Closing a Queue

DosCloseQueue can be used both to end access to a queue and to delete a queue. The action taken as a result of a DosCloseQueue request depends on:

• Whether the requesting process is the server process or a client process
  
• The value of the access count, which is maintained for each client process by OS/2. The access count for a client process is incremented whenever DosOpenQueue is called, and decremented whenever DosCloseQueue is called.

If the requesting process is a client, and the access count equals 0, DosCloseQueue ends the client's access to the queue, but the queue itself is not affected. If the access count does not equal 0, the count is decremented, but the process retains access to the queue.

If the requesting process is the server, DosCloseQueue purges any outstanding elements from the queue and deletes the queue regardless of the access count; client processes that still have the queue open receive ERROR_QUE_INVALID_HANDLE on their next request.