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