[libcxx] r175506 - Fix a bug in mutex_try_to_lock. This was previously trying to unlock a mutex that it didn't own, causing an assertion failure in mutex.cpp. The issue was that the unique_lock went out of scope, releasing the lock on m, then m.unlock() was called on an already-unlocked mutex.

[David Chisnall]

Author: theraven
Date: Tue Feb 19 05:28:45 2013
New Revision: 175506

URL: http://llvm.org/viewvc/llvm-project?rev=175506&view=rev
Log:
Fix a bug in mutex_try_to_lock.  This was previously trying to unlock a mutex that it didn't own, causing an assertion failure in mutex.cpp.  The issue was that the unique_lock went out of scope, releasing the lock on m, then m.unlock() was called on an already-unlocked mutex.  

This change removes the spurious m.unlock() call.  

If this test was previously passing for anyone with assertions enabled, then they should investigate bugs in their pthread implementation, as pthread_unlock() should not return 0 if the mutex is currently unlocked.


Modified:
    libcxx/trunk/test/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/mutex_try_to_lock.pass.cpp

Modified: libcxx/trunk/test/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/mutex_try_to_lock.pass.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/mutex_try_to_lock.pass.cpp?rev=175506&r1=175505&r2=175506&view=diff
==============================================================================
--- libcxx/trunk/test/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/mutex_try_to_lock.pass.cpp (original)
+++ libcxx/trunk/test/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/mutex_try_to_lock.pass.cpp Tue Feb 19 05:28:45 2013
@@ -48,7 +48,6 @@ void f()
             break;
     }
     time_point t1 = Clock::now();
-    m.unlock();
     ns d = t1 - t0 - ms(250);
     assert(d < ms(200));  // within 200ms
 }