TsctlAIOUnlockDesc
From embeddedTS Manuals
This function releases lock num previously successfully acquired by a call to Lock. The flags parameter must be SHARED if the lock was acquired with that flag, otherwise it must be zero. The other flags do not apply to Unlock and should not be presented. It is an error to unlock with a different SHARED state than the lock was acquired with; the results in this case will be undefined.
enum {
NONBLOCKING=1, SHARED=2, NOUNLOCK=4
};