thr_create.c revision 114295
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: head/lib/libkse/thread/thr_create.c 114295 2003-04-30 15:05:17Z deischen $ 34 */ 35#include <errno.h> 36#include <stdlib.h> 37#include <string.h> 38#include <fcntl.h> 39#include <unistd.h> 40#include <stddef.h> 41#include <sys/time.h> 42#include <machine/reg.h> 43#include <pthread.h> 44#include "thr_private.h" 45#include "libc_private.h" 46 47static u_int64_t next_uniqueid = 1; 48 49#define OFF(f) offsetof(struct pthread, f) 50int _thread_next_offset = OFF(tle.tqe_next); 51int _thread_uniqueid_offset = OFF(uniqueid); 52int _thread_state_offset = OFF(state); 53int _thread_name_offset = OFF(name); 54int _thread_ctx_offset = OFF(tmbx.tm_context); 55#undef OFF 56 57int _thread_PS_RUNNING_value = PS_RUNNING; 58int _thread_PS_DEAD_value = PS_DEAD; 59 60static void free_thread(struct pthread *curthread, struct pthread *thread); 61static int create_stack(struct pthread_attr *pattr); 62static void thread_start(struct pthread *curthread, 63 void *(*start_routine) (void *), void *arg); 64 65__weak_reference(_pthread_create, pthread_create); 66 67/* 68 * Some notes on new thread creation and first time initializion 69 * to enable multi-threading. 70 * 71 * There are basically two things that need to be done. 72 * 73 * 1) The internal library variables must be initialized. 74 * 2) Upcalls need to be enabled to allow multiple threads 75 * to be run. 76 * 77 * The first may be done as a result of other pthread functions 78 * being called. When _thr_initial is null, _libpthread_init is 79 * called to initialize the internal variables; this also creates 80 * or sets the initial thread. It'd be nice to automatically 81 * have _libpthread_init called on program execution so we don't 82 * have to have checks throughout the library. 83 * 84 * The second part is only triggered by the creation of the first 85 * thread (other than the initial/main thread). If the thread 86 * being created is a scope system thread, then a new KSE/KSEG 87 * pair needs to be allocated. Also, if upcalls haven't been 88 * enabled on the initial thread's KSE, they must be now that 89 * there is more than one thread; this could be delayed until 90 * the initial KSEG has more than one thread. 91 */ 92int 93_pthread_create(pthread_t * thread, const pthread_attr_t * attr, 94 void *(*start_routine) (void *), void *arg) 95{ 96 struct kse *curkse; 97 struct pthread *curthread, *new_thread; 98 struct kse *kse = NULL; 99 struct kse_group *kseg = NULL; 100 void *p; 101 kse_critical_t crit; 102 int i; 103 int ret = 0; 104 105 if (_thr_initial == NULL) 106 _libpthread_init(NULL); 107 108 /* 109 * Turn on threaded mode, if failed, it is unnecessary to 110 * do further work. 111 */ 112 if (_kse_isthreaded() == 0 && _kse_setthreaded(1)) { 113 return (EAGAIN); 114 } 115 curthread = _get_curthread(); 116 117 /* 118 * Allocate memory for the thread structure. 119 * Some functions use malloc, so don't put it 120 * in a critical region. 