1 /* 2 * Copyright (c) 2005 David Xu <davidxu@freebsd.org> 3 * Copyright (c) 2003 Daniel M. Eischen <deischen@gdeb.com> 4 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by John Birrell. 18 * 4. Neither the name of the author nor the names of any co-contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * $FreeBSD: src/lib/libpthread/thread/thr_create.c,v 1.58 2004/10/23 23:28:36 davidxu Exp $ 35 * $DragonFly: src/lib/libthread_xu/thread/thr_create.c,v 1.6 2006/03/12 11:28:06 davidxu Exp $ 36 */ 37 #include <errno.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include <fcntl.h> 41 #include <unistd.h> 42 #include <stddef.h> 43 #include <sys/time.h> 44 #include <machine/reg.h> 45 #include <machine/tls.h> 46 47 #include <pthread.h> 48 #include <sys/signalvar.h> 49 50 #include "thr_private.h" 51 #include "libc_private.h" 52 53 struct start_arg { 54 struct pthread *thread; 55 volatile umtx_t started; 56 }; 57 58 static int create_stack(struct pthread_attr *pattr); 59 static void thread_start(void *); 60 61 __weak_reference(_pthread_create, pthread_create); 62 63 int 64 _pthread_create(pthread_t * thread, const pthread_attr_t * attr, 65 void *(*start_routine) (void *), void *arg) 66 { 67 struct start_arg start_arg; 68 void *stack; 69 sigset_t sigmask, oldsigmask; 70 struct pthread *curthread, *new_thread; 71 int ret = 0, locked; 72 73 _thr_check_init(); 74 75 /* 76 * Tell libc and others now they need lock to protect their data. 77 */ 78 if (_thr_isthreaded() == 0 && _thr_setthreaded(1)) 79 return (EAGAIN); 80 81 curthread = tls_get_curthread(); 82 if ((new_thread = _thr_alloc(curthread)) == NULL) 83 return (EAGAIN); 84 85 if (attr == NULL || *attr == NULL) 86 /* Use the default thread attributes: */ 87 new_thread->attr = _pthread_attr_default; 88 else 89 new_thread->attr = *(*attr); 90 if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) { 91 /* inherit scheduling contention scope */ 92 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM) 93 new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM; 94 else 95 new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM; 96 /* 97 * scheduling policy and scheduling parameters will be 98 * inherited in following code. 99 */ 100 } 101 102 if (_thread_scope_system > 0) 103 new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM; 104 else if (_thread_scope_system < 0) 105 new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM; 106 107 if (create_stack(&new_thread->attr) != 0) { 108 /* Insufficient memory to create a stack: */ 109 new_thread->terminated = 1; 110 _thr_free(curthread, new_thread); 111 return (EAGAIN); 112 } 113 /* 114 * Write a magic value to the thread structure 115 * to help identify valid ones: 116 */ 117 new_thread->magic = THR_MAGIC; 118 new_thread->start_routine = start_routine; 119 new_thread->arg = arg; 120 new_thread->cancelflags = PTHREAD_CANCEL_ENABLE | 121 PTHREAD_CANCEL_DEFERRED; 122 /* 123 * Check if this thread is to inherit the scheduling 124 * attributes from its parent: 125 */ 126 if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) { 127 /* 128 * Copy the scheduling attributes. Lock the scheduling 129 * lock to get consistent scheduling parameters. 