Function rdbSaveToSlavesSocketsThread

src/rdb.cpp:3725–3772

    const redisDbPersistentDataSnapshot *rgpdb[1];
};
void *rdbSaveToSlavesSocketsThread(void *vargs)
{
    serverAssert(!g_pserver->rdbThreadVars.fDone);
    /* Child */
    serverAssert(serverTL == nullptr);
    rdbSaveSocketThreadArgs *args = (rdbSaveSocketThreadArgs*)vargs;
    int retval;
    rio rdb;

    aeThreadOnline();
    serverAssert(serverTL == nullptr);
    redisServerThreadVars vars;
    serverTL = &vars;
    vars.gcEpoch = g_pserver->garbageCollector.startEpoch();

    rioInitWithFd(&rdb,args->rdb_pipe_write);

    retval = rdbSaveRioWithEOFMark(&rdb,args->rgpdb,NULL,&args->rsi);
    if (retval == C_OK && rioFlush(&rdb) == 0)
        retval = C_ERR;

    if (retval == C_OK) {
        sendChildCowInfo(CHILD_INFO_TYPE_RDB_COW_SIZE, "RDB");
    }

    rioFreeFd(&rdb);
    close(args->rdb_pipe_write); /* wake up the reader, tell it we're done. */
    /* hold exit until the parent tells us it's safe. we're not expecting
     * to read anything, just get the error when the pipe is closed. */
    if (!g_pserver->rdbThreadVars.fRdbThreadCancel) {
        char dummyBuffer;
        auto dummy = read(args->safe_to_exit_pipe, &dummyBuffer, 1);
        UNUSED(dummy);
    }

    // If we were told to cancel the requesting thread is holding the lock for us
    for (int idb = 0; idb < cserver.dbnum; ++idb)
        g_pserver->db[idb]->endSnapshotAsync(args->rgpdb[idb]);

    g_pserver->garbageCollector.endEpoch(vars.gcEpoch);
    aeThreadOffline();

    close(args->safe_to_exit_pipe);
    args->rsi.~rdbSaveInfo();
    zfree(args);
    g_pserver->rdbThreadVars.fDone = true;
    return (retval == C_OK) ? (void*)0 : (void*)1;
}

/* Spawn an RDB child that writes the RDB to the sockets of the slaves
 * that are currently in SLAVE_STATE_WAIT_BGSAVE_START state. */