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SGI Freeware 2002 November
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SGI Freeware 2002 November - Disc 1.iso
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dist
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fw_apache2.idb
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apache2
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include
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apr_shm.h.z
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apr_shm.h
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2002-07-08
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/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000-2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
#ifndef APR_SHM_H
#define APR_SHM_H
#include "apr.h"
#include "apr_pools.h"
#include "apr_errno.h"
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/**
* @file apr_shm.h
* @brief APR Shared Memory Routines
*/
/**
* @defgroup APR_SHM Shared Memory Routines
* @ingroup APR
* @{
*/
/**
* Private, platform-specific data struture representing a shared memory
* segment.
*/
typedef struct apr_shm_t apr_shm_t;
/**
* Create and make accessable a shared memory segment.
* @param m The shared memory structure to create.
* @param reqsize The desired size of the segment.
* @param file The file to use for shared memory on platforms that
* require it.
* @param pool the pool from which to allocate the shared memory
* structure.
* @remark A note about Anonymous vs. Named shared memory segments:
* Not all plaforms support anonymous shared memory segments, but in
* some cases it is prefered over other types of shared memory
* implementations. Passing a NULL 'file' parameter to this function
* will cause the subsystem to use anonymous shared memory segments.
* If such a system is not available, APR_ENOTIMPL is returned.
* @remark A note about allocation sizes:
* On some platforms it is necessary to store some metainformation
* about the segment within the actual segment. In order to supply
* the caller with the requested size it may be necessary for the
* implementation to request a slightly greater segment length
* from the subsystem. In all cases, the apr_shm_baseaddr_get()
* function will return the first usable byte of memory.
*
*/
APR_DECLARE(apr_status_t) apr_shm_create(apr_shm_t **m,
apr_size_t reqsize,
const char *filename,
apr_pool_t *pool);
/**
* Destroy a shared memory segment and associated memory.
* @param m The shared memory segment structure to destroy.
*/
APR_DECLARE(apr_status_t) apr_shm_destroy(apr_shm_t *m);
/**
* Attach to a shared memory segment that was created
* by another process.
* @param m The shared memory structure to create.
* @param file The file used to create the original segment.
* (This MUST match the original filename.)
* @param pool the pool from which to allocate the shared memory
* structure for this process.
*/
APR_DECLARE(apr_status_t) apr_shm_attach(apr_shm_t **m,
const char *filename,
apr_pool_t *pool);
/**
* Detach from a shared memory segment without destroying it.
* @param m The shared memory structure representing the segment
* to detach from.
*/
APR_DECLARE(apr_status_t) apr_shm_detach(apr_shm_t *m);
/**
* Retrieve the base address of the shared memory segment.
* NOTE: This address is only usable within the callers address
* space, since this API does not guarantee that other attaching
* processes will maintain the same address mapping.
* @param m The shared memory segment from which to retrieve
* the base address.
*/
APR_DECLARE(void *) apr_shm_baseaddr_get(const apr_shm_t *m);
/**
* Retrieve the length of a shared memory segment in bytes.
* @param m The shared memory segment from which to retrieve
* the segment length.
*/
APR_DECLARE(apr_size_t) apr_shm_size_get(const apr_shm_t *m);
/**
* Get the pool used by this shared memory segment.
*/
APR_POOL_DECLARE_ACCESSOR(shm);
#ifdef __cplusplus
}
#endif
#endif /* APR_SHM_T */