thr_join.c revision 67097
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: head/lib/libkse/thread/thr_join.c 67097 2000-10-13 22:12:32Z deischen $ 33 */ 34#include <errno.h> 35#ifdef _THREAD_SAFE 36#include <pthread.h> 37#include "pthread_private.h" 38 39int 40pthread_join(pthread_t pthread, void **thread_return) 41{ 42 int ret = 0; 43 44 _thread_enter_cancellation_point(); 45 46 /* Check if the caller has specified an invalid thread: */ 47 if (pthread == NULL || pthread->magic != PTHREAD_MAGIC) { 48 /* Invalid thread: */ 49 _thread_leave_cancellation_point(); 50 return(EINVAL); 51 } 52 53 /* Check if the caller has specified itself: */ 54 if (pthread == _thread_run) { 55 /* Avoid a deadlock condition: */ 56 _thread_leave_cancellation_point(); 57 return(EDEADLK); 58 } 59 60 /* 61 * Find the thread in the list of active threads or in the 62 * list of dead threads: 63 */ 64 if ((_find_thread(pthread) != 0) && (_find_dead_thread(pthread) != 0)) 65 /* Return an error: */ 66 ret = ESRCH; 67 68 /* Check if this thread has been detached: */ 69 else if ((pthread->attr.flags & PTHREAD_DETACHED) != 0) 70 /* Return an error: */ 71 ret = ESRCH; 72 73 /* Check if the thread is not dead: */ 74 else if (pthread->state != PS_DEAD) { 75 PTHREAD_ASSERT_NOT_IN_SYNCQ(_thread_run); 76 77 /* Clear the interrupted flag: */ 78 _thread_run->interrupted = 0; 79 80 /* 81 * Protect against being context switched out while 82 * adding this thread to the join queue. 83 */ 84 _thread_kern_sig_defer(); 85 86 /* Add the running thread to the join queue: */ 87 TAILQ_INSERT_TAIL(&(pthread->join_queue), _thread_run, sqe); 88 _thread_run->flags |= PTHREAD_FLAGS_IN_JOINQ; 89 _thread_run->data.thread = pthread; 90 91 /* Schedule the next thread: */ 92 _thread_kern_sched_state(PS_JOIN, __FILE__, __LINE__); 93 94 if (_thread_run->interrupted != 0) { 95 TAILQ_REMOVE(&(pthread->join_queue), _thread_run, sqe); 96 _thread_run->flags &= ~PTHREAD_FLAGS_IN_JOINQ; 97 } 98 _thread_run->data.thread = NULL; 99 100 _thread_kern_sig_undefer(); 101 102 if (_thread_run->interrupted != 0 && 103 _thread_run->continuation != NULL) 104 _thread_run->continuation(_thread_run); 105 106 /* Check if the thread is not detached: */ 107 if ((pthread->attr.flags & PTHREAD_DETACHED) == 0) { 108 /* Check if the return value is required: */ 109 if (thread_return) 110 /* Return the thread's return value: */ 111 *thread_return = pthread->ret; 112 } 113 else 114 /* Return an error: */ 115 ret = ESRCH; 116 117 /* Check if the return value is required: */ 118 } else if (thread_return != NULL) 119 /* Return the thread's return value: */ 120 *thread_return = pthread->ret; 121 122 _thread_leave_cancellation_point(); 123 124 /* Return the completion status: */ 125 return (ret); 126} 127 128void 129_join_backout(pthread_t pthread) 130{ 131 _thread_kern_sig_defer(); 132 if (pthread->state == PS_JOIN) { 133 TAILQ_REMOVE(&pthread->data.thread->join_queue, pthread, sqe); 134 _thread_run->flags &= ~PTHREAD_FLAGS_IN_JOINQ; 135 } 136 _thread_kern_sig_undefer(); 137} 138#endif 139