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