platform: fix semaphore on mac os

src/platform-macos.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 664 matching lines @@
 
 
 Mutex* OS::CreateMutex() {
   return new MacOSMutex();
 }
 
 
 class MacOSSemaphore : public Semaphore {
  public:
   explicit MacOSSemaphore(int count) {
-    semaphore_create(mach_task_self(), &semaphore_, SYNC_POLICY_FIFO, count);
+    int r;
+    r = semaphore_create(mach_task_self(),
+                         &semaphore_,
+                         SYNC_POLICY_FIFO,
+                         count);
+    ASSERT(r == KERN_SUCCESS);
   }
 
   ~MacOSSemaphore() {
-    semaphore_destroy(mach_task_self(), semaphore_);
+    int r;
+    r = semaphore_destroy(mach_task_self(), semaphore_);
+    ASSERT(r == KERN_SUCCESS);
   }
 
-  // The MacOS mach semaphore documentation claims it does not have spurious
-  // wakeups, the way pthreads semaphores do.  So the code from the linux
-  // platform is not needed here.
-  void Wait() { semaphore_wait(semaphore_); }
+  void Wait() {
+    int r;
+    do {
+      r = semaphore_wait(semaphore_);
+    } while (r == KERN_ABORTED);
+
+    ASSERT(r == KERN_SUCCESS);

[Erik Corry, 2012/08/23 09:23:39]

I will move this up into the loop and assert that it is either SUCCESS or
ABORTED.  That way it doesn't loop if the assumption is wrong.

+  }
 
   bool Wait(int timeout);
 
   void Signal() { semaphore_signal(semaphore_); }
 
  private:
   semaphore_t semaphore_;
 };
 
 
@@ skipping 202 matching lines @@
 
 
 void Sampler::Stop() {
   ASSERT(IsActive());
   SamplerThread::RemoveActiveSampler(this);
   SetActive(false);
 }
 
 
 } }  // namespace v8::internal