thr_create.c revision 154055
1/* 2 * Copyright (c) 2003 Daniel M. Eischen <deischen@gdeb.com> 3 * Copyright (c) 2005, David Xu <davidxu@freebsd.org> 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 unmodified, this list of conditions, and the following 11 * 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 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 * 27 * $FreeBSD: head/lib/libthr/thread/thr_create.c 154055 2006-01-05 13:51:22Z davidxu $ 28 */ 29 30#include <sys/types.h> 31#include <sys/signalvar.h> 32#include <errno.h> 33#include <stdlib.h> 34#include <string.h> 35#include <stddef.h> 36#include <pthread.h> 37 38#include "thr_private.h" 39 40static int create_stack(struct pthread_attr *pattr); 41static void thread_start(struct pthread *curthread); 42 43__weak_reference(_pthread_create, pthread_create); 44 45int 46_pthread_create(pthread_t * thread, const pthread_attr_t * attr, 47 void *(*start_routine) (void *), void *arg) 48{ 49 struct pthread *curthread, *new_thread; 50 struct thr_param param; 51 int ret = 0, locked, create_suspended; 52 sigset_t set, oset; 53 54 _thr_check_init(); 55 56 /* 57 * Tell libc and others now they need lock to protect their data. 58 */ 59 if (_thr_isthreaded() == 0 && _thr_setthreaded(1)) 60 return (EAGAIN); 61 62 curthread = _get_curthread(); 63 if ((new_thread = _thr_alloc(curthread)) == NULL) 64 return (EAGAIN); 65 66 memset(¶m, 0, sizeof(param)); 67 68 if (attr == NULL || *attr == NULL) 69 /* Use the default thread attributes: */ 70 new_thread->attr = _pthread_attr_default; 71 else 72 new_thread->attr = *(*attr); 73 if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) { 74 /* inherit scheduling contention scope */ 75 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM) 76 new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM; 77 else 78 new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM; 79 /* 80 * scheduling policy and scheduling parameters will be 81 * inherited in following code. 82 */ 83 } 84 85 if (_thr_scope_system > 0) 86 new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM; 87 else if (_thr_scope_system < 0) 88 new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM; 89 90 new_thread->tid = TID_TERMINATED; 91 92 if (create_stack(&new_thread->attr) != 0) { 93 /* Insufficient memory to create a stack: */ 94 _thr_free(curthread, new_thread); 95 return (EAGAIN); 96 } 97 /* 98 * Write a magic value to the thread structure 99 * to help identify valid ones: 100 */ 101 new_thread->magic = THR_MAGIC; 102 new_thread->start_routine = start_routine; 103 new_thread->arg = arg; 104 new_thread->cancelflags = PTHREAD_CANCEL_ENABLE | 105 PTHREAD_CANCEL_DEFERRED; 106 /* 107 * Check if this thread is to inherit the scheduling 108 * attributes from its parent: 109 */ 110 if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) { 111 /* 112 * Copy the scheduling attributes. Lock the scheduling 113 * lock to get consistent scheduling parameters. 