Critical Sections Versus Mutexes

• Microsoft Win32 Application Programming Interface (API) included with:

      - Microsoft Windows NT versions 3.5, 3.51, 4.0
      - Microsoft Windows 95 version 4.0
  

Critical sections and mutexes provide synchronization that is very similar, except that critical sections can be used only by the threads of a single process. There are two areas to consider when choosing which method to use within a single process:

1. Speed. The Synchronization overview says the following about critical sections:

         ... critical section objects provide a slightly faster, more
         efficient mechanism for mutual-exclusion synchronization.
   

   Critical sections use a processor-specific test and set instruction to determine mutual exclusion.

2. Deadlock. The Synchronization overview says the following about mutexes:

         If a thread terminates without releasing its ownership of a
         mutex object, the mutex is considered to be abandoned. A waiting
         thread can acquire ownership of an abandoned mutex, but the wait
         function's return value indicates that the mutex is abandoned.
   

   WaitForSingleObject() will return WAIT_ABANDONED for a mutex that has been abandoned. However, the resource that the mutex is protecting is left in an unknown state.

   There is no way to tell whether a critical section has been abandoned.