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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996, 1997
* Sleepycat Software. All rights reserved.
*/
#include "config.h"
#ifndef lint
static const char sccsid[] = "@(#)os_map.c 10.7 (Sleepycat) 10/25/97";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <sys/mman.h>
#include <errno.h>
#endif
#include "db_int.h"
/*
* __os_map --
* Map in some shared memory backed by a file descriptor.
*
* PUBLIC: int __os_map __P((int, size_t, int, int, void **));
*/
int
__os_map(fd, len, is_private, is_rdonly, addr)
int fd, is_private, is_rdonly;
size_t len;
void **addr;
{
void *p;
int flags, prot;
flags = is_private ? MAP_PRIVATE : MAP_SHARED;
#ifdef MAP_HASSEMAPHORE
flags |= MAP_HASSEMAPHORE;
#endif
prot = PROT_READ | (is_rdonly ? 0 : PROT_WRITE);
#ifndef MAP_FAILED /* XXX: Mmap(2) failure return. */
#define MAP_FAILED -1
#endif
if ((p =
mmap(NULL, len, prot, flags, fd, (off_t)0)) == (void *)MAP_FAILED)
return (errno);
*addr = p;
return (0);
}
/*
* __os_unmap --
* Release the specified shared memory.
*
* PUBLIC: int __os_unmap __P((void *, size_t));
*/
int
__os_unmap(addr, len)
void *addr;
size_t len;
{
/*
* !!!
* The argument len is always the same length as was mapped.
*/
return (munmap(addr, len) ? errno : 0);
}
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