thr_create.c revision 116974
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 116974 2003-06-28 09:41:59Z davidxu $ 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 47#define OFF(f) offsetof(struct pthread, f) 48int _thread_next_offset = OFF(tle.tqe_next); 49int _thread_uniqueid_offset = OFF(uniqueid); 50int _thread_state_offset = OFF(state); 51int _thread_name_offset = OFF(name); 52int _thread_ctx_offset = OFF(tmbx.tm_context); 53#undef OFF 54 55int _thread_PS_RUNNING_value = PS_RUNNING; 56int _thread_PS_DEAD_value = PS_DEAD; 57 58static void free_thread(struct pthread *curthread, struct pthread *thread); 59static int create_stack(struct pthread_attr *pattr); 60static void thread_start(struct pthread *curthread, 61 void *(*start_routine) (void *), void *arg); 62 63__weak_reference(_pthread_create, pthread_create); 64 65/* 66 * Some notes on new thread creation and first time initializion 67 * to enable multi-threading. 68 * 69 * There are basically two things that need to be done. 70 * 71 * 1) The internal library variables must be initialized. 72 * 2) Upcalls need to be enabled to allow multiple threads 73 * to be run. 74 * 75 * The first may be done as a result of other pthread functions 76 * being called. When _thr_initial is null, _libpthread_init is 77 * called to initialize the internal variables; this also creates 78 * or sets the initial thread. It'd be nice to automatically 79 * have _libpthread_init called on program execution so we don't 80 * have to have checks throughout the library. 81 * 82 * The second part is only triggered by the creation of the first 83 * thread (other than the initial/main thread). If the thread 84 * being created is a scope system thread, then a new KSE/KSEG 85 * pair needs to be allocated. Also, if upcalls haven't been 86 * enabled on the initial thread's KSE, they must be now that 87 * there is more than one thread; this could be delayed until 88 * the initial KSEG has more than one thread. 89 */ 90int 91_pthread_create(pthread_t * thread, const pthread_attr_t * attr, 92 void *(*start_routine) (void *), void *arg) 93{ 94 struct kse *curkse; 95 struct pthread *curthread, *new_thread; 96 struct kse *kse = NULL; 97 struct kse_group *kseg = NULL; 98 void *p; 99 kse_critical_t crit; 100 int i; 101 int ret = 0; 102 103 if (_thr_initial == NULL) 104 _libpthread_init(NULL); 105 106 /* 107 * Turn on threaded mode, if failed, it is unnecessary to 108 * do further work. 109 */ 110 if (_kse_isthreaded() == 0 && _kse_setthreaded(1)) { 111 return (EAGAIN); 112 } 113 curthread = _get_curthread(); 114 115 /* 116 * Allocate memory for the thread structure. 117 * Some functions use malloc, so don't put it 118 * in a critical region. 119 */ 120 if ((new_thread = _thr_alloc(curthread)) == NULL) { 121 /* Insufficient memory to create a thread: */ 122 ret = EAGAIN; 123 } else { 124 /* Initialize the thread structure: */ 125 p = new_thread->alloc_addr; 126 memset(new_thread, 0, sizeof(struct pthread)); 127 new_thread->alloc_addr = p; 128 129 /* Check if default thread attributes are required: */ 130 if (attr == NULL || *attr == NULL) 131 /* Use the default thread attributes: */ 132 new_thread->attr = _pthread_attr_default; 133 else 134 new_thread->attr = *(*attr); 135 136 if (create_stack(&new_thread->attr) != 0) { 137 /* Insufficient memory to create a stack: */ 138 ret = EAGAIN; 139 _thr_free(curthread, new_thread); 140 } 141 else if (((new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) && 142 (((kse = _kse_alloc(curthread)) == NULL) 143 || ((kseg = _kseg_alloc(curthread)) == NULL))) { 144 /* Insufficient memory to create a new KSE/KSEG: */ 145 ret = EAGAIN; 146 if (kse != NULL) { 147 kse->k_mbx.km_flags |= KMF_DONE; 148 _kse_free(curthread, kse); 149 } 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_kgqe); 165 kseg->kg_ksecount = 1; 166 kse->k_kseg = kseg; 167 kse->k_schedq = &kseg->kg_schedq; 168 } 169 /* 170 * Write a magic value to the thread structure 171 * to help identify valid ones: 172 */ 173 new_thread->magic = THR_MAGIC; 174 175 new_thread->slice_usec = -1; 176 new_thread->start_routine = start_routine; 177 new_thread->arg = arg; 178 new_thread->cancelflags = PTHREAD_CANCEL_ENABLE | 179 PTHREAD_CANCEL_DEFERRED; 180 181 /* Initialize the thread for signals: */ 182 new_thread->sigmask = curthread->sigmask; 183 184 /* No thread is wanting to join to this one: */ 185 new_thread->joiner = NULL; 186 187 /* Initialize the signal frame: */ 188 new_thread->curframe = NULL; 189 190 /* 191 * Initialize the machine context. 