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
  32 #include "namespace.h"
  33 #include <errno.h>
  34 #include <pthread.h>
  35 #include "un-namespace.h"
  36 #include "thr_private.h"
  37
  38 int     _pthread_suspend_np(pthread_t thread);
  39 void    _pthread_suspend_all_np(void);
  40
  41 static void suspend_common(struct pthread *thread);
  42
  43 __weak_reference(_pthread_suspend_np, pthread_suspend_np);
  44 __weak_reference(_pthread_suspend_all_np, pthread_suspend_all_np);
  45
  46 /* Suspend a thread: */
  47 int
  48 _pthread_suspend_np(pthread_t thread)
  49 {
  50         struct pthread *curthread = _get_curthread();
  51         int ret;
  52
  53         /* Suspending the current thread doesn't make sense. */
  54         if (thread == _get_curthread())
  55                 ret = EDEADLK;
  56
  57         /* Add a reference to the thread: */
  58         else if ((ret = _thr_ref_add(curthread, thread, /*include dead*/0))
  59             == 0) {
  60                 /* Lock the threads scheduling queue: */
  61                 THR_SCHED_LOCK(curthread, thread);
  62                 suspend_common(thread);
  63                 /* Unlock the threads scheduling queue: */
  64                 THR_SCHED_UNLOCK(curthread, thread);
  65
  66                 /* Don't forget to remove the reference: */
  67                 _thr_ref_delete(curthread, thread);
  68         }
  69         return (ret);
  70 }
  71
  72 void
  73 _pthread_suspend_all_np(void)
  74 {
  75         struct pthread  *curthread = _get_curthread();
  76         struct pthread  *thread;
  77         kse_critical_t crit;
  78
  79         /* Take the thread list lock: */
  80         crit = _kse_critical_enter();
  81         KSE_LOCK_ACQUIRE(curthread->kse, &_thread_list_lock);
  82
  83         TAILQ_FOREACH(thread, &_thread_list, tle) {
  84                 if (thread != curthread) {
  85                         THR_SCHED_LOCK(curthread, thread);
  86                         suspend_common(thread);
  87                         THR_SCHED_UNLOCK(curthread, thread);
  88                 }
  89         }
  90
  91         /* Release the thread list lock: */
  92         KSE_LOCK_RELEASE(curthread->kse, &_thread_list_lock);
  93         _kse_critical_leave(crit);
  94 }
  95
  96 void
  97 suspend_common(struct pthread *thread)
  98 {
  99         if ((thread->state != PS_DEAD) &&
 100             (thread->state != PS_DEADLOCK) &&
 101             ((thread->flags & THR_FLAGS_EXITING) == 0)) {
 102                 thread->flags |= THR_FLAGS_SUSPENDED;
 103                 if ((thread->flags & THR_FLAGS_IN_RUNQ) != 0) {
 104                         THR_RUNQ_REMOVE(thread);
 105                         THR_SET_STATE(thread, PS_SUSPENDED);
 106                 }
 107 #ifdef NOT_YET
 108                 if ((thread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0)
 109                         /* ??? */
 110 #endif
 111         }
 112 }