REGISTRYINDEX);
+
+    lua_rawgeti(lua, LUA_REGISTRYINDEX, f_ctx->lua_function_ref);
+
+    serverAssert(lua_isfunction(lua, -1));
+
+    luaCallFunction(run_ctx, lua, keys, nkeys, args, nargs, 0);
+    lua_pop(lua, 1); /* Pop error handler */
+}
+
+static size_t luaEngineGetUsedMemoy(void *engine_ctx) {
+    luaEngineCtx *lua_engine_ctx = engine_ctx;
+    return luaMemory(lua_engine_ctx->lua);
+}
+
+static size_t luaEngineFunctionMemoryOverhead(void *compiled_function) {
+    return zmalloc_size(compiled_function);
+}
+
+static size_t luaEngineMemoryOverhead(void *engine_ctx) {
+    luaEngineCtx *lua_engine_ctx = engine_ctx;
+    return zmalloc_size(lua_engine_ctx);
+}
+
+static void luaEngineFreeFunction(void *engine_ctx, void *compiled_function) {
+    luaEngineCtx *lua_engine_ctx = engine_ctx;
+    lua_State *lua = lua_engine_ctx->lua;
+    luaFunctionCtx *f_ctx = compiled_function;
+    lua_unref(lua, f_ctx->lua_function_ref);
+    zfree(f_ctx);
+}
+
+/* Initialize Lua engine, should be called once on start. */
+int luaEngineInitEngine() {
+    luaEngineCtx *lua_engine_ctx = zmalloc(sizeof(*lua_engine_ctx));
+    lua_engine_ctx->lua = lua_open();
+
+    luaRegisterRedisAPI(lua_engine_ctx->lua);
+
+    /* Save error handler to registry */
+    lua_pushstring(lua_engine_ctx->lua, REGISTRY_ERROR_HANDLER_NAME);
+    char *errh_func =       "local dbg = debug\n"
+                            "local error_handler = function (err)\n"
+                            "  local i = dbg.getinfo(2,'nSl')\n"
+                            "  if i and i.what == 'C' then\n"
+                            "    i = dbg.getinfo(3,'nSl')\n"
+                            "  end\n"
+                            "  if i then\n"
+                            "    return i.source .. ':' .. i.currentline .. ': ' .. err\n"
+                            "  else\n"
+                            "    return err\n"
+                            "  end\n"
+                            "end\n"
+                            "return error_handler";
+    luaL_loadbuffer(lua_engine_ctx->lua, errh_func, strlen(errh_func), "@err_handler_def");
+    lua_pcall(lua_engine_ctx->lua,0,1,0);
+    lua_settable(lua_engine_ctx->lua, LUA_REGISTRYINDEX);
+
+    /* save the engine_ctx on the registry so we can get it from the Lua interpreter */
+    luaSaveOnRegistry(lua_engine_ctx->lua, REGISTRY_ENGINE_CTX_NAME, lua_engine_ctx);
+
+    luaEnableGlobalsProtection(lua_engine_ctx->lua, 0);
+
+
+    engine *lua_engine = zmalloc(sizeof(*lua_engine));
+    *lua_engine = (engine) {
+        .engine_ctx = lua_engine_ctx,
+        .create = luaEngineCreate,
+        .call = luaEngineCall,
+        .get_used_memory = luaEngineGetUsedMemoy,
+        .get_function_memory_overhead = luaEngineFunctionMemoryOverhead,
+        .get_engine_memory_overhead = luaEngineMemoryOverhead,
+        .free_function = luaEngineFreeFunction,
+    };
+    return functionsRegisterEngine(LUA_ENGINE_NAME, lua_engine);
+}

src/functions.c

@@ -0,0 +1,538 @@
+/*
+ * Copyright (c) 2021, Redis Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "functions.h"
+#include "sds.h"
+#include "dict.h"
+#include "adlist.h"
+#include "atomicvar.h"
+
+static size_t engine_cache_memory = 0;
+
+/* Forward declaration */
+static void engineFunctionDispose(dict *d, void *obj);
+
+struct functionsCtx {
+    dict *functions;    /* Function name -> Function object that can be used to run the function */
+    size_t cache_memory /* Overhead memory (structs, dictionaries, ..) used by all the functions */;
+};
+
+dictType engineDictType = {
+        dictSdsCaseHash,       /* hash function */
+        dictSdsDup,            /* key dup */
+        NULL,                  /* val dup */
+        dictSdsKeyCaseCompare, /* key compare */
+        dictSdsDestructor,     /* key destructor */
+        NULL,                  /* val destructor */
+        NULL                   /* allow to expand */
+};
+
+dictType functionDictType = {
+        dictSdsHash,          /* hash function */
+        dictSdsDup,           /* key dup */
+        NULL,                 /* val dup */
+        dictSdsKeyCompare,    /* key compare */
+        dictSdsDestructor,    /* key destructor */
+        engineFunctionDispose,/* val destructor */
+        NULL                  /* allow to expand */
+};
+
+/* Dictionary of engines */
+static dict *engines = NULL;
+
+/* Functions Ctx.
+ * Contains the dictionary that map a function name to
+ * function object and the cache memory used by all the functions */
+static functionsCtx *functions_ctx = NULL;
+
+static size_t functionMallocSize(functionInfo *fi) {
+    return zmalloc_size(fi) + sdsZmallocSize(fi->name)
+            + (fi->desc ? sdsZmallocSize(fi->desc) : 0)
+            + sdsZmallocSize(fi->code)
+            + fi->ei->engine->get_function_memory_overhead(fi->function);
+}
+
+/* Dispose function memory */
+static void engineFunctionDispose(dict *d, void *obj) {
+    UNUSED(d);
+    functionInfo *fi = obj;
+    sdsfree(fi->code);
+    sdsfree(fi->name);
+    if (fi->desc) {
+        sdsfree(fi->desc);
+    }
+    engine *engine = fi->ei->engine;
+    engine->free_function(engine->engine_ctx, fi->function);
+    zfree(fi);
+}
+
+/* Free function memory and detele it from the functions dictionary */
+static void engineFunctionFree(functionInfo *fi, functionsCtx *functions) {
+    functions->cache_memory -= functionMallocSize(fi);
+
+    dictDelete(functions->functions, fi->name);
+}
+
+/* Clear all the functions from the given functions ctx */
+void functionsCtxClear(functionsCtx *functions_ctx) {
+    dictEmpty(functions_ctx->functions, NULL);
+    functions_ctx->cache_memory = 0;
+}
+
+/* Free the given functions ctx */
+void functionsCtxFree(functionsCtx *functions_ctx) {
+    functionsCtxClear(functions_ctx);
+    dictRelease(functions_ctx->functions);
+    zfree(functions_ctx);
+}
+
+/* Swap the current functions ctx with the given one.
+ * Free the old functions ctx. */
+void functionsCtxSwapWithCurrent(functionsCtx *new_functions_ctx) {
+    functionsCtxFree(functions_ctx);
+    functions_ctx = new_functions_ctx;
+}
+
+/* return the current functions ctx */
+functionsCtx* functionsCtxGetCurrent() {
+    return functions_ctx;
+}
+
+/* Create a new functions ctx */
+functionsCtx* functionsCtxCreate() {
+    functionsCtx *ret = zmalloc(sizeof(functionsCtx));
+    ret->functions = dictCreate(&functionDictType);
+    ret->cache_memory = 0;
+    return ret;
+}
+
+/*
+ * Register a function info to functions dictionary
+ * 1. Set the function client
+ * 2. Add function to functions dictionary
+ * 3. update cache memory
+ */
+static void engineFunctionRegister(functionInfo *fi, functionsCtx *functions) {
+    int res = dictAdd(functions->functions, fi->name, fi);
+    serverAssert(res == DICT_OK);
+
+    functions->cache_memory += functionMallocSize(fi);
+}
+
+/*
+ * Creating a function info object and register it.
+ * Return the created object
+ */
+static functionInfo* engineFunctionCreate(sds name, void *function, engineInfo *ei,
+        sds desc, sds code, functionsCtx *functions)
+{
+
+    functionInfo *fi = zmalloc(sizeof(*fi));
+    *fi = (functionInfo ) {
+        .name = sdsdup(name),
+        .function = function,
+        .ei = ei,
+        .code = sdsdup(code),
+        .desc = desc ? sdsdup(desc) : NULL,
+    };
+
+    engineFunctionRegister(fi, functions);
+
+    return fi;
+}
+
+/* Register an engine, should be called once by the engine on startup and give the following:
+ *
+ * - engine_name - name of the engine to register
+ * - engine_ctx - the engine ctx that should be used by Redis to interact with the engine */
+int functionsRegisterEngine(const char *engine_name, engine *engine) {
+    sds engine_name_sds = sdsnew(engine_name);
+    if (dictFetchValue(engines, engine_name_sds)) {
+        serverLog(LL_WARNING, "Same engine was registered twice");
+        sdsfree(engine_name_sds);
+        return C_ERR;
+    }
+
+    client *c = createClient(NULL);
+    c->flags |= (CLIENT_DENY_BLOCKING | CLIENT_SCRIPT);
+    engineInfo *ei = zmalloc(sizeof(*ei));
+    *ei = (engineInfo ) { .name = engine_name_sds, .engine = engine, .c = c,};
+
+    dictAdd(engines, engine_name_sds, ei);
+
+    engine_cache_memory += zmalloc_size(ei) + sdsZmallocSize(ei->name) +
+            zmalloc_size(engine) +
+            engine->get_engine_memory_overhead(engine->engine_ctx);
+
+    return C_OK;
+}
+
+/*
+ * FUNCTION STATS
+ */
+void functionsStatsCommand(client *c) {
+    if (scriptIsRunning() && scriptIsEval()) {
+        addReplyErrorObject(c, shared.slowevalerr);
+        return;
+    }
+
+    addReplyMapLen(c, 2);
+
+    addReplyBulkCString(c, "running_script");
+    if (!scriptIsRunning()) {
+        addReplyNull(c);
+    } else {
+        addReplyMapLen(c, 3);
+        addReplyBulkCString(c, "name");
+        addReplyBulkCString(c, scriptCurrFunction());
+        addReplyBulkCString(c, "command");
+        client *script_client = scriptGetCaller();
+        addReplyArrayLen(c, script_client->argc);
+        for (int i = 0 ; i < script_client->argc ; ++i) {
+            addReplyBulkCBuffer(c, script_client->argv[i]->ptr, sdslen(script_client->argv[i]->ptr));
+        }
+        addReplyBulkCString(c, "duration_ms");
+        addReplyLongLong(c, scriptRunDuration());
+    }
+
+    addReplyBulkCString(c, "engines");
+    addReplyArrayLen(c, dictSize(engines));
+    dictIterator *iter = dictGetIterator(engines);
+    dictEntry *entry = NULL;
+    while ((entry = dictNext(iter))) {
+        engineInfo *ei = dictGetVal(entry);
+        addReplyBulkCString(c, ei->name);
+    }
+    dictReleaseIterator(iter);
+}
+
+/*
+ * FUNCTION LIST
+ */
+void functionsListCommand(client *c) {
+    /* general information on all the functions */
+    addReplyArrayLen(c, dictSize(functions_ctx->functions));
+    dictIterator *iter = dictGetIterator(functions_ctx->functions);
+    dictEntry *entry = NULL;
+    while ((entry = dictNext(iter))) {
+        functionInfo *fi = dictGetVal(entry);
+        addReplyMapLen(c, 3);
+        addReplyBulkCString(c, "name");
+        addReplyBulkCBuffer(c, fi->name, sdslen(fi->name));
+        addReplyBulkCString(c, "engine");
+        addReplyBulkCBuffer(c, fi->ei->name, sdslen(fi->ei->name));
+        addReplyBulkCString(c, "description");
+        if (fi->desc) {
+            addReplyBulkCBuffer(c, fi->desc, sdslen(fi->desc));
+        } else {
+            addReplyNull(c);
+        }
+    }
+    dictReleaseIterator(iter);
+}
+
+/*
+ * FUNCTION INFO <FUNCTION NAME> [WITHCODE]
+ */
+void functionsInfoCommand(client *c) {
+    if (c->argc > 4) {
+        addReplyErrorFormat(c,"wrong number of arguments for '%s' command or subcommand", c->cmd->name);
+        return;
+    }
+    /* dedicated information on specific function */
+    robj *function_name = c->argv[2];
+    int with_code = 0;
+    if (c->argc == 4) {
+        robj *with_code_arg = c->argv[3];
+        if (!strcasecmp(with_code_arg->ptr, "withcode")) {
+            with_code = 1;
+        }
+    }
+
+    functionInfo *fi = dictFetchValue(functions_ctx->functions, function_name->ptr);
+    if (!fi) {
+        addReplyError(c, "Function does not exists");
+        return;
+    }
+    addReplyMapLen(c, with_code? 4 : 3);
+    addReplyBulkCString(c, "name");
+    addReplyBulkCBuffer(c, fi->name, sdslen(fi->name));
+    addReplyBulkCString(c, "engine");
+    addReplyBulkCBuffer(c, fi->ei->name, sdslen(fi->ei->name));
+    addReplyBulkCString(c, "description");
+    if (fi->desc) {
+        addReplyBulkCBuffer(c, fi->desc, sdslen(fi->desc));
+    } else {
+        addReplyNull(c);
+    }
+    if (with_code) {
+        addReplyBulkCString(c, "code");
+        addReplyBulkCBuffer(c, fi->code, sdslen(fi->code));
+    }
+}
+
+/*
+ * FUNCTION DELETE <FUNCTION NAME>
+ */
+void functionsDeleteCommand(client *c) {
+    if (server.masterhost && server.repl_slave_ro && !(c->flags & CLIENT_MASTER)) {
+        addReplyError(c, "Can not delete a function on a read only replica");
+        return;
+    }
+
+    robj *function_name = c->argv[2];
+    functionInfo *fi = dictFetchValue(functions_ctx->functions, function_name->ptr);
+    if (!fi) {
+        addReplyError(c, "Function not found");
+        return;
+    }
+
+    engineFunctionFree(fi, functions_ctx);
+    forceCommandPropagation(c, PROPAGATE_REPL | PROPAGATE_AOF);
+    addReply(c, shared.ok);
+}
+
+void functionsKillCommand(client *c) {
+    scriptKill(c, 0);
+}
+
+static void fcallCommandGeneric(client *c, int ro) {
+    robj *function_name = c->argv[1];
+    functionInfo *fi = dictFetchValue(functions_ctx->functions, function_name->ptr);
+    if (!fi) {
+        addReplyError(c, "Function not found");
+        return;
+    }
+    engine *engine = fi->ei->engine;
+
+    long long numkeys;
+    /* Get the number of arguments that are keys */
+    if (getLongLongFromObject(c->argv[2], &numkeys) != C_OK) {
+        addReplyError(c, "Bad number of keys provided");
+        return;
+    }
+    if (numkeys > (c->argc - 3)) {
+        addReplyError(c, "Number of keys can't be greater than number of args");
+        return;
+    } else if (numkeys < 0) {
+        addReplyError(c, "Number of keys can't be negative");
+        return;
+    }
+
+    scriptRunCtx run_ctx;
+
+    scriptPrepareForRun(&run_ctx, fi->ei->c, c, fi->name);
+    if (ro) {
+        run_ctx.flags |= SCRIPT_READ_ONLY;
+    }
+    engine->call(&run_ctx, engine->engine_ctx, fi->function, c->argv + 3, numkeys,
+                 c->argv + 3 + numkeys, c->argc - 3 - numkeys);
+    scriptResetRun(&run_ctx);
+}
+
+/*
+ * FCALL <FUNCTION NAME> nkeys <key1 .. keyn> <arg1 .. argn>
+ */
+void fcallCommand(client *c) {
+    fcallCommandGeneric(c, 0);
+}
+
+/*
+ * FCALL_RO <FUNCTION NAME> nkeys <key1 .. keyn> <arg1 .. argn>
+ */
+void fcallCommandReadOnly(client *c) {
+    fcallCommandGeneric(c, 1);
+}
+
+void functionsHelpCommand(client *c) {
+    const char *help[] = {
+"CREATE <ENGINE NAME> <FUNCTION NAME> [REPLACE] [DESC <FUNCTION DESCRIPTION>] <FUNCTION CODE>",
+"    Create a new function with the given function name and code.",
+"DELETE <FUNCTION NAME>",
+"    Delete the given function.",
+"INFO <FUNCTION NAME> [WITHCODE]",
+"    For each function, print the following information about the function:",
+"    * Function name",
+"    * The engine used to run the function",
+"    * Function description",
+"    * Function code (only if WITHCODE is given)",
+"LIST",
+"    Return general information on all the functions:",
+"    * Function name",
+"    * The engine used to run the function",
+"    * Function description",
+"STATS",
+"    Return information about the current function running:",
+"    * Function name",
+"    * Command used to run the function",
+"    * Duration in MS that the function is running",
+"    If not function is running, return nil",
+"    In addition, returns a list of available engines.",
+"KILL",
+"    Kill the current running function.",
+NULL };
+    addReplyHelp(c, help);
+}
+
+/* Compile and save the given function, return C_OK on success and C_ERR on failure.
+ * In case on failure the err out param is set with relevant error message */
+int functionsCreateWithFunctionCtx(sds function_name,sds engine_name, sds desc, sds code,
+                                   int replace, sds* err, functionsCtx *functions) {
+    engineInfo *ei = dictFetchValue(engines, engine_name);
+    if (!ei) {
+        *err = sdsnew("Engine not found");
+        return C_ERR;
+    }
+    engine *engine = ei->engine;
+
+    functionInfo *fi = dictFetchValue(functions->functions, function_name);
+    if (fi && !replace) {
+        *err = sdsnew("Function already exists");
+        return C_ERR;
+    }
+
+    void *function = engine->create(engine->engine_ctx, code, err);
+    if (*err) {
+        return C_ERR;
+    }
+
+    if (fi) {
+        /* free the already existing function as we are going to replace it */
+        engineFunctionFree(fi, functions);
+    }
+
+    engineFunctionCreate(function_name, function, ei, desc, code, functions);
+
+    return C_OK;
+}
+
+/*
+ * FUNCTION CREATE <ENGINE NAME> <FUNCTION NAME>
+ *             [REPLACE] [DESC <FUNCTION DESCRIPTION>] <FUNCTION CODE>
+ *
+ * ENGINE NAME     - name of the engine to use the run the function
+ * FUNCTION NAME   - name to use to invoke the function
+ * REPLACE         - optional, replace existing function
+ * DESCRIPTION     - optional, function description
+ * FUNCTION CODE   - function code to pass to the engine
+ */
+void functionsCreateCommand(client *c) {
+
+    if (server.masterhost && server.repl_slave_ro && !(c->flags & CLIENT_MASTER)) {
+        addReplyError(c, "Can not create a function on a read only replica");
+        return;
+    }
+
+    robj *engine_name = c->argv[2];
+    robj *function_name = c->argv[3];
+
+    int replace = 0;
+    int argc_pos = 4;
+    sds desc = NULL;
+    while (argc_pos < c->argc - 1) {
+        robj *next_arg = c->argv[argc_pos++];
+        if (!strcasecmp(next_arg->ptr, "replace")) {
+            replace = 1;
+            continue;
+        }
+        if (!strcasecmp(next_arg->ptr, "description")) {
+            if (argc_pos >= c->argc) {
+                addReplyError(c, "Bad function description");
+                return;
+            }
+            desc = c->argv[argc_pos++]->ptr;
+            continue;
+        }
+    }
+
+    if (argc_pos >= c->argc) {
+        addReplyError(c, "Function code is missing");
+        return;
+    }
+
+    robj *code = c->argv[argc_pos];
+    sds err = NULL;
+    if (functionsCreateWithFunctionCtx(function_name->ptr, engine_name->ptr,
+                                       desc, code->ptr, replace, &err, functions_ctx) != C_OK)
+    {
+        addReplyErrorSds(c, err);
+        return;
+    }
+    forceCommandPropagation(c, PROPAGATE_REPL | PROPAGATE_AOF);
+    addReply(c, shared.ok);
+}
+
+/* Return memory usage of all the engines combine */
+unsigned long functionsMemory() {
+    dictIterator *iter = dictGetIterator(engines);
+    dictEntry *entry = NULL;
+    size_t engines_nemory = 0;
+    while ((entry = dictNext(iter))) {
+        engineInfo *ei = dictGetVal(entry);
+        engine *engine = ei->engine;
+        engines_nemory += engine->get_used_memory(engine->engine_ctx);
+    }
+    dictReleaseIterator(iter);
+
+    return engines_nemory;
+}
+
+/* Return memory overhead of all the engines combine */
+unsigned long functionsMemoryOverhead() {
+    size_t memory_overhead = dictSize(engines) * sizeof(dictEntry) +
+            dictSlots(engines) * sizeof(dictEntry*);
+    memory_overhead += dictSize(functions_ctx->functions) * sizeof(dictEntry) +
+            dictSlots(functions_ctx->functions) * sizeof(dictEntry*) + sizeof(functionsCtx);
+    memory_overhead += functions_ctx->cache_memory;
+    memory_overhead += engine_cache_memory;
+
+    return memory_overhead;
+}
+
+/* Returns the number of functions */
+unsigned long functionsNum() {
+    return dictSize(functions_ctx->functions);
+}
+
+dict* functionsGet() {
+    return functions_ctx->functions;
+}
+
+/* Initialize engine data structures.
+ * Should be called once on server initialization */
+int functionsInit() {
+    engines = dictCreate(&engineDictType);
+    functions_ctx = functionsCtxCreate();
+
+    if (luaEngineInitEngine() != C_OK) {
+        return C_ERR;
+    }
+
+    return C_OK;
+}

