Subj : Re: stl & threads
To   : comp.programming.threads
From : Uenal Mutlu
Date : Wed May 25 2005 04:12 am

"Uenal Mutlu" wrote

>       bool   IsLockedByAny() const { return cLocked > 0; }
>       bool   IsLockedByMe()  const { return cLocked > 0 && dwThrId == GetCurrentThreadId(); }
>       size_t GetLockCount()  const { return cLocked;     }

The above methods should be called only by current lock owner.
A safer variant to achieve this are the following replacements:

      bool IsLockedByAny() const
        {
          assert(dwThrId == GetCurrentThreadId());
          return cLocked > 0;
        }

      bool IsLockedByMe() const
        {
          assert(dwThrId == GetCurrentThreadId());
          return cLocked > 0 && dwThrId == GetCurrentThreadId();
        }

      size_t GetLockCount() const
        {
          assert(dwThrId == GetCurrentThreadId());
          return cLocked;
        }

Also the dtor can be made safer by this replacement:
      ~mutex()
        {
          assert(cLocked == 0);
          DeleteCriticalSection(&cs);
        }
If it asserts in dtor then it means the lock was still held in user code,
which of course shouldn't be the case when the dtor is called.
Since assert() is executed only in Debug build the program needs
to be throughly tested in Debug build first.

.