Fix asyncio queue management when there is blocked requests.

diff --git a/src/fs/aufs/aiops.cc b/src/fs/aufs/aiops.cc
index b5105ff0ef88e3e2bd935c2c50cfd3eba548e23d..d05f4a578a48381bcde46de1401c770aedb7e5b0 100644 (file)
--- a/src/fs/aufs/aiops.cc
+++ b/src/fs/aufs/aiops.cc
@@ -1,5 +1,5 @@
 /*
- * $Id: aiops.cc,v 1.15 2002/10/13 20:35:24 robertc Exp $
+ * $Id: aiops.cc,v 1.16 2002/10/22 07:02:00 hno Exp $
  *
  * DEBUG: section 43    AIOPS
  * AUTHOR: Stewart Forster <slf@connect.com.au>
@@ -408,34 +408,26 @@ squidaio_queue_request(squidaio_request_t * request)
     request->resultp->_data = request;
     /* Play some tricks with the request_queue2 queue */
     request->next = NULL;
-    if (!request_queue2.head) {
-       if (pthread_mutex_trylock(&request_queue.mutex) == 0) {
-           /* Normal path */
-           *request_queue.tailp = request;
-           request_queue.tailp = &request->next;
-           pthread_cond_signal(&request_queue.cond);
-           pthread_mutex_unlock(&request_queue.mutex);
-       } else {
-           /* Oops, the request queue is blocked, use request_queue2 */
-           *request_queue2.tailp = request;
-           request_queue2.tailp = &request->next;
-       }
-    } else {
-       /* Secondary path. We have blocked requests to deal with */
-       /* add the request to the chain */
-       *request_queue2.tailp = request;
-       if (pthread_mutex_trylock(&request_queue.mutex) == 0) {
-           /* Ok, the queue is no longer blocked */
+    if (pthread_mutex_trylock(&request_queue.mutex) == 0) {
+       if (request_queue2.head) {
+           /* Grab blocked requests */
            *request_queue.tailp = request_queue2.head;
-           request_queue.tailp = &request->next;
-           pthread_cond_signal(&request_queue.cond);
-           pthread_mutex_unlock(&request_queue.mutex);
+           request_queue.tailp = request_queue2.tailp;
+       }
+       /* Enqueue request */
+       *request_queue.tailp = request;
+       request_queue.tailp = &request->next;
+       pthread_cond_signal(&request_queue.cond);
+       pthread_mutex_unlock(&request_queue.mutex);
+       if (request_queue2.head) {
+           /* Clear queue of blocked requests */
            request_queue2.head = NULL;
            request_queue2.tailp = &request_queue2.head;
-       } else {
-           /* still blocked, bump the blocked request chain */
-           request_queue2.tailp = &request->next;
        }
+    } else {
+       /* Oops, the request queue is blocked, use request_queue2 */
+       *request_queue2.tailp = request;
+       request_queue2.tailp = &request->next;
     }
     if (request_queue2.head) {
        static int filter = 0;