Method wrapperExecutionLockLockExcl

src/threadsync.cpp:249–268

* Execute fork() and exec() wrappers in exclusive mode * * fork() and exec() wrappers pass on the state/information about the current * process/program to the to-be-created process/program. * * There can be a potential race in the wrappers if this information gets * changed between the point where it was acquired and the point where the * process/program is created. An example of this situa

 *    repeated calls to _real_epoll_wait with smaller timeout.
 */
void
ThreadSync::wrapperExecutionLockLockExcl()
{
  int saved_errno = errno;

  // The process is still initializing. We don't need to acquire lock.
  if (WorkerState::currentState() == WorkerState::UNKNOWN) {
    return;
  }

  Thread *thread = dmtcp_get_current_thread();

  if (DmtcpRWLockWrLock(&_wrapperExecutionLock) != 0) {
    fprintf(stderr, "ERROR %s:%d %s: Failed to acquire lock\n",
            __FILE__, __LINE__, __PRETTY_FUNCTION__);
    _exit(DMTCP_FAIL_RC);
  }
  thread->wrapperLockCount++;
  errno = saved_errno;
}

// NOTE: Don't do any fancy stuff in this wrapper which can cause the process
// to go into DEADLOCK