DosCloseEventSem

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Syntax

DosCloseEventSem( hevSemaphore )

Parameters

HEV hevSemaphore (input)

This is a handle to the event semaphore (HEV) to be closed.

Returns

APIRET rc
The following values can be returned
0 NO_ERROR Semaphore closed successfully
6 ERROR_INVALID_HANDLE Error, The value in hevSemaphore does not point to a valid semaphore
301 ERROR_SEM_BUSY Error, Another thread in this process is blocked on the semaphore

Usage Explanation

DosCloseEventSem decrements, by one (1), the usage count for the semaphore specified by the handle hevSemaphore. If the usage count goes to zero (0) then the semaphore is freed from the system.

  • The usage count for private semaphores is always one (1) so all private semaphores will be freed on successful completion of this call.
  • Shared (named or unnamed) semaphores may have usage counts greater than one (1), therefore they may or may not be freed from system resources on successful completion of DosCloseEventSem.

Sample Code

#define INCL_DOSSEMAPHORES
#include <os2.h>

HEV hevMySemaphore; /* pointer to my semaphore handle */

	/* an event semaphore is successfully created */
	/* its handle is placed in hevMySemaphore  */

	rc = DosCloseEventSem(hevMySemaphore);

	if (rc != 0)
	{
	  /* We got an error to take care of. */
	}
	else
	{
	  /* The semaphore was successfully closed */
	}

See Also