192 * Enter a critical region to get consistent context. 193 */ 194 crit = _kse_critical_enter(); 195 THR_GETCONTEXT(&new_thread->tmbx.tm_context); 196 _kse_critical_leave(crit); 197 new_thread->tmbx.tm_udata = new_thread; 198 new_thread->tmbx.tm_context.uc_sigmask = 199 new_thread->sigmask; 200 new_thread->tmbx.tm_context.uc_stack.ss_size = 201 new_thread->attr.stacksize_attr; 202 new_thread->tmbx.tm_context.uc_stack.ss_sp = 203 new_thread->attr.stackaddr_attr; 204 makecontext(&new_thread->tmbx.tm_context, 205 (void (*)(void))thread_start, 4, new_thread, 206 start_routine, arg); 207 /* 208 * Check if this thread is to inherit the scheduling 209 * attributes from its parent: 210 */ 211 if ((new_thread->attr.flags & PTHREAD_INHERIT_SCHED) != 0) { 212 /* 213 * Copy the scheduling attributes. 214 * Lock the scheduling lock to get consistent 215 * scheduling parameters. 216 */ 217 THR_SCHED_LOCK(curthread, curthread); 218 new_thread->base_priority = 219 curthread->base_priority & 220 ~THR_SIGNAL_PRIORITY; 221 new_thread->attr.prio = 222 curthread->base_priority & 223 ~THR_SIGNAL_PRIORITY; 224 new_thread->attr.sched_policy = 225 curthread->attr.sched_policy; 226 THR_SCHED_UNLOCK(curthread, curthread); 227 } else { 228 /* 229 * Use just the thread priority, leaving the 230 * other scheduling attributes as their 231 * default values: 232 */ 233 new_thread->base_priority = 234 new_thread->attr.prio; 235 } 236 new_thread->active_priority = new_thread->base_priority; 237 new_thread->inherited_priority = 0; 238 239 /* Initialize the mutex queue: */ 240 TAILQ_INIT(&new_thread->mutexq); 241 242 /* 243 * Initialize thread locking. 244 * Lock initializing needs malloc, so don't 245 * enter critical region before doing this! 246 */ 247 if (_lock_init(&new_thread->lock, LCK_ADAPTIVE, 248 _thr_lock_wait, _thr_lock_wakeup) != 0) 249 PANIC("Cannot initialize thread lock"); 250 for (i = 0; i < MAX_THR_LOCKLEVEL; i++) { 251 _lockuser_init(&new_thread->lockusers[i], 252 (void *)new_thread); 253 _LCK_SET_PRIVATE2(&new_thread->lockusers[i], 254 (void *)new_thread); 255 } 256 257 /* Initialise hooks in the thread structure: */ 258 new_thread->specific = NULL; 259 new_thread->cleanup = NULL; 260 new_thread->flags = 0; 261 new_thread->continuation = NULL; 262 263 if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) { 264 new_thread->state = PS_SUSPENDED; 265 new_thread->flags = THR_FLAGS_SUSPENDED; 266 } 267 else 268 new_thread->state = PS_RUNNING; 269 270 /* 271 * System scope threads have their own kse and 272 * kseg. Process scope threads are all hung 273 * off the main process kseg. 274 */ 275 if ((new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM) == 0) { 276 new_thread->kseg = _kse_initial->k_kseg; 277 new_thread->kse = _kse_initial; 278 } 279 else { 280 kse->k_curthread = NULL; 281#ifdef NOT_YET 282 kse->k_kseg->kg_flags |= KGF_SINGLE_THREAD; 283#endif 284 new_thread->kse = kse; 285 new_thread->kseg = kse->k_kseg; 286 kse->k_mbx.km_udata = kse; 287 kse->k_mbx.km_curthread = NULL; 288 } 289 290 /* 291 * Schedule the new thread starting a new KSEG/KSE 292 * pair if necessary. 293 */ 294 ret = _thr_schedule_add(curthread, new_thread); 295 if (ret != 0) 296 free_thread(curthread, new_thread); 297 else { 298 /* Return a pointer to the thread structure: */ 299 (*thread) = new_thread; 300 } 301 } 302 } 303 304 /* Return the status: */ 305 return (ret); 306} 307 308static void 309free_thread(struct pthread *curthread, struct pthread *thread) 310{ 311 if ((thread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) { 312 /* Free the KSE and KSEG. */ 313 _kseg_free(thread->kseg); 314 _kse_free(curthread, thread->kse); 315 } 316 _thr_free(curthread, thread); 317} 318 319static int 320create_stack(struct pthread_attr *pattr) 321{ 322 int ret; 323 324 /* Check if a stack was specified in the thread attributes: */ 325 if ((pattr->stackaddr_attr) != NULL) { 326 pattr->guardsize_attr = 0; 327 pattr->flags |= THR_STACK_USER; 328 ret = 0; 329 } 330 else 331 ret = _thr_stack_alloc(pattr); 332 return (ret); 333} 334 335 336static void 337thread_start(struct pthread *curthread, void *(*start_routine) (void *), 338 void *arg) 339{ 340 /* Run the current thread's start routine with argument: */ 341 pthread_exit(start_routine(arg)); 342 343 /* This point should never be reached. */ 344 PANIC("Thread has resumed after exit"); 345} 346