/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (c) 2003 Daniel M. Eischen <deischen@freebsd.org>
 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by John Birrell.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#define _WANT_P_OSREL
#include "namespace.h"
#include <sys/param.h>
#include <sys/auxv.h>
#include <sys/signalvar.h>
#include <sys/ioctl.h>
#include <sys/link_elf.h>
#include <sys/resource.h>
#include <sys/sysctl.h>
#include <sys/ttycom.h>
#include <sys/mman.h>
#include <sys/rtprio.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <pthread.h>
#include <pthread_np.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "un-namespace.h"

#include "libc_private.h"
#include "thr_private.h"

int             __getosreldate(void);
char            *_usrstack;
struct pthread  *_thr_initial;
int             _libthr_debug;
int             _thread_event_mask;
struct pthread  *_thread_last_event;
pthreadlist     _thread_list = TAILQ_HEAD_INITIALIZER(_thread_list);
pthreadlist     _thread_gc_list = TAILQ_HEAD_INITIALIZER(_thread_gc_list);
int             _thread_active_threads = 1;
atfork_head     _thr_atfork_list = TAILQ_HEAD_INITIALIZER(_thr_atfork_list);
struct urwlock  _thr_atfork_lock = DEFAULT_URWLOCK;

struct pthread_prio     _thr_priorities[3] = {
        {RTP_PRIO_MIN,  RTP_PRIO_MAX, 0}, /* FIFO */
        {0, 0, 63}, /* OTHER */
        {RTP_PRIO_MIN, RTP_PRIO_MAX, 0}  /* RR */
};

struct pthread_attr _pthread_attr_default = {
        .sched_policy = SCHED_OTHER,
        .sched_inherit = PTHREAD_INHERIT_SCHED,
        .prio = 0,
        .suspend = THR_CREATE_RUNNING,
        .flags = PTHREAD_SCOPE_SYSTEM,
        .stackaddr_attr = NULL,
        .stacksize_attr = THR_STACK_DEFAULT,
        .guardsize_attr = 0,
        .cpusetsize = 0,
        .cpuset = NULL
};

struct pthread_mutex_attr _pthread_mutexattr_default = {
        .m_type = PTHREAD_MUTEX_DEFAULT,
        .m_protocol = PTHREAD_PRIO_NONE,
        .m_ceiling = 0,
        .m_pshared = PTHREAD_PROCESS_PRIVATE,
        .m_robust = PTHREAD_MUTEX_STALLED,
};

struct pthread_mutex_attr _pthread_mutexattr_adaptive_default = {
        .m_type = PTHREAD_MUTEX_ADAPTIVE_NP,
        .m_protocol = PTHREAD_PRIO_NONE,
        .m_ceiling = 0,
        .m_pshared = PTHREAD_PROCESS_PRIVATE,
        .m_robust = PTHREAD_MUTEX_STALLED,
};

/* Default condition variable attributes: */
struct pthread_cond_attr _pthread_condattr_default = {
        .c_pshared = PTHREAD_PROCESS_PRIVATE,
        .c_clockid = CLOCK_REALTIME
};

int             _thr_is_smp = 0;
size_t          _thr_guard_default;
size_t          _thr_stack_default = THR_STACK_DEFAULT;
size_t          _thr_stack_initial = THR_STACK_INITIAL;
int             _thr_page_size;
int             _thr_spinloops;
int             _thr_yieldloops;
int             _thr_queuefifo = 4;
int             _gc_count;
struct umutex   _mutex_static_lock = DEFAULT_UMUTEX;
struct umutex   _cond_static_lock = DEFAULT_UMUTEX;
struct umutex   _rwlock_static_lock = DEFAULT_UMUTEX;
struct umutex   _keytable_lock = DEFAULT_UMUTEX;
struct urwlock  _thr_list_lock = DEFAULT_URWLOCK;
struct umutex   _thr_event_lock = DEFAULT_UMUTEX;
struct umutex   _suspend_all_lock = DEFAULT_UMUTEX;
struct pthread  *_single_thread;
int             _suspend_all_cycle;
int             _suspend_all_waiters;

int     __pthread_cond_wait(pthread_cond_t *, pthread_mutex_t *);
int     __pthread_mutex_lock(pthread_mutex_t *);
int     __pthread_mutex_trylock(pthread_mutex_t *);
void    _thread_init_hack(void) __attribute__ ((constructor));

static void init_private(void);
static void init_main_thread(struct pthread *thread);

