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 */ 30 31 #include "namespace.h" 32 #include <errno.h> 33 #include <pthread.h> 34 #include <pthread_np.h> 35 #include "un-namespace.h" 36 37 #include "thr_private.h" 38 39 static int suspend_common(struct pthread *, struct pthread *, 40 int); 41 42 /* Suspend a thread: */ 43 int 44 _pthread_suspend_np(pthread_t thread) 45 { 46 struct pthread *curthread = tls_get_curthread(); 47 int ret; 48 49 /* Suspending the current thread doesn't make sense. */ 50 if (thread == curthread) 51 ret = EDEADLK; 52 53 /* Add a reference to the thread: */ 54 else if ((ret = _thr_ref_add(curthread, thread, /*include dead*/0)) 55 == 0) { 56 /* Lock the threads scheduling queue: */ 57 THR_THREAD_LOCK(curthread, thread); 58 suspend_common(curthread, thread, 1); 59 /* Unlock the threads scheduling queue: */ 60 THR_THREAD_UNLOCK(curthread, thread); 61 62 /* Don't forget to remove the reference: */ 63 _thr_ref_delete(curthread, thread); 64 } 65 return (ret); 66 } 67 68 void 69 _pthread_suspend_all_np(void) 70 { 71 struct pthread *curthread = tls_get_curthread(); 72 struct pthread *thread; 73 int ret; 74 75 THREAD_LIST_LOCK(curthread); 76 77 TAILQ_FOREACH(thread, &_thread_list, tle) { 78 if (thread != curthread) { 79 THR_THREAD_LOCK(curthread, thread); 80 if (thread->state != PS_DEAD && 81 !(thread->flags & THR_FLAGS_SUSPENDED)) 82 thread->flags |= THR_FLAGS_NEED_SUSPEND; 83 THR_THREAD_UNLOCK(curthread, thread); 84 } 85 } 86 /* thr_kill(-1, SIGCANCEL); */ 87 88 restart: 89 TAILQ_FOREACH(thread, &_thread_list, tle) { 90 if (thread != curthread) { 91 /* First try to suspend the thread without waiting */ 92 THR_THREAD_LOCK(curthread, thread); 93 ret = suspend_common(curthread, thread, 0); 94 if (ret == 0) { 95 /* Can not suspend, try to wait */ 96 thread->refcount++; 97 THREAD_LIST_UNLOCK(curthread); 98 suspend_common(curthread, thread, 1); 99 THR_THREAD_UNLOCK(curthread, thread); 100 THREAD_LIST_LOCK(curthread); 101 _thr_ref_delete_unlocked(curthread, thread); 102 /* 103 * Because we were blocked, things may have 104 * been changed, we have to restart the 105 * process. 106 */ 107 goto restart; 108 } 109 THR_THREAD_UNLOCK(curthread, thread); 110 } 111 } 112 113 THREAD_LIST_UNLOCK(curthread); 114 } 115 116 static int 117 suspend_common(struct pthread *curthread, struct pthread *thread, 118 int waitok) 119 { 120 umtx_t tmp; 121 122 while (thread->state != PS_DEAD && 123 !(thread->flags & THR_FLAGS_SUSPENDED)) { 124 thread->flags |= THR_FLAGS_NEED_SUSPEND; 125 tmp = thread->cycle; 126 _thr_send_sig(thread, SIGCANCEL); 127 THR_THREAD_UNLOCK(curthread, thread); 128 if (waitok) { 129 _thr_umtx_wait(&thread->cycle, tmp, NULL, 0); 130 THR_THREAD_LOCK(curthread, thread); 131 } else { 132 THR_THREAD_LOCK(curthread, thread); 133 return (0); 134 } 135 } 136 137 return (1); 138 } 139 140 __strong_reference(_pthread_suspend_np, pthread_suspend_np); 141 __strong_reference(_pthread_suspend_all_np, pthread_suspend_all_np); 142