void checkChildrenDone(void) {
    int statloc;
    pid_t pid;

    if ((pid = wait3(&statloc,WNOHANG,NULL)) != 0) {
        int exitcode = WEXITSTATUS(statloc);
        int bysignal = 0;

        if (WIFSIGNALED(statloc)) bysignal = WTERMSIG(statloc);

        /* sigKillChildHandler catches the signal and calls exit(), but we
         * must make sure not to flag lastbgsave_status, etc incorrectly.
         * We could directly terminate the child process via SIGUSR1
         * without handling it, but in this case Valgrind will log an
         * annoying error. */
        if (exitcode == SERVER_CHILD_NOERROR_RETVAL) {
            bysignal = SIGUSR1;
            exitcode = 1;
        }

        if (pid == -1) {
            serverLog(LL_WARNING,"wait3() returned an error: %s. "
                "rdb_child_pid = %d, aof_child_pid = %d, module_child_pid = %d",
                strerror(errno),
                (int) server.rdb_child_pid,
                (int) server.aof_child_pid,
                (int) server.module_child_pid);
        } else if (pid == server.rdb_child_pid) {
            backgroundSaveDoneHandler(exitcode,bysignal);
            if (!bysignal && exitcode == 0) receiveChildInfo();
        } else if (pid == server.aof_child_pid) {
            backgroundRewriteDoneHandler(exitcode,bysignal);
            if (!bysignal && exitcode == 0) receiveChildInfo();
        } else if (pid == server.module_child_pid) {
            ModuleForkDoneHandler(exitcode,bysignal);
            if (!bysignal && exitcode == 0) receiveChildInfo();
        } else {
            if (!ldbRemoveChild(pid)) {
                serverLog(LL_WARNING,
                    "Warning, detected child with unmatched pid: %ld",
                    (long)pid);
            }
        }
        updateDictResizePolicy();
        closeChildInfoPipe();
    }
}
void checkChildrenDone(void) {
    int statloc;
    pid_t pid;

    if ((pid = wait3(&statloc,WNOHANG,NULL)) != 0) {
        int exitcode = WEXITSTATUS(statloc);
        int bysignal = 0;

        if (WIFSIGNALED(statloc)) bysignal = WTERMSIG(statloc);

         
        if (exitcode == SERVER_CHILD_NOERROR_RETVAL) {
            bysignal = SIGUSR1;
            exitcode = 1;
        }

        if (pid == -1) {
            serverLog(LL_WARNING,"wait3() returned an error: %s. "
                "rdb_child_pid = %d, aof_child_pid = %d, module_child_pid = %d",
                strerror(errno),
                (int) server.rdb_child_pid,
                (int) server.aof_child_pid,
                (int) server.module_child_pid);
        } else if (pid == server.rdb_child_pid) {
            backgroundSaveDoneHandler(exitcode,bysignal);
            if (!bysignal && exitcode == 0) receiveChildInfo();
        } else if (pid == server.aof_child_pid) {
            backgroundRewriteDoneHandler(exitcode,bysignal);
            if (!bysignal && exitcode == 0) receiveChildInfo();
        } else if (pid == server.module_child_pid) {
            ModuleForkDoneHandler(exitcode,bysignal);
            if (!bysignal && exitcode == 0) receiveChildInfo();
        } else {
            if (!ldbRemoveChild(pid)) {
                serverLog(LL_WARNING,
                    "Warning, detected child with unmatched pid: %ld",
                    (long)pid);
            }
        }
        updateDictResizePolicy();
        closeChildInfoPipe();
    }
}