sysdeps/mach/msync.c

   1 /* msync -- Synchronize mapped memory to external storage.  Mach version.
   2    Copyright (C) 2002-2023 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    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <sys/types.h>
  20 #include <sys/mman.h>
  21 #include <errno.h>
  22 #include <mach.h>
  23 #include <sysdep-cancel.h>
  24
  25 /* Some Mach variants have vm_msync and some don't.  Those that have it
  26    define the VM_SYNC_* bits when we include <mach/mach_types.h>.  */
  27
  28 #ifndef VM_SYNC_SYNCHRONOUS
  29 # include <misc/msync.c>
  30 #else
  31
  32 /* Synchronize the region starting at ADDR and extending LEN bytes with the
  33    file it maps.  Filesystem operations on a file being mapped are
  34    unpredictable before this is done.  */
  35
  36 int
  37 msync (void *addr, size_t len, int flags)
  38 {
  39   vm_sync_t sync_flags = 0;
  40   kern_return_t err;
  41   int cancel_oldtype;
  42
  43   if (flags & MS_SYNC)
  44     sync_flags |= VM_SYNC_SYNCHRONOUS;
  45   if (flags & MS_ASYNC)
  46     sync_flags |= VM_SYNC_ASYNCHRONOUS;
  47   if (flags & MS_INVALIDATE)
  48     sync_flags |= VM_SYNC_INVALIDATE;
  49
  50   cancel_oldtype = LIBC_CANCEL_ASYNC();
  51   err = __vm_msync (__mach_task_self (),
  52                     (vm_address_t) addr, (vm_size_t) len, sync_flags);
  53   LIBC_CANCEL_RESET (cancel_oldtype);
  54   if (err)
  55     {
  56       errno = err;
  57       return -1;
  58     }
  59   return 0;
  60 }
  61 #endif