DosQueryMutexSem returns the process identification (PID) and thread identification (TID) of a mutex semaphore's current owner, as well as the request count for the semaphore. The request count is the number of calls to DosRequestMutexSem, minus the number of calls to DosReleaseMutexSem, that have been made for the semaphore by the owning thread.

This function can be called by any thread in the process that created the semaphore. Threads in other processes can also call this function, but they must first gain access to the semaphore by calling DosOpenMutexSem.