114 */ 115 THR_LOCK(curthread); 116 new_thread->base_priority = curthread->base_priority; 117 new_thread->attr.prio = curthread->base_priority; 118 new_thread->attr.sched_policy = curthread->attr.sched_policy; 119 THR_UNLOCK(curthread); 120 } else { 121 /* 122 * Use just the thread priority, leaving the 123 * other scheduling attributes as their 124 * default values: 125 */ 126 new_thread->base_priority = new_thread->attr.prio; 127 } 128 new_thread->active_priority = new_thread->base_priority; 129 130 /* Initialize the mutex queue: */ 131 TAILQ_INIT(&new_thread->mutexq); 132 TAILQ_INIT(&new_thread->pri_mutexq); 133 134 /* Initialise hooks in the thread structure: */ 135 if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) { 136 new_thread->flags = THR_FLAGS_NEED_SUSPEND; 137 create_suspended = 1; 138 } else { 139 create_suspended = 0; 140 } 141 142 new_thread->state = PS_RUNNING; 143 144 if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED) 145 new_thread->tlflags |= TLFLAGS_DETACHED; 146 147 /* Add the new thread. */ 148 new_thread->refcount = 1; 149 _thr_link(curthread, new_thread); 150 /* Return thread pointer eariler so that new thread can use it. */ 151 (*thread) = new_thread; 152 if (SHOULD_REPORT_EVENT(curthread, TD_CREATE)) { 153 THR_THREAD_LOCK(curthread, new_thread); 154 locked = 1; 155 } else 156 locked = 0; 157 param.start_func = (void (*)(void *)) thread_start; 158 param.arg = new_thread; 159 param.stack_base = new_thread->attr.stackaddr_attr; 160 param.stack_size = new_thread->attr.stacksize_attr; 161 param.tls_base = (char *)new_thread->tcb; 162 param.tls_size = sizeof(struct tcb); 163 param.child_tid = &new_thread->tid; 164 param.parent_tid = &new_thread->tid; 165 param.flags = 0; 166 if (new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM) 167 param.flags |= THR_SYSTEM_SCOPE; 168 169 /* Schedule the new thread. */ 170 if (create_suspended) { 171 SIGFILLSET(set); 172 SIGDELSET(set, SIGTRAP); 173 __sys_sigprocmask(SIG_SETMASK, &set, &oset); 174 new_thread->sigmask = oset; 175 } 176 177 ret = thr_new(¶m, sizeof(param)); 178 179 if (create_suspended) 180 __sys_sigprocmask(SIG_SETMASK, &oset, NULL); 181 182 if (ret != 0) { 183 if (!locked) 184 THR_THREAD_LOCK(curthread, new_thread); 185 new_thread->state = PS_DEAD; 186 new_thread->tid = TID_TERMINATED; 187 if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) { 188 new_thread->cycle++; 189 _thr_umtx_wake(&new_thread->cycle, INT_MAX); 190 } 191 THR_THREAD_UNLOCK(curthread, new_thread); 192 THREAD_LIST_LOCK(curthread); 193 new_thread->tlflags |= TLFLAGS_DETACHED; 194 _thr_ref_delete_unlocked(curthread, new_thread); 195 THREAD_LIST_UNLOCK(curthread); 196 (*thread) = 0; 197 ret = EAGAIN; 198 } else if (locked) { 199 _thr_report_creation(curthread, new_thread); 200 THR_THREAD_UNLOCK(curthread, new_thread); 201 } 202 return (ret); 203} 204 205static int 206create_stack(struct pthread_attr *pattr) 207{ 208 int ret; 209 210 /* Check if a stack was specified in the thread attributes: */ 211 if ((pattr->stackaddr_attr) != NULL) { 212 pattr->guardsize_attr = 0; 213 pattr->flags |= THR_STACK_USER; 214 ret = 0; 215 } 216 else 217 ret = _thr_stack_alloc(pattr); 218 return (ret); 219} 220 221static void 222thread_start(struct pthread *curthread) 223{ 224 if (curthread->attr.suspend == THR_CREATE_SUSPENDED) { 225 sigset_t set = curthread->sigmask; 226 227 _thr_ast(curthread); 228 229 /* 230 * Parent thread have stored signal mask for us, 231 * we should restore it now. 232 */ 233 sigprocmask(SIG_SETMASK, &set, NULL); 234 } 235 236 /* 237 * This is used as a serialization point to allow parent 238 * to report 'new thread' event to debugger before the thread 239 * does real work. 240 */ 241 THR_LOCK(curthread); 242 THR_UNLOCK(curthread); 243 244 /* Run the current thread's start routine with argument: */ 245 pthread_exit(curthread->start_routine(curthread->arg)); 246 247 /* This point should never be reached. */ 248 PANIC("Thread has resumed after exit"); 249} 250