linuxthreads/restart.h

   1 /* Linuxthreads - a simple clone()-based implementation of Posix        */
   2 /* threads for Linux.                                                   */
   3 /* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr)              */
   4 /*                                                                      */
   5 /* This program is free software; you can redistribute it and/or        */
   6 /* modify it under the terms of the GNU Library General Public License  */
   7 /* as published by the Free Software Foundation; either version 2       */
   8 /* of the License, or (at your option) any later version.               */
   9 /*                                                                      */
  10 /* This program 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        */
  13 /* GNU Library General Public License for more details.                 */
  14
  15 #include <signal.h>
  16
  17 /* Primitives for controlling thread execution */
  18
  19 static inline void restart(pthread_descr th)
  20 {
  21   kill(th->p_pid, PTHREAD_SIG_RESTART);
  22 }
  23
  24 static inline void suspend(pthread_descr self)
  25 {
  26   sigset_t mask;
  27
  28   sigprocmask(SIG_SETMASK, NULL, &mask); /* Get current signal mask */
  29   sigdelset(&mask, PTHREAD_SIG_RESTART); /* Unblock the restart signal */
  30   do {
  31     self->p_signal = 0;
  32     sigsuspend(&mask);                   /* Wait for signal */
  33   } while (self->p_signal != PTHREAD_SIG_RESTART);
  34 }
  35
  36 static inline void suspend_with_cancellation(pthread_descr self)
  37 {
  38   sigset_t mask;
  39   sigjmp_buf jmpbuf;
  40
  41   sigprocmask(SIG_SETMASK, NULL, &mask); /* Get current signal mask */
  42   sigdelset(&mask, PTHREAD_SIG_RESTART); /* Unblock the restart signal */
  43   /* No need to save the signal mask, we'll restore it ourselves */
  44   if (sigsetjmp(jmpbuf, 0) == 0) {
  45     self->p_cancel_jmp = &jmpbuf;
  46     if (! (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE)) {
  47       do {
  48         self->p_signal = 0;
  49         sigsuspend(&mask);               /* Wait for a signal */
  50       } while (self->p_signal != PTHREAD_SIG_RESTART);
  51     }
  52     self->p_cancel_jmp = NULL;
  53   } else {
  54     sigaddset(&mask, PTHREAD_SIG_RESTART); /* Reblock the restart signal */
  55     sigprocmask(SIG_SETMASK, &mask, NULL);
  56   }
  57 }