lib/libthread_xu/thread/thr_join.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  * $DragonFly: src/lib/libthread_xu/thread/thr_join.c,v 1.7 2006/04/06 13:03:09 davidxu Exp $
  33  */
  34
  35 #include "namespace.h"
  36 #include <machine/tls.h>
  37
  38 #include <errno.h>
  39 #include <pthread.h>
  40 #include "un-namespace.h"
  41
  42 #include "thr_private.h"
  43
  44 static int join_common(pthread_t, void **, const struct timespec *);
  45
  46 static void backout_join(void *arg)
  47 {
  48         struct pthread *curthread = tls_get_curthread();
  49         struct pthread *pthread = (struct pthread *)arg;
  50
  51         THREAD_LIST_LOCK(curthread);
  52         pthread->joiner = NULL;
  53         THREAD_LIST_UNLOCK(curthread);
  54 }
  55
  56 int
  57 _pthread_join(pthread_t pthread, void **thread_return)
  58 {
  59         return (join_common(pthread, thread_return, NULL));
  60 }
  61
  62 int
  63 _pthread_timedjoin_np(pthread_t pthread, void **thread_return,
  64         const struct timespec *abstime)
  65 {
  66         if (abstime == NULL || abstime->tv_sec < 0 || abstime->tv_nsec < 0 ||
  67             abstime->tv_nsec >= 1000000000)
  68                 return (EINVAL);
  69
  70         return (join_common(pthread, thread_return, abstime));
  71 }
  72
  73 static int
  74 join_common(pthread_t pthread, void **thread_return,
  75         const struct timespec *abstime)
  76 {
  77         struct pthread *curthread = tls_get_curthread();
  78         struct timespec ts, ts2, *tsp;
  79         void *tmp;
  80         long state;
  81         int oldcancel;
  82         int ret = 0;
  83
  84         if (pthread == NULL)
  85                 return (EINVAL);
  86
  87         if (pthread == curthread)
  88                 return (EDEADLK);
  89
  90         THREAD_LIST_LOCK(curthread);
  91         if ((ret = _thr_find_thread(curthread, pthread, 1)) != 0) {
  92                 ret = ESRCH;
  93         } else if ((pthread->tlflags & TLFLAGS_DETACHED) != 0) {
  94                 ret = ESRCH;
  95         } else if (pthread->joiner != NULL) {
  96                 /* Multiple joiners are not supported. */
  97                 ret = ENOTSUP;
  98         }
  99         if (ret) {
 100                 THREAD_LIST_UNLOCK(curthread);
 101                 return (ret);
 102         }
 103         /* Set the running thread to be the joiner: */
 104         pthread->joiner = curthread;
 105
 106         THREAD_LIST_UNLOCK(curthread);
 107
 108         THR_CLEANUP_PUSH(curthread, backout_join, pthread);
 109         oldcancel = _thr_cancel_enter(curthread);
 110
 111         while ((state = pthread->state) != PS_DEAD) {
 112                 if (abstime != NULL) {
 113                         clock_gettime(CLOCK_REALTIME, &ts);
 114                         TIMESPEC_SUB(&ts2, abstime, &ts);
 115                         if (ts2.tv_sec < 0) {
 116                                 ret = ETIMEDOUT;
 117                                 break;
 118                         }
 119                         tsp = &ts2;
 120                 } else
 121                         tsp = NULL;
 122                 ret = _thr_umtx_wait(&pthread->state, state, tsp,
 123                          CLOCK_REALTIME);
 124                 if (ret == ETIMEDOUT)
 125                         break;
 126         }
 127
 128         _thr_cancel_leave(curthread, oldcancel);
 129         THR_CLEANUP_POP(curthread, 0);
 130
 131         if (ret == ETIMEDOUT) {
 132                 THREAD_LIST_LOCK(curthread);
 133                 pthread->joiner = NULL;
 134                 THREAD_LIST_UNLOCK(curthread);
 135         } else {
 136                 ret = 0;
 137                 tmp = pthread->ret;
 138                 THREAD_LIST_LOCK(curthread);
 139                 pthread->tlflags |= TLFLAGS_DETACHED;
 140                 pthread->joiner = NULL;
 141                 THR_GCLIST_ADD(pthread);
 142                 THREAD_LIST_UNLOCK(curthread);
 143
 144                 if (thread_return != NULL)
 145                         *thread_return = tmp;
 146         }
 147         return (ret);
 148 }
 149
 150 __strong_reference(_pthread_join, pthread_join);
 151 __strong_reference(_pthread_timedjoin_np, pthread_timedjoin_np);
 152