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 <gnu/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 #define MAP_FILE        0x0001  /* Mapped from a file or device.  */
  49 #define MAP_ANON        0x0002  /* Allocated from anonymous virtual memory.  */
  50 #define MAP_TYPE        0x000f  /* Mask for type field.  */
  51
  52 /* Sharing types (must choose one and only one of these).  */
  53 #define MAP_COPY        0x0020  /* Virtual copy of region at mapping time.  */
  54 #define MAP_SHARED      0x0010  /* Share changes.  */
  55 #define MAP_PRIVATE     0x0000  /* Changes private; copy pages on write.  */
  56
  57 /* Other flags.  */
  58 #define MAP_FIXED       0x0100  /* Map address must be exactly as requested. */
  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
  63 /* Advice to `madvise'.  */
  64 #define MADV_NORMAL     0       /* No further special treatment.  */
  65 #define MADV_RANDOM     1       /* Expect random page references.  */
  66 #define MADV_SEQUENTIAL 2       /* Expect sequential page references.  */
  67 #define MADV_WILLNEED   3       /* Will need these pages.  */
  68 #define MADV_DONTNEED   4       /* Don't need these pages.  */
  69
  70 #include <sys/cdefs.h>
  71
  72 __BEGIN_DECLS
  73 /* Map addresses starting near ADDR and extending for LEN bytes.  from
  74    OFFSET into the file FD describes according to PROT and FLAGS.  If ADDR
  75    is nonzero, it is the desired mapping address.  If the MAP_FIXED bit is
  76    set in FLAGS, the mapping will be at ADDR exactly (which must be
  77    page-aligned); otherwise the system chooses a convenient nearby address.
  78    The return value is the actual mapping address chosen or (caddr_t) -1
  79    for errors (in which case `errno' is set).  A successful `mmap' call
  80    deallocates any previous mapping for the affected region.  */
  81
  82 __caddr_t __mmap __P ((__caddr_t __addr, size_t __len,
  83                        int __prot, int __flags, int __fd, __off_t __offset));
  84 __caddr_t mmap __P ((__caddr_t __addr, size_t __len,
  85                      int __prot, int __flags, int __fd, __off_t __offset));
  86
  87 /* Deallocate any mapping for the region starting at ADDR and extending LEN
  88    bytes.  Returns 0 if successful, -1 for errors (and sets errno).  */
  89 int __munmap __P ((__caddr_t __addr, size_t __len));
  90 int munmap __P ((__caddr_t __addr, size_t __len));
  91
  92 /* Change the memory protection of the region starting at ADDR and
  93    extending LEN bytes to PROT.  Returns 0 if successful, -1 for errors
  94    (and sets errno).  */
  95 int __mprotect __P ((__caddr_t __addr, size_t __len, int __prot));
  96 int mprotect __P ((__caddr_t __addr, size_t __len, int __prot));
  97
  98 /* Synchronize the region starting at ADDR and extending LEN bytes with the
  99    file it maps.  Filesystem operations on a file being mapped are
 100    unpredictable before this is done.  Flags are from the MS_* set.  */
 101 int msync __P ((__caddr_t __addr, size_t __len, int flags));
 102
 103 /* Advise the system about particular usage patterns the program follows
 104    for the region starting at ADDR and extending LEN bytes.  */
 105 int madvise __P ((__caddr_t __addr, size_t __len, int __advice));
 106
 107 __END_DECLS
 108
 109
 110 #endif  /* sys/mman.h */