/*
 * All weak references used within libc should be in this table.
 * This is so that static libraries will work.
 */

STATIC_LIB_REQUIRE(_fork);
STATIC_LIB_REQUIRE(_pthread_getspecific);
STATIC_LIB_REQUIRE(_pthread_key_create);
STATIC_LIB_REQUIRE(_pthread_key_delete);
STATIC_LIB_REQUIRE(_pthread_mutex_destroy);
STATIC_LIB_REQUIRE(_pthread_mutex_init);
STATIC_LIB_REQUIRE(_pthread_mutex_lock);
STATIC_LIB_REQUIRE(_pthread_mutex_trylock);
STATIC_LIB_REQUIRE(_pthread_mutex_unlock);
STATIC_LIB_REQUIRE(_pthread_mutexattr_init);
STATIC_LIB_REQUIRE(_pthread_mutexattr_destroy);
STATIC_LIB_REQUIRE(_pthread_mutexattr_settype);
STATIC_LIB_REQUIRE(_pthread_once);
STATIC_LIB_REQUIRE(_pthread_setspecific);
STATIC_LIB_REQUIRE(_raise);
STATIC_LIB_REQUIRE(_sem_destroy);
STATIC_LIB_REQUIRE(_sem_getvalue);
STATIC_LIB_REQUIRE(_sem_init);
STATIC_LIB_REQUIRE(_sem_post);
STATIC_LIB_REQUIRE(_sem_timedwait);
STATIC_LIB_REQUIRE(_sem_trywait);
STATIC_LIB_REQUIRE(_sem_wait);
STATIC_LIB_REQUIRE(_sigaction);
STATIC_LIB_REQUIRE(_sigprocmask);
STATIC_LIB_REQUIRE(_sigtimedwait);
STATIC_LIB_REQUIRE(_sigwait);
STATIC_LIB_REQUIRE(_sigwaitinfo);
STATIC_LIB_REQUIRE(_spinlock);
STATIC_LIB_REQUIRE(_spinunlock);
STATIC_LIB_REQUIRE(_thread_init_hack);

/*
 * These are needed when linking statically.  All references within
 * libgcc (and in the future libc) to these routines are weak, but
 * if they are not (strongly) referenced by the application or other
 * libraries, then the actual functions will not be loaded.
 */
STATIC_LIB_REQUIRE(_pthread_once);
STATIC_LIB_REQUIRE(_pthread_key_create);
STATIC_LIB_REQUIRE(_pthread_key_delete);
STATIC_LIB_REQUIRE(_pthread_getspecific);
STATIC_LIB_REQUIRE(_pthread_setspecific);
STATIC_LIB_REQUIRE(_pthread_mutex_init);
STATIC_LIB_REQUIRE(_pthread_mutex_destroy);
STATIC_LIB_REQUIRE(_pthread_mutex_lock);
STATIC_LIB_REQUIRE(_pthread_mutex_trylock);
STATIC_LIB_REQUIRE(_pthread_mutex_unlock);
STATIC_LIB_REQUIRE(_pthread_create);

/* Pull in all symbols required by libthread_db */
STATIC_LIB_REQUIRE(_thread_state_running);

