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