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-rw-r--r-- | docs/nspr/reference/pr_opensharedmemory.rst | 68 |
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diff --git a/docs/nspr/reference/pr_opensharedmemory.rst b/docs/nspr/reference/pr_opensharedmemory.rst new file mode 100644 index 0000000000..759a81dbf8 --- /dev/null +++ b/docs/nspr/reference/pr_opensharedmemory.rst @@ -0,0 +1,68 @@ +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``. |