/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2003 Daniel M. Eischen <deischen@gdeb.com>
 * Copyright (c) 2005, David Xu <davidxu@freebsd.org>
 * 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 unmodified, 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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/types.h>
#include <sys/rtprio.h>
#include <sys/signalvar.h>
#include <sys/exterrvar.h>
#include <errno.h>
#include <link.h>
#include <stdlib.h>
#include <string.h>
#include <stddef.h>
#include <pthread.h>
#include <pthread_np.h>
#include "un-namespace.h"

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

int __getosreldate(void);

static int  create_stack(struct pthread_attr *pattr);
static void thread_start(struct pthread *curthread);

int __thr_new_flags = THR_C_RUNTIME;

__weak_reference(_pthread_create, pthread_create);

int
_pthread_create(pthread_t * __restrict thread,
    const pthread_attr_t * __restrict attr, void *(*start_routine) (void *),
    void * __restrict arg)
{
        struct pthread *curthread, *new_thread;
        struct thr_param param;
        struct sched_param sched_param;
        struct rtprio rtp;
        sigset_t set, oset;
        cpuset_t *cpusetp;
        int i, cpusetsize, create_suspended, locked, old_stack_prot, ret;

        cpusetp = NULL;
        ret = cpusetsize = 0;
        _thr_check_init();

        /*
         * Tell libc and others now they need lock to protect their data.
         */
        if (_thr_isthreaded() == 0) {
                _malloc_first_thread();
                _thr_setthreaded(1);
        }

        curthread = _get_curthread();
        if ((new_thread = _thr_alloc(curthread)) == NULL)
                return (EAGAIN);

        memset(&param, 0, sizeof(param));

        if (attr == NULL || *attr == NULL)
                /* Use the default thread attributes: */
                new_thread->attr = _pthread_attr_default;
        else {
                new_thread->attr = *(*attr);
                cpusetp = new_thread->attr.cpuset;
                cpusetsize = new_thread->attr.cpusetsize;
                new_thread->attr.cpuset = NULL;
                new_thread->attr.cpusetsize = 0;
        }
        if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
                /* inherit scheduling contention scope */
                if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
                        new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
                else
                        new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;

                new_thread->attr.prio = curthread->attr.prio;
                new_thread->attr.sched_policy = curthread->attr.sched_policy;
        }

        new_thread->tid = TID_TERMINATED;

        old_stack_prot = _rtld_get_stack_prot();
        if (create_stack(&new_thread->attr) != 0) {
                /* Insufficient memory to create a stack: */
                _thr_free(curthread, new_thread);
                return (EAGAIN);
        }
        /*
         * Write a magic value to the thread structure
         * to help identify valid ones:
         */
        new_thread->magic = THR_MAGIC;
        new_thread->start_routine = start_routine;
        new_thread->arg = arg;
        new_thread->cancel_enable = 1;
        new_thread->cancel_async = 0;
        /* Initialize the mutex queue: */
        for (i = 0; i < TMQ_NITEMS; i++)
                TAILQ_INIT(&new_thread->mq[i]);

        /* Initialise hooks in the thread structure: */
        if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) {
                new_thread->flags = THR_FLAGS_NEED_SUSPEND;
                create_suspended = 1;
        } else {
                create_suspended = 0;
        }

        new_thread->state = PS_RUNNING;

        if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED)
                new_thread->flags |= THR_FLAGS_DETACHED;

        /* Add the new thread. */
        new_thread->refcount = 1;
        _thr_link(curthread, new_thread);

        /*
         * Handle the race between __pthread_map_stacks_exec and
         * thread linkage.
         */
        if (old_stack_prot != _rtld_get_stack_prot())
                _thr_stack_fix_protection(new_thread);

        /* Return thread pointer eariler so that new thread can use it. */
        *thread = new_thread;
        if (SHOULD_REPORT_EVENT(curthread, TD_CREATE) || cpusetp != NULL) {
                THR_THREAD_LOCK(curthread, new_thread);
                locked = 1;
        } else
                locked = 0;
        param.start_func = (void (*)(void *)) thread_start;
        param.arg = new_thread;
        param.stack_base = new_thread->attr.stackaddr_attr;
        param.stack_size = new_thread->attr.stacksize_attr;
        param.tls_base = (char *)new_thread->tcb;
        param.tls_size = sizeof(struct tcb);
        param.child_tid = &new_thread->tid;
        param.parent_tid = &new_thread->tid;
        param.flags = __thr_new_flags;
        if (new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM)
                param.flags |= THR_SYSTEM_SCOPE;
        if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED)
                param.rtp = NULL;
        else {
                sched_param.sched_priority = new_thread->attr.prio;
                _schedparam_to_rtp(new_thread->attr.sched_policy,
                        &sched_param, &rtp);
                param.rtp = &rtp;
        }

