libdispatch-500.10.1.tar.gz

diff --git a/src/semaphore.c b/src/semaphore.c
index f356fb876b0f23b8b049fa2df53eb7cfcf5518bd..b8c8971afa8134e59d3e190b92dd349fac7f2191 100644 (file)
--- a/src/semaphore.c
+++ b/src/semaphore.c
@@ -93,8 +93,6 @@ _pop_timer_resolution(DWORD ms)
 DISPATCH_WEAK // rdar://problem/8503746
 long _dispatch_semaphore_signal_slow(dispatch_semaphore_t dsema);
 
-static long _dispatch_group_wake(dispatch_semaphore_t dsema);
-
 #pragma mark -
 #pragma mark dispatch_semaphore_t
 
@@ -422,6 +420,10 @@ _dispatch_group_create_with_count(long count)
        dispatch_group_t dg = (dispatch_group_t)_dispatch_alloc(
                        DISPATCH_VTABLE(group), sizeof(struct dispatch_semaphore_s));
        _dispatch_semaphore_init(LONG_MAX - count, dg);
+       if (count) {
+               dispatch_atomic_store2o((dispatch_semaphore_t)dg, do_ref_cnt, 1,
+                               relaxed); // <rdar://problem/22318411>
+       }
        return dg;
 }
 
@@ -441,8 +443,11 @@ void
 dispatch_group_enter(dispatch_group_t dg)
 {
        dispatch_semaphore_t dsema = (dispatch_semaphore_t)dg;
-       long value = dispatch_atomic_dec2o(dsema, dsema_value, acquire);
-       if (slowpath(value < 0)) {
+       long value = dispatch_atomic_dec_orig2o(dsema, dsema_value, acquire);
+       if (value == LONG_MAX) {
+               return _dispatch_retain(dg); // <rdar://problem/22318411>
+       }
+       if (slowpath(value <= 0)) {
                DISPATCH_CLIENT_CRASH(
                                "Too many nested calls to dispatch_group_enter()");
        }
@@ -450,7 +455,7 @@ dispatch_group_enter(dispatch_group_t dg)
 
 DISPATCH_NOINLINE
 static long
-_dispatch_group_wake(dispatch_semaphore_t dsema)
+_dispatch_group_wake(dispatch_semaphore_t dsema, bool needs_release)
 {
        dispatch_continuation_t next, head, tail = NULL, dc;
        long rval;
@@ -500,6 +505,9 @@ _dispatch_group_wake(dispatch_semaphore_t dsema)
                } while ((head = next));
                _dispatch_release(dsema);
        }
+       if (needs_release) {
+               _dispatch_release(dsema); // <rdar://problem/22318411>
+       }
        return 0;
 }
 
@@ -512,7 +520,7 @@ dispatch_group_leave(dispatch_group_t dg)
                DISPATCH_CLIENT_CRASH("Unbalanced call to dispatch_group_leave()");
        }
        if (slowpath(value == LONG_MAX)) {
-               (void)_dispatch_group_wake(dsema);
+               return (void)_dispatch_group_wake(dsema, true);
        }
 }
 
@@ -540,7 +548,7 @@ again:
        // dsema->dsema_group_waiters
        value = dispatch_atomic_load2o(dsema, dsema_value, seq_cst); // 19296565
        if (value == LONG_MAX) {
-               return _dispatch_group_wake(dsema);
+               return _dispatch_group_wake(dsema, false);
        }
        // Mach semaphores appear to sometimes spuriously wake up. Therefore,
        // we keep a parallel count of the number of times a Mach semaphore is
@@ -549,7 +557,7 @@ again:
        // check the values again in case we need to wake any threads
        value = dispatch_atomic_load2o(dsema, dsema_value, seq_cst); // 19296565
        if (value == LONG_MAX) {
-               return _dispatch_group_wake(dsema);
+               return _dispatch_group_wake(dsema, false);
        }
 
 #if USE_MACH_SEM
@@ -678,7 +686,7 @@ dispatch_group_notify_f(dispatch_group_t dg, dispatch_queue_t dq, void *ctxt,
                dispatch_atomic_store2o(dsema, dsema_notify_head, dsn, seq_cst);
                // seq_cst with atomic store to notify_head <rdar://problem/11750916>
                if (dispatch_atomic_load2o(dsema, dsema_value, seq_cst) == LONG_MAX) {
-                       _dispatch_group_wake(dsema);
+                       _dispatch_group_wake(dsema, false);
                }
        }
 }