DosCancelLockRequest allows a process to cancel the lock range request of an outstanding DosSetFileLocks function.

If two threads in a process are waiting on a lock file range, and another thread issues DosCancelLockRequest for that lock file range, then both waiting threads are released.

Not all file-system drivers (FSDs) can cancel an outstanding lock request.

Local Area Network (LAN) servers cannot cancel an outstanding lock request if they use a version of the operating system prior to OS/2 Version 2.00.