src/functions.h

@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2021, Redis Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __FUNCTIONS_H_
+#define __FUNCTIONS_H_
+
+/*
+ * functions.c unit provides the Redis Functions API:
+ * * FUNCTION CREATE
+ * * FUNCTION CALL
+ * * FUNCTION DELETE
+ * * FUNCTION KILL
+ * * FUNCTION INFO
+ *
+ * Also contains implementation for:
+ * * Save/Load function from rdb
+ * * Register engines
+ */
+
+#include "server.h"
+#include "script.h"
+#include "redismodule.h"
+
+typedef struct engine {
+    /* engine specific context */
+    void *engine_ctx;
+
+    /* Create function callback, get the engine_ctx, and function code.
+     * returns NULL on error and set sds to be the error message */
+    void* (*create)(void *engine_ctx, sds code, sds *err);
+
+    /* Invoking a function, r_ctx is an opaque object (from engine POV).
+     * The r_ctx should be used by the engine to interaction with Redis,
+     * such interaction could be running commands, set resp, or set
+     * replication mode
+     */
+    void (*call)(scriptRunCtx *r_ctx, void *engine_ctx, void *compiled_function,
+            robj **keys, size_t nkeys, robj **args, size_t nargs);
+
+    /* get current used memory by the engine */
+    size_t (*get_used_memory)(void *engine_ctx);
+
+    /* Return memory overhead for a given function,
+     * such memory is not counted as engine memory but as general
+     * structs memory that hold different information */
+    size_t (*get_function_memory_overhead)(void *compiled_function);
+
+    /* Return memory overhead for engine (struct size holding the engine)*/
+    size_t (*get_engine_memory_overhead)(void *engine_ctx);
+
+    /* free the given function */
+    void (*free_function)(void *engine_ctx, void *compiled_function);
+} engine;
+
+/* Hold information about an engine.
+ * Used on rdb.c so it must be declared here. */
+typedef struct engineInfo {
+    sds name;       /* Name of the engine */
+    engine *engine; /* engine callbacks that allows to interact with the engine */
+    client *c;      /* Client that is used to run commands */
+} engineInfo;
+
+/* Hold information about the specific function.
+ * Used on rdb.c so it must be declared here. */
+typedef struct functionInfo {
+    sds name;       /* Function name */
+    void *function; /* Opaque object that set by the function's engine and allow it
+                       to run the function, usually it's the function compiled code. */
+    engineInfo *ei; /* Pointer to the function engine */
+    sds code;       /* Function code */
+    sds desc;       /* Function description */
+} functionInfo;
+
+int functionsRegisterEngine(const char *engine_name, engine *engine_ctx);
+int functionsCreateWithFunctionCtx(sds function_name, sds engine_name, sds desc, sds code,
+                                   int replace, sds* err, functionsCtx *functions);
+void functionsCreateCommand(client *c);
+void fcallCommand(client *c);
+void fcallCommandReadOnly(client *c);
+void functionsDeleteCommand(client *c);
+void functionsKillCommand(client *c);
+void functionsStatsCommand(client *c);
+void functionsInfoCommand(client *c);
+void functionsListCommand(client *c);
+void functionsHelpCommand(client *c);
+unsigned long functionsMemory();
+unsigned long functionsMemoryOverhead();
+int functionsLoad(rio *rdb, int ver);
+unsigned long functionsNum();
+dict* functionsGet();
+functionsCtx* functionsCtxGetCurrent();
+functionsCtx* functionsCtxCreate();
+void functionsCtxFree(functionsCtx *functions_ctx);
+void functionsCtxClear(functionsCtx *functions_ctx);
+void functionsCtxSwapWithCurrent(functionsCtx *functions_ctx);
+
+int luaEngineInitEngine();
+int functionsInit();
+
+#endif /* __FUNCTIONS_H_ */

src/module.c

@@ -629,7 +629,7 @@ void moduleHandlePropagationAfterCommandCallback(RedisModuleCtx *ctx) {
 
     /* If this command is executed from with Lua or MULTI/EXEC we do not
      * need to propagate EXEC */
-    if (server.in_eval || server.in_exec) return;
+    if (server.in_script || server.in_exec) return;
 
     /* Handle the replication of the final EXEC, since whatever a command
      * emits is always wrapped around MULTI/EXEC. */
@@ -2333,7 +2333,7 @@ int RM_ReplyWithLongDouble(RedisModuleCtx *ctx, long double ld) {
 void moduleReplicateMultiIfNeeded(RedisModuleCtx *ctx) {
     /* Skip this if client explicitly wrap the command with MULTI, or if
      * the module command was called by a script. */
-    if (server.in_eval || server.in_exec) return;
+    if (server.in_script || server.in_exec) return;
     /* If we already emitted MULTI return ASAP. */
     if (server.propagate_in_transaction) return;
     /* If this is a thread safe context, we do not want to wrap commands
@@ -2709,7 +2709,7 @@ int RM_GetContextFlags(RedisModuleCtx *ctx) {
         }
     }
 
-    if (server.in_eval)
+    if (server.in_script)
         flags |= REDISMODULE_CTX_FLAGS_LUA;
 
     if (server.in_exec)
@@ -6215,7 +6215,7 @@ void unblockClientFromModule(client *c) {
  */
 RedisModuleBlockedClient *moduleBlockClient(RedisModuleCtx *ctx, RedisModuleCmdFunc reply_callback, RedisModuleCmdFunc timeout_callback, void (*free_privdata)(RedisModuleCtx*,void*), long long timeout_ms, RedisModuleString **keys, int numkeys, void *privdata) {
     client *c = ctx->client;
-    int islua = server.in_eval;
+    int islua = server.in_script;
     int ismulti = server.in_exec;
 
     c->bpop.module_blocked_handle = zmalloc(sizeof(RedisModuleBlockedClient));

src/networking.c

@@ -30,6 +30,7 @@
 #include "server.h"
 #include "atomicvar.h"
 #include "cluster.h"
+#include "script.h"
 #include <sys/socket.h>
 #include <sys/uio.h>
 #include <math.h>
@@ -260,7 +261,7 @@ void clientInstallWriteHandler(client *c) {
 int prepareClientToWrite(client *c) {
     /* If it's the Lua client we always return ok without installing any
      * handler since there is no socket at all. */
-    if (c->flags & (CLIENT_LUA|CLIENT_MODULE)) return C_OK;
+    if (c->flags & (CLIENT_SCRIPT|CLIENT_MODULE)) return C_OK;
 
     /* If CLIENT_CLOSE_ASAP flag is set, we need not write anything. */
     if (c->flags & CLIENT_CLOSE_ASAP) return C_ERR;
@@ -1491,7 +1492,7 @@ void freeClientAsync(client *c) {
      * may access the list while Redis uses I/O threads. All the other accesses
      * are in the context of the main thread while the other threads are
      * idle. */
-    if (c->flags & CLIENT_CLOSE_ASAP || c->flags & CLIENT_LUA) return;
+    if (c->flags & CLIENT_CLOSE_ASAP || c->flags & CLIENT_SCRIPT) return;
     c->flags |= CLIENT_CLOSE_ASAP;
     if (server.io_threads_num == 1) {
         /* no need to bother with locking if there's just one thread (the main thread) */
@@ -2199,7 +2200,7 @@ int processInputBuffer(client *c) {
          * condition on the slave. We want just to accumulate the replication
          * stream (instead of replying -BUSY like we do with other clients) and
          * later resume the processing. */
-        if (server.lua_timedout && c->flags & CLIENT_MASTER) break;
+        if (scriptIsTimedout() && c->flags & CLIENT_MASTER) break;
 
         /* CLIENT_CLOSE_AFTER_REPLY closes the connection once the reply is
          * written to the client. Make sure to not let the reply grow after

src/object.c

@@ -29,6 +29,7 @@
  */
 
 #include "server.h"
+#include "functions.h"
 #include <math.h>
 #include <ctype.h>
 
@@ -1203,9 +1204,7 @@ struct redisMemOverhead *getMemoryOverheadData(void) {
     mh->aof_buffer = mem;
     mem_total+=mem;
 
-    mem = server.lua_scripts_mem;
-    mem += dictSize(server.lua_scripts) * sizeof(dictEntry) +
-        dictSlots(server.lua_scripts) * sizeof(dictEntry*);
+    mem = evalScriptsMemory();
     mem += dictSize(server.repl_scriptcache_dict) * sizeof(dictEntry) +
         dictSlots(server.repl_scriptcache_dict) * sizeof(dictEntry*);
     if (listLength(server.repl_scriptcache_fifo) > 0) {
@@ -1214,6 +1213,8 @@ struct redisMemOverhead *getMemoryOverheadData(void) {
     }
     mh->lua_caches = mem;
     mem_total+=mem;
+    mh->functions_caches = functionsMemoryOverhead();
+    mem_total+=mh->functions_caches;
 
     for (j = 0; j < server.dbnum; j++) {
         redisDb *db = server.db+j;
@@ -1325,7 +1326,7 @@ sds getMemoryDoctorReport(void) {
         }
 
         /* Too many scripts are cached? */
-        if (dictSize(server.lua_scripts) > 1000) {
+        if (dictSize(evalScriptsDict()) > 1000) {
             many_scripts = 1;
             num_reports++;
         }
@@ -1529,7 +1530,7 @@ NULL
     } else if (!strcasecmp(c->argv[1]->ptr,"stats") && c->argc == 2) {
         struct redisMemOverhead *mh = getMemoryOverheadData();
 
-        addReplyMapLen(c,25+mh->num_dbs);
+        addReplyMapLen(c,26+mh->num_dbs);
 
         addReplyBulkCString(c,"peak.allocated");
         addReplyLongLong(c,mh->peak_allocated);
@@ -1555,6 +1556,9 @@ NULL
         addReplyBulkCString(c,"lua.caches");
         addReplyLongLong(c,mh->lua_caches);
 
+        addReplyBulkCString(c,"functions.caches");
+        addReplyLongLong(c,mh->functions_caches);
+
         for (size_t j = 0; j < mh->num_dbs; j++) {
             char dbname[32];
             snprintf(dbname,sizeof(dbname),"db.%zd",mh->db[j].dbid);

src/rdb.c

@@ -32,6 +32,7 @@
 #include "zipmap.h"
 #include "endianconv.h"
 #include "stream.h"
+#include "functions.h"
 
 #include <math.h>
 #include <fcntl.h>
@@ -1239,6 +1240,25 @@ int rdbSaveRio(rio *rdb, int *error, int rdbflags, rdbSaveInfo *rsi) {
     if (rdbSaveInfoAuxFields(rdb,rdbflags,rsi) == -1) goto werr;
     if (rdbSaveModulesAux(rdb, REDISMODULE_AUX_BEFORE_RDB) == -1) goto werr;
 
+    /* save functions */
+    dict *functions = functionsGet();
+    dictIterator *iter = dictGetIterator(functions);
+    dictEntry *entry = NULL;
+    while ((entry = dictNext(iter))) {
+        rdbSaveType(rdb, RDB_OPCODE_FUNCTION);
+        functionInfo* fi = dictGetVal(entry);
+        if (rdbSaveRawString(rdb, (unsigned char *) fi->name, sdslen(fi->name)) == -1) goto werr;
+        if (rdbSaveRawString(rdb, (unsigned char *) fi->ei->name, sdslen(fi->ei->name)) == -1) goto werr;
+        if (fi->desc) {
+            if (rdbSaveLen(rdb, 1) == -1) goto werr; /* desc exists */
+            if (rdbSaveRawString(rdb, (unsigned char *) fi->desc, sdslen(fi->desc)) == -1) goto werr;
+        } else {
+            if (rdbSaveLen(rdb, 0) == -1) goto werr; /* desc not exists */
+        }
+        if (rdbSaveRawString(rdb, (unsigned char *) fi->code, sdslen(fi->code)) == -1) goto werr;
+    }
+    dictReleaseIterator(iter);
+
     for (j = 0; j < server.dbnum; j++) {
         redisDb *db = server.db+j;
         dict *d = db->dict;
@@ -1303,8 +1323,8 @@ int rdbSaveRio(rio *rdb, int *error, int rdbflags, rdbSaveInfo *rsi) {
      * the script cache as well: on successful PSYNC after a restart, we need
      * to be able to process any EVALSHA inside the replication backlog the
      * master will send us. */
-    if (rsi && dictSize(server.lua_scripts)) {
-        di = dictGetIterator(server.lua_scripts);
+    if (rsi && dictSize(evalScriptsDict())) {
+        di = dictGetIterator(evalScriptsDict());
         while((de = dictNext(di)) != NULL) {
             robj *body = dictGetVal(de);
             if (rdbSaveAuxField(rdb,"lua",3,body->ptr,sdslen(body->ptr)) == -1)
@@ -2687,12 +2707,80 @@ void rdbLoadProgressCallback(rio *r, const void *buf, size_t len) {
     }
 }
 
