xnu-1699.26.8.tar.gz

[apple/xnu.git] / osfmk / ipc / ipc_mqueue.c

diff --git a/osfmk/ipc/ipc_mqueue.c b/osfmk/ipc/ipc_mqueue.c
index 9d17b81b9455e3cc09c97f3a4de030b3ebe1d412..406b5ae932c7bb768c3b608bf2c154828402813b 100644 (file)
--- a/osfmk/ipc/ipc_mqueue.c
+++ b/osfmk/ipc/ipc_mqueue.c
@@ -949,7 +949,7 @@ ipc_mqueue_select_on_thread(
  *             Locks may be held by callers, so this routine cannot block.
  *             Caller holds reference on the message queue.
  */
-int
+unsigned
 ipc_mqueue_peek(ipc_mqueue_t mq)
 {
        wait_queue_link_t       wql;
@@ -963,10 +963,7 @@ ipc_mqueue_peek(ipc_mqueue_t mq)
         * Don't block trying to get the lock.
         */
        s = splsched();
-       if (!imq_lock_try(mq)) {
-               splx(s);
-               return -1;
-       }
+       imq_lock(mq);
 
        /* 
         * peek at the contained port message queues, return as soon as
@@ -992,7 +989,8 @@ ipc_mqueue_peek(ipc_mqueue_t mq)
 /*
  *     Routine:        ipc_mqueue_destroy
  *     Purpose:
- *             Destroy a message queue.  Set any blocked senders running.
+ *             Destroy a (non-set) message queue.
+ *             Set any blocked senders running.
  *             Destroy the kmsgs in the queue.
  *     Conditions:
  *             Nothing locked.
@@ -1000,10 +998,11 @@ ipc_mqueue_peek(ipc_mqueue_t mq)
  */
 void
 ipc_mqueue_destroy(
-       ipc_mqueue_t    mqueue) 
+       ipc_mqueue_t    mqueue)
 {
        ipc_kmsg_queue_t kmqueue;
        ipc_kmsg_t kmsg;
+       boolean_t reap = FALSE;
        spl_t s;
 
 
@@ -1019,19 +1018,27 @@ ipc_mqueue_destroy(
                                THREAD_RESTART,
                                FALSE);
 
+       /*
+        * Move messages from the specified queue to the per-thread
+        * clean/drain queue while we have the mqueue lock.
+        */
        kmqueue = &mqueue->imq_messages;
-
        while ((kmsg = ipc_kmsg_dequeue(kmqueue)) != IKM_NULL) {
-               imq_unlock(mqueue);
-               splx(s);
-
-               ipc_kmsg_destroy_dest(kmsg);
-
-               s = splsched();
-               imq_lock(mqueue);
+               boolean_t first;
+               first = ipc_kmsg_delayed_destroy(kmsg);
+               if (first)
+                       reap = first;
        }
+
        imq_unlock(mqueue);
        splx(s);
+
+       /*
+        * Destroy the messages we enqueued if we aren't nested
+        * inside some other attempt to drain the same queue.
+        */
+       if (reap)
+               ipc_kmsg_reap_delayed();
 }
 
 /*