| Index: mozilla/nsprpub/pr/include/prshm.h
|
| ===================================================================
|
| --- mozilla/nsprpub/pr/include/prshm.h (revision 191424)
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| +++ mozilla/nsprpub/pr/include/prshm.h (working copy)
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| @@ -1,257 +0,0 @@
|
| -/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
| -/* This Source Code Form is subject to the terms of the Mozilla Public
|
| - * License, v. 2.0. If a copy of the MPL was not distributed with this
|
| - * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
| -
|
| -/*
|
| -** prshm.h -- NSPR Shared Memory
|
| -**
|
| -** NSPR Named Shared Memory API provides a cross-platform named
|
| -** shared-memory interface. NSPR Named Shared Memory is modeled on
|
| -** similar constructs in Unix and Windows operating systems. Shared
|
| -** memory allows multiple processes to access one or more common shared
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| -** memory regions, using it as an inter-process communication channel.
|
| -**
|
| -** Notes on Platform Independence:
|
| -** NSPR Named Shared Memory is built on the native services offered
|
| -** by most platforms. The NSPR Named Shared Memory API tries to
|
| -** provide a least common denominator interface so that it works
|
| -** across all supported platforms. To ensure that it works everywhere,
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| -** some platform considerations must be accomodated and the protocol
|
| -** for using NSPR Shared Memory API must be observed.
|
| -**
|
| -** Protocol:
|
| -** Multiple shared memories can be created using NSPR's Shared Memory
|
| -** feature. For each named shared memory, as defined by the name
|
| -** given in the PR_OpenSharedMemory() call, a protocol for using the
|
| -** shared memory API is required to ensure desired behavior. Failing
|
| -** to follow the protocol may yield unpredictable results.
|
| -**
|
| -** PR_OpenSharedMemory() will create the shared memory segment, if it
|
| -** does not already exist, or open a connection that the existing
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| -** shared memory segment if it already exists.
|
| -**
|
| -** PR_AttachSharedMemory() should be called following
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| -** PR_OpenSharedMemory() to map the memory segment to an address in
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| -** the application's address space.
|
| -**
|
| -** PR_AttachSharedMemory() may be called to re-map a shared memory
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| -** segment after detaching the same PRSharedMemory object. Be
|
| -** sure to detach it when done.
|
| -**
|
| -** PR_DetachSharedMemory() should be called to un-map the shared
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| -** memory segment from the application's address space.
|
| -**
|
| -** PR_CloseSharedMemory() should be called when no further use of the
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| -** PRSharedMemory object is required within a process. Following a
|
| -** call to PR_CloseSharedMemory() the PRSharedMemory object is
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| -** invalid and cannot be reused.
|
| -**
|
| -** PR_DeleteSharedMemory() should be called before process
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| -** termination. After calling PR_DeleteSharedMemory() any further use
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| -** of the shared memory associated with the name may cause
|
| -** unpredictable results.
|
| -**
|
| -** Files:
|
| -** The name passed to PR_OpenSharedMemory() should be a valid filename
|
| -** for a unix platform. PR_OpenSharedMemory() creates file using the
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| -** name passed in. Some platforms may mangle the name before creating
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| -** the file and the shared memory.
|
| -**
|
| -** The unix implementation may use SysV IPC shared memory, Posix
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| -** shared memory, or memory mapped files; the filename may used to
|
| -** define the namespace. On Windows, the name is significant, but
|
| -** there is no file associated with name.
|
| -**
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| -** No assumptions about the persistence of data in the named file
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| -** should be made. Depending on platform, the shared memory may be
|
| -** mapped onto system paging space and be discarded at process
|
| -** termination.
|
| -**
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| -** All names provided to PR_OpenSharedMemory() should be valid
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| -** filename syntax or name syntax for shared memory for the target
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| -** platform. Referenced directories should have permissions
|
| -** appropriate for writing.
|
| -**
|
| -** Limits:
|
| -** Different platforms have limits on both the number and size of
|
| -** shared memory resources. The default system limits on some
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| -** platforms may be smaller than your requirements. These limits may
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| -** be adjusted on some platforms either via boot-time options or by
|
| -** setting the size of the system paging space to accomodate more
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| -** and/or larger shared memory segment(s).
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| -**
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| -** Security:
|
| -** On unix platforms, depending on implementation, contents of the
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| -** backing store for the shared memory can be exposed via the file
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| -** system. Set permissions and or access controls at create and attach
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| -** time to ensure you get the desired security.
|
| -**
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| -** On windows platforms, no special security measures are provided.
|
| -**
|
| -** Example:
|
| -** The test case pr/tests/nameshm1.c provides an example of use as
|
| -** well as testing the operation of NSPR's Named Shared Memory.
|
| -**
|
| -** lth. 18-Aug-1999.
|
| -*/
|
| -
|
| -#ifndef prshm_h___
|
| -#define prshm_h___
|
| -
|
| -#include "prtypes.h"
|
| -#include "prio.h"
|
| -
|
| -PR_BEGIN_EXTERN_C
|
| -
|
| -/*
|
| -** Declare opaque type PRSharedMemory.
|
| -*/
|
| -typedef struct PRSharedMemory PRSharedMemory;
|
| -
|
| -/*
|
| -** FUNCTION: PR_OpenSharedMemory()
|
| -**
|
| -** DESCRIPTION:
|
| -** PR_OpenSharedMemory() creates a new shared-memory segment or
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| -** associates a previously created memory segment with name.
