Method suspendThreads

src/threadlist.cpp:442–525

}

void
ThreadList::suspendThreads()
{
  int needrescan;
  Thread *thread;
  Thread *next;

  DmtcpRWLockInit(&threadResumeLock);
  JASSERT(DmtcpRWLockWrLock(&threadResumeLock) == 0);

  /* Halt all other threads - force them to call stopthisthread
   * If any have blocked checkpointing, wait for them to unblock before
   * signalling
   */
  lock_threads();
  do {
    needrescan = 0;
    numUserThreads = 0;
    for (thread = activeThreads; thread != NULL; thread = next) {
      next = thread->next;

      if (thread == curThread) {
        continue;
      }

      if (thread->exiting == 1) {
        continue;
      }

      /* Do various things based on thread's state */
      switch (thread->state) {
      case ST_RUNNING:

        /* Thread is running. Send it a signal so it will call stopthisthread.
         * We will need to rescan (hopefully it will be suspended by then)
         */
        if (Thread_UpdateState(thread, ST_SIGNALED, ST_RUNNING)) {
          if (THREAD_TGKILL(motherpid, thread->tid,
                            SigInfo::ckptSignal()) < 0) {
            JASSERT(errno == ESRCH) (JASSERT_ERRNO) (thread->tid)
            .Text("error signalling thread");
            ThreadList::threadIsDead(thread);
          } else {
            needrescan = 1;
          }
        }
        break;

      case ST_SIGNALED:
        if (THREAD_TGKILL(motherpid, thread->tid, 0) == -1 && errno == ESRCH) {
          ThreadList::threadIsDead(thread);
        } else {
          needrescan = 1;
        }
        break;

      case ST_SUSPINPROG:
        numUserThreads++;