xnu-1504.15.3.tar.gz

[apple/xnu.git] / bsd / kern / pthread_synch.c

diff --git a/bsd/kern/pthread_synch.c b/bsd/kern/pthread_synch.c
index a290655846b5237454a6c5e573c39489be8a163f..7a00399cc23cd26e444a9a958bbd04a946858f8f 100644 (file)
--- a/bsd/kern/pthread_synch.c
+++ b/bsd/kern/pthread_synch.c
@@ -2033,6 +2033,7 @@ wq_runitem(proc_t p, user_addr_t item, thread_t th, struct threadlist *tl,
           int reuse_thread, int wake_thread, int return_directly)
 {
        int ret = 0;
+       boolean_t need_resume = FALSE;
 
        KERNEL_DEBUG1(0xefffd004 | DBG_FUNC_START, tl->th_workq, tl->th_priority, tl->th_affinity_tag, thread_tid(current_thread()), thread_tid(th));
 
@@ -2063,11 +2064,19 @@ wq_runitem(proc_t p, user_addr_t item, thread_t th, struct threadlist *tl,
                if (tl->th_flags & TH_LIST_NEED_WAKEUP)
                        wakeup(tl);
                else
-                       thread_resume(th);
+                       need_resume = TRUE;
 
                tl->th_flags &= ~(TH_LIST_BUSY | TH_LIST_NEED_WAKEUP);
                
                workqueue_unlock(p);
+
+               if (need_resume) {
+                       /*
+                        * need to do this outside of the workqueue spin lock
+                        * since thread_resume locks the thread via a full mutex
+                        */
+                       thread_resume(th);
+               }
        }
 }