sysdeps/generic/sys/mman.h

   1 /* Definitions for BSD-style memory management.  Generic/4.4 BSD version.
   2    Copyright (C) 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 /* These are the bits used by 4.4 BSD and its derivatives.  On systems
  21    (such as GNU) where these facilities are not system services but can be
  22    emulated in the C library, these are the definitions we emulate.  */
  23
  24 #ifndef _SYS_MMAN_H
  25
  26 #define _SYS_MMAN_H     1
  27 #include <features.h>
  28
  29 #include <bits/types.h>
  30 #define __need_size_t
  31 #include <stddef.h>
  32
  33
  34 /* Protections are chosen from these bits, OR'd together.  The
  35    implementation does not necessarily support PROT_EXEC or PROT_WRITE
  36    without PROT_READ.  The only guarantees are that no writing will be
  37    allowed without PROT_WRITE and no access will be allowed for PROT_NONE. */
  38
  39 #define PROT_NONE        0x00   /* No access.  */
  40 #define PROT_READ        0x04   /* Pages can be read.  */
  41 #define PROT_WRITE       0x02   /* Pages can be written.  */
  42 #define PROT_EXEC        0x01   /* Pages can be executed.  */
  43
  44
  45 /* Flags contain mapping type, sharing type and options.  */
  46
  47 /* Mapping type (must choose one and only one of these).  */
  48 #ifdef __USE_BSD
  49 # define MAP_FILE        0x0001 /* Mapped from a file or device.  */
  50 # define MAP_ANON        0x0002 /* Allocated from anonymous virtual memory.  */
  51 # define MAP_TYPE        0x000f /* Mask for type field.  */
  52 #endif
  53
  54 /* Sharing types (must choose one and only one of these).  */
  55 #ifdef __USE_BSD
  56 # define MAP_COPY        0x0020 /* Virtual copy of region at mapping time.  */
  57 #endif
  58 #define MAP_SHARED       0x0010 /* Share changes.  */
  59 #define MAP_PRIVATE      0x0000 /* Changes private; copy pages on write.  */
  60
  61 /* Other flags.  */
  62 #define MAP_FIXED        0x0100 /* Map address must be exactly as requested. */
  63 #ifdef __USE_BSD
  64 # define MAP_NOEXTEND    0x0200 /* For MAP_FILE, don't change file size.  */
  65 # define MAP_HASSEMPHORE 0x0400 /* Region may contain semaphores.  */
  66 # define MAP_INHERIT     0x0800 /* Region is retained after exec.  */
  67 #endif
  68
  69 /* Advice to `madvise'.  */
  70 #ifdef __USE_BSD
  71 # define MADV_NORMAL     0      /* No further special treatment.  */
  72 # define MADV_RANDOM     1      /* Expect random page references.  */
  73 # define MADV_SEQUENTIAL 2      /* Expect sequential page references.  */
  74 # define MADV_WILLNEED   3      /* Will need these pages.  */
  75 # define MADV_DONTNEED   4      /* Don't need these pages.  */
  76 #endif
  77
  78 /* Return value of `mmap' in case of an error.  */
  79 #define MAP_FAILED      ((__caddr_t) -1)
  80
  81
  82 __BEGIN_DECLS
  83 /* Map addresses starting near ADDR and extending for LEN bytes.  from
  84    OFFSET into the file FD describes according to PROT and FLAGS.  If ADDR
  85    is nonzero, it is the desired mapping address.  If the MAP_FIXED bit is
  86    set in FLAGS, the mapping will be at ADDR exactly (which must be
  87    page-aligned); otherwise the system chooses a convenient nearby address.
  88    The return value is the actual mapping address chosen or MAP_FAILED
  89    for errors (in which case `errno' is set).  A successful `mmap' call
  90    deallocates any previous mapping for the affected region.  */
  91
  92 extern __caddr_t __mmap __P ((__caddr_t __addr, size_t __len, int __prot,
  93                               int __flags, int __fd, __off_t __offset));
  94 #ifndef __USE_FILE_OFFSET64
  95 extern __caddr_t mmap __P ((__caddr_t __addr, size_t __len, int __prot,
  96                             int __flags, int __fd, __off_t __offset));
  97 #else
  98 extern __caddr_t mmap __P ((__caddr_t __addr, size_t __len, int __prot,
  99                             int __flags, int __fd, __off_t __offset))
 100      __asm__ ("mmap64");
 101 #endif
 102 #ifdef __USE_LARGEFILE64
 103 extern __caddr_t mmap64 __P ((__caddr_t __addr, size_t __len, int __prot,
 104                               int __flags, int __fd, __off64_t __offset));
 105 #endif
 106
 107 /* Deallocate any mapping for the region starting at ADDR and extending LEN
 108    bytes.  Returns 0 if successful, -1 for errors (and sets errno).  */
 109 extern int __munmap __P ((__caddr_t __addr, size_t __len));
 110 extern int munmap __P ((__caddr_t __addr, size_t __len));
 111
 112 /* Change the memory protection of the region starting at ADDR and
 113    extending LEN bytes to PROT.  Returns 0 if successful, -1 for errors
 114    (and sets errno).  */
 115 extern int __mprotect __P ((__caddr_t __addr, size_t __len, int __prot));
 116 extern int mprotect __P ((__caddr_t __addr, size_t __len, int __prot));
 117
 118 /* Synchronize the region starting at ADDR and extending LEN bytes with the
 119    file it maps.  Filesystem operations on a file being mapped are
 120    unpredictable before this is done.  Flags are from the MS_* set.  */
 121 extern int msync __P ((__caddr_t __addr, size_t __len, int __flags));
 122
 123 #ifdef __USE_BSD
 124 /* Advise the system about particular usage patterns the program follows
 125    for the region starting at ADDR and extending LEN bytes.  */
 126 extern int madvise __P ((__caddr_t __addr, size_t __len, int __advice));
 127 #endif
 128
 129 __END_DECLS
 130
 131
 132 #endif  /* sys/mman.h */