[compiler-rt] r254412 - [tsan] Add interceptors and sychronization for libdispatch semaphores on OS X

[Kuba Brecka via llvm-commits]

Author: kuba.brecka
Date: Tue Dec  1 07:11:42 2015
New Revision: 254412

URL: http://llvm.org/viewvc/llvm-project?rev=254412&view=rev
Log:
[tsan] Add interceptors and sychronization for libdispatch semaphores on OS X

This patch adds release and acquire semantics for libdispatch semaphores and a test case.

Differential Revision: http://reviews.llvm.org/D14992


Added:
    compiler-rt/trunk/test/tsan/Darwin/gcd-semaphore-norace.mm
Modified:
    compiler-rt/trunk/lib/tsan/rtl/tsan_libdispatch_mac.cc

Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_libdispatch_mac.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_libdispatch_mac.cc?rev=254412&r1=254411&r2=254412&view=diff
==============================================================================
--- compiler-rt/trunk/lib/tsan/rtl/tsan_libdispatch_mac.cc (original)
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_libdispatch_mac.cc Tue Dec  1 07:11:42 2015
@@ -25,6 +25,8 @@
 #include <dispatch/dispatch.h>
 #include <pthread.h>
 
+typedef long long_t;  // NOLINT
+
 namespace __tsan {
 
 typedef struct {
@@ -166,6 +168,21 @@ TSAN_INTERCEPTOR(void, dispatch_once_f,
   });
 }
 
+TSAN_INTERCEPTOR(long_t, dispatch_semaphore_signal,
+                 dispatch_semaphore_t dsema) {
+  SCOPED_TSAN_INTERCEPTOR(dispatch_semaphore_signal, dsema);
+  Release(thr, pc, (uptr)dsema);
+  return REAL(dispatch_semaphore_signal)(dsema);
+}
+
+TSAN_INTERCEPTOR(long_t, dispatch_semaphore_wait, dispatch_semaphore_t dsema,
+                 dispatch_time_t timeout) {
+  SCOPED_TSAN_INTERCEPTOR(dispatch_semaphore_wait, dsema, timeout);
+  long_t result = REAL(dispatch_semaphore_wait)(dsema, timeout);
+  if (result == 0) Acquire(thr, pc, (uptr)dsema);
+  return result;
+}
+
 }  // namespace __tsan
 
 #endif  // SANITIZER_MAC

Added: compiler-rt/trunk/test/tsan/Darwin/gcd-semaphore-norace.mm
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/tsan/Darwin/gcd-semaphore-norace.mm?rev=254412&view=auto
==============================================================================
--- compiler-rt/trunk/test/tsan/Darwin/gcd-semaphore-norace.mm (added)
+++ compiler-rt/trunk/test/tsan/Darwin/gcd-semaphore-norace.mm Tue Dec  1 07:11:42 2015
@@ -0,0 +1,29 @@
+// RUN: %clang_tsan %s -o %t -framework Foundation
+// RUN: %run %t 2>&1
+
+#import <Foundation/Foundation.h>
+
+long global;
+
+int main() {
+    NSLog(@"Hello world.");
+
+    global = 42;
+    
+    dispatch_semaphore_t sem = dispatch_semaphore_create(0);
+    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
+        
+        global = 43;
+        dispatch_semaphore_signal(sem);
+    });
+    
+    dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);
+    global = 44;
+
+    NSLog(@"Done.");
+    return 0;
+}
+
+// CHECK: Hello world.
+// CHECK: Done.
+// CHECK-NOT: WARNING: ThreadSanitizer