lib/libc_r/uthread/uthread_suspend_np.c

   1 /*
   2  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by John Birrell.
  16  * 4. Neither the name of the author nor the names of any co-contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * $FreeBSD: src/lib/libc_r/uthread/uthread_suspend_np.c,v 1.7.2.6 2002/10/22 14:44:03 fjoe Exp $
  33  * $DragonFly: src/lib/libc_r/uthread/uthread_suspend_np.c,v 1.3 2005/05/30 20:50:53 joerg Exp $
  34  */
  35 #include <errno.h>
  36 #include <pthread.h>
  37 #include "pthread_private.h"
  38
  39 static void     suspend_common(struct pthread *thread);
  40
  41 /* Suspend a thread: */
  42 int
  43 _pthread_suspend_np(pthread_t thread)
  44 {
  45         int ret;
  46
  47         /* Suspending the current thread doesn't make sense. */
  48         if (thread == _get_curthread())
  49                 ret = EDEADLK;
  50
  51         /* Find the thread in the list of active threads: */
  52         else if ((ret = _find_thread(thread)) == 0) {
  53                 /*
  54                  * Defer signals to protect the scheduling queues from
  55                  * access by the signal handler:
  56                  */
  57                 _thread_kern_sig_defer();
  58
  59                 suspend_common(thread);
  60
  61                 /*
  62                  * Undefer and handle pending signals, yielding if
  63                  * necessary:
  64                  */
  65                 _thread_kern_sig_undefer();
  66         }
  67         return (ret);
  68 }
  69
  70 void
  71 _pthread_suspend_all_np(void)
  72 {
  73         struct pthread  *curthread = _get_curthread();
  74         struct pthread  *thread;
  75
  76         /*
  77          * Defer signals to protect the scheduling queues from
  78          * access by the signal handler:
  79          */
  80         _thread_kern_sig_defer();
  81
  82         TAILQ_FOREACH(thread, &_thread_list, tle) {
  83                 if (thread != curthread)
  84                         suspend_common(thread);
  85         }
  86
  87         /*
  88          * Undefer and handle pending signals, yielding if
  89          * necessary:
  90          */
  91         _thread_kern_sig_undefer();
  92 }
  93
  94 void
  95 suspend_common(struct pthread *thread)
  96 {
  97         thread->flags |= PTHREAD_FLAGS_SUSPENDED;
  98         if (thread->flags & PTHREAD_FLAGS_IN_PRIOQ) {
  99                 PTHREAD_PRIOQ_REMOVE(thread);
 100                 PTHREAD_SET_STATE(thread, PS_SUSPENDED);
 101         }
 102 }
 103
 104 __strong_reference(_pthread_suspend_np, pthread_suspend_np);
 105 __strong_reference(_pthread_suspend_all_np, pthread_suspend_all_np);