+static int rdbFunctionLoad(rio *rdb, int ver, functionsCtx* functions_ctx) {
+    UNUSED(ver);
+    sds name = NULL;
+    sds engine_name = NULL;
+    sds desc = NULL;
+    sds blob = NULL;
+    sds err = NULL;
+    uint64_t has_desc;
+    int res = C_ERR;
+    if (!(name = rdbGenericLoadStringObject(rdb, RDB_LOAD_SDS, NULL))) {
+        serverLog(LL_WARNING, "Failed loading function name");
+        goto error;
+    }
+
+    if (!(engine_name = rdbGenericLoadStringObject(rdb, RDB_LOAD_SDS, NULL))) {
+        serverLog(LL_WARNING, "Failed loading engine name");
+        goto error;
+    }
+
+    if ((has_desc = rdbLoadLen(rdb, NULL)) == RDB_LENERR) {
+        serverLog(LL_WARNING, "Failed loading function desc indicator");
+        goto error;
+    }
+
+    if (has_desc && !(desc = rdbGenericLoadStringObject(rdb, RDB_LOAD_SDS, NULL))) {
+        serverLog(LL_WARNING, "Failed loading function desc");
+        goto error;
+    }
+
+    if (!(blob = rdbGenericLoadStringObject(rdb, RDB_LOAD_SDS, NULL))) {
+        serverLog(LL_WARNING, "Failed loading function blob");
+        goto error;
+    }
+
+    if (functionsCreateWithFunctionCtx(name, engine_name, desc, blob, 0, &err, functions_ctx) != C_OK) {
+        serverLog(LL_WARNING, "Failed compiling and saving the function %s", err);
+        goto error;
+    }
+
+    res = C_OK;
+
+error:
+    if (name) sdsfree(name);
+    if (engine_name) sdsfree(engine_name);
+    if (desc) sdsfree(desc);
+    if (blob) sdsfree(blob);
+    if (err)  sdsfree(err);
+    return res;
+}
+
 /* Load an RDB file from the rio stream 'rdb'. On success C_OK is returned,
  * otherwise C_ERR is returned and 'errno' is set accordingly. */
-int rdbLoadRio(rio *rdb, int rdbflags, rdbSaveInfo *rsi, redisDb *dbarray) {
+int rdbLoadRio(rio *rdb, int rdbflags, rdbSaveInfo *rsi) {
+    functionsCtx* functions_ctx = functionsCtxGetCurrent();
+    functionsCtxClear(functions_ctx);
+    rdbLoadingCtx loading_ctx = { .dbarray = server.db, .functions_ctx = functions_ctx };
+    int retval = rdbLoadRioWithLoadingCtx(rdb,rdbflags,rsi,&loading_ctx);
+    if (retval != C_OK) {
+        /* Loading failed, clear the function ctx */
+        functionsCtxClear(functions_ctx);
+    }
+    return retval;
+}
+
+
+/* Load an RDB file from the rio stream 'rdb'. On success C_OK is returned,
+ * otherwise C_ERR is returned and 'errno' is set accordingly. 
+ * The rdb_loading_ctx argument holds objects to which the rdb will be loaded to,
+ * currently it only allow to set db object and functionsCtx to which the data
+ * will be loaded (in the future it might contains more such objects). */
+int rdbLoadRioWithLoadingCtx(rio *rdb, int rdbflags, rdbSaveInfo *rsi, rdbLoadingCtx *rdb_loading_ctx) {
     uint64_t dbid = 0;
     int type, rdbver;
-    redisDb *db = dbarray+0;
+    redisDb *db = rdb_loading_ctx->dbarray+0;
     char buf[1024];
     int error;
     long long empty_keys_skipped = 0;
@@ -2764,7 +2852,7 @@ int rdbLoadRio(rio *rdb, int rdbflags, rdbSaveInfo *rsi, redisDb *dbarray) {
                     "databases. Exiting\n", server.dbnum);
                 exit(1);
             }
-            db = dbarray+dbid;
+            db = rdb_loading_ctx->dbarray+dbid;
             continue; /* Read next opcode. */
         } else if (type == RDB_OPCODE_RESIZEDB) {
             /* RESIZEDB: Hint about the size of the keys in the currently
@@ -2808,7 +2896,7 @@ int rdbLoadRio(rio *rdb, int rdbflags, rdbSaveInfo *rsi, redisDb *dbarray) {
                 if (rsi) rsi->repl_offset = strtoll(auxval->ptr,NULL,10);
             } else if (!strcasecmp(auxkey->ptr,"lua")) {
                 /* Load the script back in memory. */
-                if (luaCreateFunction(NULL,server.lua,auxval) == NULL) {
+                if (luaCreateFunction(NULL, auxval) == NULL) {
                     rdbReportCorruptRDB(
                         "Can't load Lua script from RDB file! "
                         "BODY: %s", (char*)auxval->ptr);
@@ -2895,6 +2983,12 @@ int rdbLoadRio(rio *rdb, int rdbflags, rdbSaveInfo *rsi, redisDb *dbarray) {
                 decrRefCount(aux);
                 continue; /* Read next opcode. */
             }
+        } else if (type == RDB_OPCODE_FUNCTION) {
+            if (rdbFunctionLoad(rdb, rdbver, rdb_loading_ctx->functions_ctx) != C_OK) {
+                serverLog(LL_WARNING,"Failed loading function");
+                goto eoferr;
+            }
+            continue;
         }
 
         /* Read key */
@@ -3044,7 +3138,9 @@ int rdbLoad(char *filename, rdbSaveInfo *rsi, int rdbflags) {
     if ((fp = fopen(filename,"r")) == NULL) return C_ERR;
     startLoadingFile(fp, filename,rdbflags);
     rioInitWithFile(&rdb,fp);
-    retval = rdbLoadRio(&rdb,rdbflags,rsi,server.db);
+
+    retval = rdbLoadRio(&rdb,rdbflags,rsi);
+
     fclose(fp);
     stopLoading(retval==C_OK);
     return retval;

src/rdb.h

@@ -100,6 +100,7 @@
 #define rdbIsObjectType(t) ((t >= 0 && t <= 7) || (t >= 9 && t <= 18))
 
 /* Special RDB opcodes (saved/loaded with rdbSaveType/rdbLoadType). */
+#define RDB_OPCODE_FUNCTION   246   /* engine data */
 #define RDB_OPCODE_MODULE_AUX 247   /* Module auxiliary data. */
 #define RDB_OPCODE_IDLE       248   /* LRU idle time. */
 #define RDB_OPCODE_FREQ       249   /* LFU frequency. */
@@ -166,7 +167,8 @@ int rdbSaveBinaryDoubleValue(rio *rdb, double val);
 int rdbLoadBinaryDoubleValue(rio *rdb, double *val);
 int rdbSaveBinaryFloatValue(rio *rdb, float val);
 int rdbLoadBinaryFloatValue(rio *rdb, float *val);
-int rdbLoadRio(rio *rdb, int rdbflags, rdbSaveInfo *rsi, redisDb *db);
+int rdbLoadRio(rio *rdb, int rdbflags, rdbSaveInfo *rsi);
+int rdbLoadRioWithLoadingCtx(rio *rdb, int rdbflags, rdbSaveInfo *rsi, rdbLoadingCtx *rdb_loading_ctx);
 int rdbSaveRio(rio *rdb, int *error, int rdbflags, rdbSaveInfo *rsi);
 rdbSaveInfo *rdbPopulateSaveInfo(rdbSaveInfo *rsi);
 

src/replication.c

@@ -32,6 +32,7 @@
 #include "server.h"
 #include "cluster.h"
 #include "bio.h"
+#include "functions.h"
 
 #include <memory.h>
 #include <sys/time.h>
@@ -546,7 +547,7 @@ void replicationFeedMonitors(client *c, list *monitors, int dictid, robj **argv,
 
     gettimeofday(&tv,NULL);
     cmdrepr = sdscatprintf(cmdrepr,"%ld.%06ld ",(long)tv.tv_sec,(long)tv.tv_usec);
-    if (c->flags & CLIENT_LUA) {
+    if (c->flags & CLIENT_SCRIPT) {
         cmdrepr = sdscatprintf(cmdrepr,"[%d lua] ",dictid);
     } else if (c->flags & CLIENT_UNIX_SOCKET) {
         cmdrepr = sdscatprintf(cmdrepr,"[%d unix:%s] ",dictid,server.unixsocket);
@@ -1738,6 +1739,7 @@ void readSyncBulkPayload(connection *conn) {
     ssize_t nread, readlen, nwritten;
     int use_diskless_load = useDisklessLoad();
     redisDb *diskless_load_tempDb = NULL;
+    functionsCtx* temp_functions_ctx = NULL;
     int empty_db_flags = server.repl_slave_lazy_flush ? EMPTYDB_ASYNC :
                                                         EMPTYDB_NO_FLAGS;
     off_t left;
@@ -1913,6 +1915,7 @@ void readSyncBulkPayload(connection *conn) {
     if (use_diskless_load && server.repl_diskless_load == REPL_DISKLESS_LOAD_SWAPDB) {
         /* Initialize empty tempDb dictionaries. */
         diskless_load_tempDb = disklessLoadInitTempDb();
+        temp_functions_ctx = functionsCtxCreate();
 
         moduleFireServerEvent(REDISMODULE_EVENT_REPL_ASYNC_LOAD,
                               REDISMODULE_SUBEVENT_REPL_ASYNC_LOAD_STARTED,
@@ -1935,6 +1938,7 @@ void readSyncBulkPayload(connection *conn) {
     if (use_diskless_load) {
         rio rdb;
         redisDb *dbarray;
+        functionsCtx* functions_ctx;
         int asyncLoading = 0;
 
         if (server.repl_diskless_load == REPL_DISKLESS_LOAD_SWAPDB) {
@@ -1947,8 +1951,11 @@ void readSyncBulkPayload(connection *conn) {
                 asyncLoading = 1;
             }
             dbarray = diskless_load_tempDb;
+            functions_ctx = temp_functions_ctx;
         } else {
             dbarray = server.db;
+            functions_ctx = functionsCtxGetCurrent();
+            functionsCtxClear(functions_ctx);
         }
 
         rioInitWithConn(&rdb,conn,server.repl_transfer_size);
@@ -1960,7 +1967,8 @@ void readSyncBulkPayload(connection *conn) {
         startLoading(server.repl_transfer_size, RDBFLAGS_REPLICATION, asyncLoading);
 
         int loadingFailed = 0;
-        if (rdbLoadRio(&rdb,RDBFLAGS_REPLICATION,&rsi,dbarray) != C_OK) {
+        rdbLoadingCtx loadingCtx = { .dbarray = dbarray, .functions_ctx = functions_ctx };
+        if (rdbLoadRioWithLoadingCtx(&rdb,RDBFLAGS_REPLICATION,&rsi,&loadingCtx) != C_OK) {
             /* RDB loading failed. */
             serverLog(LL_WARNING,
                       "Failed trying to load the MASTER synchronization DB "
@@ -1988,6 +1996,7 @@ void readSyncBulkPayload(connection *conn) {
                                       NULL);
 
                 disklessLoadDiscardTempDb(diskless_load_tempDb);
+                functionsCtxFree(temp_functions_ctx);
                 serverLog(LL_NOTICE, "MASTER <-> REPLICA sync: Discarding temporary DB in background");
             } else {
                 /* Remove the half-loaded data in case we started with an empty replica. */
@@ -2010,6 +2019,9 @@ void readSyncBulkPayload(connection *conn) {
             serverLog(LL_NOTICE, "MASTER <-> REPLICA sync: Swapping active DB with loaded DB");
             swapMainDbWithTempDb(diskless_load_tempDb);
 
+            /* swap existing functions ctx with the temporary one */
+            functionsCtxSwapWithCurrent(temp_functions_ctx);
+
             moduleFireServerEvent(REDISMODULE_EVENT_REPL_ASYNC_LOAD,
                         REDISMODULE_SUBEVENT_REPL_ASYNC_LOAD_COMPLETED,
                         NULL);