121 */ 122 if ((new_thread = _thr_alloc(curthread)) == NULL) { 123 /* Insufficient memory to create a thread: */ 124 ret = EAGAIN; 125 } else { 126 /* Initialize the thread structure: */ 127 p = new_thread->alloc_addr; 128 memset(new_thread, 0, sizeof(struct pthread)); 129 new_thread->alloc_addr = p; 130 131 /* Check if default thread attributes are required: */ 132 if (attr == NULL || *attr == NULL) 133 /* Use the default thread attributes: */ 134 new_thread->attr = _pthread_attr_default; 135 else 136 new_thread->attr = *(*attr); 137 138 if (create_stack(&new_thread->attr) != 0) { 139 /* Insufficient memory to create a stack: */ 140 ret = EAGAIN; 141 _thr_free(curthread, new_thread); 142 } 143 else if (((new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) && 144 (((kse = _kse_alloc(curthread)) == NULL) 145 || ((kseg = _kseg_alloc(curthread)) == NULL))) { 146 /* Insufficient memory to create a new KSE/KSEG: */ 147 ret = EAGAIN; 148 if (kse != NULL) 149 _kse_free(curthread, kse); 150 if ((new_thread->attr.flags & THR_STACK_USER) == 0) { 151 crit = _kse_critical_enter(); 152 curkse = _get_curkse(); 153 KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock); 154 /* Stack routines don't use malloc/free. */ 155 _thr_stack_free(&new_thread->attr); 156 KSE_LOCK_RELEASE(curkse, &_thread_list_lock); 157 _kse_critical_leave(crit); 158 } 159 _thr_free(curthread, new_thread); 160 } 161 else { 162 if (kseg != NULL) { 163 /* Add the KSE to the KSEG's list of KSEs. */ 164 TAILQ_INSERT_HEAD(&kseg->kg_kseq, kse, k_qe); 165 kse->k_kseg = kseg; 166 kse->k_schedq = &kseg->kg_schedq; 167 } 168 /* 169 * Write a magic value to the thread structure 170 * to help identify valid ones: 171 */ 172 new_thread->magic = THR_MAGIC; 173 174 new_thread->slice_usec = -1; 175 new_thread->start_routine = start_routine; 176 new_thread->arg = arg; 177 new_thread->cancelflags = PTHREAD_CANCEL_ENABLE | 178 PTHREAD_CANCEL_DEFERRED; 179 180 /* Initialize the thread for signals: */ 181 new_thread->sigmask = curthread->sigmask; 182 183 /* No thread is wanting to join to this one: */ 184 new_thread->joiner = NULL; 185 186 /* Initialize the signal frame: */ 187 new_thread->curframe = NULL; 188 189 /* 190 * Initialize the machine context. 191 * Enter a critical region to get consistent context. 192 */ 193 crit = _kse_critical_enter(); 194 THR_GETCONTEXT(&new_thread->tmbx.tm_context); 195 _kse_critical_leave(crit); 196 new_thread->tmbx.tm_udata = new_thread; 197 new_thread->tmbx.tm_context.uc_sigmask = 198 new_thread->sigmask; 199 new_thread->tmbx.tm_context.uc_stack.ss_size = 200 new_thread->attr.stacksize_attr; 201 new_thread->tmbx.tm_context.uc_stack.ss_sp = 202 new_thread->attr.stackaddr_attr; 203 makecontext(&new_thread->tmbx.tm_context, 204 (void (*)(void))thread_start, 4, new_thread, 205 start_routine, arg); 206 /* 207 * Check if this thread is to inherit the scheduling 208 * attributes from its parent: 209 */ 210 if ((new_thread->attr.flags & PTHREAD_INHERIT_SCHED) != 0) { 211 /* 212 * Copy the scheduling attributes. 213 * Lock the scheduling lock to get consistent 214 * scheduling parameters. 215 */ 216 THR_SCHED_LOCK(curthread, curthread); 217 new_thread->base_priority = 218 curthread->base_priority & 219 ~THR_SIGNAL_PRIORITY; 220 new_thread->attr.prio = 221 curthread->base_priority & 222 ~THR_SIGNAL_PRIORITY; 223 new_thread->attr.sched_policy = 224 curthread->attr.sched_policy; 225 THR_SCHED_UNLOCK(curthread, curthread); 226 } else { 227 /* 228 * Use just the thread priority, leaving the 229 * other scheduling attributes as their 230 * default values: 231 */ 232 new_thread->base_priority = 233 new_thread->attr.prio; 234 } 235 new_thread->active_priority = new_thread->base_priority; 236 new_thread->inherited_priority = 0; 237 238 /* Initialize the mutex queue: */ 239 TAILQ_INIT(&new_thread->mutexq); 240 241 /* 242 * Initialize thread locking. 