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; 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 if (create_stack(&new_thread->attr) != 0) { 96 /* Insufficient memory to create a stack: */ 97 new_thread->terminated = 1; 98 _thr_free(curthread, new_thread); 99 return (EAGAIN); 100 } 101 /* 102 * Write a magic value to the thread structure 103 * to help identify valid ones: 104 */ 105 new_thread->magic = THR_MAGIC; 106 new_thread->start_routine = start_routine; 107 new_thread->arg = arg; 108 new_thread->cancelflags = PTHREAD_CANCEL_ENABLE | 109 PTHREAD_CANCEL_DEFERRED; 110 getcontext(&uc); 111 SIGFILLSET(uc.uc_sigmask); 112 uc.uc_stack.ss_sp = new_thread->attr.stackaddr_attr; 113 uc.uc_stack.ss_size = new_thread->attr.stacksize_attr; 114 makecontext(&uc, (void (*)(void))thread_start, 1, new_thread); 115 116 /* 117 * Check if this thread is to inherit the scheduling 118 * attributes from its parent: 119 */ 120 if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) { 121 /* 122 * Copy the scheduling attributes. Lock the scheduling 123 * lock to get consistent scheduling parameters. 124 */ 125 THR_LOCK(curthread); 126 new_thread->base_priority = curthread->base_priority; 127 new_thread->attr.prio = curthread->base_priority; 128 new_thread->attr.sched_policy = curthread->attr.sched_policy; 129 THR_UNLOCK(curthread); 130 } else { 131 /* 132 * Use just the thread priority, leaving the 133 * other scheduling attributes as their 134 * default values: 135 */ 136 new_thread->base_priority = new_thread->attr.prio; 137 } 138 new_thread->active_priority = new_thread->base_priority; 139 140 /* Initialize the mutex queue: */ 141 TAILQ_INIT(&new_thread->mutexq); 142 TAILQ_INIT(&new_thread->pri_mutexq); 143 144 /* Initialise hooks in the thread structure: */ 145 if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) 146 new_thread->flags = THR_FLAGS_SUSPENDED; 147 new_thread->state = PS_RUNNING; 148 /* 149 * Thread created by thr_create() inherits currrent thread 150 * sigmask, however, before new thread setup itself correctly, 151 * it can not handle signal, so we should masks all signals here. 152 */ 153 SIGFILLSET(sigmask); 154 __sys_sigprocmask(SIG_SETMASK, &sigmask, &oldsigmask); 155 new_thread->sigmask = oldsigmask; 156 /* Add the new thread. */ 157 _thr_link(curthread, new_thread); 158 /* Return thread pointer eariler so that new thread can use it. */ 159 (*thread) = new_thread; 160 /* Schedule the new thread. */ 161 ret = thr_create(&uc, &new_thread->tid, 0); 162 __sys_sigprocmask(SIG_SETMASK, &oldsigmask, NULL); 163 if (ret != 0) { 164 _thr_unlink(curthread, new_thread); 165 free_thread(curthread, new_thread); 166 (*thread) = 0; 167 ret = EAGAIN; 168 } 169 return (ret); 170 } 171 172 static void 173 free_thread(struct pthread *curthread, struct pthread *thread) 174 { 175 free_stack(curthread, &thread->attr); 176 curthread->terminated = 1; 177 _thr_free(curthread, thread); 178 } 179 180 static int 181 create_stack(struct pthread_attr *pattr) 182 { 183 int ret; 184 185 /* Check if a stack was specified in the thread attributes: */ 186 if ((pattr->stackaddr_attr) != NULL) { 187 pattr->guardsize_attr = 0; 188 pattr->flags |= THR_STACK_USER; 189 ret = 0; 190 } 191 else 192 ret = _thr_stack_alloc(pattr); 193 return (ret); 194 } 195 196 static void 197 free_stack(struct pthread *curthread, struct pthread_attr *pattr) 198 { 199 if ((pattr->flags & THR_STACK_USER) == 0) { 200 THREAD_LIST_LOCK(curthread); 201 /* Stack routines don't use malloc/free. */ 202 _thr_stack_free(pattr); 203 THREAD_LIST_UNLOCK(curthread); 204 } 205 } 206 207 static void 208 thread_start(struct pthread *curthread) 209 { 210 _tcb_set(curthread->tcb); 211 212 /* Thread was created with all signals blocked, unblock them. */ 213 __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL); 214 215 if (curthread->flags & THR_FLAGS_NEED_SUSPEND) 216 _thr_suspend_check(curthread); 217 218 /* Run the current thread's start routine with argument: */ 219 pthread_exit(curthread->start_routine(curthread->arg)); 220 221 /* This point should never be reached. */ 222 PANIC("Thread has resumed after exit"); 223 } 224