lib/libthr/thread/thr_init.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-4-Clause
   3  *
   4  * Copyright (c) 2003 Daniel M. Eischen <deischen@freebsd.org>
   5  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by John Birrell.
  19  * 4. Neither the name of the author nor the names of any co-contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <sys/cdefs.h>
  37 __FBSDID("$FreeBSD$");
  38
  39 #include "namespace.h"
  40 #include <sys/types.h>
  41 #include <sys/signalvar.h>
  42 #include <sys/ioctl.h>
  43 #include <sys/link_elf.h>
  44 #include <sys/resource.h>
  45 #include <sys/sysctl.h>
  46 #include <sys/ttycom.h>
  47 #include <sys/mman.h>
  48 #include <sys/rtprio.h>
  49 #include <errno.h>
  50 #include <fcntl.h>
  51 #include <paths.h>
  52 #include <pthread.h>
  53 #include <pthread_np.h>
  54 #include <signal.h>
  55 #include <stdlib.h>
  56 #include <string.h>
  57 #include <time.h>
  58 #include <unistd.h>
  59 #include "un-namespace.h"
  60
  61 #include "libc_private.h"
  62 #include "thr_private.h"
  63
  64 char            *_usrstack;
  65 struct pthread  *_thr_initial;
  66 int             _libthr_debug;
  67 int             _thread_event_mask;
  68 struct pthread  *_thread_last_event;
  69 pthreadlist     _thread_list = TAILQ_HEAD_INITIALIZER(_thread_list);
  70 pthreadlist     _thread_gc_list = TAILQ_HEAD_INITIALIZER(_thread_gc_list);
  71 int             _thread_active_threads = 1;
  72 atfork_head     _thr_atfork_list = TAILQ_HEAD_INITIALIZER(_thr_atfork_list);
  73 struct urwlock  _thr_atfork_lock = DEFAULT_URWLOCK;
  74
  75 struct pthread_prio     _thr_priorities[3] = {
  76         {RTP_PRIO_MIN,  RTP_PRIO_MAX, 0}, /* FIFO */
  77         {0, 0, 63}, /* OTHER */
  78         {RTP_PRIO_MIN, RTP_PRIO_MAX, 0}  /* RR */
  79 };
  80
  81 struct pthread_attr _pthread_attr_default = {
  82         .sched_policy = SCHED_OTHER,
  83         .sched_inherit = PTHREAD_INHERIT_SCHED,
  84         .prio = 0,
  85         .suspend = THR_CREATE_RUNNING,
  86         .flags = PTHREAD_SCOPE_SYSTEM,
  87         .stackaddr_attr = NULL,
  88         .stacksize_attr = THR_STACK_DEFAULT,
  89         .guardsize_attr = 0,
  90         .cpusetsize = 0,
  91         .cpuset = NULL
  92 };
  93
  94 struct pthread_mutex_attr _pthread_mutexattr_default = {
  95         .m_type = PTHREAD_MUTEX_DEFAULT,
  96         .m_protocol = PTHREAD_PRIO_NONE,
  97         .m_ceiling = 0,
  98         .m_pshared = PTHREAD_PROCESS_PRIVATE,
  99         .m_robust = PTHREAD_MUTEX_STALLED,
 100 };
 101
 102 struct pthread_mutex_attr _pthread_mutexattr_adaptive_default = {
 103         .m_type = PTHREAD_MUTEX_ADAPTIVE_NP,
 104         .m_protocol = PTHREAD_PRIO_NONE,
 105         .m_ceiling = 0,
 106         .m_pshared = PTHREAD_PROCESS_PRIVATE,
 107         .m_robust = PTHREAD_MUTEX_STALLED,
 108 };
 109
 110 /* Default condition variable attributes: */
 111 struct pthread_cond_attr _pthread_condattr_default = {
 112         .c_pshared = PTHREAD_PROCESS_PRIVATE,
 113         .c_clockid = CLOCK_REALTIME
 114 };
 115
 116 int             _thr_is_smp = 0;
 117 size_t          _thr_guard_default;
 118 size_t          _thr_stack_default = THR_STACK_DEFAULT;
 119 size_t          _thr_stack_initial = THR_STACK_INITIAL;
 120 int             _thr_page_size;
 121 int             _thr_spinloops;
 122 int             _thr_yieldloops;
 123 int             _thr_queuefifo = 4;
 124 int             _gc_count;
 125 struct umutex   _mutex_static_lock = DEFAULT_UMUTEX;
 126 struct umutex   _cond_static_lock = DEFAULT_UMUTEX;
 127 struct umutex   _rwlock_static_lock = DEFAULT_UMUTEX;
 128 struct umutex   _keytable_lock = DEFAULT_UMUTEX;
 129 struct urwlock  _thr_list_lock = DEFAULT_URWLOCK;
 130 struct umutex   _thr_event_lock = DEFAULT_UMUTEX;
 131 struct umutex   _suspend_all_lock = DEFAULT_UMUTEX;
 132 struct pthread  *_single_thread;
 133 int             _suspend_all_cycle;
 134 int             _suspend_all_waiters;
 135
 136 int     __pthread_cond_wait(pthread_cond_t *, pthread_mutex_t *);
 137 int     __pthread_mutex_lock(pthread_mutex_t *);
 138 int     __pthread_mutex_trylock(pthread_mutex_t *);
 139 void    _thread_init_hack(void) __attribute__ ((constructor));
 140
 141 static void init_private(void);
 142 static void init_main_thread(struct pthread *thread);
 143
 144 /*
 145  * All weak references used within libc should be in this table.
