DosReleaseMutexSem
From EDM2
DosReleaseMutexSem releases ownership of mutex semaphore.
Syntax
DosReleaseMutexSem( hmtxSemaphore );
Parameters
HMTX hmtxSemaphore (input)
The handle of the semaphore to be released.
Returns
- APIRET rc
- The following values can be returned
| 0 | NO_ERROR | Semaphore released successfully |
| 6 | ERROR_INVALID_HANDLE | Error, The value in phmtxSemaphore does not point to a valid semaphore, The calling process must first have access to the semaphore in question |
| 288 | ERROR_NOT_OWNER | Error, The calling process does not currently own the semaphore |
Usage Explanation
It decrements, by one (1), the usage count of the mutex semaphore referred to by hmtxSemaphore. If the usage count for the mutex semaphore goes to zero (0), ownership of the semaphore will be passed on to another thread that has been blocked for requesting it.
The process calling DosReleaseMutexSem must first obtain access to the semaphore in question or ERROR_INVALID_HANDLE will be returned.
Sample Code
#define INCL_DOSSEMAPHORES
#include <os2.h>
HMTX hmtxMySemaphore; /* MySemaphore handle */
/* access is gained to the semaphore in question */
/* either by DosCreateMutexSem ... */
/* ... or by DosOpenMutexSem */
/* its handle is placed in hmtxMySemaphore */
/* process becomes owner of semaphore */
/* by way of successful call to DosRequestMutexSem */
rc = DosReleaseMutexSem(hmtxMySemaphore);
if (rc != 0)
{
/* We got an error to take care of. */
}