src/script.c

@@ -0,0 +1,464 @@
+/*
+ * Copyright (c) 2009-2021, Redis Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "server.h"
+#include "script.h"
+#include "cluster.h"
+
+/* On script invocation, holding the current run context */
+static scriptRunCtx *curr_run_ctx = NULL;
+
+static void exitScriptTimedoutMode(scriptRunCtx *run_ctx) {
+    serverAssert(run_ctx == curr_run_ctx);
+    serverAssert(scriptIsTimedout());
+    run_ctx->flags &= ~SCRIPT_TIMEDOUT;
+    blockingOperationEnds();
+    /* if we are a replica and we have an active master, set it for continue processing */
+    if (server.masterhost && server.master) queueClientForReprocessing(server.master);
+}
+
+static void enterScriptTimedoutMode(scriptRunCtx *run_ctx) {
+    serverAssert(run_ctx == curr_run_ctx);
+    serverAssert(!scriptIsTimedout());
+    /* Mark script as timedout */
+    run_ctx->flags |= SCRIPT_TIMEDOUT;
+    blockingOperationStarts();
+}
+
+int scriptIsTimedout() {
+    return scriptIsRunning() && (curr_run_ctx->flags & SCRIPT_TIMEDOUT);
+}
+
+client* scriptGetClient() {
+    serverAssert(scriptIsRunning());
+    return curr_run_ctx->c;
+}
+
+client* scriptGetCaller() {
+    serverAssert(scriptIsRunning());
+    return curr_run_ctx->original_client;
+}
+
+/* interrupt function for scripts, should be call
+ * from time to time to reply some special command (like ping)
+ * and also check if the run should be terminated. */
+int scriptInterrupt(scriptRunCtx *run_ctx) {
+    if (run_ctx->flags & SCRIPT_TIMEDOUT) {
+        /* script already timedout
+           we just need to precess some events and return */
+        processEventsWhileBlocked();
+        return (run_ctx->flags & SCRIPT_KILLED) ? SCRIPT_KILL : SCRIPT_CONTINUE;
+    }
+
+    long long elapsed = elapsedMs(run_ctx->start_time);
+    if (elapsed < server.script_time_limit) {
+        return SCRIPT_CONTINUE;
+    }
+
+    serverLog(LL_WARNING,
+            "Slow script detected: still in execution after %lld milliseconds. "
+                    "You can try killing the script using the %s command.",
+            elapsed, (run_ctx->flags & SCRIPT_EVAL_MODE) ? "SCRIPT KILL" : "FUNCTION KILL");
+
+    enterScriptTimedoutMode(run_ctx);
+    /* Once the script timeouts we reenter the event loop to permit others
+     * some commands execution. For this reason
+     * we need to mask the client executing the script from the event loop.
+     * If we don't do that the client may disconnect and could no longer be
+     * here when the EVAL command will return. */
+    protectClient(run_ctx->original_client);
+
+    processEventsWhileBlocked();
+
+    return (run_ctx->flags & SCRIPT_KILLED) ? SCRIPT_KILL : SCRIPT_CONTINUE;
+}
+
+/* Prepare the given run ctx for execution */
+void scriptPrepareForRun(scriptRunCtx *run_ctx, client *engine_client, client *caller, const char *funcname) {
+    serverAssert(!curr_run_ctx);
+    /* set the curr_run_ctx so we can use it to kill the script if needed */
+    curr_run_ctx = run_ctx;
+
+    run_ctx->c = engine_client;
+    run_ctx->original_client = caller;
+    run_ctx->funcname = funcname;
+
+    client *script_client = run_ctx->c;
+    client *curr_client = run_ctx->original_client;
+    server.script_caller = curr_client;
+
+    /* Select the right DB in the context of the Lua client */
+    selectDb(script_client, curr_client->db->id);
+    script_client->resp = 2; /* Default is RESP2, scripts can change it. */
+
+    /* If we are in MULTI context, flag Lua client as CLIENT_MULTI. */
+    if (curr_client->flags & CLIENT_MULTI) {
+        script_client->flags |= CLIENT_MULTI;
+    }
+
+    server.in_script = 1;
+
+    run_ctx->start_time = getMonotonicUs();
+    run_ctx->snapshot_time = mstime();
+
+    run_ctx->flags = 0;
+    run_ctx->repl_flags = PROPAGATE_AOF | PROPAGATE_REPL;
+}
+
+/* Reset the given run ctx after execution */
+void scriptResetRun(scriptRunCtx *run_ctx) {
+    serverAssert(curr_run_ctx);
+
+    /* After the script done, remove the MULTI state. */
+    run_ctx->c->flags &= ~CLIENT_MULTI;
+
+    server.in_script = 0;
+    server.script_caller = NULL;
+
+    if (scriptIsTimedout()) {
+        exitScriptTimedoutMode(run_ctx);
+        /* Restore the client that was protected when the script timeout
+         * was detected. */
+        unprotectClient(run_ctx->original_client);
+    }
+
+    if (!(run_ctx->flags & SCRIPT_EVAL_REPLICATION)) {
+        preventCommandPropagation(run_ctx->original_client);
+        if (run_ctx->flags & SCRIPT_MULTI_EMMITED) {
+            execCommandPropagateExec(run_ctx->original_client->db->id);
+        }
+    }
+
+    /*  unset curr_run_ctx so we will know there is no running script */
+    curr_run_ctx = NULL;
+}
+
+/* return true if a script is currently running */
+int scriptIsRunning() {
+    return curr_run_ctx != NULL;
+}
+
+const char* scriptCurrFunction() {
+    serverAssert(scriptIsRunning());
+    return curr_run_ctx->funcname;
+}
+
+int scriptIsEval() {
+    serverAssert(scriptIsRunning());
+    return curr_run_ctx->flags & SCRIPT_EVAL_MODE;
+}
+
+/* Kill the current running script */
+void scriptKill(client *c, int is_eval) {
+    if (!curr_run_ctx) {
+        addReplyError(c, "-NOTBUSY No scripts in execution right now.");
+        return;
+    }
+    if (curr_run_ctx->original_client->flags & CLIENT_MASTER) {
+        addReplyError(c,
+                "-UNKILLABLE The busy script was sent by a master instance in the context of replication and cannot be killed.");
+    }
+    if (curr_run_ctx->flags & SCRIPT_WRITE_DIRTY) {
+        addReplyError(c,
+                "-UNKILLABLE Sorry the script already executed write "
+                        "commands against the dataset. You can either wait the "
+                        "script termination or kill the server in a hard way "
+                        "using the SHUTDOWN NOSAVE command.");
+        return;
+    }
+    if (is_eval && !(curr_run_ctx->flags & SCRIPT_EVAL_MODE)) {
+        /* Kill a function with 'SCRIPT KILL' is not allow */
+        addReplyErrorObject(c, shared.slowscripterr);
+        return;
+    }
+    if (!is_eval && (curr_run_ctx->flags & SCRIPT_EVAL_MODE)) {
+        /* Kill an eval with 'FUNCTION KILL' is not allow */
+        addReplyErrorObject(c, shared.slowevalerr);
+        return;
+    }
+    curr_run_ctx->flags |= SCRIPT_KILLED;
+    addReply(c, shared.ok);
+}
+
+static int scriptVerifyCommandArity(struct redisCommand *cmd, int argc, sds *err) {
+    if (!cmd || ((cmd->arity > 0 && cmd->arity != argc) || (argc < cmd->arity))) {
+        if (cmd)
+            *err = sdsnew("Wrong number of args calling Redis command from script");
+        else
+            *err = sdsnew("Unknown Redis command called from script");
+        return C_ERR;
+    }
+    return C_OK;
+}
+
+static int scriptVerifyACL(client *c, sds *err) {
+    /* Check the ACLs. */
+    int acl_errpos;
+    int acl_retval = ACLCheckAllPerm(c, &acl_errpos);
+    if (acl_retval != ACL_OK) {
+        addACLLogEntry(c,acl_retval,ACL_LOG_CTX_LUA,acl_errpos,NULL,NULL);
+        switch (acl_retval) {
+        case ACL_DENIED_CMD:
+            *err = sdsnew("The user executing the script can't run this "
+                          "command or subcommand");
+            break;
+        case ACL_DENIED_KEY:
+            *err = sdsnew("The user executing the script can't access "
+                          "at least one of the keys mentioned in the "
+                          "command arguments");
+            break;
+        case ACL_DENIED_CHANNEL:
+            *err = sdsnew("The user executing the script can't publish "
+                          "to the channel mentioned in the command");
+            break;
+        default:
+            *err = sdsnew("The user executing the script is lacking the "
+                          "permissions for the command");
+            break;
+        }
+        return C_ERR;
+    }
+    return C_OK;
+}
+
+static int scriptVerifyWriteCommandAllow(scriptRunCtx *run_ctx, char **err) {
+    if (!(run_ctx->c->cmd->flags & CMD_WRITE)) {
+        return C_OK;
+    }
+
+    if (run_ctx->flags & SCRIPT_READ_ONLY) {
+        /* We know its a write command, on a read only run we do not allow it. */
+        *err = sdsnew("Write commands are not allowed from read-only scripts.");
+        return C_ERR;
+    }
+
+    if ((run_ctx->flags & SCRIPT_RANDOM_DIRTY) && (run_ctx->flags & SCRIPT_EVAL_REPLICATION)) {
+        *err = sdsnew("Write commands not allowed after non deterministic commands. Call redis.replicate_commands() at the start of your script in order to switch to single commands replication mode.");
+        return C_ERR;
+    }
+
+    /* Write commands are forbidden against read-only slaves, or if a
+     * command marked as non-deterministic was already called in the context
+     * of this script. */
+    int deny_write_type = writeCommandsDeniedByDiskError();
+
+    if (server.masterhost && server.repl_slave_ro && run_ctx->original_client->flags != CLIENT_ID_AOF
+        && !(run_ctx->original_client->flags & CLIENT_MASTER))
+    {
+        *err = sdsdup(shared.roslaveerr->ptr);
+        return C_ERR;
+    }
+
+    if (deny_write_type != DISK_ERROR_TYPE_NONE) {
+        if (deny_write_type == DISK_ERROR_TYPE_RDB) {
+            *err = sdsdup(shared.bgsaveerr->ptr);
+        } else {
+            *err = sdsempty();
+            *err = sdscatfmt(*err,
+                    "MISCONF Errors writing to the AOF file: %s\r\n",
+                    strerror(server.aof_last_write_errno));
+        }
+        return C_ERR;
+    }
+
+    return C_OK;
+}
+
+static int scriptVerifyOOM(scriptRunCtx *run_ctx, char **err) {
+    /* If we reached the memory limit configured via maxmemory, commands that
+     * could enlarge the memory usage are not allowed, but only if this is the
+     * first write in the context of this script, otherwise we can't stop
+     * in the middle. */
+
+    if (server.maxmemory &&                            /* Maxmemory is actually enabled. */
+        run_ctx->original_client->id != CLIENT_ID_AOF && /* Don't care about mem if loading from AOF. */
+        !server.masterhost &&                          /* Slave must execute the script. */
+        !(run_ctx->flags & SCRIPT_WRITE_DIRTY) &&        /* Script had no side effects so far. */
+        server.script_oom &&                           /* Detected OOM when script start. */
+        (run_ctx->c->cmd->flags & CMD_DENYOOM))
+    {
+        *err = sdsdup(shared.oomerr->ptr);
+        return C_ERR;
+    }
+
+    return C_OK;
+}
+
+static int scriptVerifyClusterState(client *c, client *original_c, sds *err) {
+    if (!server.cluster_enabled || original_c->id == CLIENT_ID_AOF || (original_c->flags & CLIENT_MASTER)) {
+        return C_OK;
+    }
+    /* If this is a Redis Cluster node, we need to make sure the script is not
+     * trying to access non-local keys, with the exception of commands
+     * received from our master or when loading the AOF back in memory. */
+    int error_code;
+    /* Duplicate relevant flags in the script client. */
+    c->flags &= ~(CLIENT_READONLY | CLIENT_ASKING);
+    c->flags |= original_c->flags & (CLIENT_READONLY | CLIENT_ASKING);
+    if (getNodeByQuery(c, c->cmd, c->argv, c->argc, NULL, &error_code) != server.cluster->myself) {
+        if (error_code == CLUSTER_REDIR_DOWN_RO_STATE) {
+            *err = sdsnew(
+                    "Script attempted to execute a write command while the "
+                            "cluster is down and readonly");
+        } else if (error_code == CLUSTER_REDIR_DOWN_STATE) {
+            *err = sdsnew("Script attempted to execute a command while the "
+                    "cluster is down");
+        } else {
+            *err = sdsnew("Script attempted to access a non local key in a "
+                    "cluster node");
+        }
+        return C_ERR;
+    }
+    return C_OK;
+}
+
+static void scriptEmitMultiIfNeeded(scriptRunCtx *run_ctx) {
+    /* If we are using single commands replication, we need to wrap what
+     * we propagate into a MULTI/EXEC block, so that it will be atomic like
+     * a Lua script in the context of AOF and slaves. */
+    client *c = run_ctx->c;
+    if (!(run_ctx->flags & SCRIPT_EVAL_REPLICATION)
+         && !(run_ctx->flags & SCRIPT_MULTI_EMMITED)
+         && !(run_ctx->original_client->flags & CLIENT_MULTI)
+         && (run_ctx->flags & SCRIPT_WRITE_DIRTY)
+         && ((run_ctx->repl_flags & PROPAGATE_AOF)
+             || (run_ctx->repl_flags & PROPAGATE_REPL)))
+    {
+        execCommandPropagateMulti(run_ctx->original_client->db->id);
+        run_ctx->flags |= SCRIPT_MULTI_EMMITED;
+        /* Now we are in the MULTI context, the lua_client should be
+         * flag as CLIENT_MULTI. */
+        c->flags |= CLIENT_MULTI;
+    }
+}
+
+/* set RESP for a given run_ctx */
+int scriptSetResp(scriptRunCtx *run_ctx, int resp) {
+    if (resp != 2 && resp != 3) {
+        return C_ERR;
+    }
+
+    run_ctx->c->resp = resp;
+    return C_OK;
+}
+
+/* set Repl for a given run_ctx
+ * either: PROPAGATE_AOF | PROPAGATE_REPL*/
+int scriptSetRepl(scriptRunCtx *run_ctx, int repl) {
+    if ((repl & ~(PROPAGATE_AOF | PROPAGATE_REPL)) != 0) {
+        return C_ERR;
+    }
+    run_ctx->repl_flags = repl;
+    return C_OK;
+}
+
+/* Call a Redis command.
+ * The reply is written to the run_ctx client and it is
+ * up to the engine to take and parse.
+ * The err out variable is set only if error occurs and describe the error.
+ * If err is set on reply is written to the run_ctx client. */
+void scriptCall(scriptRunCtx *run_ctx, robj* *argv, int argc, sds *err) {
+    client *c = run_ctx->c;
+
+    /* Setup our fake client for command execution */
+    c->argv = argv;
+    c->argc = argc;
+    c->user = run_ctx->original_client->user;
+
+    /* Process module hooks */
+    moduleCallCommandFilters(c);
+    argv = c->argv;
+    argc = c->argc;
+
+    struct redisCommand *cmd = lookupCommand(argv, argc);
+    if (scriptVerifyCommandArity(cmd, argc, err) != C_OK) {
+        return;
+    }
+
+    c->cmd = c->lastcmd = cmd;
+
+    /* There are commands that are not allowed inside scripts. */
+    if (!server.script_disable_deny_script && (cmd->flags & CMD_NOSCRIPT)) {
+        *err = sdsnew("This Redis command is not allowed from script");
+        return;
+    }
+
+    if (scriptVerifyACL(c, err) != C_OK) {
+        return;
+    }
+
+    if (scriptVerifyWriteCommandAllow(run_ctx, err) != C_OK) {
+        return;
+    }
+
+    if (scriptVerifyOOM(run_ctx, err) != C_OK) {
+        return;
+    }
+
+    if (cmd->flags & CMD_WRITE) {
+        /* signify that we already change the data in this execution */
+        run_ctx->flags |= SCRIPT_WRITE_DIRTY;
+    }
+
+    if (cmd->flags & CMD_RANDOM) {
+        /* signify that we already perform a random command in this execution */
+        run_ctx->flags |= SCRIPT_RANDOM_DIRTY;
+    }
+
+    if (scriptVerifyClusterState(c, run_ctx->original_client, err) != C_OK) {
+        return;
+    }
+
+    scriptEmitMultiIfNeeded(run_ctx);
+
+    int call_flags = CMD_CALL_SLOWLOG | CMD_CALL_STATS;
+    if (!(run_ctx->flags & SCRIPT_EVAL_REPLICATION)) {
+        if (run_ctx->repl_flags & PROPAGATE_AOF) {
+            call_flags |= CMD_CALL_PROPAGATE_AOF;
+        }
+        if (run_ctx->repl_flags & PROPAGATE_REPL) {
+            call_flags |= CMD_CALL_PROPAGATE_REPL;
+        }
+    }
+    call(c, call_flags);
+    serverAssert((c->flags & CLIENT_BLOCKED) == 0);
+}
+
+/* Returns the time when the script invocation started */
+mstime_t scriptTimeSnapshot() {
+    serverAssert(!curr_run_ctx);
+    return curr_run_ctx->snapshot_time;
+}
+
+long long scriptRunDuration() {
+    serverAssert(scriptIsRunning());
+    return elapsedMs(curr_run_ctx->start_time);
+}
+
+

src/script.h

@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2009-2021, Redis Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __SCRIPT_H_
+#define __SCRIPT_H_
+
+/*
+ * Script.c unit provides an API for functions and eval 
+ * to interact with Redis. Interaction includes mostly
+ * executing commands, but also functionalities like calling
+ * Redis back on long scripts or check if the script was killed.
+ *
+ * The interaction is done using a scriptRunCtx object that
+ * need to be created by the user and initialized using scriptPrepareForRun.
+ *
+ * Detailed list of functionalities expose by the unit:
+ * 1. Calling commands (including all the validation checks such as
+ *    acl, cluster, read only run, ...)
+ * 2. Set Resp
+ * 3. Set Replication method (AOF/REPLICATION/NONE)
+ * 4. Call Redis back to on long running scripts to allow Redis reply
+ *    to clients and perform script kill
+ */
+
+/*
+ * scriptInterrupt function will return one of those value,
+ *
+ * - SCRIPT_KILL - kill the current running script.
+ * - SCRIPT_CONTINUE - keep running the current script.
+ */
+#define SCRIPT_KILL 1
+#define SCRIPT_CONTINUE 2
+
+/* runCtx flags */
+#define SCRIPT_WRITE_DIRTY            (1ULL<<0) /* indicate that the current script already performed a write command */
+#define SCRIPT_RANDOM_DIRTY           (1ULL<<1) /* indicate that the current script already performed a random reply command.
+                                                   Thanks to this flag we'll raise an error every time a write command
+                                                   is called after a random command and prevent none deterministic
+                                                   replication or AOF. */
+#define SCRIPT_MULTI_EMMITED          (1ULL<<2) /* indicate that we already wrote a multi command to replication/aof */
+#define SCRIPT_TIMEDOUT               (1ULL<<3) /* indicate that the current script timedout */
+#define SCRIPT_KILLED                 (1ULL<<4) /* indicate that the current script was marked to be killed */
+#define SCRIPT_READ_ONLY              (1ULL<<5) /* indicate that the current script should only perform read commands */
+#define SCRIPT_EVAL_REPLICATION       (1ULL<<6) /* mode for eval, indicate that we replicate the
+                                                   script invocation and not the effects */
+#define SCRIPT_EVAL_MODE              (1ULL<<7) /* Indicate that the current script called from legacy Lua */
+typedef struct scriptRunCtx scriptRunCtx;
+
+struct scriptRunCtx {
+    const char *funcname;
+    client *c;
+    client *original_client;
+    int flags;
+    int repl_flags;
+    monotime start_time;
+    mstime_t snapshot_time;
+};
+
+void scriptPrepareForRun(scriptRunCtx *r_ctx, client *engine_client, client *caller, const char *funcname);
+void scriptResetRun(scriptRunCtx *r_ctx);
+int scriptSetResp(scriptRunCtx *r_ctx, int resp);
+int scriptSetRepl(scriptRunCtx *r_ctx, int repl);
+void scriptCall(scriptRunCtx *r_ctx, robj **argv, int argc, sds *err);
+int scriptInterrupt(scriptRunCtx *r_ctx);
+void scriptKill(client *c, int is_eval);
+int scriptIsRunning();
+const char* scriptCurrFunction();
+int scriptIsEval();
+int scriptIsTimedout();
+client* scriptGetClient();
+client* scriptGetCaller();
+mstime_t scriptTimeSnapshot();
+long long scriptRunDuration();
+
+#endif /* __SCRIPT_H_ */

src/script_lua.h

@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2009-2021, Redis Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __SCRIPT_LUA_H_
+#define __SCRIPT_LUA_H_
+
+/*
+ * script_lua.c unit provides shared functionality between
+ * eval.c and function_lua.c. Functionality provided:
+ *
+ * * Execute Lua code, assuming that the code is located on
+ *   the top of the Lua stack. In addition, parsing the execution
+ *   result and convert it to the resp and reply ot the client.
+ *
+ * * Run Redis commands from within the Lua code (Including
+ *   parsing the reply and create a Lua object out of it).
+ *
+ * * Register Redis API to the Lua interpreter. Only shared
+ *   API are registered (API that is only relevant on eval.c
+ *   (like debugging) are registered on eval.c).
+ *
+ * Uses script.c for interaction back with Redis.
+ */
+
+#include "server.h"
+#include "script.h"
+#include <lua.h>
+#include <lauxlib.h>
+#include <lualib.h>
+
+#define REGISTRY_RUN_CTX_NAME "__RUN_CTX__"
+
+void luaRegisterRedisAPI(lua_State* lua);
+void luaEnableGlobalsProtection(lua_State *lua, int is_eval);
+void luaSaveOnRegistry(lua_State* lua, const char* name, void* ptr);
+void* luaGetFromRegistry(lua_State* lua, const char* name);
+void luaCallFunction(scriptRunCtx* r_ctx, lua_State *lua, robj** keys, size_t nkeys, robj** args, size_t nargs, int debug_enabled);
+unsigned long luaMemory(lua_State *lua);
+
+
+#endif /* __SCRIPT_LUA_H_ */

src/server.c

@@ -35,6 +35,7 @@
 #include "latency.h"
 #include "atomicvar.h"
 #include "mt19937-64.h"
+#include "functions.h"
 
 #include <time.h>
 #include <signal.h>
@@ -471,6 +472,31 @@ struct redisCommand scriptSubcommands[] = {
     {NULL},
 };
 
+struct redisCommand functionSubcommands[] = {
+    {"create",functionsCreateCommand,-5,
+     "may-replicate no-script @scripting"},
+
+    {"delete",functionsDeleteCommand,3,
+     "may-replicate no-script @scripting"},
+
+    {"kill",functionsKillCommand,2,
+     "no-script @scripting"},
+
+    {"info",functionsInfoCommand,-3,
+     "no-script @scripting"},
+
+    {"list",functionsListCommand,2,
+     "no-script @scripting"},
+
+    {"stats",functionsStatsCommand,2,
+     "no-script @scripting"},
+
+    {"help",functionsHelpCommand,2,
+     "ok-loading ok-stale @scripting"},
+
+    {NULL},
+};
+
 struct redisCommand clientSubcommands[] = {
     {"caching",clientCommand,3,
      "no-script ok-loading ok-stale @connection"},
@@ -2032,7 +2058,25 @@ struct redisCommand redisCommandTable[] = {
      "no-auth no-script ok-stale ok-loading fast @connection"},
 
