title: How do you protect a common resource using mutexes?
body: <p>I have a common resource, which I want 1 and only 1 instance of my application (or it's COM API) to have access to at any time. I have tried to protect this resource using mutexes, but when multiple threads of a host dotnet application try to access the COM object, the mutex doesn't seem to be released. This is the code I have used to protect my resource.</p>
  
  <pre><code>repeat
    Mutex := CreateMutex(nil, True, PChar('Connections'));
  until (Mutex &lt;&gt; 0) and (GetLastError &lt;&gt; ERROR_ALREADY_EXISTS);
    try
      //use resource here!
    finally
      CloseHandle(Mutex);
    end;
  </code></pre>
  
  <p>If I run the threads simultaneously, the first thread get's through (obviously, being the first one to create the mutex), but subsequent threads are caught in the repeat loop. If I run each thread at 5 second intervals, then all is ok.</p>
  
  <p>I suspect I'm not using mutexes correctly here, but I have found very little documentation about how to do this.</p>
  
  <p>Any ideas?</p>