1 /* 2 * Copyright (c) 2005 David Xu <davidxu@freebsd.org> 3 * Copyright (c) 2003 Daniel M. Eischen <deischen@gdeb.com> 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 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 * 26 * $FreeBSD: src/lib/libpthread/thread/thr_create.c,v 1.58 2004/10/23 23:28:36 davidxu Exp $ 27 */ 28 29 #include "namespace.h" 30 #include <errno.h> 31 #include <stdlib.h> 32 #include <string.h> 33 #include <fcntl.h> 34 #include <unistd.h> 35 #include <stddef.h> 36 #include <sys/time.h> 37 #include <machine/reg.h> 38 #include <machine/tls.h> 39 #include <pthread.h> 40 #include <sys/signalvar.h> 41 #include "un-namespace.h" 42 43 #include "libc_private.h" 44 #include "thr_private.h" 45 46 static int create_stack(struct pthread_attr *pattr); 47 static void thread_start(void *); 48 49 int 50 _pthread_create(pthread_t * thread, const pthread_attr_t * attr, 51 void *(*start_routine) (void *), void *arg) 52 { 53 struct lwp_params create_params; 54 void *stack; 55 sigset_t sigmask, oldsigmask; 56 struct pthread *curthread, *new_thread; 57 int ret = 0, locked; 58 59 _thr_check_init(); 60 61 /* 62 * Tell libc and others now they need lock to protect their data. 63 */ 64 if (_thr_isthreaded() == 0 && _thr_setthreaded(1)) 65 return (EAGAIN); 66 67 curthread = tls_get_curthread(); 68 if ((new_thread = _thr_alloc(curthread)) == NULL) 69 return (EAGAIN); 70 71 if (attr == NULL || *attr == NULL) { 72 /* Use the default thread attributes: */ 73 new_thread->attr = _pthread_attr_default; 74 } else { 75 new_thread->attr = *(*attr); 76 } 77 if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) { 78 /* inherit scheduling contention scope */ 79 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM) 80 new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM; 81 else 82 new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM; 83 /* 84 * scheduling policy and scheduling parameters will be 85 * inherited in following code. 86 */ 87 } 88 89 if (create_stack(&new_thread->attr) != 0) { 90 /* Insufficient memory to create a stack: */ 91 new_thread->terminated = 1; 92 _thr_free(curthread, new_thread); 93 return (EAGAIN); 94 } 95 /* 96 * Write a magic value to the thread structure 97 * to help identify valid ones: 98 */ 99 new_thread->magic = THR_MAGIC; 100 new_thread->start_routine = start_routine; 101 new_thread->arg = arg; 102 new_thread->cancelflags = PTHREAD_CANCEL_ENABLE | 103 PTHREAD_CANCEL_DEFERRED; 104 /* 105 * Check if this thread is to inherit the scheduling 106 * attributes from its parent: 107 */ 108 if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) { 109 /* 110 * Copy the scheduling attributes. Lock the scheduling 111 * lock to get consistent scheduling parameters. 112 */ 113 THR_LOCK(curthread); 114 new_thread->base_priority = curthread->base_priority; 115 new_thread->attr.prio = curthread->attr.prio; 116 new_thread->attr.sched_policy = curthread->attr.sched_policy; 117 THR_UNLOCK(curthread); 118 } else { 119 /* 120 * Use just the thread priority, leaving the 121 * other scheduling attributes as their 122 * default values: 123 */ 124 new_thread->base_priority = new_thread->attr.prio; 125 } 126 new_thread->active_priority = new_thread->base_priority; 127 128 /* Initialize the mutex queue: */ 129 TAILQ_INIT(&new_thread->mutexq); 130 131 /* Initialise hooks in the thread structure: */ 132 if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) 133 new_thread->flags = THR_FLAGS_NEED_SUSPEND; 134 135 new_thread->state = PS_RUNNING; 136 137 if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED) 138 new_thread->tlflags |= TLFLAGS_DETACHED; 139 140 /* Add the new thread. */ 141 new_thread->refcount = 1; 142 _thr_link(curthread, new_thread); 143 /* Return thread pointer eariler so that new thread can use it. */ 144 (*thread) = new_thread; 145 if (SHOULD_REPORT_EVENT(curthread, TD_CREATE)) { 146 THR_THREAD_LOCK(curthread, new_thread); 147 locked = 1; 148 } else 149 locked = 0; 150 /* Schedule the new thread. */ 151 stack = (char *)new_thread->attr.stackaddr_attr + 152 new_thread->attr.stacksize_attr; 153 bzero(&create_params, sizeof(create_params)); 154 create_params.lwp_func = thread_start; 155 create_params.lwp_arg = new_thread; 156 create_params.lwp_stack = stack; 157 create_params.lwp_tid1 = &new_thread->tid; 158 /* 159 * Thread created by thr_create() inherits currrent thread 160 * sigmask, however, before new thread setup itself correctly, 161 * it can not handle signal, so we should mask all signals here. 162 * We do this at the very last moment, so that we don't run 163 * into problems while we have all signals disabled. 164 */ 165 SIGFILLSET(sigmask); 166 __sys_sigprocmask(SIG_SETMASK, &sigmask, &oldsigmask); 167 new_thread->sigmask = oldsigmask; 168 ret = lwp_create(&create_params); 169 __sys_sigprocmask(SIG_SETMASK, &oldsigmask, NULL); 170 if (ret != 0) { 171 if (!locked) 172 THR_THREAD_LOCK(curthread, new_thread); 173 new_thread->state = PS_DEAD; 174 new_thread->terminated = 1; 175 if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) { 176 new_thread->cycle++; 177 _thr_umtx_wake(&new_thread->cycle, INT_MAX); 178 } 179 THR_THREAD_UNLOCK(curthread, new_thread); 180 THREAD_LIST_LOCK(curthread); 181 _thread_active_threads--; 182 new_thread->tlflags |= TLFLAGS_DETACHED; 183 _thr_ref_delete_unlocked(curthread, new_thread); 184 THREAD_LIST_UNLOCK(curthread); 185 (*thread) = NULL; 186 ret = EAGAIN; 187 } else if (locked) { 188 _thr_report_creation(curthread, new_thread); 189 THR_THREAD_UNLOCK(curthread, new_thread); 190 } 191 return (ret); 192 } 193 194 static int 195 create_stack(struct pthread_attr *pattr) 196 { 197 int ret; 198 199 /* Check if a stack was specified in the thread attributes: */ 200 if ((pattr->stackaddr_attr) != NULL) { 201 pattr->guardsize_attr = 0; 202 pattr->flags |= THR_STACK_USER; 203 ret = 0; 204 } 205 else 206 ret = _thr_stack_alloc(pattr); 207 return (ret); 208 } 209 210 static void 211 thread_start(void *arg) 212 { 213 struct pthread *curthread = (struct pthread *)arg; 214 215 tls_set_tcb(curthread->tcb); 216 217 /* Thread was created with all signals blocked, unblock them. */ 218 __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL); 219 220 THR_LOCK(curthread); 221 THR_UNLOCK(curthread); 222 223 if (curthread->flags & THR_FLAGS_NEED_SUSPEND) 224 _thr_suspend_check(curthread); 225 _nmalloc_thr_init(); 226 227 /* Run the current thread's start routine with argument: */ 228 _pthread_exit(curthread->start_routine(curthread->arg)); 229 230 /* This point should never be reached. */ 231 PANIC("Thread has resumed after exit"); 232 } 233 234 __strong_reference(_pthread_create, pthread_create); 235