     {"failover",failoverCommand,-1,
-     "admin no-script ok-stale"}
+     "admin no-script ok-stale"},
+
+    {"function",NULL,-2,
+        "",
+        .subcommands=functionSubcommands},
+
+    {"fcall",fcallCommand,-3,
+     "no-script no-monitor may-replicate no-mandatory-keys @scripting",
+     {{"read write", /* We pass both read and write because these flag are worst-case-scenario */
+       KSPEC_BS_INDEX,.bs.index={2},
+       KSPEC_FK_KEYNUM,.fk.keynum={0,1,1}}},
+     functionGetKeys},
+
+    {"fcall_ro",fcallCommandReadOnly,-3,
+     "no-script no-monitor no-mandatory-keys @scripting",
+     {{"read",
+       KSPEC_BS_INDEX,.bs.index={2},
+       KSPEC_FK_KEYNUM,.fk.keynum={0,1,1}}},
+     functionGetKeys},
 };
 
 /*============================ Utility functions ============================ */
@@ -2208,6 +2252,11 @@ void dictSdsDestructor(dict *d, void *val)
     sdsfree(val);
 }
 
+void *dictSdsDup(dict *d, const void *key) {
+    UNUSED(d);
+    return sdsdup((const sds) key);
+}
+
 int dictObjKeyCompare(dict *d, const void *key1,
         const void *key2)
 {
@@ -2994,7 +3043,7 @@ void cronUpdateMemoryStats() {
             /* LUA memory isn't part of zmalloc_used, but it is part of the process RSS,
              * so we must deduct it in order to be able to calculate correct
              * "allocator fragmentation" ratio */
-            size_t lua_memory = lua_gc(server.lua,LUA_GCCOUNT,0)*1024LL;
+            size_t lua_memory = evalMemory();
             server.cron_malloc_stats.allocator_resident = server.cron_malloc_stats.process_rss - lua_memory;
         }
         if (!server.cron_malloc_stats.allocator_active)
@@ -3516,8 +3565,10 @@ void createSharedObjects(void) {
         "-NOSCRIPT No matching script. Please use EVAL.\r\n"));
     shared.loadingerr = createObject(OBJ_STRING,sdsnew(
         "-LOADING Redis is loading the dataset in memory\r\n"));
-    shared.slowscripterr = createObject(OBJ_STRING,sdsnew(
+    shared.slowevalerr = createObject(OBJ_STRING,sdsnew(
         "-BUSY Redis is busy running a script. You can only call SCRIPT KILL or SHUTDOWN NOSAVE.\r\n"));
+    shared.slowscripterr = createObject(OBJ_STRING,sdsnew(
+        "-BUSY Redis is busy running a script. You can only call FUNCTION KILL or SHUTDOWN NOSAVE.\r\n"));
     shared.masterdownerr = createObject(OBJ_STRING,sdsnew(
         "-MASTERDOWN Link with MASTER is down and replica-serve-stale-data is set to 'no'.\r\n"));
     shared.bgsaveerr = createObject(OBJ_STRING,sdsnew(
@@ -4247,7 +4298,7 @@ void initServer(void) {
     server.pubsub_channels = dictCreate(&keylistDictType);
     server.pubsub_patterns = dictCreate(&keylistDictType);
     server.cronloops = 0;
-    server.in_eval = 0;
+    server.in_script = 0;
     server.in_exec = 0;
     server.propagate_in_transaction = 0;
     server.client_pause_in_transaction = 0;
@@ -4344,6 +4395,7 @@ void initServer(void) {
     if (server.cluster_enabled) clusterInit();
     replicationScriptCacheInit();
     scriptingInit(1);
+    functionsInit();
     slowlogInit();
     latencyMonitorInit();
     
@@ -4931,17 +4983,17 @@ void call(client *c, int flags) {
 
     /* When EVAL is called loading the AOF we don't want commands called
      * from Lua to go into the slowlog or to populate statistics. */
-    if (server.loading && c->flags & CLIENT_LUA)
+    if (server.loading && c->flags & CLIENT_SCRIPT)
         flags &= ~(CMD_CALL_SLOWLOG | CMD_CALL_STATS);
 
     /* If the caller is Lua, we want to force the EVAL caller to propagate
      * the script if the command flag or client flag are forcing the
      * propagation. */
-    if (c->flags & CLIENT_LUA && server.lua_caller) {
+    if (c->flags & CLIENT_SCRIPT && server.script_caller) {
         if (c->flags & CLIENT_FORCE_REPL)
-            server.lua_caller->flags |= CLIENT_FORCE_REPL;
+            server.script_caller->flags |= CLIENT_FORCE_REPL;
         if (c->flags & CLIENT_FORCE_AOF)
-            server.lua_caller->flags |= CLIENT_FORCE_AOF;
+            server.script_caller->flags |= CLIENT_FORCE_AOF;
     }
 
     /* Note: the code below uses the real command that was executed
@@ -5070,8 +5122,8 @@ void call(client *c, int flags) {
     /* If the client has keys tracking enabled for client side caching,
      * make sure to remember the keys it fetched via this command. */
     if (c->cmd->flags & CMD_READONLY) {
-        client *caller = (c->flags & CLIENT_LUA && server.lua_caller) ?
-                            server.lua_caller : c;
+        client *caller = (c->flags & CLIENT_SCRIPT && server.script_caller) ?
+                            server.script_caller : c;
         if (caller->flags & CLIENT_TRACKING &&
             !(caller->flags & CLIENT_TRACKING_BCAST))
         {
@@ -5172,14 +5224,14 @@ void populateCommandMovableKeys(struct redisCommand *cmd) {
  * other operations can be performed by the caller. Otherwise
  * if C_ERR is returned the client was destroyed (i.e. after QUIT). */
 int processCommand(client *c) {
-    if (!server.lua_timedout) {
+    if (!scriptIsTimedout()) {
         /* Both EXEC and EVAL call call() directly so there should be
          * no way in_exec or in_eval or propagate_in_transaction is 1.
          * That is unless lua_timedout, in which case client may run
          * some commands. */
         serverAssert(!server.propagate_in_transaction);
         serverAssert(!server.in_exec);
-        serverAssert(!server.in_eval);
+        serverAssert(!server.in_script);
     }
 
     moduleCallCommandFilters(c);
@@ -5273,8 +5325,8 @@ int processCommand(client *c) {
      * 2) The command has no key arguments. */
     if (server.cluster_enabled &&
         !(c->flags & CLIENT_MASTER) &&
-        !(c->flags & CLIENT_LUA &&
-          server.lua_caller->flags & CLIENT_MASTER) &&
+        !(c->flags & CLIENT_SCRIPT &&
+          server.script_caller->flags & CLIENT_MASTER) &&
         !(!c->cmd->movablekeys && c->cmd->key_specs_num == 0 &&
           c->cmd->proc != execCommand))
     {
@@ -5309,7 +5361,7 @@ int processCommand(client *c) {
      * the event loop since there is a busy Lua script running in timeout
      * condition, to avoid mixing the propagation of scripts with the
      * propagation of DELs due to eviction. */
-    if (server.maxmemory && !server.lua_timedout) {
+    if (server.maxmemory && !scriptIsTimedout()) {
         int out_of_memory = (performEvictions() == EVICT_FAIL);
 
         /* performEvictions may evict keys, so we need flush pending tracking
@@ -5345,7 +5397,7 @@ int processCommand(client *c) {
          * until first write within script, memory used by lua stack and
          * arguments might interfere. */
         if (c->cmd->proc == evalCommand || c->cmd->proc == evalShaCommand) {
-            server.lua_oom = out_of_memory;
+            server.script_oom = out_of_memory;
         }
     }
 
@@ -5432,7 +5484,7 @@ int processCommand(client *c) {
      * the MULTI plus a few initial commands refused, then the timeout
      * condition resolves, and the bottom-half of the transaction gets
      * executed, see Github PR #7022. */
-    if (server.lua_timedout &&
+    if (scriptIsTimedout() &&
           c->cmd->proc != authCommand &&
           c->cmd->proc != helloCommand &&
           c->cmd->proc != replconfCommand &&
@@ -5447,9 +5499,15 @@ int processCommand(client *c) {
           tolower(((char*)c->argv[1]->ptr)[0]) == 'n') &&
         !(c->cmd->proc == scriptCommand &&
           c->argc == 2 &&
-          tolower(((char*)c->argv[1]->ptr)[0]) == 'k'))
+          tolower(((char*)c->argv[1]->ptr)[0]) == 'k') &&
+        !(c->cmd->proc == functionsKillCommand) &&
+        !(c->cmd->proc == functionsStatsCommand))
     {
-        rejectCommand(c, shared.slowscripterr);
+        if (scriptIsEval()) {
+            rejectCommand(c, shared.slowevalerr);
+        } else {
+            rejectCommand(c, shared.slowscripterr);
+        }
         return C_OK;
     }
 
@@ -6280,13 +6338,15 @@ sds genRedisInfoString(const char *section) {
         char peak_hmem[64];
         char total_system_hmem[64];
         char used_memory_lua_hmem[64];
+        char used_memory_vm_total_hmem[64];
         char used_memory_scripts_hmem[64];
         char used_memory_rss_hmem[64];
         char maxmemory_hmem[64];
         size_t zmalloc_used = zmalloc_used_memory();
         size_t total_system_mem = server.system_memory_size;
         const char *evict_policy = evictPolicyToString();
-        long long memory_lua = server.lua ? (long long)lua_gc(server.lua,LUA_GCCOUNT,0)*1024 : 0;
+        long long memory_lua = evalMemory();
+        long long memory_functions = functionsMemory();
         struct redisMemOverhead *mh = getMemoryOverheadData();
 
         /* Peak memory is updated from time to time by serverCron() so it
@@ -6300,7 +6360,8 @@ sds genRedisInfoString(const char *section) {
         bytesToHuman(peak_hmem,server.stat_peak_memory);
         bytesToHuman(total_system_hmem,total_system_mem);
         bytesToHuman(used_memory_lua_hmem,memory_lua);
-        bytesToHuman(used_memory_scripts_hmem,mh->lua_caches);
+        bytesToHuman(used_memory_vm_total_hmem,memory_functions + memory_lua);
+        bytesToHuman(used_memory_scripts_hmem,mh->lua_caches + mh->functions_caches);
         bytesToHuman(used_memory_rss_hmem,server.cron_malloc_stats.process_rss);
         bytesToHuman(maxmemory_hmem,server.maxmemory);
 
@@ -6323,11 +6384,18 @@ sds genRedisInfoString(const char *section) {
             "allocator_resident:%zu\r\n"
             "total_system_memory:%lu\r\n"
             "total_system_memory_human:%s\r\n"
-            "used_memory_lua:%lld\r\n"
-            "used_memory_lua_human:%s\r\n"
+            "used_memory_lua:%lld\r\n" /* deprecated, renamed to used_memory_vm_eval */
+            "used_memory_vm_eval:%lld\r\n"
+            "used_memory_lua_human:%s\r\n" /* deprecated */
+            "used_memory_scripts_eval:%lld\r\n"
+            "number_of_cached_scripts:%lu\r\n"
+            "number_of_functions:%lu\r\n"
+            "used_memory_vm_functions:%lld\r\n"
+            "used_memory_vm_total:%lld\r\n"
+            "used_memory_vm_total_human:%s\r\n"
+            "used_memory_functions:%lld\r\n"
             "used_memory_scripts:%lld\r\n"
             "used_memory_scripts_human:%s\r\n"
-            "number_of_cached_scripts:%lu\r\n"
             "maxmemory:%lld\r\n"
             "maxmemory_human:%s\r\n"
             "maxmemory_policy:%s\r\n"
@@ -6366,10 +6434,17 @@ sds genRedisInfoString(const char *section) {
             (unsigned long)total_system_mem,
             total_system_hmem,
             memory_lua,
+            memory_lua,
             used_memory_lua_hmem,
             (long long) mh->lua_caches,
+            dictSize(evalScriptsDict()),
+            functionsNum(),
+            memory_functions,
+            memory_functions + memory_lua,
+            used_memory_vm_total_hmem,
+            (long long) mh->functions_caches,
+            (long long) mh->lua_caches + (long long) mh->functions_caches,
             used_memory_scripts_hmem,
-            dictSize(server.lua_scripts),
             server.maxmemory,
             maxmemory_hmem,
             evict_policy,

src/server.h

@@ -260,7 +260,7 @@ extern int configOOMScoreAdjValuesDefaults[CONFIG_OOM_COUNT];
 #define CLIENT_CLOSE_AFTER_REPLY (1<<6) /* Close after writing entire reply. */
 #define CLIENT_UNBLOCKED (1<<7) /* This client was unblocked and is stored in
                                   server.unblocked_clients */
-#define CLIENT_LUA (1<<8) /* This is a non connected client used by Lua */
+#define CLIENT_SCRIPT (1<<8) /* This is a non connected client used by Lua */
 #define CLIENT_ASKING (1<<9)     /* Client issued the ASKING command */
 #define CLIENT_CLOSE_ASAP (1<<10)/* Close this client ASAP */
 #define CLIENT_UNIX_SOCKET (1<<11) /* Client connected via Unix domain socket */
@@ -822,6 +822,19 @@ typedef struct redisDb {
     clusterSlotToKeyMapping *slots_to_keys; /* Array of slots to keys. Only used in cluster mode (db 0). */
 } redisDb;
 
+/* forward declaration for functions ctx */
+typedef struct functionsCtx functionsCtx;
+
+/* Holding object that need to be populated during
+ * rdb loading. On loading end it is possible to decide
+ * whether not to set those objects on their rightful place.
+ * For example: dbarray need to be set as main database on
+ *              successful loading and dropped on failure. */
+typedef struct rdbLoadingCtx {
+    redisDb* dbarray;
+    functionsCtx* functions_ctx;
+}rdbLoadingCtx;
+
 /* Client MULTI/EXEC state */
 typedef struct multiCmd {
     robj **argv;
@@ -1122,7 +1135,7 @@ struct sharedObjectsStruct {
     robj *crlf, *ok, *err, *emptybulk, *czero, *cone, *pong, *space,
     *queued, *null[4], *nullarray[4], *emptymap[4], *emptyset[4],
     *emptyarray, *wrongtypeerr, *nokeyerr, *syntaxerr, *sameobjecterr,
-    *outofrangeerr, *noscripterr, *loadingerr, *slowscripterr, *bgsaveerr,
+    *outofrangeerr, *noscripterr, *loadingerr, *slowevalerr, *slowscripterr, *bgsaveerr,
     *masterdownerr, *roslaveerr, *execaborterr, *noautherr, *noreplicaserr,
     *busykeyerr, *oomerr, *plus, *messagebulk, *pmessagebulk, *subscribebulk,
     *unsubscribebulk, *psubscribebulk, *punsubscribebulk, *del, *unlink,
@@ -1203,6 +1216,7 @@ struct redisMemOverhead {
     size_t clients_normal;
     size_t aof_buffer;
     size_t lua_caches;
+    size_t functions_caches;
     size_t overhead_total;
     size_t dataset;
     size_t total_keys;
@@ -1334,7 +1348,7 @@ struct redisServer {
     int sentinel_mode;          /* True if this instance is a Sentinel. */
     size_t initial_memory_usage; /* Bytes used after initialization. */
     int always_show_logo;       /* Show logo even for non-stdout logging. */
-    int in_eval;                /* Are we inside EVAL? */
+    int in_script;                /* Are we inside EVAL? */
     int in_exec;                /* Are we inside EXEC? */
     int propagate_in_transaction;  /* Make sure we don't propagate nested MULTI/EXEC */
     char *ignore_warnings;      /* Config: warnings that should be ignored. */
@@ -1719,28 +1733,11 @@ struct redisServer {
                                         is down? */
     int cluster_config_file_lock_fd;   /* cluster config fd, will be flock */
     /* Scripting */
-    lua_State *lua; /* The Lua interpreter. We use just one for all clients */
-    client *lua_client;   /* The "fake client" to query Redis from Lua */
-    client *lua_caller;   /* The client running EVAL right now, or NULL */
-    char* lua_cur_script; /* SHA1 of the script currently running, or NULL */
-    dict *lua_scripts;         /* A dictionary of SHA1 -> Lua scripts */
-    unsigned long long lua_scripts_mem;  /* Cached scripts' memory + oh */
-    mstime_t lua_time_limit;  /* Script timeout in milliseconds */
-    monotime lua_time_start;  /* monotonic timer to detect timed-out script */
-    mstime_t lua_time_snapshot; /* Snapshot of mstime when script is started */
-    int lua_write_dirty;  /* True if a write command was called during the
-                             execution of the current script. */
-    int lua_random_dirty; /* True if a random command was called during the
-                             execution of the current script. */
-    int lua_replicate_commands; /* True if we are doing single commands repl. */
-    int lua_multi_emitted;/* True if we already propagated MULTI. */
-    int lua_repl;         /* Script replication flags for redis.set_repl(). */
-    int lua_timedout;     /* True if we reached the time limit for script
-                             execution. */
-    int lua_kill;         /* Kill the script if true. */
+    client *script_caller;       /* The client running script right now, or NULL */
+    mstime_t script_time_limit;  /* Script timeout in milliseconds */
     int lua_always_replicate_commands; /* Default replication type. */
-    int lua_oom;          /* OOM detected when script start? */
-    int lua_disable_deny_script; /* Allow running commands marked "no-script" inside a script. */
+    int script_oom;                    /* OOM detected when script start */
+    int script_disable_deny_script;    /* Allow running commands marked "no-script" inside a script. */
     /* Lazy free */
     int lazyfree_lazy_eviction;
     int lazyfree_lazy_expire;
@@ -2687,6 +2684,7 @@ int sintercardGetKeys(struct redisCommand *cmd,robj **argv, int argc, getKeysRes
 int zunionInterDiffGetKeys(struct redisCommand *cmd,robj **argv, int argc, getKeysResult *result);
 int zunionInterDiffStoreGetKeys(struct redisCommand *cmd,robj **argv, int argc, getKeysResult *result);
 int evalGetKeys(struct redisCommand *cmd, robj **argv, int argc, getKeysResult *result);
+int functionGetKeys(struct redisCommand *cmd, robj **argv, int argc, getKeysResult *result);
 int sortGetKeys(struct redisCommand *cmd, robj **argv, int argc, getKeysResult *result);
 int migrateGetKeys(struct redisCommand *cmd, robj **argv, int argc, getKeysResult *result);
 int georadiusGetKeys(struct redisCommand *cmd, robj **argv, int argc, getKeysResult *result);
@@ -2722,8 +2720,17 @@ void scriptingInit(int setup);
 int ldbRemoveChild(pid_t pid);
 void ldbKillForkedSessions(void);
 int ldbPendingChildren(void);
-sds luaCreateFunction(client *c, lua_State *lua, robj *body);
+sds luaCreateFunction(client *c, robj *body);
+void luaLdbLineHook(lua_State *lua, lua_Debug *ar);
 void freeLuaScriptsAsync(dict *lua_scripts);
+int ldbIsEnabled();
+void ldbLog(sds entry);
+void ldbLogRedisReply(char *reply);
+void sha1hex(char *digest, char *script, size_t len);
+unsigned long evalMemory();
+dict* evalScriptsDict();
+unsigned long evalScriptsMemory();
+mstime_t evalTimeSnapshot();
 
