Releases ownership of the specified mutex object.

BOOLEAN ReleaseMutex(
    HANDLE hMutex
);

BOOLEAN RtReleaseMutex(
    HANDLE hMutex
);

Parameters

hMutex

Handle to the mutex object. RtCreateMutex returns this handle.

Remarks

You cannot call this function from a pure INtime thread. RtReleaseMutex can also be used from a Windows application to release an iwin32 mutex.

If the calling thread does not own the mutex object, ReleaseMutex fails.

A thread gets ownership of a mutex by specifying a handle to the mutex in a wait function. The thread that creates a mutex object can also get immediate ownership without using a wait function. When the owning thread no longer needs to own the mutex object, it calls ReleaseMutex.

While a thread owns a mutex, it can specify the same mutex in additional wait-function calls without blocking its execution. This prevents a thread from deadlocking itself while waiting for a mutex it already owns. However, to release its ownership, the thread must call ReleaseMutex once for each time the mutex satisfied a wait function call.

When a thread fully releases the last mutex it owns, its priority is restored to what it was upon entering the first mutex (it may have changed when a better priority thread entered the wait queue for an owned mutex).

Return Values

Non-zero

Success.

0 (zero)

Failure. For extended error information, see GetLastError

Requirements

Notes

• In the iwin32 API, ReleaseMutex and RtReleaseMutex are synonyms.
• This function operates in the real-time portion of your application.
• The iwin32x API also includes an RtReleaseMutex function that operates in the Windows portion of your application.

See Also

RtCreateMutex, iwin32 API, iwin32 Overview