Do fastpath if timeout is 0 on threadqueue_get

src/ucore_threadqueue.c

@@ -126,7 +126,12 @@ int uc_thread_queue_get(struct uc_threadqueue *queue, const struct timespec *tim
         //another thread popped the remaining elment before we did
         queue->num_read_waiters++;
         if (timeout) {
-            rc = pthread_cond_timedwait(&queue->read_cond, &queue->mutex, &abstimeout);
+            //fastpath, check for a poll
+            if(timeout->tv_sec == 0 && timeout->tv_nsec == 0) {
+                rc = ETIMEDOUT;
+            } else {
+                rc = pthread_cond_timedwait(&queue->read_cond, &queue->mutex, &abstimeout);
+            }
         } else {
             pthread_cond_wait(&queue->read_cond, &queue->mutex);