 /* Blocked clients */
 void processUnblockedClients(void);
@@ -2769,6 +2776,7 @@ uint64_t dictSdsCaseHash(const void *key);
 int dictSdsKeyCompare(dict *d, const void *key1, const void *key2);
 int dictSdsKeyCaseCompare(dict *d, const void *key1, const void *key2);
 void dictSdsDestructor(dict *d, void *val);
+void *dictSdsDup(dict *d, const void *key);
 
 /* Git SHA1 */
 char *redisGitSHA1(void);

src/sort.c

@@ -294,7 +294,7 @@ void sortCommandGeneric(client *c, int readonly) {
      * scripting and replication. */
     if (dontsort &&
         sortval->type == OBJ_SET &&
-        (storekey || c->flags & CLIENT_LUA))
+        (storekey || c->flags & CLIENT_SCRIPT))
     {
         /* Force ALPHA sorting */
         dontsort = 0;

src/t_stream.c

@@ -1998,7 +1998,7 @@ void xreadCommand(client *c) {
         int moreargs = c->argc-i-1;
         char *o = c->argv[i]->ptr;
         if (!strcasecmp(o,"BLOCK") && moreargs) {
-            if (c->flags & CLIENT_LUA) {
+            if (c->flags & CLIENT_SCRIPT) {
                 /*
                  * Although the CLIENT_DENY_BLOCKING flag should protect from blocking the client
                  * on Lua/MULTI/RM_Call we want special treatment for Lua to keep backward compatibility.

tests/integration/replication.tcl

@@ -521,6 +521,12 @@ foreach testType {Successful Aborted} {
             # Set a key value on replica to check status during loading, on failure and after swapping db
             $replica set mykey myvalue
 
+            # Set a function value on replica to check status during loading, on failure and after swapping db
+            $replica function create LUA test {return 'hello1'}
+
+            # Set a function value on master to check it reaches the replica when replication ends
+            $master function create LUA test {return 'hello2'}
+
             # Force the replica to try another full sync (this time it will have matching master replid)
             $master multi
             $master client kill type replica
@@ -552,6 +558,9 @@ foreach testType {Successful Aborted} {
                         # Ensure we still see old values while async_loading is in progress and also not LOADING status
                         assert_equal [$replica get mykey] "myvalue"
 
+                        # Ensure we still can call old function while async_loading is in progress
+                        assert_equal [$replica fcall test 0] "hello1"
+
                         # Make sure we're still async_loading to validate previous assertion
                         assert_equal [s -1 async_loading] 1
 
@@ -576,6 +585,9 @@ foreach testType {Successful Aborted} {
                         # Ensure we see old values from replica
                         assert_equal [$replica get mykey] "myvalue"
 
+                        # Ensure we still can call old function
+                        assert_equal [$replica fcall test 0] "hello1"
+
                         # Make sure amount of replica keys didn't change
                         assert_equal [$replica dbsize] 2001
                     }
@@ -595,6 +607,9 @@ foreach testType {Successful Aborted} {
                         # Ensure we don't see anymore the key that was stored only to replica and also that we don't get LOADING status
                         assert_equal [$replica GET mykey] ""
 
+                        # Ensure we got the new function
+                        assert_equal [$replica fcall test 0] "hello2"
+
                         # Make sure amount of keys matches master
                         assert_equal [$replica dbsize] 1010
                     }
@@ -624,6 +639,10 @@ test {diskless loading short read} {
             $replica config set dynamic-hz no
             # Try to fill the master with all types of data types / encodings
             set start [clock clicks -milliseconds]
+
+            # Set a function value to check short read handling on functions
+            r function create LUA test {return 'hello1'}
+
             for {set k 0} {$k < 3} {incr k} {
                 for {set i 0} {$i < 10} {incr i} {
                     r set "$k int_$i" [expr {int(rand()*10000)}]

tests/unit/functions.tcl

@@ -0,0 +1,280 @@
+start_server {tags {"scripting"}} {
+    test {FUNCTION - Basic usage} {
+        r function create LUA test {return 'hello'}
+        r fcall test 0
+    } {hello}
+
+    test {FUNCTION - Create an already exiting function raise error} {
+        catch {
+            r function create LUA test {return 'hello1'}
+        } e
+        set _ $e
+    } {*Function already exists*}
+
+    test {FUNCTION - Create function with unexisting engine} {
+        catch {
+            r function create bad_engine test {return 'hello1'}
+        } e
+        set _ $e
+    } {*Engine not found*}
+
+    test {FUNCTION - Test uncompiled script} {
+        catch {
+            r function create LUA test1 {bad script}
+        } e
+        set _ $e
+    } {*Error compiling function*}
+
+    test {FUNCTION - test replace argument} {
+        r function create LUA test REPLACE {return 'hello1'}
+        r fcall test 0
+    } {hello1}
+
+    test {FUNCTION - test replace argument with function creation failure keeps old function} {
+         catch {r function create LUA test REPLACE {error}}
+        r fcall test 0
+    } {hello1}
+
+    test {FUNCTION - test function delete} {
+        r function delete test
+        catch {
+            r fcall test 0
+        } e
+        set _ $e
+    } {*Function not found*}
+
+    test {FUNCTION - test description argument} {
+        r function create LUA test DESCRIPTION {some description} {return 'hello'}
+        r function list
+    } {{name test engine LUA description {some description}}}
+
+    test {FUNCTION - test info specific function} {
+        r function info test WITHCODE
+    } {name test engine LUA description {some description} code {return 'hello'}}
+
+    test {FUNCTION - test info without code} {
+        r function info test
+    } {name test engine LUA description {some description}}
+
+    test {FUNCTION - test info on function that does not exists} {
+        catch {
+            r function info bad_function_name
+        } e
+        set _ $e
+    } {*Function does not exists*}
+
+    test {FUNCTION - test info with bad number of arguments} {
+        catch {
+            r function info test WITHCODE bad_arg
+        } e
+        set _ $e
+    } {*wrong number of arguments*}
+
+    test {FUNCTION - test fcall bad arguments} {
+        catch {
+            r fcall test bad_arg
+        } e
+        set _ $e
+    } {*Bad number of keys provided*}
+
+    test {FUNCTION - test fcall bad number of keys arguments} {
+        catch {
+            r fcall test 10 key1
+        } e
+        set _ $e
+    } {*Number of keys can't be greater than number of args*}
+
+    test {FUNCTION - test fcall negative number of keys} {
+        catch {
+            r fcall test -1 key1
+        } e
+        set _ $e
+    } {*Number of keys can't be negative*}
+
+    test {FUNCTION - test function delete on not exiting function} {
+        catch {
+            r function delete test1
+        } e
+        set _ $e
+    } {*Function not found*}
+
+    test {FUNCTION - test function kill when function is not running} {
+        catch {
+            r function kill
+        } e
+        set _ $e
+    } {*No scripts in execution*}
+
+    test {FUNCTION - test wrong subcommand} {
+        catch {
+            r function bad_subcommand
+        } e
+        set _ $e
+    } {*Unknown subcommand*}
+
+    test {FUNCTION - test loading from rdb} {
+        r debug reload
+        r fcall test 0
+    } {hello}
+
+    test {FUNCTION - test fcall_ro with write command} {
+        r function create lua test REPLACE {return redis.call('set', 'x', '1')}
+        catch { r fcall_ro test 0 } e
+        set _ $e
+    } {*Write commands are not allowed from read-only scripts*}
+
+    test {FUNCTION - test fcall_ro with read only commands} {
+        r function create lua test REPLACE {return redis.call('get', 'x')}
+        r set x 1
+        r fcall_ro test 0
+    } {1}
+
+    test {FUNCTION - test keys and argv} {
+        r function create lua test REPLACE {return redis.call('set', KEYS[1], ARGV[1])}
+        r fcall test 1 x foo
+        r get x
+    } {foo}
+
+    test {FUNCTION - test command get keys on fcall} {
+        r COMMAND GETKEYS fcall test 1 x foo
+    } {x}
+
+    test {FUNCTION - test command get keys on fcall_ro} {
+        r COMMAND GETKEYS fcall_ro test 1 x foo
+    } {x}
+
+    test {FUNCTION - test function kill} {
+        set rd [redis_deferring_client]
+        r config set script-time-limit 10
+        r function create lua test REPLACE {local a = 1 while true do a = a + 1 end}
+        $rd fcall test 0
+        after 200
+        catch {r ping} e
+        assert_match {BUSY*} $e
+        assert_match {running_script {name test command {fcall test 0} duration_ms *} engines LUA} [r FUNCTION STATS]
+        r function kill
+        after 200 ; # Give some time to Lua to call the hook again...
+        assert_equal [r ping] "PONG"
+    }
+
+    test {FUNCTION - test script kill not working on function} {
+        set rd [redis_deferring_client]
+        r config set script-time-limit 10
+        r function create lua test REPLACE {local a = 1 while true do a = a + 1 end}
+        $rd fcall test 0
+        after 200
+        catch {r ping} e
+        assert_match {BUSY*} $e
+        catch {r script kill} e
+        assert_match {BUSY*} $e
+        r function kill
+        after 200 ; # Give some time to Lua to call the hook again...
+        assert_equal [r ping] "PONG"
+    }
+
+    test {FUNCTION - test function kill not working on eval} {
+        set rd [redis_deferring_client]
+        r config set script-time-limit 10
+        $rd eval {local a = 1 while true do a = a + 1 end} 0
+        after 200
+        catch {r ping} e
+        assert_match {BUSY*} $e
+        catch {r function kill} e
+        assert_match {BUSY*} $e
+        r script kill
+        after 200 ; # Give some time to Lua to call the hook again...
+        assert_equal [r ping] "PONG"
+    }
+}
+
+start_server {tags {"scripting repl"}} {
+    start_server {} {
+        test "Connect a replica to the master instance" {
+            r -1 slaveof [srv 0 host] [srv 0 port]
+            wait_for_condition 50 100 {
+                [s -1 role] eq {slave} &&
+                [string match {*master_link_status:up*} [r -1 info replication]]
+            } else {
+                fail "Can't turn the instance into a replica"
+            }
+        }
+
+        test {FUNCTION - creation is replicated to replica} {
+            r function create LUA test DESCRIPTION {some description} {return 'hello'}
+            wait_for_condition 50 100 {
+                [r -1 function list] eq {{name test engine LUA description {some description}}}
+            } else {
+                fail "Failed waiting for function to replicate to replica"
+            }
+        }
+
+        test {FUNCTION - call on replica} {
+            r -1 fcall test 0
+        } {hello}
+
+        test {FUNCTION - delete is replicated to replica} {
+            r function delete test
+            wait_for_condition 50 100 {
+                [r -1 function list] eq {}
+            } else {
+                fail "Failed waiting for function to replicate to replica"
+            }
+        }
+
+        test "Disconnecting the replica from master instance" {
+            r -1 slaveof no one
+            # creating a function after disconnect to make sure function
+            # is replicated on rdb phase
+            r function create LUA test DESCRIPTION {some description} {return 'hello'}
+
+            # reconnect the replica
+            r -1 slaveof [srv 0 host] [srv 0 port]
+            wait_for_condition 50 100 {
+                [s -1 role] eq {slave} &&
+                [string match {*master_link_status:up*} [r -1 info replication]]
+            } else {
+                fail "Can't turn the instance into a replica"
+            }
+        }
+
+        test "FUNCTION - test replication to replica on rdb phase" {
+            r -1 fcall test 0
+        } {hello}
+
+        test "FUNCTION - test replication to replica on rdb phase info command" {
+            r -1 function info test WITHCODE
+        } {name test engine LUA description {some description} code {return 'hello'}}
+
+        test "FUNCTION - create on read only replica" {
+            catch {
+                r -1 function create LUA test DESCRIPTION {some description} {return 'hello'}
+            } e
+            set _ $e
+        } {*Can not create a function on a read only replica*}
+
+        test "FUNCTION - delete on read only replica" {
+            catch {
+                r -1 function delete test
+            } e
+            set _ $e
+        } {*Can not delete a function on a read only replica*}
+
+        test "FUNCTION - function effect is replicated to replica" {
+            r function create LUA test REPLACE {return redis.call('set', 'x', '1')}
+            r fcall test 0
+            assert {[r get x] eq {1}}
+            wait_for_condition 50 100 {
+                [r -1 get x] eq {1}
+            } else {
+                fail "Failed waiting function effect to be replicated to replica"
+            }
+        }
+
+        test "FUNCTION - modify key space of read only replica" {
+            catch {
+                r -1 fcall test 0
+            } e
+            set _ $e
+        } {*can't write against a read only replica*}
+    }
+}

tests/unit/scripting.tcl

@@ -1,48 +1,87 @@
+foreach is_eval {0 1} {
+
+if {$is_eval == 1} {
+    proc run_script {args} {
+        r eval {*}$args
+    }
+    proc run_script_ro {args} {
+        r eval_ro {*}$args
+    }
+    proc run_script_on_connection {args} {
+        [lindex $args 0] eval {*}[lrange $args 1 end]
+    }
+    proc kill_script {args} {
+        r script kill
+    }
+} else {
+    proc run_script {args} {
+        r function create LUA test replace [lindex $args 0]
+        r fcall test {*}[lrange $args 1 end]
+    }
+    proc run_script_ro {args} {
+        r function create LUA test replace [lindex $args 0]
+        r fcall_ro test {*}[lrange $args 1 end]
+    }
+    proc run_script_on_connection {args} {
+        set rd [lindex $args 0]
+        $rd function create LUA test replace [lindex $args 1]
+        # read the ok reply of function create
+        $rd read
+        $rd fcall test {*}[lrange $args 2 end]
+    }
+    proc kill_script {args} {
+        r function kill
+    }
+}
+
 start_server {tags {"scripting"}} {
+
     test {EVAL - Does Lua interpreter replies to our requests?} {
-        r eval {return 'hello'} 0
+        run_script {return 'hello'} 0
     } {hello}
 
     test {EVAL - Lua integer -> Redis protocol type conversion} {
-        r eval {return 100.5} 0
+        run_script {return 100.5} 0
     } {100}
 
     test {EVAL - Lua string -> Redis protocol type conversion} {
-        r eval {return 'hello world'} 0
+        run_script {return 'hello world'} 0
     } {hello world}
 
     test {EVAL - Lua true boolean -> Redis protocol type conversion} {
-        r eval {return true} 0
+        run_script {return true} 0
     } {1}
 
     test {EVAL - Lua false boolean -> Redis protocol type conversion} {
-        r eval {return false} 0
+        run_script {return false} 0
     } {}
 
     test {EVAL - Lua status code reply -> Redis protocol type conversion} {
-        r eval {return {ok='fine'}} 0
+        run_script {return {ok='fine'}} 0
     } {fine}
 
     test {EVAL - Lua error reply -> Redis protocol type conversion} {
         catch {
-            r eval {return {err='this is an error'}} 0
+            run_script {return {err='this is an error'}} 0
         } e
         set _ $e
     } {this is an error}
 
     test {EVAL - Lua table -> Redis protocol type conversion} {
-        r eval {return {1,2,3,'ciao',{1,2}}} 0
+        run_script {return {1,2,3,'ciao',{1,2}}} 0
     } {1 2 3 ciao {1 2}}
 
     test {EVAL - Are the KEYS and ARGV arrays populated correctly?} {
-        r eval {return {KEYS[1],KEYS[2],ARGV[1],ARGV[2]}} 2 a{t} b{t} c{t} d{t}
+        run_script {return {KEYS[1],KEYS[2],ARGV[1],ARGV[2]}} 2 a{t} b{t} c{t} d{t}
     } {a{t} b{t} c{t} d{t}}
 
     test {EVAL - is Lua able to call Redis API?} {
         r set mykey myval
-        r eval {return redis.call('get',KEYS[1])} 1 mykey
+        run_script {return redis.call('get',KEYS[1])} 1 mykey
     } {myval}
 