 146  * This is so that static libraries will work.
 147  */
 148
 149 STATIC_LIB_REQUIRE(_fork);
 150 STATIC_LIB_REQUIRE(_pthread_getspecific);
 151 STATIC_LIB_REQUIRE(_pthread_key_create);
 152 STATIC_LIB_REQUIRE(_pthread_key_delete);
 153 STATIC_LIB_REQUIRE(_pthread_mutex_destroy);
 154 STATIC_LIB_REQUIRE(_pthread_mutex_init);
 155 STATIC_LIB_REQUIRE(_pthread_mutex_lock);
 156 STATIC_LIB_REQUIRE(_pthread_mutex_trylock);
 157 STATIC_LIB_REQUIRE(_pthread_mutex_unlock);
 158 STATIC_LIB_REQUIRE(_pthread_mutexattr_init);
 159 STATIC_LIB_REQUIRE(_pthread_mutexattr_destroy);
 160 STATIC_LIB_REQUIRE(_pthread_mutexattr_settype);
 161 STATIC_LIB_REQUIRE(_pthread_once);
 162 STATIC_LIB_REQUIRE(_pthread_setspecific);
 163 STATIC_LIB_REQUIRE(_raise);
 164 STATIC_LIB_REQUIRE(_sem_destroy);
 165 STATIC_LIB_REQUIRE(_sem_getvalue);
 166 STATIC_LIB_REQUIRE(_sem_init);
 167 STATIC_LIB_REQUIRE(_sem_post);
 168 STATIC_LIB_REQUIRE(_sem_timedwait);
 169 STATIC_LIB_REQUIRE(_sem_trywait);
 170 STATIC_LIB_REQUIRE(_sem_wait);
 171 STATIC_LIB_REQUIRE(_sigaction);
 172 STATIC_LIB_REQUIRE(_sigprocmask);
 173 STATIC_LIB_REQUIRE(_sigsuspend);
 174 STATIC_LIB_REQUIRE(_sigtimedwait);
 175 STATIC_LIB_REQUIRE(_sigwait);
 176 STATIC_LIB_REQUIRE(_sigwaitinfo);
 177 STATIC_LIB_REQUIRE(_spinlock);
 178 STATIC_LIB_REQUIRE(_spinunlock);
 179 STATIC_LIB_REQUIRE(_thread_init_hack);
 180
 181 /*
 182  * These are needed when linking statically.  All references within
 183  * libgcc (and in the future libc) to these routines are weak, but
 184  * if they are not (strongly) referenced by the application or other
 185  * libraries, then the actual functions will not be loaded.
