sysdeps/mach/pagecopy.h

   1 /* Macros for copying by pages; used in memcpy, memmove.  Mach version.
   2    Copyright (C) 1995-2017 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 #include <mach.h>
  20
  21 /* Threshold at which vm_copy is more efficient than well-optimized copying
  22    by words.  This parameter should be tuned as necessary.  */
  23 #define PAGE_THRESHOLD          (2 * PAGE_SIZE) /* XXX ? */
  24
  25 #define PAGE_SIZE               __vm_page_size
  26 #define PAGE_COPY_FWD(dstp, srcp, nbytes_left, nbytes)                        \
  27   ((nbytes_left) = ((nbytes) -                                                \
  28                     (__vm_copy (__mach_task_self (),                          \
  29                                 (vm_address_t) srcp, trunc_page (nbytes),     \
  30                                 (vm_address_t) dstp) == KERN_SUCCESS          \
  31                      ? trunc_page (nbytes)                                    \
  32                      : 0)))