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