+    if {$is_eval eq 1} {
+    # eval sha is only relevant for is_eval Lua
     test {EVALSHA - Can we call a SHA1 if already defined?} {
         r evalsha fd758d1589d044dd850a6f05d52f2eefd27f033f 1 mykey
     } {myval}
@@ -60,10 +99,11 @@ start_server {tags {"scripting"}} {
         catch {r evalsha ffd632c7d33e571e9f24556ebed26c3479a87130 0} e
         set _ $e
     } {NOSCRIPT*}
+    } ;# is_eval
 
     test {EVAL - Redis integer -> Lua type conversion} {
         r set x 0
-        r eval {
+        run_script {
             local foo = redis.pcall('incr',KEYS[1])
             return {type(foo),foo}
         } 1 x
@@ -71,7 +111,7 @@ start_server {tags {"scripting"}} {
 
     test {EVAL - Redis bulk -> Lua type conversion} {
         r set mykey myval
-        r eval {
+        run_script {
             local foo = redis.pcall('get',KEYS[1])
             return {type(foo),foo}
         } 1 mykey
@@ -82,14 +122,14 @@ start_server {tags {"scripting"}} {
         r rpush mylist a
         r rpush mylist b
         r rpush mylist c
-        r eval {
+        run_script {
             local foo = redis.pcall('lrange',KEYS[1],0,-1)
             return {type(foo),foo[1],foo[2],foo[3],# foo}
         } 1 mylist
     } {table a b c 3}
 
     test {EVAL - Redis status reply -> Lua type conversion} {
-        r eval {
+        run_script {
             local foo = redis.pcall('set',KEYS[1],'myval')
             return {type(foo),foo['ok']}
         } 1 mykey
@@ -97,7 +137,7 @@ start_server {tags {"scripting"}} {
 
     test {EVAL - Redis error reply -> Lua type conversion} {
         r set mykey myval
-        r eval {
+        run_script {
             local foo = redis.pcall('incr',KEYS[1])
             return {type(foo),foo['err']}
         } 1 mykey
@@ -105,7 +145,7 @@ start_server {tags {"scripting"}} {
 
     test {EVAL - Redis nil bulk reply -> Lua type conversion} {
         r del mykey
-        r eval {
+        run_script {
             local foo = redis.pcall('get',KEYS[1])
             return {type(foo),foo == false}
         } 1 mykey
@@ -115,13 +155,13 @@ start_server {tags {"scripting"}} {
         r set mykey "this is DB 9"
         r select 10
         r set mykey "this is DB 10"
-        r eval {return redis.pcall('get',KEYS[1])} 1 mykey
+        run_script {return redis.pcall('get',KEYS[1])} 1 mykey
     } {this is DB 10} {singledb:skip}
 
     test {EVAL - SELECT inside Lua should not affect the caller} {
         # here we DB 10 is selected
         r set mykey "original value"
-        r eval {return redis.pcall('select','9')} 0
+        run_script {return redis.pcall('select','9')} 0
         set res [r get mykey]
         r select 9
         set res
@@ -131,7 +171,7 @@ start_server {tags {"scripting"}} {
         test {EVAL - Script can't run more than configured time limit} {
             r config set lua-time-limit 1
             catch {
-                r eval {
+                run_script {
                     local i = 0
                     while true do i=i+1 end
                 } 0
@@ -142,71 +182,74 @@ start_server {tags {"scripting"}} {
 
     test {EVAL - Scripts can't run blpop command} {
         set e {}
-        catch {r eval {return redis.pcall('blpop','x',0)} 0} e
+        catch {run_script {return redis.pcall('blpop','x',0)} 0} e
         set e
     } {*not allowed*}
 
     test {EVAL - Scripts can't run brpop command} {
         set e {}
-        catch {r eval {return redis.pcall('brpop','empty_list',0)} 0} e
+        catch {run_script {return redis.pcall('brpop','empty_list',0)} 0} e
         set e
     } {*not allowed*}
 
     test {EVAL - Scripts can't run brpoplpush command} {
         set e {}
-        catch {r eval {return redis.pcall('brpoplpush','empty_list1', 'empty_list2',0)} 0} e
+        catch {run_script {return redis.pcall('brpoplpush','empty_list1', 'empty_list2',0)} 0} e
         set e
     } {*not allowed*}
 
     test {EVAL - Scripts can't run blmove command} {
         set e {}
-        catch {r eval {return redis.pcall('blmove','empty_list1', 'empty_list2', 'LEFT', 'LEFT', 0)} 0} e
+        catch {run_script {return redis.pcall('blmove','empty_list1', 'empty_list2', 'LEFT', 'LEFT', 0)} 0} e
         set e
     } {*not allowed*}
 
     test {EVAL - Scripts can't run bzpopmin command} {
         set e {}
-        catch {r eval {return redis.pcall('bzpopmin','empty_zset', 0)} 0} e
+        catch {run_script {return redis.pcall('bzpopmin','empty_zset', 0)} 0} e
         set e
     } {*not allowed*}
 
     test {EVAL - Scripts can't run bzpopmax command} {
         set e {}
-        catch {r eval {return redis.pcall('bzpopmax','empty_zset', 0)} 0} e
+        catch {run_script {return redis.pcall('bzpopmax','empty_zset', 0)} 0} e
         set e
     } {*not allowed*}
 
     test {EVAL - Scripts can't run XREAD and XREADGROUP with BLOCK option} {
         r del s
         r xgroup create s g $ MKSTREAM
-        set res [r eval {return redis.pcall('xread','STREAMS','s','$')} 1 s]
+        set res [run_script {return redis.pcall('xread','STREAMS','s','$')} 1 s]
         assert {$res eq {}}
-        assert_error "*xread command is not allowed with BLOCK option from scripts" {r eval {return redis.pcall('xread','BLOCK',0,'STREAMS','s','$')} 1 s}
-        set res [r eval {return redis.pcall('xreadgroup','group','g','c','STREAMS','s','>')} 1 s]
+        assert_error "*xread command is not allowed with BLOCK option from scripts" {run_script {return redis.pcall('xread','BLOCK',0,'STREAMS','s','$')} 1 s}
+        set res [run_script {return redis.pcall('xreadgroup','group','g','c','STREAMS','s','>')} 1 s]
         assert {$res eq {}}
-        assert_error "*xreadgroup command is not allowed with BLOCK option from scripts" {r eval {return redis.pcall('xreadgroup','group','g','c','BLOCK',0,'STREAMS','s','>')} 1 s}
+        assert_error "*xreadgroup command is not allowed with BLOCK option from scripts" {run_script {return redis.pcall('xreadgroup','group','g','c','BLOCK',0,'STREAMS','s','>')} 1 s}
     }
 
+    if {$is_eval eq 1} {
+    # only is_eval Lua can not execute randomkey
     test {EVAL - Scripts can't run certain commands} {
         set e {}
         r debug lua-always-replicate-commands 0
         catch {
-            r eval "redis.pcall('randomkey'); return redis.pcall('set','x','ciao')" 0
+            run_script "redis.pcall('randomkey'); return redis.pcall('set','x','ciao')" 0
         } e
         r debug lua-always-replicate-commands 1
         set e
     } {*not allowed after*} {needs:debug}
+    } ;# is_eval
 
     test {EVAL - No arguments to redis.call/pcall is considered an error} {
         set e {}
-        catch {r eval {return redis.call()} 0} e
+        catch {run_script {return redis.call()} 0} e
         set e
     } {*one argument*}
 
     test {EVAL - redis.call variant raises a Lua error on Redis cmd error (1)} {
         set e {}
         catch {
-            r eval "redis.call('nosuchcommand')" 0
+            run_script "redis.call('nosuchcommand')" 0
         } e
         set e
     } {*Unknown Redis*}
@@ -214,7 +257,7 @@ start_server {tags {"scripting"}} {
     test {EVAL - redis.call variant raises a Lua error on Redis cmd error (1)} {
         set e {}
         catch {
-            r eval "redis.call('get','a','b','c')" 0
+            run_script "redis.call('get','a','b','c')" 0
         } e
         set e
     } {*number of args*}
@@ -223,7 +266,7 @@ start_server {tags {"scripting"}} {
         set e {}
         r set foo bar
         catch {
-            r eval {redis.call('lpush',KEYS[1],'val')} 1 foo
+            run_script {redis.call('lpush',KEYS[1],'val')} 1 foo
         } e
         set e
     } {*against a key*}
@@ -232,7 +275,7 @@ start_server {tags {"scripting"}} {
         # We must return the table as a string because otherwise
         # Redis converts floats to ints and we get 0 and 1023 instead
         # of 0.0003 and 1023.2 as the parsed output.
-        r eval {return
+        run_script {return
                  table.concat(
                    cjson.decode(
                     "[0.0, -5e3, -1, 0.3e-3, 1023.2, 0e10]"), " ")
@@ -240,13 +283,13 @@ start_server {tags {"scripting"}} {
     } {0 -5000 -1 0.0003 1023.2 0}
 
     test {EVAL - JSON string decoding} {
-        r eval {local decoded = cjson.decode('{"keya": "a", "keyb": "b"}')
+        run_script {local decoded = cjson.decode('{"keya": "a", "keyb": "b"}')
                 return {decoded.keya, decoded.keyb}
         } 0
     } {a b}
 
     test {EVAL - cmsgpack can pack double?} {
-        r eval {local encoded = cmsgpack.pack(0.1)
+        run_script {local encoded = cmsgpack.pack(0.1)
                 local h = ""
                 for i = 1, #encoded do
                     h = h .. string.format("%02x",string.byte(encoded,i))
@@ -256,7 +299,7 @@ start_server {tags {"scripting"}} {
     } {cb3fb999999999999a}
 
     test {EVAL - cmsgpack can pack negative int64?} {
-        r eval {local encoded = cmsgpack.pack(-1099511627776)
+        run_script {local encoded = cmsgpack.pack(-1099511627776)
                 local h = ""
                 for i = 1, #encoded do
                     h = h .. string.format("%02x",string.byte(encoded,i))
@@ -266,7 +309,7 @@ start_server {tags {"scripting"}} {
     } {d3ffffff0000000000}
 
     test {EVAL - cmsgpack can pack and unpack circular references?} {
-        r eval {local a = {x=nil,y=5}
+        run_script {local a = {x=nil,y=5}
                 local b = {x=a}
                 a['x'] = b
                 local encoded = cmsgpack.pack(a)
@@ -298,7 +341,7 @@ start_server {tags {"scripting"}} {
     } {82a17905a17881a17882a17905a17881a17882a17905a17881a17882a17905a17881a17882a17905a17881a17882a17905a17881a17882a17905a17881a17882a17905a17881a178c0 1 1}
 
     test {EVAL - Numerical sanity check from bitop} {
-        r eval {assert(0x7fffffff == 2147483647, "broken hex literals");
+        run_script {assert(0x7fffffff == 2147483647, "broken hex literals");
                 assert(0xffffffff == -1 or 0xffffffff == 2^32-1,
                     "broken hex literals");
                 assert(tostring(-1) == "-1", "broken tostring()");
@@ -309,7 +352,7 @@ start_server {tags {"scripting"}} {
     } {}
 
     test {EVAL - Verify minimal bitop functionality} {
-        r eval {assert(bit.tobit(1) == 1);
+        run_script {assert(bit.tobit(1) == 1);
                 assert(bit.band(1) == 1);
                 assert(bit.bxor(1,2) == 3);
                 assert(bit.bor(1,2,4,8,16,32,64,128) == 255)
@@ -317,20 +360,22 @@ start_server {tags {"scripting"}} {
     } {}
 
     test {EVAL - Able to parse trailing comments} {
-        r eval {return 'hello' --trailing comment} 0
+        run_script {return 'hello' --trailing comment} 0
     } {hello}
 
     test {EVAL_RO - Successful case} {
         r set foo bar
-        assert_equal bar [r eval_ro {return redis.call('get', KEYS[1]);} 1 foo]
+        assert_equal bar [run_script_ro {return redis.call('get', KEYS[1]);} 1 foo]
     }
 
     test {EVAL_RO - Cannot run write commands} {
         r set foo bar
-        catch {r eval_ro {redis.call('del', KEYS[1]);} 1 foo} e
+        catch {run_script_ro {redis.call('del', KEYS[1]);} 1 foo} e
         set e
     } {*Write commands are not allowed from read-only scripts*}
 
+    if {$is_eval eq 1} {
+    # script command is only relevant for is_eval Lua
     test {SCRIPTING FLUSH - is able to clear the scripts cache?} {
         r set mykey myval
         set v [r evalsha fd758d1589d044dd850a6f05d52f2eefd27f033f 1 mykey]
@@ -361,6 +406,7 @@ start_server {tags {"scripting"}} {
             [r evalsha b534286061d4b9e4026607613b95c06c06015ae8 0]
     } {b534286061d4b9e4026607613b95c06c06015ae8 loaded}
 
+    # reply oredering is only relevant for is_eval Lua
     test "In the context of Lua the output of random commands gets ordered" {
         r debug lua-always-replicate-commands 0
         r del myset
@@ -387,19 +433,20 @@ start_server {tags {"scripting"}} {
         r sadd myset a b c
         r eval {return redis.call('sort',KEYS[1],'by','_','get','#','get','_:*')} 1 myset
     } {a {} b {} c {}} {cluster:skip}
+    } ;# is_eval
 
     test "redis.sha1hex() implementation" {
-        list [r eval {return redis.sha1hex('')} 0] \
-             [r eval {return redis.sha1hex('Pizza & Mandolino')} 0]
+        list [run_script {return redis.sha1hex('')} 0] \
+             [run_script {return redis.sha1hex('Pizza & Mandolino')} 0]
     } {da39a3ee5e6b4b0d3255bfef95601890afd80709 74822d82031af7493c20eefa13bd07ec4fada82f}
 
     test {Globals protection reading an undeclared global variable} {
-        catch {r eval {return a} 0} e
+        catch {run_script {return a} 0} e
         set e
     } {*ERR*attempted to access * global*}
 
     test {Globals protection setting an undeclared global*} {
-        catch {r eval {a=10} 0} e
+        catch {run_script {a=10} 0} e
         set e
     } {*ERR*attempted to create global*}
 
@@ -417,14 +464,16 @@ start_server {tags {"scripting"}} {
         }
         r set foo 5
         set res {}
-        lappend res [r eval $decr_if_gt 1 foo 2]
-        lappend res [r eval $decr_if_gt 1 foo 2]
-        lappend res [r eval $decr_if_gt 1 foo 2]
-        lappend res [r eval $decr_if_gt 1 foo 2]
-        lappend res [r eval $decr_if_gt 1 foo 2]
+        lappend res [run_script $decr_if_gt 1 foo 2]
+        lappend res [run_script $decr_if_gt 1 foo 2]
+        lappend res [run_script $decr_if_gt 1 foo 2]
+        lappend res [run_script $decr_if_gt 1 foo 2]
+        lappend res [run_script $decr_if_gt 1 foo 2]
         set res
     } {4 3 2 2 2}
 
+    if {$is_eval eq 1} {
+    # random handling is only relevant for is_eval Lua
     test {Scripting engine resets PRNG at every script execution} {
         set rand1 [r eval {return tostring(math.random())} 0]
         set rand2 [r eval {return tostring(math.random())} 0]
@@ -444,13 +493,14 @@ start_server {tags {"scripting"}} {
         assert_equal $rand1 $rand2
         assert {$rand2 ne $rand3}
     }
+    } ;# is_eval
 
     test {EVAL does not leak in the Lua stack} {
         r set x 0
         # Use a non blocking client to speedup the loop.
         set rd [redis_deferring_client]
         for {set j 0} {$j < 10000} {incr j} {
-            $rd eval {return redis.call("incr",KEYS[1])} 1 x
+            run_script_on_connection $rd {return redis.call("incr",KEYS[1])} 1 x
         }
         for {set j 0} {$j < 10000} {incr j} {
             $rd read
@@ -464,9 +514,9 @@ start_server {tags {"scripting"}} {
         r flushall
         r config set appendonly yes
         r config set aof-use-rdb-preamble no
-        r eval {redis.call("set",KEYS[1],"100")} 1 foo
-        r eval {redis.call("incr",KEYS[1])} 1 foo
-        r eval {redis.call("incr",KEYS[1])} 1 foo
+        run_script {redis.call("set",KEYS[1],"100")} 1 foo
+        run_script {redis.call("incr",KEYS[1])} 1 foo
+        run_script {redis.call("incr",KEYS[1])} 1 foo
         wait_for_condition 50 100 {
             [s aof_rewrite_in_progress] == 0
         } else {
@@ -481,6 +531,8 @@ start_server {tags {"scripting"}} {
         set res
     } {102} {external:skip}
 
