mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-27 06:43:32 +00:00
69 lines
1.8 KiB
ReStructuredText
69 lines
1.8 KiB
ReStructuredText
PR_OpenSharedMemory
|
|
===================
|
|
|
|
Opens an existing shared memory segment or, if one with the specified
|
|
name doesn't exist, creates a new one.
|
|
|
|
|
|
Syntax
|
|
------
|
|
|
|
.. code::
|
|
|
|
#include <prshm.h>
|
|
|
|
NSPR_API( PRSharedMemory * )
|
|
PR_OpenSharedMemory(
|
|
const char *name,
|
|
PRSize size,
|
|
PRIntn flags,
|
|
PRIntn mode
|
|
);
|
|
|
|
/* Define values for PR_OpenShareMemory(...,create) */
|
|
#define PR_SHM_CREATE 0x1 /* create if not exist */
|
|
#define PR_SHM_EXCL 0x2 /* fail if already exists */
|
|
|
|
|
|
Parameters
|
|
~~~~~~~~~~
|
|
|
|
The function has the following parameters:
|
|
|
|
name
|
|
The name of the shared memory segment.
|
|
size
|
|
The size of the shared memory segment.
|
|
flags
|
|
Options for creating the shared memory.
|
|
mode
|
|
Same as passed to :ref:`PR_Open`.
|
|
|
|
|
|
Returns
|
|
~~~~~~~
|
|
|
|
Pointer to opaque structure ``PRSharedMemory``, or ``NULL`` if an error
|
|
occurs. Retrieve the reason for the failure by calling :ref:`PR_GetError`
|
|
and :ref:`PR_GetOSError`.
|
|
|
|
|
|
Description
|
|
-----------
|
|
|
|
:ref:`PR_OpenSharedMemory` creates a new shared memory segment or
|
|
associates a previously created memory segment with the specified name.
|
|
When parameter ``create`` is (``PR_SHM_EXCL`` \| ``PR_SHM_CREATE``) and
|
|
the shared memory already exists, the function returns ``NULL`` with the
|
|
error set to ``PR_FILE_EXISTS_ERROR``.
|
|
|
|
When parameter ``create`` is ``PR_SHM_CREATE`` and the shared memory
|
|
already exists, a handle to that memory segment is returned. If the
|
|
segment does not exist, it is created and a pointer to the related
|
|
``PRSharedMemory`` structure is returned.
|
|
|
|
When parameter ``create`` is 0, and the shared memory exists, a pointer
|
|
to a ``PRSharedMemory`` structure is returned. If the shared memory does
|
|
not exist, ``NULL`` is returned with the error set to
|
|
``PR_FILE_NOT_FOUND_ERROR``.
|