 186  */
 187 STATIC_LIB_REQUIRE(_pthread_once);
 188 STATIC_LIB_REQUIRE(_pthread_key_create);
 189 STATIC_LIB_REQUIRE(_pthread_key_delete);
 190 STATIC_LIB_REQUIRE(_pthread_getspecific);
 191 STATIC_LIB_REQUIRE(_pthread_setspecific);
 192 STATIC_LIB_REQUIRE(_pthread_mutex_init);
 193 STATIC_LIB_REQUIRE(_pthread_mutex_destroy);
 194 STATIC_LIB_REQUIRE(_pthread_mutex_lock);
 195 STATIC_LIB_REQUIRE(_pthread_mutex_trylock);
 196 STATIC_LIB_REQUIRE(_pthread_mutex_unlock);
 197 STATIC_LIB_REQUIRE(_pthread_create);
 198
 199 /* Pull in all symbols required by libthread_db */
 200 STATIC_LIB_REQUIRE(_thread_state_running);
 201
 202 #define DUAL_ENTRY(entry)       \
 203         (pthread_func_t)entry, (pthread_func_t)entry
 204
 205 static pthread_func_t jmp_table[][2] = {
 206         {DUAL_ENTRY(_pthread_atfork)},  /* PJT_ATFORK */
 207         {DUAL_ENTRY(_pthread_attr_destroy)},    /* PJT_ATTR_DESTROY */
 208         {DUAL_ENTRY(_pthread_attr_getdetachstate)},     /* PJT_ATTR_GETDETACHSTATE */
 209         {DUAL_ENTRY(_pthread_attr_getguardsize)},       /* PJT_ATTR_GETGUARDSIZE */
 210         {DUAL_ENTRY(_pthread_attr_getinheritsched)},    /* PJT_ATTR_GETINHERITSCHED */
 211         {DUAL_ENTRY(_pthread_attr_getschedparam)},      /* PJT_ATTR_GETSCHEDPARAM */
 212         {DUAL_ENTRY(_pthread_attr_getschedpolicy)},     /* PJT_ATTR_GETSCHEDPOLICY */
 213         {DUAL_ENTRY(_pthread_attr_getscope)},   /* PJT_ATTR_GETSCOPE */
 214         {DUAL_ENTRY(_pthread_attr_getstackaddr)},       /* PJT_ATTR_GETSTACKADDR */
 215         {DUAL_ENTRY(_pthread_attr_getstacksize)},       /* PJT_ATTR_GETSTACKSIZE */
 216         {DUAL_ENTRY(_pthread_attr_init)},       /* PJT_ATTR_INIT */
 217         {DUAL_ENTRY(_pthread_attr_setdetachstate)},     /* PJT_ATTR_SETDETACHSTATE */
 218         {DUAL_ENTRY(_pthread_attr_setguardsize)},       /* PJT_ATTR_SETGUARDSIZE */
 219         {DUAL_ENTRY(_pthread_attr_setinheritsched)},    /* PJT_ATTR_SETINHERITSCHED */
 220         {DUAL_ENTRY(_pthread_attr_setschedparam)},      /* PJT_ATTR_SETSCHEDPARAM */
 221         {DUAL_ENTRY(_pthread_attr_setschedpolicy)},     /* PJT_ATTR_SETSCHEDPOLICY */
 222         {DUAL_ENTRY(_pthread_attr_setscope)},   /* PJT_ATTR_SETSCOPE */
 223         {DUAL_ENTRY(_pthread_attr_setstackaddr)},       /* PJT_ATTR_SETSTACKADDR */
 224         {DUAL_ENTRY(_pthread_attr_setstacksize)},       /* PJT_ATTR_SETSTACKSIZE */
 225         {DUAL_ENTRY(_pthread_cancel)},  /* PJT_CANCEL */
 226         {DUAL_ENTRY(_pthread_cleanup_pop)},     /* PJT_CLEANUP_POP */
 227         {DUAL_ENTRY(_pthread_cleanup_push)},    /* PJT_CLEANUP_PUSH */
 228         {DUAL_ENTRY(_pthread_cond_broadcast)},  /* PJT_COND_BROADCAST */
 229         {DUAL_ENTRY(_pthread_cond_destroy)},    /* PJT_COND_DESTROY */
 230         {DUAL_ENTRY(_pthread_cond_init)},       /* PJT_COND_INIT */
 231         {DUAL_ENTRY(_pthread_cond_signal)},     /* PJT_COND_SIGNAL */
 232         {DUAL_ENTRY(_pthread_cond_timedwait)},  /* PJT_COND_TIMEDWAIT */
 233         {(pthread_func_t)__pthread_cond_wait,
 234          (pthread_func_t)_pthread_cond_wait},   /* PJT_COND_WAIT */
