lib/libc_r/uthread/uthread_resume_np.c

   1 /*
   2  * Copyright (c) 1995 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_resume_np.c,v 1.7.2.4 2002/10/22 14:44:03 fjoe Exp $
  33  * $DragonFly: src/lib/libc_r/uthread/uthread_resume_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     resume_common(struct pthread *);
  40
  41 /* Resume a thread: */
  42 int
  43 _pthread_resume_np(pthread_t thread)
  44 {
  45         int ret;
  46
  47         /* Find the thread in the list of active threads: */
  48         if ((ret = _find_thread(thread)) == 0) {
  49                 /*
  50                  * Defer signals to protect the scheduling queues
  51                  * from access by the signal handler:
  52                  */
  53                 _thread_kern_sig_defer();
  54
  55                 if ((thread->flags & PTHREAD_FLAGS_SUSPENDED) != 0)
  56                         resume_common(thread);
  57
  58                 /*
  59                  * Undefer and handle pending signals, yielding if
  60                  * necessary:
  61                  */
  62                 _thread_kern_sig_undefer();
  63         }
  64         return (ret);
  65 }
  66
  67 void
  68 _pthread_resume_all_np(void)
  69 {
  70         struct pthread  *curthread = _get_curthread();
  71         struct pthread  *thread;
  72
  73         /*
  74          * Defer signals to protect the scheduling queues from access
  75          * by the signal handler:
  76          */
  77         _thread_kern_sig_defer();
  78
  79         TAILQ_FOREACH(thread, &_thread_list, tle) {
  80                 if ((thread != curthread) &&
  81                     ((thread->flags & PTHREAD_FLAGS_SUSPENDED) != 0))
  82                         resume_common(thread);
  83         }
  84
  85         /*
  86          * Undefer and handle pending signals, yielding if necessary:
  87          */
  88         _thread_kern_sig_undefer();
  89 }
  90
  91 static void
  92 resume_common(struct pthread *thread)
  93 {
  94         /* Clear the suspend flag: */
  95         thread->flags &= ~PTHREAD_FLAGS_SUSPENDED;
  96
  97         /*
  98          * If the thread's state is suspended, that means it is
  99          * now runnable but not in any scheduling queue.  Set the
 100          * state to running and insert it into the run queue.
 101          */
 102         if (thread->state == PS_SUSPENDED) {
 103                 PTHREAD_SET_STATE(thread, PS_RUNNING);
 104                 if (thread->priority_mutex_count > 0)
 105                         PTHREAD_PRIOQ_INSERT_HEAD(thread);
 106                 else
 107                         PTHREAD_PRIOQ_INSERT_TAIL(thread);
 108         }
 109 }
 110
 111 __strong_reference(_pthread_resume_np, pthread_resume_np);
 112 __strong_reference(_pthread_resume_all_np, pthread_resume_all_np);