thr_init.c revision 245630
1/* 2 * Copyright (c) 2003 Daniel M. Eischen <deischen@freebsd.org> 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/libthr/thread/thr_init.c 245630 2013-01-18 23:08:40Z jilles $ 34 */ 35 36#include "namespace.h" 37#include <sys/types.h> 38#include <sys/signalvar.h> 39#include <sys/ioctl.h> 40#include <sys/sysctl.h> 41#include <sys/ttycom.h> 42#include <sys/mman.h> 43#include <sys/rtprio.h> 44#include <errno.h> 45#include <fcntl.h> 46#include <paths.h> 47#include <pthread.h> 48#include <pthread_np.h> 49#include <signal.h> 50#include <stdlib.h> 51#include <string.h> 52#include <time.h> 53#include <unistd.h> 54#include "un-namespace.h" 55 56#include "libc_private.h" 57#include "thr_private.h" 58 59char *_usrstack; 60struct pthread *_thr_initial; 61int _libthr_debug; 62int _thread_event_mask; 63struct pthread *_thread_last_event; 64pthreadlist _thread_list = TAILQ_HEAD_INITIALIZER(_thread_list); 65pthreadlist _thread_gc_list = TAILQ_HEAD_INITIALIZER(_thread_gc_list); 66int _thread_active_threads = 1; 67atfork_head _thr_atfork_list = TAILQ_HEAD_INITIALIZER(_thr_atfork_list); 68struct urwlock _thr_atfork_lock = DEFAULT_URWLOCK; 69 70struct pthread_prio _thr_priorities[3] = { 71 {RTP_PRIO_MIN, RTP_PRIO_MAX, 0}, /* FIFO */ 72 {0, 0, 63}, /* OTHER */ 73 {RTP_PRIO_MIN, RTP_PRIO_MAX, 0} /* RR */ 74}; 75 76struct pthread_attr _pthread_attr_default = { 77 .sched_policy = SCHED_OTHER, 78 .sched_inherit = PTHREAD_INHERIT_SCHED, 79 .prio = 0, 80 .suspend = THR_CREATE_RUNNING, 81 .flags = PTHREAD_SCOPE_SYSTEM, 82 .stackaddr_attr = NULL, 83 .stacksize_attr = THR_STACK_DEFAULT, 84 .guardsize_attr = 0, 85 .cpusetsize = 0, 86 .cpuset = NULL 87}; 88 89struct pthread_mutex_attr _pthread_mutexattr_default = { 90 .m_type = PTHREAD_MUTEX_DEFAULT, 91 .m_protocol = PTHREAD_PRIO_NONE, 92 .m_ceiling = 0 93}; 94 95struct pthread_mutex_attr _pthread_mutexattr_adaptive_default = { 96 .m_type = PTHREAD_MUTEX_ADAPTIVE_NP, 97 .m_protocol = PTHREAD_PRIO_NONE, 98 .m_ceiling = 0 99}; 100 101/* Default condition variable attributes: */ 102struct pthread_cond_attr _pthread_condattr_default = { 103 .c_pshared = PTHREAD_PROCESS_PRIVATE, 104 .c_clockid = CLOCK_REALTIME 105}; 106 107pid_t _thr_pid; 108int _thr_is_smp = 0; 109size_t _thr_guard_default; 110size_t _thr_stack_default = THR_STACK_DEFAULT; 111size_t _thr_stack_initial = THR_STACK_INITIAL; 112int _thr_page_size; 113int _thr_spinloops; 114int _thr_yieldloops; 115int _thr_queuefifo = 4; 116int _gc_count; 117struct umutex _mutex_static_lock = DEFAULT_UMUTEX; 118struct umutex _cond_static_lock = DEFAULT_UMUTEX; 119struct umutex _rwlock_static_lock = DEFAULT_UMUTEX; 120struct umutex _keytable_lock = DEFAULT_UMUTEX; 121struct urwlock _thr_list_lock = DEFAULT_URWLOCK; 122struct umutex _thr_event_lock = DEFAULT_UMUTEX; 