 235         {DUAL_ENTRY(_pthread_detach)},  /* PJT_DETACH */
 236         {DUAL_ENTRY(_pthread_equal)},   /* PJT_EQUAL */
 237         {DUAL_ENTRY(_pthread_exit)},    /* PJT_EXIT */
 238         {DUAL_ENTRY(_pthread_getspecific)},     /* PJT_GETSPECIFIC */
 239         {DUAL_ENTRY(_pthread_join)},    /* PJT_JOIN */
 240         {DUAL_ENTRY(_pthread_key_create)},      /* PJT_KEY_CREATE */
 241         {DUAL_ENTRY(_pthread_key_delete)},      /* PJT_KEY_DELETE*/
 242         {DUAL_ENTRY(_pthread_kill)},    /* PJT_KILL */
 243         {DUAL_ENTRY(_pthread_main_np)},         /* PJT_MAIN_NP */
 244         {DUAL_ENTRY(_pthread_mutexattr_destroy)}, /* PJT_MUTEXATTR_DESTROY */
 245         {DUAL_ENTRY(_pthread_mutexattr_init)},  /* PJT_MUTEXATTR_INIT */
 246         {DUAL_ENTRY(_pthread_mutexattr_settype)}, /* PJT_MUTEXATTR_SETTYPE */
 247         {DUAL_ENTRY(_pthread_mutex_destroy)},   /* PJT_MUTEX_DESTROY */
 248         {DUAL_ENTRY(_pthread_mutex_init)},      /* PJT_MUTEX_INIT */
 249         {(pthread_func_t)__pthread_mutex_lock,
 250          (pthread_func_t)_pthread_mutex_lock},  /* PJT_MUTEX_LOCK */
 251         {(pthread_func_t)__pthread_mutex_trylock,
 252          (pthread_func_t)_pthread_mutex_trylock},/* PJT_MUTEX_TRYLOCK */
 253         {DUAL_ENTRY(_pthread_mutex_unlock)},    /* PJT_MUTEX_UNLOCK */
 254         {DUAL_ENTRY(_pthread_once)},            /* PJT_ONCE */
 255         {DUAL_ENTRY(_pthread_rwlock_destroy)},  /* PJT_RWLOCK_DESTROY */
 256         {DUAL_ENTRY(_pthread_rwlock_init)},     /* PJT_RWLOCK_INIT */
 257         {DUAL_ENTRY(_pthread_rwlock_rdlock)},   /* PJT_RWLOCK_RDLOCK */
 258         {DUAL_ENTRY(_pthread_rwlock_tryrdlock)},/* PJT_RWLOCK_TRYRDLOCK */
 259         {DUAL_ENTRY(_pthread_rwlock_trywrlock)},/* PJT_RWLOCK_TRYWRLOCK */
 260         {DUAL_ENTRY(_pthread_rwlock_unlock)},   /* PJT_RWLOCK_UNLOCK */
 261         {DUAL_ENTRY(_pthread_rwlock_wrlock)},   /* PJT_RWLOCK_WRLOCK */
 262         {DUAL_ENTRY(_pthread_self)},            /* PJT_SELF */
 263         {DUAL_ENTRY(_pthread_setcancelstate)},  /* PJT_SETCANCELSTATE */
 264         {DUAL_ENTRY(_pthread_setcanceltype)},   /* PJT_SETCANCELTYPE */
 265         {DUAL_ENTRY(_pthread_setspecific)},     /* PJT_SETSPECIFIC */
 266         {DUAL_ENTRY(_pthread_sigmask)},         /* PJT_SIGMASK */
 267         {DUAL_ENTRY(_pthread_testcancel)},      /* PJT_TESTCANCEL */
 268         {DUAL_ENTRY(__pthread_cleanup_pop_imp)},/* PJT_CLEANUP_POP_IMP */
 269         {DUAL_ENTRY(__pthread_cleanup_push_imp)},/* PJT_CLEANUP_PUSH_IMP */
 270         {DUAL_ENTRY(_pthread_cancel_enter)},    /* PJT_CANCEL_ENTER */
 271         {DUAL_ENTRY(_pthread_cancel_leave)},    /* PJT_CANCEL_LEAVE */
 272         {DUAL_ENTRY(_pthread_mutex_consistent)},/* PJT_MUTEX_CONSISTENT */
 273         {DUAL_ENTRY(_pthread_mutexattr_getrobust)},/* PJT_MUTEXATTR_GETROBUST */
 274         {DUAL_ENTRY(_pthread_mutexattr_setrobust)},/* PJT_MUTEXATTR_SETROBUST */
 275 };
 276
 277 static int init_once = 0;
 278
 279 /*
 280  * For the shared version of the threads library, the above is sufficient.
