sysdeps/unix/sysv/linux/hppa/swapcontext.c

   1 /* Swap to new context.
   2    Copyright (C) 2008 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Helge Deller <deller@gmx.de>, 2008.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library.  If not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <ucontext.h>
  21
  22 extern int __getcontext (ucontext_t *ucp);
  23 extern int __setcontext (const ucontext_t *ucp);
  24
  25 int
  26 __swapcontext (ucontext_t *oucp, const ucontext_t *ucp)
  27 {
  28   /* Save the current machine context to oucp.  */
  29   __getcontext (oucp);
  30
  31   /* mark sc_sar flag to skip the setcontext call on reactivation.  */
  32   if (oucp->uc_mcontext.sc_sar == 0) {
  33         oucp->uc_mcontext.sc_sar++;
  34
  35         /* Restore the machine context in ucp.  */
  36         __setcontext (ucp);
  37   }
  38
  39   return 0;
  40 }
  41
  42 weak_alias (__swapcontext, swapcontext)