#define DUAL_ENTRY(entry)       \
        (pthread_func_t)entry, (pthread_func_t)entry

static pthread_func_t jmp_table[][2] = {
        [PJT_ATFORK] = {DUAL_ENTRY(_thr_atfork)},
        [PJT_ATTR_DESTROY] = {DUAL_ENTRY(_thr_attr_destroy)},
        [PJT_ATTR_GETDETACHSTATE] = {DUAL_ENTRY(_thr_attr_getdetachstate)},
        [PJT_ATTR_GETGUARDSIZE] = {DUAL_ENTRY(_thr_attr_getguardsize)},
        [PJT_ATTR_GETINHERITSCHED] = {DUAL_ENTRY(_thr_attr_getinheritsched)},
        [PJT_ATTR_GETSCHEDPARAM] = {DUAL_ENTRY(_thr_attr_getschedparam)},
        [PJT_ATTR_GETSCHEDPOLICY] = {DUAL_ENTRY(_thr_attr_getschedpolicy)},
        [PJT_ATTR_GETSCOPE] = {DUAL_ENTRY(_thr_attr_getscope)},
        [PJT_ATTR_GETSTACKADDR] = {DUAL_ENTRY(_thr_attr_getstackaddr)},
        [PJT_ATTR_GETSTACKSIZE] = {DUAL_ENTRY(_thr_attr_getstacksize)},
        [PJT_ATTR_INIT] = {DUAL_ENTRY(_thr_attr_init)},
        [PJT_ATTR_SETDETACHSTATE] = {DUAL_ENTRY(_thr_attr_setdetachstate)},
        [PJT_ATTR_SETGUARDSIZE] = {DUAL_ENTRY(_thr_attr_setguardsize)},
        [PJT_ATTR_SETINHERITSCHED] = {DUAL_ENTRY(_thr_attr_setinheritsched)},
        [PJT_ATTR_SETSCHEDPARAM] = {DUAL_ENTRY(_thr_attr_setschedparam)},
        [PJT_ATTR_SETSCHEDPOLICY] = {DUAL_ENTRY(_thr_attr_setschedpolicy)},
        [PJT_ATTR_SETSCOPE] = {DUAL_ENTRY(_thr_attr_setscope)},
        [PJT_ATTR_SETSTACKADDR] = {DUAL_ENTRY(_thr_attr_setstackaddr)},
        [PJT_ATTR_SETSTACKSIZE] = {DUAL_ENTRY(_thr_attr_setstacksize)},
        [PJT_CANCEL] = {DUAL_ENTRY(_thr_cancel)},
        [PJT_CLEANUP_POP] = {DUAL_ENTRY(_thr_cleanup_pop)},
        [PJT_CLEANUP_PUSH] = {DUAL_ENTRY(_thr_cleanup_push)},
        [PJT_COND_BROADCAST] = {DUAL_ENTRY(_thr_cond_broadcast)},
        [PJT_COND_DESTROY] = {DUAL_ENTRY(_thr_cond_destroy)},
        [PJT_COND_INIT] = {DUAL_ENTRY(_thr_cond_init)},
        [PJT_COND_SIGNAL] = {DUAL_ENTRY(_thr_cond_signal)},
        [PJT_COND_TIMEDWAIT] = {DUAL_ENTRY(_thr_cond_timedwait)},
        [PJT_COND_WAIT] = {(pthread_func_t)__thr_cond_wait,
            (pthread_func_t)_thr_cond_wait},
        [PJT_DETACH] = {DUAL_ENTRY(_thr_detach)},
        [PJT_EQUAL] = {DUAL_ENTRY(_thr_equal)},
        [PJT_EXIT] = {DUAL_ENTRY(_Tthr_exit)},
        [PJT_GETSPECIFIC] = {DUAL_ENTRY(_thr_getspecific)},
        [PJT_JOIN] = {DUAL_ENTRY(_thr_join)},
        [PJT_KEY_CREATE] = {DUAL_ENTRY(_thr_key_create)},
