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/*
* Copyright (c) 1994, 1995. Netscape Communications Corporation. All
* rights reserved.
*
* Use of this software is governed by the terms of the license agreement for
* the Netscape Communications or Netscape Comemrce Server between the
* parties.
*/
/* ------------------------------------------------------------------------ */
/*
* shmem.h: Portable abstraction for memory shared among a server's workers
*
* Rob McCool
*/
#ifndef _SHMEM_H
#define _SHMEM_H
#include "netsite.h"
#include "systems.h"
/* --------------------------- Data structures ---------------------------- */
#if defined (SHMEM_UNIX_MMAP) || defined (SHMEM_WIN32_MMAP)
#include "file.h" /* SYS_FILE */
typedef struct {
void *data; /* the data */
#ifdef SHMEM_WIN32_MMAP
HANDLE fdmap;
#endif /* SHMEM_WIN32_MMAP */
int size; /* the maximum length of the data */
char *name; /* internal use: filename to unlink if exposed */
SYS_FILE fd; /* internal use: file descriptor for region */
} shmem_s;
/* ------------------------------ Prototypes ------------------------------ */
/*
* shmem_alloc allocates a region of shared memory of the given size, using
* the given name to avoid conflicts between multiple regions within the
* program. The region will not be automatically grown if its boundaries
* are over-run, use shmem_realloc for that.
*
* If expose is non-zero and the underlying system supports it, the
* file used to create the shared region will be visible to other processes
* running on the system.
*
* name should be unique to the program which calls this routine, otherwise
* conflicts will arise.
*
* Returns a new shared memory region, with the data element being a
* pointer to the shared memory. This function must be called before any
* daemon workers are spawned, in order for the handle to the shared region
* to be inherited by the children.
*
* Because of the requirement that the region must be inherited by the
* children, the region cannot be re-allocated with a larger size when
* necessary.
*/
shmem_s *shmem_alloc(char *name, int size, int expose);
/*
* shmem_free de-allocates the specified region of shared memory.
*/
void shmem_free(shmem_s *region);
#endif /* SHMEM_UNIX_MMAP || SHMEM_WIN32_MMAP */
#endif
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