OS_UnlockMutex[R|W|RW]

Syntax

#include <nitro/os.h>

void OS_UnlockMutexR( OSMutex* mutex );

void OS_UnlockMutexW( OSMutex* mutex );

void OS_UnlockMutexRW( OSMutex* mutex );

Arguments

mutex Pointer to the OSMutex structure

Return Values

None.

Description

The thread calling this function unlocks the mutex.

The OS_UnlockMutexR function unlocks a read lock. When unlocking a read lock, it does not matter if the calling thread is not the owner of mutex. Note that if mutex has been locked n times, only the nth OS_UnlockMutexR function call actually releases the lock.

The OS_UnlockMutexW function unlocks a write lock. To unlock a write lock, the calling thread must be the owner of mutex. Note that if mutex has been locked n times by the calling thread, it is only released by the nth call to the OS_UnlockMutexW function.

The OS_UnlockMutexRW function can unlock both a read lock and a write lock. It has the characteristics of both the OS_UnlockMutexR and OS_UnlockMutexW functions noted above. It can also unlock a mutex locked with the OS_LockMutex function.

Lock and Unlock Correlation

If mutex has been locked by the OS_LockMutexR function, unlock it using the OS_UnlockMutexR or OS_UnlockMutexRW function. If you try to unlock using the OS_UnlockMutexW function the process will stop with the OS_Panic function.

If mutex has been locked by the OS_LockMutexW function, unlock it using the OS_UnlockMutexW or OS_UnlockMutexRW function. If you try to unlock using the OS_UnlockMutexR function, the process will stop with the OS_Panic function.

The process will also stop with the OS_Panic function if you try using the OS_UnlockMutexR, OS_UnlockMutexW or OS_UnlockMutexRW function to unlock a mutex that is not locked.

If the process stops with the OS_Panic function, check the correlation of lock and unlock functions in the application.

Exiting the Thread

When the thread that is locking mutex is terminated with the OS_ExitThread function, mutex is automatically unlocked.

Revision History

2008/12/16 Initial version.

CONFIDENTIAL