123struct umutex _suspend_all_lock = DEFAULT_UMUTEX; 124struct pthread *_single_thread; 125int _suspend_all_cycle; 126int _suspend_all_waiters; 127 128int __pthread_cond_wait(pthread_cond_t *, pthread_mutex_t *); 129int __pthread_mutex_lock(pthread_mutex_t *); 130int __pthread_mutex_trylock(pthread_mutex_t *); 131void _thread_init_hack(void) __attribute__ ((constructor)); 132 133static void init_private(void); 134static void init_main_thread(struct pthread *thread); 135 136/* 137 * All weak references used within libc should be in this table. 138 * This is so that static libraries will work. 139 */ 140 141STATIC_LIB_REQUIRE(_fork); 142STATIC_LIB_REQUIRE(_pthread_getspecific); 143STATIC_LIB_REQUIRE(_pthread_key_create); 144STATIC_LIB_REQUIRE(_pthread_key_delete); 145STATIC_LIB_REQUIRE(_pthread_mutex_destroy); 146STATIC_LIB_REQUIRE(_pthread_mutex_init); 147STATIC_LIB_REQUIRE(_pthread_mutex_lock); 148STATIC_LIB_REQUIRE(_pthread_mutex_trylock); 149STATIC_LIB_REQUIRE(_pthread_mutex_unlock); 150STATIC_LIB_REQUIRE(_pthread_mutexattr_init); 151STATIC_LIB_REQUIRE(_pthread_mutexattr_destroy); 152STATIC_LIB_REQUIRE(_pthread_mutexattr_settype); 153STATIC_LIB_REQUIRE(_pthread_once); 154STATIC_LIB_REQUIRE(_pthread_setspecific); 155STATIC_LIB_REQUIRE(_raise); 156STATIC_LIB_REQUIRE(_sem_destroy); 157STATIC_LIB_REQUIRE(_sem_getvalue); 158STATIC_LIB_REQUIRE(_sem_init); 159STATIC_LIB_REQUIRE(_sem_post); 160STATIC_LIB_REQUIRE(_sem_timedwait); 161STATIC_LIB_REQUIRE(_sem_trywait); 162STATIC_LIB_REQUIRE(_sem_wait); 163STATIC_LIB_REQUIRE(_sigaction); 164STATIC_LIB_REQUIRE(_sigprocmask); 165STATIC_LIB_REQUIRE(_sigsuspend); 166STATIC_LIB_REQUIRE(_sigtimedwait); 167STATIC_LIB_REQUIRE(_sigwait); 168STATIC_LIB_REQUIRE(_sigwaitinfo); 169STATIC_LIB_REQUIRE(_spinlock); 170STATIC_LIB_REQUIRE(_spinlock_debug); 171STATIC_LIB_REQUIRE(_spinunlock); 172STATIC_LIB_REQUIRE(_thread_init_hack); 173 174/* 175 * These are needed when linking statically. All references within 176 * libgcc (and in the future libc) to these routines are weak, but 177 * if they are not (strongly) referenced by the application or other 178 * libraries, then the actual functions will not be loaded. 179 */ 180STATIC_LIB_REQUIRE(_pthread_once); 181STATIC_LIB_REQUIRE(_pthread_key_create); 182STATIC_LIB_REQUIRE(_pthread_key_delete); 183STATIC_LIB_REQUIRE(_pthread_getspecific); 184STATIC_LIB_REQUIRE(_pthread_setspecific); 185STATIC_LIB_REQUIRE(_pthread_mutex_init); 186STATIC_LIB_REQUIRE(_pthread_mutex_destroy); 187STATIC_LIB_REQUIRE(_pthread_mutex_lock); 188STATIC_LIB_REQUIRE(_pthread_mutex_trylock); 189STATIC_LIB_REQUIRE(_pthread_mutex_unlock); 190STATIC_LIB_REQUIRE(_pthread_create); 191 192/* Pull in all symbols required by libthread_db */ 193STATIC_LIB_REQUIRE(_thread_state_running); 194 195#define DUAL_ENTRY(entry) \ 196 (pthread_func_t)entry, (pthread_func_t)entry 197 198static pthread_func_t jmp_table[][2] = { 199 {DUAL_ENTRY(_pthread_atfork)}, /* PJT_ATFORK */ 200 {DUAL_ENTRY(_pthread_attr_destroy)}, /* PJT_ATTR_DESTROY */ 201 {DUAL_ENTRY(_pthread_attr_getdetachstate)}, /* PJT_ATTR_GETDETACHSTATE */ 202 {DUAL_ENTRY(_pthread_attr_getguardsize)}, /* PJT_ATTR_GETGUARDSIZE */ 203 {DUAL_ENTRY(_pthread_attr_getinheritsched)}, /* PJT_ATTR_GETINHERITSCHED */ 204 {DUAL_ENTRY(_pthread_attr_getschedparam)}, /* PJT_ATTR_GETSCHEDPARAM */ 205 {DUAL_ENTRY(_pthread_attr_getschedpolicy)}, /* PJT_ATTR_GETSCHEDPOLICY */ 206 {DUAL_ENTRY(_pthread_attr_getscope)}, /* PJT_ATTR_GETSCOPE */ 207 {DUAL_ENTRY(_pthread_attr_getstackaddr)}, /* PJT_ATTR_GETSTACKADDR */ 208 {DUAL_ENTRY(_pthread_attr_getstacksize)}, /* PJT_ATTR_GETSTACKSIZE */ 209 {DUAL_ENTRY(_pthread_attr_init)}, /* PJT_ATTR_INIT */ 210 {DUAL_ENTRY(_pthread_attr_setdetachstate)}, /* PJT_ATTR_SETDETACHSTATE */ 211 {DUAL_ENTRY(_pthread_attr_setguardsize)}, /* PJT_ATTR_SETGUARDSIZE */ 212 {DUAL_ENTRY(_pthread_attr_setinheritsched)}, /* PJT_ATTR_SETINHERITSCHED */ 213 {DUAL_ENTRY(_pthread_attr_setschedparam)}, /* PJT_ATTR_SETSCHEDPARAM */ 214 {DUAL_ENTRY(_pthread_attr_setschedpolicy)}, /* PJT_ATTR_SETSCHEDPOLICY */ 215 {DUAL_ENTRY(_pthread_attr_setscope)}, /* PJT_ATTR_SETSCOPE */ 216 {DUAL_ENTRY(_pthread_attr_setstackaddr)}, /* PJT_ATTR_SETSTACKADDR */ 217 {DUAL_ENTRY(_pthread_attr_setstacksize)}, /* PJT_ATTR_SETSTACKSIZE */ 218 {DUAL_ENTRY(_pthread_cancel)}, /* PJT_CANCEL */ 219 {DUAL_ENTRY(_pthread_cleanup_pop)}, /* PJT_CLEANUP_POP */ 220 {DUAL_ENTRY(_pthread_cleanup_push)}, /* PJT_CLEANUP_PUSH */ 221 {DUAL_ENTRY(_pthread_cond_broadcast)}, /* PJT_COND_BROADCAST */ 222 {DUAL_ENTRY(_pthread_cond_destroy)}, /* PJT_COND_DESTROY */ 223 {DUAL_ENTRY(_pthread_cond_init)}, /* PJT_COND_INIT */ 224 {DUAL_ENTRY(_pthread_cond_signal)}, /* PJT_COND_SIGNAL */ 225 {DUAL_ENTRY(_pthread_cond_timedwait)}, /* PJT_COND_TIMEDWAIT */ 226 {(pthread_func_t)__pthread_cond_wait, 227 (pthread_func_t)_pthread_cond_wait}, /* PJT_COND_WAIT */ 228 {DUAL_ENTRY(_pthread_detach)}, /* PJT_DETACH */ 229 {DUAL_ENTRY(_pthread_equal)}, /* PJT_EQUAL */ 230 {DUAL_ENTRY(_pthread_exit)}, /* PJT_EXIT */ 231 {DUAL_ENTRY(_pthread_getspecific)}, /* PJT_GETSPECIFIC */ 232 {DUAL_ENTRY(_pthread_join)}, /* PJT_JOIN */ 233 {DUAL_ENTRY(_pthread_key_create)}, /* PJT_KEY_CREATE */ 234 {DUAL_ENTRY(_pthread_key_delete)}, /* PJT_KEY_DELETE*/ 235 {DUAL_ENTRY(_pthread_kill)}, /* PJT_KILL */ 236 {DUAL_ENTRY(_pthread_main_np)}, /* PJT_MAIN_NP */ 237 {DUAL_ENTRY(_pthread_mutexattr_destroy)}, /* PJT_MUTEXATTR_DESTROY */ 238 {DUAL_ENTRY(_pthread_mutexattr_init)}, /* PJT_MUTEXATTR_INIT */ 239 {DUAL_ENTRY(_pthread_mutexattr_settype)}, /* PJT_MUTEXATTR_SETTYPE */ 240 {DUAL_ENTRY(_pthread_mutex_destroy)}, /* PJT_MUTEX_DESTROY */ 241 {DUAL_ENTRY(_pthread_mutex_init)}, /* PJT_MUTEX_INIT */ 242 {(pthread_func_t)__pthread_mutex_lock, 243 (pthread_func_t)_pthread_mutex_lock}, /* PJT_MUTEX_LOCK */ 244 {(pthread_func_t)__pthread_mutex_trylock, 245 (pthread_func_t)_pthread_mutex_trylock},/* PJT_MUTEX_TRYLOCK */ 246 {DUAL_ENTRY(_pthread_mutex_unlock)}, /* PJT_MUTEX_UNLOCK */ 247 {DUAL_ENTRY(_pthread_once)}, /* PJT_ONCE */ 248 {DUAL_ENTRY(_pthread_rwlock_destroy)}, /* PJT_RWLOCK_DESTROY */ 249 {DUAL_ENTRY(_pthread_rwlock_init)}, /* PJT_RWLOCK_INIT */ 250 {DUAL_ENTRY(_pthread_rwlock_rdlock)}, /* PJT_RWLOCK_RDLOCK */ 251 {DUAL_ENTRY(_pthread_rwlock_tryrdlock)},/* PJT_RWLOCK_TRYRDLOCK */ 252 {DUAL_ENTRY(_pthread_rwlock_trywrlock)},/* PJT_RWLOCK_TRYWRLOCK */ 253 {DUAL_ENTRY(_pthread_rwlock_unlock)}, /* PJT_RWLOCK_UNLOCK */ 254 {DUAL_ENTRY(_pthread_rwlock_wrlock)}, /* PJT_RWLOCK_WRLOCK */ 255 {DUAL_ENTRY(_pthread_self)}, /* PJT_SELF */ 256 {DUAL_ENTRY(_pthread_setcancelstate)}, /* PJT_SETCANCELSTATE */ 257 {DUAL_ENTRY(_pthread_setcanceltype)}, /* PJT_SETCANCELTYPE */ 258 {DUAL_ENTRY(_pthread_setspecific)}, /* PJT_SETSPECIFIC */ 259 {DUAL_ENTRY(_pthread_sigmask)}, /* PJT_SIGMASK */ 260 {DUAL_ENTRY(_pthread_testcancel)}, /* PJT_TESTCANCEL */ 261 {DUAL_ENTRY(__pthread_cleanup_pop_imp)},/* PJT_CLEANUP_POP_IMP */ 262 {DUAL_ENTRY(__pthread_cleanup_push_imp)},/* PJT_CLEANUP_PUSH_IMP */ 263 {DUAL_ENTRY(_pthread_cancel_enter)}, /* PJT_CANCEL_ENTER */ 264 {DUAL_ENTRY(_pthread_cancel_leave)} /* PJT_CANCEL_LEAVE */ 265}; 266 267static int init_once = 0; 268 269/* 270 * For the shared version of the threads library, the above is sufficient. 271 * But for the archive version of the library, we need a little bit more. 272 * Namely, we must arrange for this particular module to be pulled in from 273 * the archive library at link time. To accomplish that, we define and 274 * initialize a variable, "_thread_autoinit_dummy_decl". This variable is 275 * referenced (as an extern) from libc/stdlib/exit.c. This will always 276 * create a need for this module, ensuring that it is present in the 277 * executable. 278 */ 279extern int _thread_autoinit_dummy_decl; 280int _thread_autoinit_dummy_decl = 0; 281 282void 283_thread_init_hack(void) 284{ 285 286 _libpthread_init(NULL); 287} 288 289 290/* 291 * Threaded process initialization. 292 * 293 * This is only called under two conditions: 294 * 295 * 1) Some thread routines have detected that the library hasn't yet 296 * been initialized (_thr_initial == NULL && curthread == NULL), or 297 * 298 * 2) An explicit call to reinitialize after a fork (indicated 299 * by curthread != NULL) 300 */ 301void 302_libpthread_init(struct pthread *curthread) 303{ 304 int fd, first = 0; 305 306 /* Check if this function has already been called: */ 307 if ((_thr_initial != NULL) && (curthread == NULL)) 308 /* Only initialize the threaded application once. */ 309 return; 310 311 /* 312 * Check the size of the jump table to make sure it is preset 313 * with the correct number of entries. 