thr_create.c revision 118514
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 118514 2003-08-06 00:23:40Z marcel $ 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); 52void *_thread_tcb_offset = OFF(tcb); 53#undef OFF 54#define OFF(f) offsetof(struct tcb, f) 55int _thread_ctx_offset = OFF(tcb_tmbx.tm_context); 56#undef OFF 57 58int _thread_PS_RUNNING_value = PS_RUNNING; 59int _thread_PS_DEAD_value = PS_DEAD; 60 61static void free_thread(struct pthread *curthread, struct pthread *thread); 62static int create_stack(struct pthread_attr *pattr); 63static void free_stack(struct pthread_attr *pattr); 64static void thread_start(struct pthread *curthread, 65 void *(*start_routine) (void *), void *arg); 66 67__weak_reference(_pthread_create, pthread_create); 68 69/* 70 * Some notes on new thread creation and first time initializion 71 * to enable multi-threading. 72 * 73 * There are basically two things that need to be done. 74 * 75 * 1) The internal library variables must be initialized. 76 * 2) Upcalls need to be enabled to allow multiple threads 77 * to be run. 78 * 79 * The first may be done as a result of other pthread functions 80 * being called. When _thr_initial is null, _libpthread_init is 81 * called to initialize the internal variables; this also creates 82 * or sets the initial thread. It'd be nice to automatically 83 * have _libpthread_init called on program execution so we don't 84 * have to have checks throughout the library. 85 * 86 * The second part is only triggered by the creation of the first 87 * thread (other than the initial/main thread). If the thread 88 * being created is a scope system thread, then a new KSE/KSEG 89 * pair needs to be allocated. Also, if upcalls haven't been 90 * enabled on the initial thread's KSE, they must be now that 91 * there is more than one thread; this could be delayed until 92 * the initial KSEG has more than one thread. 93 */ 94int 95_pthread_create(pthread_t * thread, const pthread_attr_t * attr, 96 void *(*start_routine) (void *), void *arg) 97{ 98 struct pthread *curthread, *new_thread; 99 struct kse *kse = NULL; 100 struct kse_group *kseg = NULL; 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 /* Check if default thread attributes are required: */ 127 if (attr == NULL || *attr == NULL) 128 /* Use the default thread attributes: */ 129 new_thread->attr = _pthread_attr_default; 130 else 131 new_thread->attr = *(*attr); 132#ifdef SYSTEM_SCOPE_ONLY 133 new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM; 134#endif 135 if (create_stack(&new_thread->attr) != 0) { 136 /* Insufficient memory to create a stack: */ 137 ret = EAGAIN; 138 _thr_free(curthread, new_thread); 139 } 140 else if (((new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) && 141 (((kse = _kse_alloc(curthread, 1)) == NULL) 142 || ((kseg = _kseg_alloc(curthread)) == NULL))) { 143 /* Insufficient memory to create a new KSE/KSEG: */ 144 ret = EAGAIN; 145 if (kse != NULL) { 146 kse->k_kcb->kcb_kmbx.km_flags |= KMF_DONE; 147 _kse_free(curthread, kse); 148 } 149 free_stack(&new_thread->attr); 150 _thr_free(curthread, new_thread); 151 } 152 else { 153 if (kseg != NULL) { 154 /* Add the KSE to the KSEG's list of KSEs. */ 155 TAILQ_INSERT_HEAD(&kseg->kg_kseq, kse, k_kgqe); 156 kseg->kg_ksecount = 1; 157 kse->k_kseg = kseg; 158 kse->k_schedq = &kseg->kg_schedq; 159 } 160 /* 161 * Write a magic value to the thread structure 162 * to help identify valid ones: 163 */ 164 new_thread->magic = THR_MAGIC; 165 166 new_thread->slice_usec = -1; 167 new_thread->start_routine = start_routine; 168 new_thread->arg = arg; 169 new_thread->cancelflags = PTHREAD_CANCEL_ENABLE | 170 PTHREAD_CANCEL_DEFERRED; 171 172 /* No thread is wanting to join to this one: */ 173 new_thread->joiner = NULL; 174 175 /* Initialize the signal frame: */ 176 new_thread->curframe = NULL; 177 178 /* 179 * Initialize the machine context. 180 * Enter a critical region to get consistent context. 181 */ 182 crit = _kse_critical_enter(); 183 THR_GETCONTEXT(&new_thread->tcb->tcb_tmbx.tm_context); 184 /* Initialize the thread for signals: */ 185 new_thread->sigmask = curthread->sigmask; 186 _kse_critical_leave(crit); 187 188 new_thread->tcb->tcb_tmbx.tm_udata = new_thread; 189 new_thread->tcb->tcb_tmbx.tm_context.uc_sigmask = 190 new_thread->sigmask; 191 new_thread->tcb->tcb_tmbx.tm_context.uc_stack.ss_size = 192 new_thread->attr.stacksize_attr; 193 new_thread->tcb->tcb_tmbx.tm_context.uc_stack.ss_sp = 194 new_thread->attr.stackaddr_attr; 195 makecontext(&new_thread->tcb->tcb_tmbx.tm_context, 196 (void (*)(void))thread_start, 3, new_thread, 197 start_routine, arg); 198 /* 199 * Check if this thread is to inherit the scheduling 200 * attributes from its parent: 201 */ 202 if ((new_thread->attr.flags & PTHREAD_INHERIT_SCHED) != 0) { 203 /* 204 * Copy the scheduling attributes. 