Function luaMaskCountHook

app/redis-6.2.6/src/scripting.c:1460–1496

This is the Lua script "count" hook that we use to detect scripts timeout. */

/* This is the Lua script "count" hook that we use to detect scripts timeout. */
void luaMaskCountHook(lua_State *lua, lua_Debug *ar) {
    long long elapsed = elapsedMs(server.lua_time_start);
    UNUSED(ar);
    UNUSED(lua);

    /* Set the timeout condition if not already set and the maximum
     * execution time was reached. */
    if (elapsed >= server.lua_time_limit && server.lua_timedout == 0) {
        serverLog(LL_WARNING,
            "Lua slow script detected: still in execution after %lld milliseconds. "
            "You can try killing the script using the SCRIPT KILL command. "
            "Script SHA1 is: %s",
            elapsed, server.lua_cur_script);
        server.lua_timedout = 1;
        blockingOperationStarts();
        /* Once the script timeouts we reenter the event loop to permit others
         * to call SCRIPT KILL or SHUTDOWN NOSAVE if needed. 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(server.lua_caller);
    }
    if (server.lua_timedout) processEventsWhileBlocked();
    if (server.lua_kill) {
        serverLog(LL_WARNING,"Lua script killed by user with SCRIPT KILL.");

        /*
         * Set the hook to invoke all the time so the user
         * will not be able to catch the error with pcall and invoke
         * pcall again which will prevent the script from ever been killed
         */
        lua_sethook(lua, luaMaskCountHook, LUA_MASKLINE, 0);

        lua_pushstring(lua,"Script killed by user with SCRIPT KILL...");
        lua_error(lua);
    }
}

void prepareLuaClient(void) {
    /* Select the right DB in the context of the Lua client */