314 */ 315 if (sizeof(jmp_table) != (sizeof(pthread_func_t) * PJT_MAX * 2)) 316 PANIC("Thread jump table not properly initialized"); 317 memcpy(__thr_jtable, jmp_table, sizeof(jmp_table)); 318 319 /* 320 * Check for the special case of this process running as 321 * or in place of init as pid = 1: 322 */ 323 if ((_thr_pid = getpid()) == 1) { 324 /* 325 * Setup a new session for this process which is 326 * assumed to be running as root. 327 */ 328 if (setsid() == -1) 329 PANIC("Can't set session ID"); 330 if (revoke(_PATH_CONSOLE) != 0) 331 PANIC("Can't revoke console"); 332 if ((fd = __sys_open(_PATH_CONSOLE, O_RDWR)) < 0) 333 PANIC("Can't open console"); 334 if (setlogin("root") == -1) 335 PANIC("Can't set login to root"); 336 if (_ioctl(fd, TIOCSCTTY, (char *) NULL) == -1) 337 PANIC("Can't set controlling terminal"); 338 } 339 340 /* Initialize pthread private data. */ 341 init_private(); 342 343 /* Set the initial thread. */ 344 if (curthread == NULL) { 345 first = 1; 346 /* Create and initialize the initial thread. */ 347 curthread = _thr_alloc(NULL); 348 if (curthread == NULL) 349 PANIC("Can't allocate initial thread"); 350 init_main_thread(curthread); 351 } 352 /* 353 * Add the thread to the thread list queue. 354 */ 355 THR_LIST_ADD(curthread); 356 _thread_active_threads = 1; 357 358 /* Setup the thread specific data */ 359 _tcb_set(curthread->tcb); 360 361 if (first) { 362 _thr_initial = curthread; 363 _thr_signal_init(); 364 if (_thread_event_mask & TD_CREATE) 365 _thr_report_creation(curthread, curthread); 366 /* 367 * Always use our rtld lock implementation. 368 * It is faster because it postpones signal handlers 369 * instead of calling sigprocmask(2). 370 */ 371 _thr_rtld_init(); 372 } 373} 374 375/* 376 * This function and pthread_create() do a lot of the same things. 377 * It'd be nice to consolidate the common stuff in one place. 378 */ 379static void 380init_main_thread(struct pthread *thread) 381{ 382 struct sched_param sched_param; 383 384 /* Setup the thread attributes. */ 385 thr_self(&thread->tid); 386 thread->attr = _pthread_attr_default; 387 /* 388 * Set up the thread stack. 389 * 390 * Create a red zone below the main stack. All other stacks 391 * are constrained to a maximum size by the parameters 392 * passed to mmap(), but this stack is only limited by 393 * resource limits, so this stack needs an explicitly mapped 394 * red zone to protect the thread stack that is just beyond. 