PR_OpenSemaphore

Creates or opens a named semaphore with the specified name.

Syntax

#include <pripcsem.h>

#define PR_SEM_CREATE 0x1 /* create if not exist */

#define PR_SEM_EXCL 0x2 /* fail if already exists */

NSPR_API(PRSem *) PR_OpenSemaphore(
  const char *name,
  PRIntn flags,
  PRIntn mode,
  PRUintn value
);

Parameters

The function has the following parameters:

name: The name to be given the semaphore.
flags: How to create or open the semaphore.
mode: Unix style file mode to be used when creating the semaphore.
value: The initial value assigned to the semaphore.

Returns

A pointer to a PRSem structure or NULL/code> on error.

Description

If the named semaphore doesn’t exist and the PR_SEM_CREATE flag is specified, the named semaphore is created. The created semaphore needs to be removed from the system with a PR_DeleteSemaphore call.

If PR_SEM_CREATE is specified, the third argument is the access permission bits of the new semaphore (same interpretation as the mode argument to PR_Open) and the fourth argument is the initial value of the new semaphore. If PR_SEM_CREATE is not specified, the third and fourth arguments are ignored.