        [PJT_KEY_DELETE] = {DUAL_ENTRY(_thr_key_delete)},
        [PJT_KILL] = {DUAL_ENTRY(_Tthr_kill)},
        [PJT_MAIN_NP] = {DUAL_ENTRY(_thr_main_np)},
        [PJT_MUTEXATTR_DESTROY] = {DUAL_ENTRY(_thr_mutexattr_destroy)},
        [PJT_MUTEXATTR_INIT] = {DUAL_ENTRY(_thr_mutexattr_init)},
        [PJT_MUTEXATTR_SETTYPE] = {DUAL_ENTRY(_thr_mutexattr_settype)},
        [PJT_MUTEX_DESTROY] = {DUAL_ENTRY(_thr_mutex_destroy)},
        [PJT_MUTEX_INIT] = {DUAL_ENTRY(__Tthr_mutex_init)},
        [PJT_MUTEX_LOCK] = {DUAL_ENTRY(__Tthr_mutex_lock)},
        [PJT_MUTEX_TRYLOCK] = {DUAL_ENTRY(__Tthr_mutex_trylock)},
        [PJT_MUTEX_UNLOCK] = {DUAL_ENTRY(_thr_mutex_unlock)},
        [PJT_ONCE] = {DUAL_ENTRY(_thr_once)},
        [PJT_RWLOCK_DESTROY] = {DUAL_ENTRY(_thr_rwlock_destroy)},
        [PJT_RWLOCK_INIT] = {DUAL_ENTRY(_thr_rwlock_init)},
        [PJT_RWLOCK_RDLOCK] = {DUAL_ENTRY(_Tthr_rwlock_rdlock)},
        [PJT_RWLOCK_TRYRDLOCK] = {DUAL_ENTRY(_Tthr_rwlock_tryrdlock)},
        [PJT_RWLOCK_TRYWRLOCK] = {DUAL_ENTRY(_Tthr_rwlock_trywrlock)},
        [PJT_RWLOCK_UNLOCK] = {DUAL_ENTRY(_Tthr_rwlock_unlock)},
        [PJT_RWLOCK_WRLOCK] = {DUAL_ENTRY(_Tthr_rwlock_wrlock)},
        [PJT_SELF] = {DUAL_ENTRY(_Tthr_self)},
        [PJT_SETCANCELSTATE] = {DUAL_ENTRY(_thr_setcancelstate)},
        [PJT_SETCANCELTYPE] = {DUAL_ENTRY(_thr_setcanceltype)},
        [PJT_SETSPECIFIC] = {DUAL_ENTRY(_thr_setspecific)},
        [PJT_SIGMASK] = {DUAL_ENTRY(_thr_sigmask)},
        [PJT_TESTCANCEL] = {DUAL_ENTRY(_Tthr_testcancel)},
        [PJT_CLEANUP_POP_IMP] = {DUAL_ENTRY(__thr_cleanup_pop_imp)},
        [PJT_CLEANUP_PUSH_IMP] = {DUAL_ENTRY(__thr_cleanup_push_imp)},
        [PJT_CANCEL_ENTER] = {DUAL_ENTRY(_Tthr_cancel_enter)},
        [PJT_CANCEL_LEAVE] = {DUAL_ENTRY(_Tthr_cancel_leave)},
        [PJT_MUTEX_CONSISTENT] = {DUAL_ENTRY(_Tthr_mutex_consistent)},
        [PJT_MUTEXATTR_GETROBUST] = {DUAL_ENTRY(_thr_mutexattr_getrobust)},
        [PJT_MUTEXATTR_SETROBUST] = {DUAL_ENTRY(_thr_mutexattr_setrobust)},
        [PJT_GETTHREADID_NP] = {DUAL_ENTRY(_thr_getthreadid_np)},
        [PJT_ATTR_GET_NP] = {DUAL_ENTRY(_thr_attr_get_np)},
        [PJT_GETNAME_NP] = {DUAL_ENTRY(_thr_getname_np)},
        [PJT_SUSPEND_ALL_NP] = {DUAL_ENTRY(_thr_suspend_all_np)},
        [PJT_RESUME_ALL_NP] = {DUAL_ENTRY(_thr_resume_all_np)},
};