 281  * But for the archive version of the library, we need a little bit more.
 282  * Namely, we must arrange for this particular module to be pulled in from
 283  * the archive library at link time.  To accomplish that, we define and
 284  * initialize a variable, "_thread_autoinit_dummy_decl".  This variable is
 285  * referenced (as an extern) from libc/stdlib/exit.c. This will always
 286  * create a need for this module, ensuring that it is present in the
 287  * executable.
 288  */
 289 extern int _thread_autoinit_dummy_decl;
 290 int _thread_autoinit_dummy_decl = 0;
 291
 292 void
 293 _thread_init_hack(void)
 294 {
 295
 296         _libpthread_init(NULL);
 297 }
 298
 299
 300 /*
 301  * Threaded process initialization.
 302  *
 303  * This is only called under two conditions:
 304  *
 305  *   1) Some thread routines have detected that the library hasn't yet
 306  *      been initialized (_thr_initial == NULL && curthread == NULL), or
 307  *
 308  *   2) An explicit call to reinitialize after a fork (indicated
 309  *      by curthread != NULL)
 310  */
 311 void
 312 _libpthread_init(struct pthread *curthread)
 313 {
 314         int first, dlopened;
 315
 316         /* Check if this function has already been called: */
 317         if (_thr_initial != NULL && curthread == NULL)
 318                 /* Only initialize the threaded application once. */
 319                 return;
 320
 321         /*
 322          * Check the size of the jump table to make sure it is preset
 323          * with the correct number of entries.
 324          */
 325         if (sizeof(jmp_table) != sizeof(pthread_func_t) * PJT_MAX * 2)
 326                 PANIC("Thread jump table not properly initialized");
 327         memcpy(__thr_jtable, jmp_table, sizeof(jmp_table));
 328         __thr_interpose_libc();
 329
 330         /* Initialize pthread private data. */
 331         init_private();
 332
 333         /* Set the initial thread. */
 334         if (curthread == NULL) {
 335                 first = 1;
 336                 /* Create and initialize the initial thread. */
 337                 curthread = _thr_alloc(NULL);
 338                 if (curthread == NULL)
 339                         PANIC("Can't allocate initial thread");
 340                 init_main_thread(curthread);
 341         } else {
 342                 first = 0;
 343         }
 344
 345         /*
 346          * Add the thread to the thread list queue.
 347          */
 348         THR_LIST_ADD(curthread);
 349         _thread_active_threads = 1;
 350
 351         /* Setup the thread specific data */
 352         _tcb_set(curthread->tcb);
 353
 354         if (first) {
 355                 _thr_initial = curthread;
 356                 dlopened = _rtld_is_dlopened(&_thread_autoinit_dummy_decl) != 0;
 357                 _thr_signal_init(dlopened);
 358                 if (_thread_event_mask & TD_CREATE)
 359                         _thr_report_creation(curthread, curthread);
 360                 /*
 361                  * Always use our rtld lock implementation.
 362                  * It is faster because it postpones signal handlers
 363                  * instead of calling sigprocmask(2).
 364                  */
 365                 _thr_rtld_init();
 366         }
 367 }
 368
 369 /*
 370  * This function and pthread_create() do a lot of the same things.
 371  * It'd be nice to consolidate the common stuff in one place.
 372  */
 373 static void
 374 init_main_thread(struct pthread *thread)
 375 {
 376         struct sched_param sched_param;
 377         int i;
 378
 379         /* Setup the thread attributes. */
 380         thr_self(&thread->tid);
 381         thread->attr = _pthread_attr_default;
 382         /*
 383          * Set up the thread stack.
 384          *
 385          * Create a red zone below the main stack.  All other stacks
 386          * are constrained to a maximum size by the parameters
 387          * passed to mmap(), but this stack is only limited by
 388          * resource limits, so this stack needs an explicitly mapped
 389          * red zone to protect the thread stack that is just beyond.
 390          */
 391         if (mmap(_usrstack - _thr_stack_initial -
 392             _thr_guard_default, _thr_guard_default, 0, MAP_ANON,
 393             -1, 0) == MAP_FAILED)
 394                 PANIC("Cannot allocate red zone for initial thread");
 395
 396         /*
 397          * Mark the stack as an application supplied stack so that it
 398          * isn't deallocated.
