Temporary instrumentation to help understand lock errors on mac debug bots.

base/synchronization/lock_impl.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_SYNCHRONIZATION_LOCK_IMPL_H_
 #define BASE_SYNCHRONIZATION_LOCK_IMPL_H_
 #pragma once
 
 #include "build/build_config.h"
 
@@ skipping 35 matching lines @@
   void Unlock();
 
   // Return the native underlying lock.  Not supported for Windows builds.
   // TODO(awalker): refactor lock and condition variables so that this is
   // unnecessary.
 #if !defined(OS_WIN)
   OSLockType* os_lock() { return &os_lock_; }
 #endif
 
  private:
+#if defined(OS_MAC) && !defined(NDEBUG)

[Mark Mentovai, 2011/10/28 19:58:26]

This won’t ever work. It’s OS_MACOSX.

You can add another #define inside this #ifdef so that you don’t need to keep
checking the same condition over and over again in the .cc file.

[eroman, 2011/10/28 20:00:53]

Thanks Mark!

I'll do that, and ping back once I have actually tested this :)  I just wanted
to get feedback early.

+  // Some instrumentation to help track down http://crbug.com/102161. Used to
+  // assert in debug builds when trying to use a freed lock.
+  enum LivenessToken {
+    LT_ALIVE = 0xCa11ab1e,
+    LT_DELETED = 0xDecea5ed,
+  };
+
+  void CheckIsAlive();
+
+  uint32 liveness_token_;
+#endif
+
   OSLockType os_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(LockImpl);
 };
 
 }  // namespace internal
 }  // namespace base
 
 #endif  // BASE_SYNCHRONIZATION_LOCK_IMPL_H_