static int init_once = 0;

/*
 * For the shared version of the threads library, the above is sufficient.
 * But for the archive version of the library, we need a little bit more.
 * Namely, we must arrange for this particular module to be pulled in from
 * the archive library at link time.  To accomplish that, we define and
 * initialize a variable, "_thread_autoinit_dummy_decl".  This variable is
 * referenced (as an extern) from libc/stdlib/exit.c. This will always
 * create a need for this module, ensuring that it is present in the
 * executable.
 */
extern int _thread_autoinit_dummy_decl;
int _thread_autoinit_dummy_decl = 0;

void
_thread_init_hack(void)
{

        _libpthread_init(NULL);
}


/*
 * Threaded process initialization.
 *
 * This is only called under two conditions:
 *
 *   1) Some thread routines have detected that the library hasn't yet
 *      been initialized (_thr_initial == NULL && curthread == NULL), or
 *
 *   2) An explicit call to reinitialize after a fork (indicated
 *      by curthread != NULL)
 */
void
_libpthread_init(struct pthread *curthread)
{
        int first, dlopened;

        /* Check if this function has already been called: */
        if (_thr_initial != NULL && curthread == NULL)
                /* Only initialize the threaded application once. */
                return;

        /*
         * Check the size of the jump table to make sure it is preset
         * with the correct number of entries.
         */
        if (sizeof(jmp_table) != sizeof(pthread_func_t) * PJT_MAX * 2)
                PANIC("Thread jump table not properly initialized");
        memcpy(__thr_jtable, jmp_table, sizeof(jmp_table));
        __thr_interpose_libc();

        /* Initialize pthread private data. */
        init_private();

        /* Set the initial thread. */
        if (curthread == NULL) {
                first = 1;
                /* Force _get_curthread() return NULL until set. */
                _tcb_get()->tcb_thread = NULL;
                /* Create and initialize the initial thread. */
                curthread = _thr_alloc(NULL);
                if (curthread == NULL)
                        PANIC("Can't allocate initial thread");
                init_main_thread(curthread);
        } else {
                first = 0;
        }
                
        /*
         * Add the thread to the thread list queue.
         */
        THR_LIST_ADD(curthread);
        _thread_active_threads = 1;

        /* Setup the thread specific data */
        __thr_setup_tsd(curthread);

        if (first) {
                _thr_initial = curthread;
                dlopened = _rtld_is_dlopened(&_thread_autoinit_dummy_decl) != 0;
                _thr_signal_init(dlopened);
                if (_thread_event_mask & TD_CREATE)
                        _thr_report_creation(curthread, curthread);
                /*
                 * Always use our rtld lock implementation.
                 * It is faster because it postpones signal handlers
                 * instead of calling sigprocmask(2).
                 */
                _thr_rtld_init();
        }
}

/*
 * This function and pthread_create() do a lot of the same things.
 * It'd be nice to consolidate the common stuff in one place.
 */
static void
init_main_thread(struct pthread *thread)
{
        struct sched_param sched_param;
        int i;

        /* Setup the thread attributes. */
        thr_self(&thread->tid);
        thread->attr = _pthread_attr_default;
        /*
         * Set up the thread stack.
         *
         * Create a red zone below the main stack.  All other stacks
         * are constrained to a maximum size by the parameters
         * passed to mmap(), but this stack is only limited by
         * resource limits, so this stack needs an explicitly mapped
         * red zone to protect the thread stack that is just beyond.
         */
        if (mmap(_usrstack - _thr_stack_initial -
            _thr_guard_default, _thr_guard_default, 0, MAP_ANON,
            -1, 0) == MAP_FAILED)
                PANIC("Cannot allocate red zone for initial thread");

        /*
         * Mark the stack as an application supplied stack so that it
         * isn't deallocated.
         *
         * XXX - I'm not sure it would hurt anything to deallocate
         *       the main thread stack because deallocation doesn't
         *       actually free() it; it just puts it in the free
         *       stack queue for later reuse.
         */
        thread->attr.stackaddr_attr = _usrstack - _thr_stack_initial;
        thread->attr.stacksize_attr = _thr_stack_initial;
        thread->attr.guardsize_attr = _thr_guard_default;
        thread->attr.flags |= THR_STACK_USER;

        /*
         * Write a magic value to the thread structure
         * to help identify valid ones:
         */
        thread->magic = THR_MAGIC;

        thread->cancel_enable = 1;
        thread->cancel_async = 0;

        /* Initialize the mutex queues */
        for (i = 0; i < TMQ_NITEMS; i++)
                TAILQ_INIT(&thread->mq[i]);

        thread->state = PS_RUNNING;