243 * Lock initializing needs malloc, so don't 244 * enter critical region before doing this! 245 */ 246 if (_lock_init(&new_thread->lock, LCK_ADAPTIVE, 247 _thr_lock_wait, _thr_lock_wakeup) != 0) 248 PANIC("Cannot initialize thread lock"); 249 for (i = 0; i < MAX_THR_LOCKLEVEL; i++) { 250 _lockuser_init(&new_thread->lockusers[i], 251 (void *)new_thread); 252 _LCK_SET_PRIVATE2(&new_thread->lockusers[i], 253 (void *)new_thread); 254 } 255 256 /* Initialise hooks in the thread structure: */ 257 new_thread->specific = NULL; 258 new_thread->cleanup = NULL; 259 new_thread->flags = 0; 260 new_thread->continuation = NULL; 261 262 if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) 263 new_thread->state = PS_SUSPENDED; 264 else 265 new_thread->state = PS_RUNNING; 266 267 /* 268 * System scope threads have their own kse and 269 * kseg. Process scope threads are all hung 270 * off the main process kseg. 271 */ 272 if ((new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM) == 0) { 273 new_thread->kseg = _kse_initial->k_kseg; 274 new_thread->kse = _kse_initial; 275 } 276 else { 277 kse->k_curthread = NULL; 278#ifdef NOT_YET 279 kse->k_kseg->kg_flags |= KGF_SINGLE_THREAD; 280#endif 281 new_thread->kse = kse; 282 new_thread->kseg = kse->k_kseg; 283 kse->k_mbx.km_udata = kse; 284 kse->k_mbx.km_curthread = NULL; 285 } 286 287 crit = _kse_critical_enter(); 288 KSE_LOCK_ACQUIRE(curthread->kse, &_thread_list_lock); 289 /* 290 * Initialise the unique id which GDB uses to 291 * track threads. 292 */ 293 new_thread->uniqueid = next_uniqueid++; 294 /* Add the thread to the linked list of all threads: */ 295 THR_LIST_ADD(new_thread); 296 KSE_LOCK_RELEASE(curthread->kse, &_thread_list_lock); 297 298 /* 299 * Schedule the new thread starting a new KSEG/KSE 300 * pair if necessary. 301 */ 302 ret = _thr_schedule_add(curthread, new_thread); 303 if (ret != 0) { 304 KSE_LOCK_ACQUIRE(curthread->kse, 305 &_thread_list_lock); 306 THR_LIST_REMOVE(new_thread); 307 KSE_LOCK_RELEASE(curthread->kse, 308 &_thread_list_lock); 309 } 310 _kse_critical_leave(crit); 311 if (ret != 0) 312 free_thread(curthread, new_thread); 313 314 /* Return a pointer to the thread structure: */ 315 (*thread) = new_thread; 316 } 317 } 318 319 /* Return the status: */ 320 return (ret); 321} 322 323static void 324free_thread(struct pthread *curthread, struct pthread *thread) 325{ 326 if ((thread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) { 327 /* Free the KSE and KSEG. */ 328 _kseg_free(thread->kseg); 329 _kse_free(curthread, thread->kse); 330 } 331 _thr_free(curthread, thread); 332} 333 334static int 335create_stack(struct pthread_attr *pattr) 336{ 337 int ret; 338 339 /* Check if a stack was specified in the thread attributes: */ 340 if ((pattr->stackaddr_attr) != NULL) { 341 pattr->guardsize_attr = 0; 342 pattr->flags = THR_STACK_USER; 343 ret = 0; 344 } 345 else 346 ret = _thr_stack_alloc(pattr); 347 return (ret); 348} 349 350 351static void 352thread_start(struct pthread *curthread, void *(*start_routine) (void *), 353 void *arg) 354{ 355 /* Run the current thread's start routine with argument: */ 356 pthread_exit(start_routine(arg)); 357 358 /* This point should never be reached. */ 359 PANIC("Thread has resumed after exit"); 360} 361