Function RM_GetThreadSafeContext

src/module.cpp:5888–5907

Return a context which can be used inside threads to make Redis context * calls with certain modules APIs. If 'bc' is not NULL then the module will * be bound to a blocked client, and it will be possible to use the * `RedisModule_Reply*` family of functions to accumulate a reply for when the * client will be unblocked. Otherwise the thread safe context will be * detached by a specific client.

 * consider using `RM_GetDetachedThreadSafeContext` which will also retain
 * the module ID and thus be more useful for logging. */
RedisModuleCtx *RM_GetThreadSafeContext(RedisModuleBlockedClient *bc) {
    RedisModuleCtx *ctx = (RedisModuleCtx*)zmalloc(sizeof(*ctx), MALLOC_LOCAL);
    RedisModuleCtx empty = REDISMODULE_CTX_INIT;
    memcpy(ctx,&empty,sizeof(empty));
    if (bc) {
        ctx->blocked_client = bc;
        ctx->module = bc->module;
    }
    ctx->flags |= REDISMODULE_CTX_THREAD_SAFE;
    /* Even when the context is associated with a blocked client, we can't
     * access it safely from another thread, so we create a fake client here
     * in order to keep things like the currently selected database and similar
     * things. */
    ctx->client = createClient(NULL, IDX_EVENT_LOOP_MAIN);
    if (bc) {
        selectDb(ctx->client,bc->dbid);
        if (bc->client) ctx->client->id = bc->client->id;
    }
    return ctx;
}

/* Return a detached thread safe context that is not associated with any
 * specific blocked client, but is associated with the module's context.