|
| -**
|
| -** When parameter create is (PR_SHM_EXCL | PR_SHM_CREATE) and the
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| -** shared memory already exists, the function returns NULL with the
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| -** error set to PR_FILE_EXISTS_ERROR.
|
| -**
|
| -** When parameter create is PR_SHM_CREATE and the shared memory
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| -** already exists, a handle to that memory segment is returned. If
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| -** the segment does not exist, it is created and a pointer to the
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| -** related PRSharedMemory structure is returned.
|
| -**
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| -** When parameter create is 0, and the shared memory exists, a
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| -** pointer to a PRSharedMemory is returned. If the shared memory does
|
| -** not exist, NULL is returned with the error set to
|
| -** PR_FILE_NOT_FOUND_ERROR.
|
| -**
|
| -** INPUTS:
|
| -** name -- the name the shared-memory segment is known as.
|
| -** size -- the size of the shared memory segment.
|
| -** flags -- Options for creating the shared memory
|
| -** mode -- Same as is passed to PR_Open()
|
| -**
|
| -** OUTPUTS:
|
| -** The shared memory is allocated.
|
| -**
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| -** RETURNS: Pointer to opaque structure PRSharedMemory or NULL.
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| -** NULL is returned on error. The reason for the error can be
|
| -** retrieved via PR_GetError() and PR_GetOSError();
|
| -**
|
| -*/
|
| -NSPR_API( PRSharedMemory * )
|
| - PR_OpenSharedMemory(
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| - const char *name,
|
| - PRSize size,
|
| - PRIntn flags,
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| - 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 */
|
| -
|
| -/*
|
| -** FUNCTION: PR_AttachSharedMemory()
|
| -**
|
| -** DESCRIPTION:
|
| -** PR_AttachSharedMemory() maps the shared-memory described by
|
| -** shm to the current process.
|
| -**
|
| -** INPUTS:
|
| -** shm -- The handle returned from PR_OpenSharedMemory().
|
| -** flags -- options for mapping the shared memory.
|
| -** PR_SHM_READONLY causes the memory to be attached
|
| -** read-only.
|
| -**
|
| -** OUTPUTS:
|
| -** On success, the shared memory segment represented by shm is mapped
|
| -** into the process' address space.
|
| -**
|
| -** RETURNS: Address where shared memory is mapped, or NULL.
|
| -** NULL is returned on error. The reason for the error can be
|
| -** retrieved via PR_GetError() and PR_GetOSError();
|
| -**
|
| -**
|
| -*/
|
| -NSPR_API( void * )
|
| - PR_AttachSharedMemory(
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| - PRSharedMemory *shm,
|
| - PRIntn flags
|
| -);
|
| -/* Define values for PR_AttachSharedMemory(...,flags) */
|
| -#define PR_SHM_READONLY 0x01
|
| -
|
| -/*
|
| -** FUNCTION: PR_DetachSharedMemory()
|
| -**
|
| -** DESCRIPTION:
|
| -** PR_DetachSharedMemory() detaches the shared-memory described
|
| -** by shm.
|
| -**
|
| -** INPUTS:
|
| -** shm -- The handle returned from PR_OpenSharedMemory().
|
| -** addr -- The address at which the memory was attached.
|
| -**
|
| -** OUTPUTS:
|
| -** The shared memory mapped to an address via a previous call to
|
| -** PR_AttachSharedMemory() is unmapped.
|
| -**
|
| -** RETURNS: PRStatus
|
| -**
|
| -*/
|
| -NSPR_API( PRStatus )
|
| - PR_DetachSharedMemory(
|
| - PRSharedMemory *shm,
|
| - void *addr
|
| -);
|
| -
|
| -/*
|
| -** FUNCTION: PR_CloseSharedMemory()
|
| -**
|
| -** DESCRIPTION:
|
| -** PR_CloseSharedMemory() closes the shared-memory described by
|
| -** shm.
|
| -**
|
| -** INPUTS:
|
| -** shm -- The handle returned from PR_OpenSharedMemory().
|
| -**
|
| -** OUTPUTS:
|
| -** the shared memory represented by shm is closed
|
| -**
|
| -** RETURNS: PRStatus
|
| -**
|
| -*/
|
| -NSPR_API( PRStatus )
|
| - PR_CloseSharedMemory(
|
| - PRSharedMemory *shm
|
| -);
|
| -
|
| -/*
|
| -** FUNCTION: PR_DeleteSharedMemory()
|
| -**
|
| -** DESCRIPTION:
|
| -** The shared memory resource represented by name is released.
|
| -**
|
| -** INPUTS:
|
| -** name -- the name the shared-memory segment
|
| -**
|
| -** OUTPUTS:
|
| -** depending on platform, resources may be returned to the underlying
|
| -** operating system.
|
| -**
|
| -** RETURNS: PRStatus
|
| -**
|
| -*/
|
| -NSPR_API( PRStatus )
|
| - PR_DeleteSharedMemory(
|
| - const char *name
|
| -);
|
| -
|
| -PR_END_EXTERN_C
|
| -
|
| -#endif /* prshm_h___ */
|
|
|