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