130 */ 131 THR_LOCK(curthread); 132 new_thread->base_priority = curthread->base_priority; 133 new_thread->attr.prio = curthread->base_priority; 134 new_thread->attr.sched_policy = curthread->attr.sched_policy; 135 THR_UNLOCK(curthread); 136 } else { 137 /* 138 * Use just the thread priority, leaving the 139 * other scheduling attributes as their 140 * default values: 141 */ 142 new_thread->base_priority = new_thread->attr.prio; 143 } 144 new_thread->active_priority = new_thread->base_priority; 145 146 /* Initialize the mutex queue: */ 147 TAILQ_INIT(&new_thread->mutexq); 148 TAILQ_INIT(&new_thread->pri_mutexq); 149 150 /* Initialise hooks in the thread structure: */ 151 if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) 152 new_thread->flags = THR_FLAGS_NEED_SUSPEND; 153 154 new_thread->state = PS_RUNNING; 155 156 if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED) 157 new_thread->tlflags |= TLFLAGS_DETACHED; 158 159 /* 160 * Thread created by thr_create() inherits currrent thread 161 * sigmask, however, before new thread setup itself correctly, 162 * it can not handle signal, so we should masks all signals here. 163 */ 164 SIGFILLSET(sigmask); 165 __sys_sigprocmask(SIG_SETMASK, &sigmask, &oldsigmask); 166 new_thread->sigmask = oldsigmask; 167 /* Add the new thread. */ 168 new_thread->refcount = 1; 169 _thr_link(curthread, new_thread); 170 /* Return thread pointer eariler so that new thread can use it. */ 171 (*thread) = new_thread; 172 if (SHOULD_REPORT_EVENT(curthread, TD_CREATE)) { 173 THR_THREAD_LOCK(curthread, new_thread); 174 locked = 1; 175 } else 176 locked = 0; 177 /* Schedule the new thread. */ 178 stack = (char *)new_thread->attr.stackaddr_attr + 179 new_thread->attr.stacksize_attr; 180 start_arg.thread = new_thread; 181 start_arg.started = 0; 182 ret = rfork_thread(RFPROC | RFNOWAIT | RFMEM | RFSIGSHARE, stack, 183 (int (*)(void *))thread_start, &start_arg); 184 __sys_sigprocmask(SIG_SETMASK, &oldsigmask, NULL); 185 if (ret >= 0) { 186 /* 187 * Wait until new thread get its thread id, so we can 188 * send signal to it immediately after we return. 189 */ 190 while (start_arg.started == 0) 191 _thr_umtx_wait(&start_arg.started, 0, NULL, 0); 192 ret = 0; 193 } else { 194 ret = EAGAIN; 195 } 196 if (ret != 0) { 197 if (!locked) 198 THR_THREAD_LOCK(curthread, new_thread); 199 new_thread->state = PS_DEAD; 200 new_thread->terminated = 1; 201 THR_THREAD_UNLOCK(curthread, new_thread); 202 THREAD_LIST_LOCK(curthread); 203 _thread_active_threads--; 204 new_thread->tlflags |= TLFLAGS_DETACHED; 205 _thr_ref_delete_unlocked(curthread, new_thread); 206 THREAD_LIST_UNLOCK(curthread); 207 (*thread) = 0; 208 ret = EAGAIN; 209 } else if (locked) { 210 _thr_report_creation(curthread, new_thread); 211 THR_THREAD_UNLOCK(curthread, new_thread); 212 } 213 return (ret); 214 } 215 216 static int 217 create_stack(struct pthread_attr *pattr) 218 { 219 int ret; 220 221 /* Check if a stack was specified in the thread attributes: */ 222 if ((pattr->stackaddr_attr) != NULL) { 223 pattr->guardsize_attr = 0; 224 pattr->flags |= THR_STACK_USER; 225 ret = 0; 226 } 227 else 228 ret = _thr_stack_alloc(pattr); 229 return (ret); 230 } 231 232 static void 233 thread_start(void *arg) 234 { 235 struct pthread *curthread; 236 struct start_arg *start_arg = arg; 237 238 curthread = start_arg->thread; 239 curthread->tid = _thr_get_tid(); 240 tls_set_tcb(curthread->tcb); 241 start_arg->started = 1; 242 _thr_umtx_wake(&start_arg->started, 1); 243 244 THR_LOCK(curthread); 245 THR_UNLOCK(curthread); 246 247 /* Thread was created with all signals blocked, unblock them. */ 248 __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL); 249 250 if (curthread->flags & THR_FLAGS_NEED_SUSPEND) 251 _thr_suspend_check(curthread); 252 253 /* Run the current thread's start routine with argument: */ 254 pthread_exit(curthread->start_routine(curthread->arg)); 255 256 /* This point should never be reached. */ 257 PANIC("Thread has resumed after exit"); 258 } 259