395 */ 396 if (mmap(_usrstack - _thr_stack_initial - 397 _thr_guard_default, _thr_guard_default, 0, MAP_ANON, 398 -1, 0) == MAP_FAILED) 399 PANIC("Cannot allocate red zone for initial thread"); 400 401 /* 402 * Mark the stack as an application supplied stack so that it 403 * isn't deallocated. 404 * 405 * XXX - I'm not sure it would hurt anything to deallocate 406 * the main thread stack because deallocation doesn't 407 * actually free() it; it just puts it in the free 408 * stack queue for later reuse. 409 */ 410 thread->attr.stackaddr_attr = _usrstack - _thr_stack_initial; 411 thread->attr.stacksize_attr = _thr_stack_initial; 412 thread->attr.guardsize_attr = _thr_guard_default; 413 thread->attr.flags |= THR_STACK_USER; 414 415 /* 416 * Write a magic value to the thread structure 417 * to help identify valid ones: 418 */ 419 thread->magic = THR_MAGIC; 420 421 thread->cancel_enable = 1; 422 thread->cancel_async = 0; 423 424 /* Initialize the mutex queue: */ 425 TAILQ_INIT(&thread->mutexq); 426 TAILQ_INIT(&thread->pp_mutexq); 427 428 thread->state = PS_RUNNING; 429 430 _thr_getscheduler(thread->tid, &thread->attr.sched_policy, 431 &sched_param); 432 thread->attr.prio = sched_param.sched_priority; 433 434#ifdef _PTHREAD_FORCED_UNWIND 435 thread->unwind_stackend = _usrstack; 436#endif 437 438 /* Others cleared to zero by thr_alloc() */ 439} 440 441static void 442init_private(void) 443{ 444 size_t len; 445 int mib[2]; 446 char *env; 447 448 _thr_umutex_init(&_mutex_static_lock); 449 _thr_umutex_init(&_cond_static_lock); 450 _thr_umutex_init(&_rwlock_static_lock); 451 _thr_umutex_init(&_keytable_lock); 452 _thr_urwlock_init(&_thr_atfork_lock); 453 _thr_umutex_init(&_thr_event_lock); 454 _thr_umutex_init(&_suspend_all_lock); 455 _thr_once_init(); 456 _thr_spinlock_init(); 457 _thr_list_init(); 458 _thr_wake_addr_init(); 459 _sleepq_init(); 460 _single_thread = NULL; 461 _suspend_all_waiters = 0; 462 463 /* 464 * Avoid reinitializing some things if they don't need to be, 465 * e.g. after a fork(). 466 */ 467 if (init_once == 0) { 468 /* Find the stack top */ 469 mib[0] = CTL_KERN; 470 mib[1] = KERN_USRSTACK; 471 len = sizeof (_usrstack); 472 if (sysctl(mib, 2, &_usrstack, &len, NULL, 0) == -1) 473 PANIC("Cannot get kern.usrstack from sysctl"); 474 len = sizeof(_thr_is_smp); 475 sysctlbyname("kern.smp.cpus", &_thr_is_smp, &len, NULL, 0); 476 _thr_is_smp = (_thr_is_smp > 1); 477 _thr_page_size = getpagesize(); 478 _thr_guard_default = _thr_page_size; 479 _pthread_attr_default.guardsize_attr = _thr_guard_default; 480 _pthread_attr_default.stacksize_attr = _thr_stack_default; 481 env = getenv("LIBPTHREAD_SPINLOOPS"); 482 if (env) 483 _thr_spinloops = atoi(env); 484 env = getenv("LIBPTHREAD_YIELDLOOPS"); 485 if (env) 486 _thr_yieldloops = atoi(env); 487 env = getenv("LIBPTHREAD_QUEUE_FIFO"); 488 if (env) 489 _thr_queuefifo = atoi(env); 490 TAILQ_INIT(&_thr_atfork_list); 491 } 492 init_once = 1; 493} 494