lib/libkse/thread/thr_detach.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. 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 <sys/types.h>
  32 #include <machine/atomic.h>
  33 #include <errno.h>
  34 #include <pthread.h>
  35 #include "thr_private.h"
  36
  37 LT10_COMPAT_PRIVATE(_pthread_detach);
  38 LT10_COMPAT_DEFAULT(pthread_detach);
  39
  40 __weak_reference(_pthread_detach, pthread_detach);
  41
  42 int
  43 _pthread_detach(pthread_t pthread)
  44 {
  45         struct pthread *curthread = _get_curthread();
  46         struct kse_mailbox *kmbx = NULL;
  47         struct pthread *joiner;
  48         int rval = 0;
  49
  50         /* Check for invalid calling parameters: */
  51         if (pthread == NULL || pthread->magic != THR_MAGIC)
  52                 /* Return an invalid argument error: */
  53                 rval = EINVAL;
  54
  55         else if ((rval = _thr_ref_add(curthread, pthread,
  56             /*include dead*/1)) != 0) {
  57                 /* Return an error: */
  58         }
  59
  60         /* Check if the thread is already detached: */
  61         else if ((pthread->attr.flags & PTHREAD_DETACHED) != 0) {
  62                 /* Return an error: */
  63                 _thr_ref_delete(curthread, pthread);
  64                 rval = EINVAL;
  65         } else {
  66                 /* Lock the detached thread: */
  67                 THR_SCHED_LOCK(curthread, pthread);
  68
  69                 /* Flag the thread as detached: */
  70                 pthread->attr.flags |= PTHREAD_DETACHED;
  71
  72                 /* Retrieve any joining thread and remove it: */
  73                 joiner = pthread->joiner;
  74                 if ((joiner != NULL) && (joiner->kseg == pthread->kseg)) {
  75                         /*
  76                          * We already own the scheduler lock for the joiner.
  77                          * Take advantage of that and make the joiner runnable.
  78                          */
  79                         if (joiner->join_status.thread == pthread) {
  80                                 /*
  81                                  * Set the return value for the woken thread:
  82                                  */
  83                                 joiner->join_status.error = ESRCH;
  84                                 joiner->join_status.ret = NULL;
  85                                 joiner->join_status.thread = NULL;
  86
  87                                 kmbx = _thr_setrunnable_unlocked(joiner);
  88                         }
  89                         joiner = NULL;
  90                 }
  91                 THR_SCHED_UNLOCK(curthread, pthread);
  92                 /* See if there is a thread waiting in pthread_join(): */
  93                 if ((joiner != NULL) &&
  94                     (_thr_ref_add(curthread, joiner, 0) == 0)) {
  95                         /* Lock the joiner before fiddling with it. */
  96                         THR_SCHED_LOCK(curthread, joiner);
  97                         if (joiner->join_status.thread == pthread) {
  98                                 /*
  99                                  * Set the return value for the woken thread:
 100                                  */
 101                                 joiner->join_status.error = ESRCH;
 102                                 joiner->join_status.ret = NULL;
 103                                 joiner->join_status.thread = NULL;
 104
 105                                 kmbx = _thr_setrunnable_unlocked(joiner);
 106                         }
 107                         THR_SCHED_UNLOCK(curthread, joiner);
 108                         _thr_ref_delete(curthread, joiner);
 109                 }
 110                 _thr_ref_delete(curthread, pthread);
 111                 if (kmbx != NULL)
 112                         kse_wakeup(kmbx);
 113         }
 114
 115         /* Return the completion status: */
 116         return (rval);
 117 }