bits/mman.h

   1 /* Definitions for BSD-style memory management.
   2    Copyright (C) 1994-2014 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 Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 /* These are the bits used by 4.4 BSD and its derivatives.  On systems
  20    (such as GNU) where these facilities are not system services but can be
  21    emulated in the C library, these are the definitions we emulate.  */
  22
  23 #ifndef _SYS_MMAN_H
  24 # error "Never use <bits/mman.h> directly; include <sys/mman.h> instead."
  25 #endif
  26
  27 /* Protections are chosen from these bits, OR'd together.  The
  28    implementation does not necessarily support PROT_EXEC or PROT_WRITE
  29    without PROT_READ.  The only guarantees are that no writing will be
  30    allowed without PROT_WRITE and no access will be allowed for PROT_NONE. */
  31
  32 #define PROT_NONE        0x00   /* No access.  */
  33 #define PROT_READ        0x04   /* Pages can be read.  */
  34 #define PROT_WRITE       0x02   /* Pages can be written.  */
  35 #define PROT_EXEC        0x01   /* Pages can be executed.  */
  36
  37 /* Flags contain mapping type, sharing type and options.  */
  38
  39 /* Mapping type (must choose one and only one of these).  */
  40 #ifdef __USE_BSD
  41 # define MAP_FILE        0x0001 /* Mapped from a file or device.  */
  42 # define MAP_ANON        0x0002 /* Allocated from anonymous virtual memory.  */
  43 # define MAP_TYPE        0x000f /* Mask for type field.  */
  44 # ifdef __USE_MISC
  45 #  define MAP_ANONYMOUS  MAP_ANON /* Linux name. */
  46 # endif
  47 #endif
  48
  49 /* Sharing types (must choose one and only one of these).  */
  50 #ifdef __USE_BSD
  51 # define MAP_COPY        0x0020 /* Virtual copy of region at mapping time.  */
  52 #endif
  53 #define MAP_SHARED       0x0010 /* Share changes.  */
  54 #define MAP_PRIVATE      0x0000 /* Changes private; copy pages on write.  */
  55
  56 /* Other flags.  */
  57 #define MAP_FIXED        0x0100 /* Map address must be exactly as requested. */
  58 #ifdef __USE_BSD
  59 # define MAP_NOEXTEND    0x0200 /* For MAP_FILE, don't change file size.  */
  60 # define MAP_HASSEMPHORE 0x0400 /* Region may contain semaphores.  */
  61 # define MAP_INHERIT     0x0800 /* Region is retained after exec.  */
  62 #endif
  63
  64 /* Advice to `madvise'.  */
  65 #ifdef __USE_BSD
  66 # define MADV_NORMAL     0      /* No further special treatment.  */
  67 # define MADV_RANDOM     1      /* Expect random page references.  */
  68 # define MADV_SEQUENTIAL 2      /* Expect sequential page references.  */
  69 # define MADV_WILLNEED   3      /* Will need these pages.  */
  70 # define MADV_DONTNEED   4      /* Don't need these pages.  */
  71 #endif
  72
  73 /* The POSIX people had to invent similar names for the same things.  */
  74 #ifdef __USE_XOPEN2K
  75 # define POSIX_MADV_NORMAL      0 /* No further special treatment.  */
  76 # define POSIX_MADV_RANDOM      1 /* Expect random page references.  */
  77 # define POSIX_MADV_SEQUENTIAL  2 /* Expect sequential page references.  */
  78 # define POSIX_MADV_WILLNEED    3 /* Will need these pages.  */
  79 # define POSIX_MADV_DONTNEED    4 /* Don't need these pages.  */
  80 #endif
  81
  82 /* Flags to `msync'.  */
  83 #define MS_ASYNC        1               /* Sync memory asynchronously.  */
  84 #define MS_SYNC         0               /* Synchronous memory sync.  */
  85 #define MS_INVALIDATE   2               /* Invalidate the caches.  */
  86
  87 /* Flags for `mremap'.  */
  88 #ifdef __USE_GNU
  89 # define MREMAP_MAYMOVE 1               /* Mapping address may change.  */
  90 # define MREMAP_FIXED   2               /* Fifth argument sets new address.  */
  91 #endif
  92
  93 /* Flags for `mlockall' (can be OR'd together).  */
  94 #define MCL_CURRENT     1               /* Lock all currently mapped pages.  */
  95 #define MCL_FUTURE      2               /* Lock all additions to address
  96                                            space.  */