lib/libkse/thread/thr_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. Neither the name of the author nor the names of any co-contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * $FreeBSD$
  30  */
  31 #include <errno.h>
  32 #include <pthread.h>
  33 #include "thr_private.h"
  34
  35 static void suspend_common(struct pthread *thread);
  36
  37 LT10_COMPAT_PRIVATE(_pthread_suspend_np);
  38 LT10_COMPAT_DEFAULT(pthread_suspend_np);
  39 LT10_COMPAT_PRIVATE(_pthread_suspend_all_np);
  40 LT10_COMPAT_DEFAULT(pthread_suspend_all_np);
  41
  42 __weak_reference(_pthread_suspend_np, pthread_suspend_np);
  43 __weak_reference(_pthread_suspend_all_np, pthread_suspend_all_np);
  44
  45 /* Suspend a thread: */
  46 int
  47 _pthread_suspend_np(pthread_t thread)
  48 {
  49         struct pthread *curthread = _get_curthread();
  50         int ret;
  51
  52         /* Suspending the current thread doesn't make sense. */
  53         if (thread == _get_curthread())
  54                 ret = EDEADLK;
  55
  56         /* Add a reference to the thread: */
  57         else if ((ret = _thr_ref_add(curthread, thread, /*include dead*/0))
  58             == 0) {
  59                 /* Lock the threads scheduling queue: */
  60                 THR_SCHED_LOCK(curthread, thread);
  61                 suspend_common(thread);
  62                 /* Unlock the threads scheduling queue: */
  63                 THR_SCHED_UNLOCK(curthread, thread);
  64
  65                 /* Don't forget to remove the reference: */
  66                 _thr_ref_delete(curthread, thread);
  67         }
  68         return (ret);
  69 }
  70
  71 void
  72 _pthread_suspend_all_np(void)
  73 {
  74         struct pthread  *curthread = _get_curthread();
  75         struct pthread  *thread;
  76         kse_critical_t crit;
  77
  78         /* Take the thread list lock: */
  79         crit = _kse_critical_enter();
  80         KSE_LOCK_ACQUIRE(curthread->kse, &_thread_list_lock);
  81
  82         TAILQ_FOREACH(thread, &_thread_list, tle) {
  83                 if (thread != curthread) {
  84                         THR_SCHED_LOCK(curthread, thread);
  85                         suspend_common(thread);
  86                         THR_SCHED_UNLOCK(curthread, thread);
  87                 }
  88         }
  89
  90         /* Release the thread list lock: */
  91         KSE_LOCK_RELEASE(curthread->kse, &_thread_list_lock);
  92         _kse_critical_leave(crit);
  93 }
  94
  95 void
  96 suspend_common(struct pthread *thread)
  97 {
  98         if ((thread->state != PS_DEAD) &&
  99             (thread->state != PS_DEADLOCK) &&
 100             ((thread->flags & THR_FLAGS_EXITING) == 0)) {
 101                 thread->flags |= THR_FLAGS_SUSPENDED;
 102                 if ((thread->flags & THR_FLAGS_IN_RUNQ) != 0) {
 103                         THR_RUNQ_REMOVE(thread);
 104                         THR_SET_STATE(thread, PS_SUSPENDED);
 105                 }
 106 #ifdef NOT_YET
 107                 if ((thread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0)
 108                         /* ??? */
 109 #endif
 110         }
 111 }