        _thr_getscheduler(thread->tid, &thread->attr.sched_policy,
                 &sched_param);
        thread->attr.prio = sched_param.sched_priority;

#ifdef _PTHREAD_FORCED_UNWIND
        thread->unwind_stackend = _usrstack;
#endif

        thread->uexterr.ver = UEXTERROR_VER;
        if (__getosreldate() >= P_OSREL_EXTERRCTL)
                exterrctl(EXTERRCTL_ENABLE, EXTERRCTLF_FORCE, &thread->uexterr);

        /* Others cleared to zero by thr_alloc() */
}

bool
__thr_get_main_stack_base(char **base)
{
        size_t len;
        int mib[2];

        if (elf_aux_info(AT_USRSTACKBASE, base, sizeof(*base)) == 0)
                return (true);

        mib[0] = CTL_KERN;
        mib[1] = KERN_USRSTACK;
        len = sizeof(*base);
        if (sysctl(mib, nitems(mib), base, &len, NULL, 0) == 0)
                return (true);

        return (false);
}

bool
__thr_get_main_stack_lim(size_t *lim)
{
        struct rlimit rlim;

        if (elf_aux_info(AT_USRSTACKLIM, lim, sizeof(*lim)) == 0)
                return (true);

        if (getrlimit(RLIMIT_STACK, &rlim) == 0) {
                *lim = rlim.rlim_cur;
                return (true);
        }

        return (false);
}

static void
init_private(void)
{
        char *env, *env_bigstack, *env_splitstack;

        _thr_umutex_init(&_mutex_static_lock);
        _thr_umutex_init(&_cond_static_lock);
        _thr_umutex_init(&_rwlock_static_lock);
        _thr_umutex_init(&_keytable_lock);
        _thr_urwlock_init(&_thr_atfork_lock);
        _thr_umutex_init(&_thr_event_lock);
        _thr_umutex_init(&_suspend_all_lock);
        _thr_spinlock_init();
        _thr_list_init();
        _thr_wake_addr_init();
        _sleepq_init();
        _single_thread = NULL;
        _suspend_all_waiters = 0;

        /*
         * Avoid reinitializing some things if they don't need to be,
         * e.g. after a fork().
         */
        if (init_once == 0) {
                __thr_pshared_init();
                __thr_malloc_init();

                /* Find the stack top */
                if (!__thr_get_main_stack_base(&_usrstack))
                        PANIC("Cannot get kern.usrstack");
                env_bigstack = getenv("LIBPTHREAD_BIGSTACK_MAIN");
                env_splitstack = getenv("LIBPTHREAD_SPLITSTACK_MAIN");
                if (env_bigstack != NULL || env_splitstack == NULL) {
                        if (!__thr_get_main_stack_lim(&_thr_stack_initial))
                                PANIC("Cannot get stack rlimit");
                }
                _thr_is_smp = sysconf(_SC_NPROCESSORS_CONF);
                if (_thr_is_smp == -1)
                        PANIC("Cannot get _SC_NPROCESSORS_CONF");
                _thr_is_smp = (_thr_is_smp > 1);
                _thr_page_size = getpagesize();
                _thr_guard_default = _thr_page_size;
                _pthread_attr_default.guardsize_attr = _thr_guard_default;
                _pthread_attr_default.stacksize_attr = _thr_stack_default;
                env = getenv("LIBPTHREAD_SPINLOOPS");
                if (env)
                        _thr_spinloops = atoi(env);
                env = getenv("LIBPTHREAD_YIELDLOOPS");
                if (env)
                        _thr_yieldloops = atoi(env);
                env = getenv("LIBPTHREAD_QUEUE_FIFO");
                if (env)
                        _thr_queuefifo = atoi(env);
                env = getenv("LIBPTHREAD_UMTX_MIN_TIMEOUT");
                if (env) {
                        char *endptr;
                        long mint;

                        mint = strtol(env, &endptr, 0);
                        if (*endptr == '\0' && mint >= 0) {
                                _umtx_op(NULL, UMTX_OP_SET_MIN_TIMEOUT,
                                    mint, NULL, NULL);
                        }
                }
        }
        init_once = 1;
}