 399          *
 400          * XXX - I'm not sure it would hurt anything to deallocate
 401          *       the main thread stack because deallocation doesn't
 402          *       actually free() it; it just puts it in the free
 403          *       stack queue for later reuse.
 404          */
 405         thread->attr.stackaddr_attr = _usrstack - _thr_stack_initial;
 406         thread->attr.stacksize_attr = _thr_stack_initial;
 407         thread->attr.guardsize_attr = _thr_guard_default;
 408         thread->attr.flags |= THR_STACK_USER;
 409
 410         /*
 411          * Write a magic value to the thread structure
 412          * to help identify valid ones:
 413          */
 414         thread->magic = THR_MAGIC;
 415
 416         thread->cancel_enable = 1;
 417         thread->cancel_async = 0;
 418
 419         /* Initialize the mutex queues */
 420         for (i = 0; i < TMQ_NITEMS; i++)
 421                 TAILQ_INIT(&thread->mq[i]);
 422
 423         thread->state = PS_RUNNING;
 424
 425         _thr_getscheduler(thread->tid, &thread->attr.sched_policy,
 426                  &sched_param);
 427         thread->attr.prio = sched_param.sched_priority;
 428
 429 #ifdef _PTHREAD_FORCED_UNWIND
 430         thread->unwind_stackend = _usrstack;
 431 #endif
 432
 433         /* Others cleared to zero by thr_alloc() */
 434 }
 435
 436 static void
 437 init_private(void)
 438 {
 439         struct rlimit rlim;
 440         size_t len;
 441         int mib[2];
 442         char *env, *env_bigstack, *env_splitstack;
 443
 444         _thr_umutex_init(&_mutex_static_lock);
 445         _thr_umutex_init(&_cond_static_lock);
 446         _thr_umutex_init(&_rwlock_static_lock);
 447         _thr_umutex_init(&_keytable_lock);
 448         _thr_urwlock_init(&_thr_atfork_lock);
 449         _thr_umutex_init(&_thr_event_lock);
 450         _thr_umutex_init(&_suspend_all_lock);
 451         _thr_spinlock_init();
 452         _thr_list_init();
 453         _thr_wake_addr_init();
 454         _sleepq_init();
 455         _single_thread = NULL;
 456         _suspend_all_waiters = 0;
 457
 458         /*
 459          * Avoid reinitializing some things if they don't need to be,
 460          * e.g. after a fork().
 461          */
 462         if (init_once == 0) {
 463                 __thr_pshared_init();
 464                 __thr_malloc_init();
 465                 /* Find the stack top */
 466                 mib[0] = CTL_KERN;
 467                 mib[1] = KERN_USRSTACK;
 468                 len = sizeof (_usrstack);
 469                 if (sysctl(mib, 2, &_usrstack, &len, NULL, 0) == -1)
 470                         PANIC("Cannot get kern.usrstack from sysctl");
 471                 env_bigstack = getenv("LIBPTHREAD_BIGSTACK_MAIN");
 472                 env_splitstack = getenv("LIBPTHREAD_SPLITSTACK_MAIN");
 473                 if (env_bigstack != NULL || env_splitstack == NULL) {
 474                         if (getrlimit(RLIMIT_STACK, &rlim) == -1)
 475                                 PANIC("Cannot get stack rlimit");
 476                         _thr_stack_initial = rlim.rlim_cur;
 477                 }
 478                 _thr_is_smp = sysconf(_SC_NPROCESSORS_CONF);
 479                 if (_thr_is_smp == -1)
 480                         PANIC("Cannot get _SC_NPROCESSORS_CONF");
 481                 _thr_is_smp = (_thr_is_smp > 1);
 482                 _thr_page_size = getpagesize();
 483                 _thr_guard_default = _thr_page_size;
 484                 _pthread_attr_default.guardsize_attr = _thr_guard_default;
 485                 _pthread_attr_default.stacksize_attr = _thr_stack_default;
 486                 env = getenv("LIBPTHREAD_SPINLOOPS");
 487                 if (env)
 488                         _thr_spinloops = atoi(env);
 489                 env = getenv("LIBPTHREAD_YIELDLOOPS");
 490                 if (env)
 491                         _thr_yieldloops = atoi(env);
 492                 env = getenv("LIBPTHREAD_QUEUE_FIFO");
 493                 if (env)
 494                         _thr_queuefifo = atoi(env);
 495                 TAILQ_INIT(&_thr_atfork_list);
 496         }
 497         init_once = 1;
 498 }