205 * Lock the scheduling lock to get consistent 206 * scheduling parameters. 207 */ 208 THR_SCHED_LOCK(curthread, curthread); 209 new_thread->base_priority = 210 curthread->base_priority & 211 ~THR_SIGNAL_PRIORITY; 212 new_thread->attr.prio = 213 curthread->base_priority & 214 ~THR_SIGNAL_PRIORITY; 215 new_thread->attr.sched_policy = 216 curthread->attr.sched_policy; 217 THR_SCHED_UNLOCK(curthread, curthread); 218 } else { 219 /* 220 * Use just the thread priority, leaving the 221 * other scheduling attributes as their 222 * default values: 223 */ 224 new_thread->base_priority = 225 new_thread->attr.prio; 226 } 227 new_thread->active_priority = new_thread->base_priority; 228 new_thread->inherited_priority = 0; 229 230 /* Initialize the mutex queue: */ 231 TAILQ_INIT(&new_thread->mutexq); 232 233 /* 234 * Initialize thread locking. 235 * Lock initializing needs malloc, so don't 236 * enter critical region before doing this! 237 */ 238 if (_lock_init(&new_thread->lock, LCK_ADAPTIVE, 239 _thr_lock_wait, _thr_lock_wakeup) != 0) 240 PANIC("Cannot initialize thread lock"); 241 for (i = 0; i < MAX_THR_LOCKLEVEL; i++) { 242 _lockuser_init(&new_thread->lockusers[i], 243 (void *)new_thread); 244 _LCK_SET_PRIVATE2(&new_thread->lockusers[i], 245 (void *)new_thread); 246 } 247 248 /* Initialise hooks in the thread structure: */ 249 new_thread->specific = NULL; 250 new_thread->cleanup = NULL; 251 new_thread->flags = 0; 252 new_thread->continuation = NULL; 253 254 if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) { 255 new_thread->state = PS_SUSPENDED; 256 new_thread->flags = THR_FLAGS_SUSPENDED; 257 } 258 else 259 new_thread->state = PS_RUNNING; 260 261 /* 262 * System scope threads have their own kse and 263 * kseg. Process scope threads are all hung 264 * off the main process kseg. 265 */ 266 if ((new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM) == 0) { 267 new_thread->kseg = _kse_initial->k_kseg; 268 new_thread->kse = _kse_initial; 269 } 270 else { 271 kse->k_curthread = NULL; 272 kse->k_kseg->kg_flags |= KGF_SINGLE_THREAD; 273 new_thread->kse = kse; 274 new_thread->kseg = kse->k_kseg; 275 kse->k_kcb->kcb_kmbx.km_udata = kse; 276 kse->k_kcb->kcb_kmbx.km_curthread = NULL; 277 } 278 279 /* 280 * Schedule the new thread starting a new KSEG/KSE 281 * pair if necessary. 282 */ 283 ret = _thr_schedule_add(curthread, new_thread); 284 if (ret != 0) 285 free_thread(curthread, new_thread); 286 else { 287 /* Return a pointer to the thread structure: */ 288 (*thread) = new_thread; 289 } 290 } 291 } 292 293 /* Return the status: */ 294 return (ret); 295} 296 297static void 298free_thread(struct pthread *curthread, struct pthread *thread) 299{ 300 free_stack(&thread->attr); 301 if ((thread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) { 302 /* Free the KSE and KSEG. */ 303 _kseg_free(thread->kseg); 304 _kse_free(curthread, thread->kse); 305 } 306 _thr_free(curthread, thread); 307} 308 309static int 310create_stack(struct pthread_attr *pattr) 311{ 312 int ret; 313 314 /* Check if a stack was specified in the thread attributes: */ 315 if ((pattr->stackaddr_attr) != NULL) { 316 pattr->guardsize_attr = 0; 317 pattr->flags |= THR_STACK_USER; 318 ret = 0; 319 } 320 else 321 ret = _thr_stack_alloc(pattr); 322 return (ret); 323} 324 325static void 326free_stack(struct pthread_attr *pattr) 327{ 328 struct kse *curkse; 329 kse_critical_t crit; 330 331 if ((pattr->flags & THR_STACK_USER) == 0) { 332 crit = _kse_critical_enter(); 333 curkse = _get_curkse(); 334 KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock); 335 /* Stack routines don't use malloc/free. */ 336 _thr_stack_free(pattr); 337 KSE_LOCK_RELEASE(curkse, &_thread_list_lock); 338 _kse_critical_leave(crit); 339 } 340} 341 342static void 343thread_start(struct pthread *curthread, void *(*start_routine) (void *), 344 void *arg) 345{ 346 /* Run the current thread's start routine with argument: */ 347 pthread_exit(start_routine(arg)); 348 349 /* This point should never be reached. */ 350 PANIC("Thread has resumed after exit"); 351} 352