include/sys/mman.h

   1 /* Definitions for BSD-style memory management.
   2    Copyright (C) 1994-2000, 2003, 2004, 2005 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 #ifndef _SYS_MMAN_H
  20 #define _SYS_MMAN_H     1
  21
  22 #include <features.h>
  23 #include <bits/types.h>
  24 #define __need_size_t
  25 #include <stddef.h>
  26
  27 #ifndef __off_t_defined
  28 # ifndef __USE_FILE_OFFSET64
  29 typedef __off_t off_t;
  30 # else
  31 typedef __off64_t off_t;
  32 # endif
  33 # define __off_t_defined
  34 #endif
  35
  36 #ifndef __mode_t_defined
  37 typedef __mode_t mode_t;
  38 # define __mode_t_defined
  39 #endif
  40
  41 #include <bits/mman.h>
  42
  43 /* Return value of `mmap' in case of an error.  */
  44 #define MAP_FAILED      ((void *) -1)
  45
  46 __BEGIN_DECLS
  47 /* Map addresses starting near ADDR and extending for LEN bytes.  from
  48    OFFSET into the file FD describes according to PROT and FLAGS.  If ADDR
  49    is nonzero, it is the desired mapping address.  If the MAP_FIXED bit is
  50    set in FLAGS, the mapping will be at ADDR exactly (which must be
  51    page-aligned); otherwise the system chooses a convenient nearby address.
  52    The return value is the actual mapping address chosen or MAP_FAILED
  53    for errors (in which case `errno' is set).  A successful `mmap' call
  54    deallocates any previous mapping for the affected region.  */
  55
  56 #ifndef __USE_FILE_OFFSET64
  57 extern void *mmap (void *__addr, size_t __len, int __prot,
  58                    int __flags, int __fd, __off_t __offset) __THROW;
  59 libc_hidden_proto(mmap)
  60 #else
  61 # ifdef __REDIRECT_NTH
  62 extern void * __REDIRECT_NTH (mmap,
  63                               (void *__addr, size_t __len, int __prot,
  64                                int __flags, int __fd, __off64_t __offset),
  65                               mmap64);
  66 # else
  67 #  define mmap mmap64
  68 # endif
  69 #endif
  70 #ifdef __USE_LARGEFILE64
  71 extern void *mmap64 (void *__addr, size_t __len, int __prot,
  72                      int __flags, int __fd, __off64_t __offset) __THROW;
  73 #endif
  74
  75 /* Deallocate any mapping for the region starting at ADDR and extending LEN
  76    bytes.  Returns 0 if successful, -1 for errors (and sets errno).  */
  77 extern int munmap (void *__addr, size_t __len) __THROW;
  78 libc_hidden_proto(munmap)
  79
  80 /* Change the memory protection of the region starting at ADDR and
  81    extending LEN bytes to PROT.  Returns 0 if successful, -1 for errors
  82    (and sets errno).  */
  83 extern int mprotect (void *__addr, size_t __len, int __prot) __THROW;
  84
  85 #ifdef __ARCH_USE_MMU__
  86
  87 /* Synchronize the region starting at ADDR and extending LEN bytes with the
  88    file it maps.  Filesystem operations on a file being mapped are
  89    unpredictable before this is done.  Flags are from the MS_* set.
  90
  91    This function is a cancellation point and therefore not marked with
  92    __THROW.  */
  93 extern int msync (void *__addr, size_t __len, int __flags);
  94
  95 #else
  96
  97 /* On no-mmu systems you can't have real private mappings.  */
  98 static __inline__ int msync (void *__addr, size_t __len, int __flags) { return 0; }
  99
 100 #endif
 101
 102 #ifdef __ARCH_USE_MMU__
 103 #if defined __USE_BSD && (defined __UCLIBC_LINUX_SPECIFIC__ || defined __UCLIBC_HAS_THREADS_NATIVE__)
 104 /* Advise the system about particular usage patterns the program follows
 105    for the region starting at ADDR and extending LEN bytes.  */
 106 extern int madvise (void *__addr, size_t __len, int __advice) __THROW;
 107 #endif
 108 #if defined __USE_XOPEN2K && defined __UCLIBC_HAS_ADVANCED_REALTIME__
 109 /* This is the POSIX name for this function.  */
 110 extern int posix_madvise (void *__addr, size_t __len, int __advice) __THROW;
 111 #endif
 112 #endif /* __ARCH_USE_MMU__ */
 113
 114
 115 #if defined __UCLIBC_HAS_REALTIME__
 116 # ifdef __ARCH_USE_MMU__
 117
 118 /* Guarantee all whole pages mapped by the range [ADDR,ADDR+LEN) to
 119    be memory resident.  */
 120 extern int mlock (const void *__addr, size_t __len) __THROW;
 121
 122 /* Unlock whole pages previously mapped by the range [ADDR,ADDR+LEN).  */
 123 extern int munlock (const void *__addr, size_t __len) __THROW;
 124
 125 /* Cause all currently mapped pages of the process to be memory resident
 126    until unlocked by a call to the `munlockall', until the process exits,
 127    or until the process calls `execve'.  */
 128 extern int mlockall (int __flags) __THROW;
 129
 130 /* All currently mapped pages of the process' address space become
 131    unlocked.  */
 132 extern int munlockall (void) __THROW;
 133
 134 #else
 135
 136 /* On no-mmu systems, memory cannot be swapped out, so
 137  * these functions will always succeed.  */
 138 static __inline__ int mlock (const void *__addr, size_t __len) { return 0; }
 139 static __inline__ int munlock (const void *__addr, size_t __len) { return 0; }
 140 static __inline__ int mlockall (int __flags) { return 0; }
 141 static __inline__ int munlockall (void) { return 0; }
 142 #endif
 143 #endif /* __UCLIBC_HAS_REALTIME__ */
 144
 145 #if defined __USE_MISC && defined __UCLIBC_BSD_SPECIFIC__
 146 /* mincore returns the memory residency status of the pages in the
 147    current process's address space specified by [start, start + len).
 148    The status is returned in a vector of bytes.  The least significant
 149    bit of each byte is 1 if the referenced page is in memory, otherwise
 150    it is zero.  */
 151 extern int mincore (void *__start, size_t __len, unsigned char *__vec)
 152      __THROW;
 153 #endif
 154
 155 #ifdef __USE_GNU
 156 /* Remap pages mapped by the range [ADDR,ADDR+OLD_LEN) to new length
 157    NEW_LEN.  If MREMAP_MAYMOVE is set in FLAGS the returned address
 158    may differ from ADDR.  If MREMAP_FIXED is set in FLAGS the function
 159    takes another paramter which is a fixed address at which the block
 160    resides after a successful call.  */
 161 extern void *mremap (void *__addr, size_t __old_len, size_t __new_len,
 162                      int __flags, ...) __THROW;
 163 libc_hidden_proto(mremap)
 164
 165 #ifdef __UCLIBC_LINUX_SPECIFIC__
 166 /* Remap arbitrary pages of a shared backing store within an existing
 167    VMA.  */
 168 extern int remap_file_pages (void *__start, size_t __size, int __prot,
 169                              size_t __pgoff, int __flags) __THROW;
 170 #endif
 171 #endif
 172
 173
 174 /* Open shared memory segment.  */
 175 extern int shm_open (const char *__name, int __oflag, mode_t __mode);
 176
 177 /* Remove shared memory segment.  */
 178 extern int shm_unlink (const char *__name);
 179
 180 __END_DECLS
 181
 182 #endif  /* sys/mman.h */