+    if {$is_eval eq 1} {
+    # script propagation is irrelevant on functions
     test {EVAL timeout from AOF} {
         # generate a long running script that is propagated to the AOF as script
         # make sure that the script times out during loading
@@ -528,9 +580,11 @@ start_server {tags {"scripting"}} {
         assert {[r mget a{t} b{t} c{t} d{t}] eq {1 2 3 4}}
         assert {[r spop myset] eq {}}
     }
+    } ;# is_eval
+
 
     test {Call Redis command with many args from Lua (issue #1764)} {
-        r eval {
+        run_script {
             local i
             local x={}
             redis.call('del','mylist')
@@ -543,7 +597,7 @@ start_server {tags {"scripting"}} {
     } {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100}
 
     test {Number conversion precision test (issue #1118)} {
-        r eval {
+        run_script {
               local value = 9007199254740991
               redis.call("set","foo",value)
               return redis.call("get","foo")
@@ -551,19 +605,19 @@ start_server {tags {"scripting"}} {
     } {9007199254740991}
 
     test {String containing number precision test (regression of issue #1118)} {
-        r eval {
+        run_script {
             redis.call("set", "key", "12039611435714932082")
             return redis.call("get", "key")
         } 1 key
     } {12039611435714932082}
 
     test {Verify negative arg count is error instead of crash (issue #1842)} {
-        catch { r eval { return "hello" } -12 } e
+        catch { run_script { return "hello" } -12 } e
         set e
     } {ERR Number of keys can't be negative}
 
     test {Correct handling of reused argv (issue #1939)} {
-        r eval {
+        run_script {
               for i = 0, 10 do
                   redis.call('SET', 'a{t}', '1')
                   redis.call('MGET', 'a{t}', 'b{t}', 'c{t}')
@@ -576,7 +630,7 @@ start_server {tags {"scripting"}} {
 
     test {Functions in the Redis namespace are able to report errors} {
         catch {
-            r eval {
+            run_script {
                   redis.sha1hex()
             } 0
         } e
@@ -594,22 +648,22 @@ start_server {tags {"scripting"}} {
         assert_equal $res $expected_dict
 
         # Test RESP3 client with script in both RESP2 and RESP3 modes
-        set res [r eval {redis.setresp(3); return redis.call('hgetall', KEYS[1])} 1 hash]
+        set res [run_script {redis.setresp(3); return redis.call('hgetall', KEYS[1])} 1 hash]
         assert_equal $res $expected_dict
-        set res [r eval {redis.setresp(2); return redis.call('hgetall', KEYS[1])} 1 hash]
+        set res [run_script {redis.setresp(2); return redis.call('hgetall', KEYS[1])} 1 hash]
         assert_equal $res $expected_list
 
         # Test RESP2 client with script in both RESP2 and RESP3 modes
         r HELLO 2
-        set res [r eval {redis.setresp(3); return redis.call('hgetall', KEYS[1])} 1 hash]
+        set res [run_script {redis.setresp(3); return redis.call('hgetall', KEYS[1])} 1 hash]
         assert_equal $res $expected_list
-        set res [r eval {redis.setresp(2); return redis.call('hgetall', KEYS[1])} 1 hash]
+        set res [run_script {redis.setresp(2); return redis.call('hgetall', KEYS[1])} 1 hash]
         assert_equal $res $expected_list
     }
 
     test {Script return recursive object} {
         r readraw 1
-        set res [r eval {local a = {}; local b = {a}; a[1] = b; return a} 0]
+        set res [run_script {local a = {}; local b = {a}; a[1] = b; return a} 0]
         # drain the response
         while {true} {
             if {$res == "-ERR reached lua stack limit"} {
@@ -640,11 +694,11 @@ start_server {tags {"scripting"}} {
     test {Timedout read-only scripts can be killed by SCRIPT KILL} {
         set rd [redis_deferring_client]
         r config set lua-time-limit 10
-        $rd eval {while true do end} 0
+        run_script_on_connection $rd {while true do end} 0
         after 200
         catch {r ping} e
         assert_match {BUSY*} $e
-        r script kill
+        kill_script
         after 200 ; # Give some time to Lua to call the hook again...
         assert_equal [r ping] "PONG"
         $rd close
@@ -653,7 +707,7 @@ start_server {tags {"scripting"}} {
     test {Timedout read-only scripts can be killed by SCRIPT KILL even when use pcall} {
         set rd [redis_deferring_client]
         r config set lua-time-limit 10
-        $rd eval {local f = function() while 1 do redis.call('ping') end end while 1 do pcall(f) end} 0
+        run_script_on_connection $rd {local f = function() while 1 do redis.call('ping') end end while 1 do pcall(f) end} 0
         
         wait_for_condition 50 100 {
             [catch {r ping} e] == 1
@@ -663,7 +717,7 @@ start_server {tags {"scripting"}} {
         catch {r ping} e
         assert_match {BUSY*} $e
 
-        r script kill
+        kill_script
 
         wait_for_condition 50 100 {
             [catch {r ping} e] == 0
@@ -685,8 +739,14 @@ start_server {tags {"scripting"}} {
         # senging (in a pipeline):
         # 1. eval "while 1 do redis.call('ping') end" 0
         # 2. ping
-        set buf "*3\r\n\$4\r\neval\r\n\$33\r\nwhile 1 do redis.call('ping') end\r\n\$1\r\n0\r\n"
-        append buf "*1\r\n\$4\r\nping\r\n"
+        if {$is_eval == 1} {
+            set buf "*3\r\n\$4\r\neval\r\n\$33\r\nwhile 1 do redis.call('ping') end\r\n\$1\r\n0\r\n"
+            append buf "*1\r\n\$4\r\nping\r\n"
+        } else {
+            set buf "*6\r\n\$8\r\nfunction\r\n\$6\r\ncreate\r\n\$3\r\nlua\r\n\$4\r\ntest\r\n\$7\r\nreplace\r\n\$33\r\nwhile 1 do redis.call('ping') end\r\n"
+            append buf "*3\r\n\$5\r\nfcall\r\n\$4\r\ntest\r\n\$1\r\n0\r\n"
+            append buf "*1\r\n\$4\r\nping\r\n"
+        }
         $rd write $buf
         $rd flush
 
@@ -698,7 +758,7 @@ start_server {tags {"scripting"}} {
         catch {r ping} e
         assert_match {BUSY*} $e
 
-        r script kill
+        kill_script
         wait_for_condition 50 100 {
             [catch {r ping} e] == 0
         } else {
@@ -706,6 +766,11 @@ start_server {tags {"scripting"}} {
         }
         assert_equal [r ping] "PONG"
 
+        if {$is_eval == 0} {
+            # read the ok reply of function create
+            assert_match {OK} [$rd read]
+        }
+
         catch {$rd read} res
         assert_match {*killed by user*} $res
 
@@ -717,18 +782,18 @@ start_server {tags {"scripting"}} {
 
     test {Timedout script link is still usable after Lua returns} {
         r config set lua-time-limit 10
-        r eval {for i=1,100000 do redis.call('ping') end return 'ok'} 0
+        run_script {for i=1,100000 do redis.call('ping') end return 'ok'} 0
         r ping
     } {PONG}
 
     test {Timedout scripts that modified data can't be killed by SCRIPT KILL} {
         set rd [redis_deferring_client]
         r config set lua-time-limit 10
-        $rd eval {redis.call('set',KEYS[1],'y'); while true do end} 1 x
+        run_script_on_connection $rd {redis.call('set',KEYS[1],'y'); while true do end} 1 x
         after 200
         catch {r ping} e
         assert_match {BUSY*} $e
-        catch {r script kill} e
+        catch {kill_script} e
         assert_match {UNKILLABLE*} $e
         catch {r ping} e
         assert_match {BUSY*} $e
@@ -761,11 +826,11 @@ foreach cmdrepl {0 1} {
                 # One with an error, but still executing a command.
                 # SHA is: 67164fc43fa971f76fd1aaeeaf60c1c178d25876
                 catch {
-                    r eval {redis.call('incr',KEYS[1]); redis.call('nonexisting')} 1 x
+                    run_script {redis.call('incr',KEYS[1]); redis.call('nonexisting')} 1 x
                 }
                 # One command is correct:
                 # SHA is: 6f5ade10a69975e903c6d07b10ea44c6382381a5
-                r eval {return redis.call('incr',KEYS[1])} 1 x
+                run_script {return redis.call('incr',KEYS[1])} 1 x
             } {2}
 
             test "Connect a replica to the master instance $rt" {
@@ -778,6 +843,7 @@ foreach cmdrepl {0 1} {
                 }
             }
 
+            if {$is_eval eq 1} {
             test "Now use EVALSHA against the master, with both SHAs $rt" {
                 # The server should replicate successful and unsuccessful
                 # commands as EVAL instead of EVALSHA.
@@ -794,11 +860,12 @@ foreach cmdrepl {0 1} {
                     fail "Expected 4 in x, but value is '[r -1 get x]'"
                 }
             }
+            } ;# is_eval
 
             test "Replication of script multiple pushes to list with BLPOP $rt" {
                 set rd [redis_deferring_client]
                 $rd brpop a 0
-                r eval {
+                run_script {
                     redis.call("lpush",KEYS[1],"1");
                     redis.call("lpush",KEYS[1],"2");
                 } 1 a
@@ -812,6 +879,7 @@ foreach cmdrepl {0 1} {
                 set res
             } {a 1}
 
+            if {$is_eval eq 1} {
             test "EVALSHA replication when first call is readonly $rt" {
                 r del x
                 r eval {if tonumber(ARGV[1]) > 0 then redis.call('incr', KEYS[1]) end} 1 x 0
@@ -823,16 +891,17 @@ foreach cmdrepl {0 1} {
                     fail "Expected 1 in x, but value is '[r -1 get x]'"
                 }
             }
+            } ;# is_eval
 
             test "Lua scripts using SELECT are replicated correctly $rt" {
-                r eval {
+                run_script {
                     redis.call("set","foo1","bar1")
                     redis.call("select","10")
                     redis.call("incr","x")
                     redis.call("select","11")
                     redis.call("incr","z")
                 } 0
-                r eval {
+                run_script {
                     redis.call("set","foo1","bar1")
                     redis.call("select","10")
                     redis.call("incr","x")
@@ -861,6 +930,8 @@ start_server {tags {"scripting repl external:skip"}} {
             }
         }
 
+        if {$is_eval eq 1} {
+        # replicate_commands is the default on Redis Function
         test "Redis.replicate_commands() must be issued before any write" {
             r eval {
                 redis.call('set','foo','bar');
@@ -884,11 +955,11 @@ start_server {tags {"scripting repl external:skip"}} {
             r debug lua-always-replicate-commands 1
             set e
         } {*only after turning on*}
+        } ;# is_eval
 
         test "Redis.set_repl() don't accept invalid values" {
             catch {
-                r eval {
-                    redis.replicate_commands();
+                run_script {
                     redis.set_repl(12345);
                 } 0
             } e
@@ -897,8 +968,7 @@ start_server {tags {"scripting repl external:skip"}} {
 
         test "Test selective replication of certain Redis commands from Lua" {
             r del a b c d
-            r eval {
-                redis.replicate_commands();
+            run_script {
                 redis.call('set','a','1');
                 redis.set_repl(redis.REPL_NONE);
                 redis.call('set','b','2');
@@ -924,24 +994,37 @@ start_server {tags {"scripting repl external:skip"}} {
         }
 
         test "PRNG is seeded randomly for command replication" {
-            set a [
-                r eval {
-                    redis.replicate_commands();
-                    return math.random()*100000;
-                } 0
-            ]
-            set b [
-                r eval {
-                    redis.replicate_commands();
-                    return math.random()*100000;
-                } 0
-            ]
+            if {$is_eval eq 1} {
+                # on is_eval Lua we need to call redis.replicate_commands() to get real randomization
+                set a [
+                    run_script {
+                        redis.replicate_commands()
+                        return math.random()*100000;
+                    } 0
+                ]
+                set b [
+                    run_script {
+                        redis.replicate_commands()
+                        return math.random()*100000;
+                    } 0
+                ]
+            } else {
+                set a [
+                    run_script {
+                        return math.random()*100000;
+                    } 0
+                ]
+                set b [
+                    run_script {
+                        return math.random()*100000;
+                    } 0
+                ]
+            }
             assert {$a ne $b}
         }
 
         test "Using side effects is not a problem with command replication" {
-            r eval {
-                redis.replicate_commands();
+            run_script {
                 redis.call('set','time',redis.call('time')[1])
             } 0
 
@@ -956,6 +1039,7 @@ start_server {tags {"scripting repl external:skip"}} {
     }
 }
 
+if {$is_eval eq 1} {
 start_server {tags {"scripting external:skip"}} {
     r script debug sync
     r eval {return 'hello'} 0
@@ -984,12 +1068,13 @@ start_server {tags {"scripting needs:debug external:skip"}} {
         r write $cmd
         r flush
         set ret [r read]
-        assert_match {*Unknown Redis command called from Lua script*} $ret
+        assert_match {*Unknown Redis command called from script*} $ret
         # make sure the server is still ok
         reconnect
         assert_equal [r ping] {PONG}
     }
 }
+} ;# is_eval
 
 start_server {tags {"scripting resp3 needs:debug"}} {
     r debug set-disable-deny-scripts 1
@@ -999,7 +1084,7 @@ start_server {tags {"scripting resp3 needs:debug"}} {
             r readraw 1
 
             test {test resp3 big number protocol parsing} {
-                set ret [r eval "redis.setresp($i);return redis.call('debug', 'protocol', 'bignum')" 0]
+                set ret [run_script "redis.setresp($i);return redis.call('debug', 'protocol', 'bignum')" 0]
                 if {$client_proto == 2 || $i == 2} {
                     # if either Lua or the clien is RESP2 the reply will be RESP2
                     assert_equal $ret {$37}
@@ -1021,7 +1106,7 @@ start_server {tags {"scripting resp3 needs:debug"}} {
             }
 
             test {test resp3 map protocol parsing} {
-                set ret [r eval "redis.setresp($i);return redis.call('debug', 'protocol', 'map')" 0]
+                set ret [run_script "redis.setresp($i);return redis.call('debug', 'protocol', 'map')" 0]
                 if {$client_proto == 2 || $i == 2} {
                     # if either Lua or the clien is RESP2 the reply will be RESP2
                     assert_equal $ret {*6}
@@ -1034,7 +1119,7 @@ start_server {tags {"scripting resp3 needs:debug"}} {
             }
 
             test {test resp3 set protocol parsing} {
-                set ret [r eval "redis.setresp($i);return redis.call('debug', 'protocol', 'set')" 0]
+                set ret [run_script "redis.setresp($i);return redis.call('debug', 'protocol', 'set')" 0]
                 if {$client_proto == 2 || $i == 2} {
                     # if either Lua or the clien is RESP2 the reply will be RESP2
                     assert_equal $ret {*3}
@@ -1047,7 +1132,7 @@ start_server {tags {"scripting resp3 needs:debug"}} {
             }
 
             test {test resp3 double protocol parsing} {
-                set ret [r eval "redis.setresp($i);return redis.call('debug', 'protocol', 'double')" 0]
+                set ret [run_script "redis.setresp($i);return redis.call('debug', 'protocol', 'double')" 0]
                 if {$client_proto == 2 || $i == 2} {
                     # if either Lua or the clien is RESP2 the reply will be RESP2
                     assert_equal $ret {$5}
@@ -1058,7 +1143,7 @@ start_server {tags {"scripting resp3 needs:debug"}} {
             }
 
             test {test resp3 null protocol parsing} {
-                set ret [r eval "redis.setresp($i);return redis.call('debug', 'protocol', 'null')" 0]
+                set ret [run_script "redis.setresp($i);return redis.call('debug', 'protocol', 'null')" 0]
                 if {$client_proto == 2} {
                     # null is a special case in which a Lua client format does not effect the reply to the client
                     assert_equal $ret {$-1}
@@ -1068,7 +1153,7 @@ start_server {tags {"scripting resp3 needs:debug"}} {
             } {}
 
             test {test resp3 verbatim protocol parsing} {
-                set ret [r eval "redis.setresp($i);return redis.call('debug', 'protocol', 'verbatim')" 0]
+                set ret [run_script "redis.setresp($i);return redis.call('debug', 'protocol', 'verbatim')" 0]
                 if {$client_proto == 2 || $i == 2} {
                     # if either Lua or the clien is RESP2 the reply will be RESP2
                     assert_equal $ret {$25}
@@ -1082,7 +1167,7 @@ start_server {tags {"scripting resp3 needs:debug"}} {
             }
 
             test {test resp3 true protocol parsing} {
-                set ret [r eval "redis.setresp($i);return redis.call('debug', 'protocol', 'true')" 0]
+                set ret [run_script "redis.setresp($i);return redis.call('debug', 'protocol', 'true')" 0]
                 if {$client_proto == 2 || $i == 2} {
                     # if either Lua or the clien is RESP2 the reply will be RESP2
                     assert_equal $ret {:1}
@@ -1092,7 +1177,7 @@ start_server {tags {"scripting resp3 needs:debug"}} {
             }
 
             test {test resp3 false protocol parsing} {
-                set ret [r eval "redis.setresp($i);return redis.call('debug', 'protocol', 'false')" 0]
+                set ret [run_script "redis.setresp($i);return redis.call('debug', 'protocol', 'false')" 0]
                 if {$client_proto == 2 || $i == 2} {
                     # if either Lua or the clien is RESP2 the reply will be RESP2
                     assert_equal $ret {:0}
@@ -1109,8 +1194,9 @@ start_server {tags {"scripting resp3 needs:debug"}} {
     test {test resp3 attribute protocol parsing} {
         # attributes are not (yet) expose to the script
         # So here we just check the parser handles them and they are ignored.
-        r eval "redis.setresp(3);return redis.call('debug', 'protocol', 'attrib')" 0
+        run_script "redis.setresp(3);return redis.call('debug', 'protocol', 'attrib')" 0
     } {Some real reply following the attribute}
 
     r debug set-disable-deny-scripts 0
 }
+} ;# foreach is_eval