ReleaseMutex

Overview

Group

Quick Info

Windows NT
Yes
Win95
Yes
Win32s
No
Import Library
kernel32.lib
Header File
winbase.h
Unicode
No
Platform Notes
None

The ReleaseMutex function releases ownership of the specified mutex object.

BOOL ReleaseMutex(

HANDLE hMutex	// handle of mutex object
);

Parameters
hMutex

Identifies the mutex object. The CreateMutex or OpenMutex function returns this handle.

Return Values
If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks
The ReleaseMutex function fails if the calling thread does not own the mutex object.

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

While a thread has ownership of 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 that it already owns. However, to release its ownership, the thread must call ReleaseMutex once for each time that the mutex satisfied a wait.