PR_OpenSemaphore
================
Creates or opens a named semaphore with the specified name.
Syntax
------
.. code::
#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 :ref:`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 :ref:`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.