        /* Schedule the new thread. */
        if (create_suspended) {
                SIGFILLSET(set);
                SIGDELSET(set, SIGTRAP);
                __sys_sigprocmask(SIG_SETMASK, &set, &oset);
                new_thread->sigmask = oset;
                SIGDELSET(new_thread->sigmask, SIGCANCEL);
        }

        ret = thr_new(&param, sizeof(param));

        if (ret != 0) {
                ret = errno;
                /*
                 * Translate EPROCLIM into well-known POSIX code EAGAIN.
                 */
                if (ret == EPROCLIM)
                        ret = EAGAIN;
        }

        if (create_suspended)
                __sys_sigprocmask(SIG_SETMASK, &oset, NULL);

        if (ret != 0) {
                if (!locked)
                        THR_THREAD_LOCK(curthread, new_thread);
                new_thread->state = PS_DEAD;
                new_thread->tid = TID_TERMINATED;
                new_thread->flags |= THR_FLAGS_DETACHED;
                new_thread->refcount--;
                if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
                        new_thread->cycle++;
                        _thr_umtx_wake(&new_thread->cycle, INT_MAX, 0);
                }
                _thr_try_gc(curthread, new_thread); /* thread lock released */
                atomic_add_int(&_thread_active_threads, -1);
        } else if (locked) {
                if (cpusetp != NULL) {
                        if (cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TID,
                                TID(new_thread), cpusetsize, cpusetp)) {
                                ret = errno;
                                /* kill the new thread */
                                new_thread->force_exit = 1;
                                new_thread->flags |= THR_FLAGS_DETACHED;
                                _thr_try_gc(curthread, new_thread);
                                 /* thread lock released */
                                goto out;
                        }
                }

                _thr_report_creation(curthread, new_thread);
                THR_THREAD_UNLOCK(curthread, new_thread);
        }
out:
        if (ret != 0)
                *thread = NULL;
        return (ret);
}

static int
create_stack(struct pthread_attr *pattr)
{
        int ret;

        /* Check if a stack was specified in the thread attributes: */
        if ((pattr->stackaddr_attr) != NULL) {
                pattr->guardsize_attr = 0;
                pattr->flags |= THR_STACK_USER;
                ret = 0;
        }
        else
                ret = _thr_stack_alloc(pattr);
        return (ret);
}

static void
thread_start(struct pthread *curthread)
{
        sigset_t set;

        if (curthread->attr.suspend == THR_CREATE_SUSPENDED)
                set = curthread->sigmask;
        _thr_signal_block_setup(curthread);

        /*
         * This is used as a serialization point to allow parent
         * to report 'new thread' event to debugger or tweak new thread's
         * attributes before the new thread does real-world work.
         */
        THR_LOCK(curthread);
        THR_UNLOCK(curthread);

        if (curthread->force_exit)
                _pthread_exit(PTHREAD_CANCELED);

        if (curthread->attr.suspend == THR_CREATE_SUSPENDED) {
#if 0
                /* Done in THR_UNLOCK() */
                _thr_ast(curthread);
#endif

                /*
                 * Parent thread have stored signal mask for us,
                 * we should restore it now.
                 */
                __sys_sigprocmask(SIG_SETMASK, &set, NULL);
        }

#ifdef _PTHREAD_FORCED_UNWIND
        curthread->unwind_stackend = (char *)curthread->attr.stackaddr_attr +
                curthread->attr.stacksize_attr;
#endif

        curthread->uexterr.ver = UEXTERROR_VER;
        if (__getosreldate() >= P_OSREL_EXTERRCTL)
                exterrctl(EXTERRCTL_ENABLE, 0, &curthread->uexterr);

        /* Run the current thread's start routine with argument: */
        _pthread_exit(curthread->start_routine(curthread->arg));

        /* This point should never be reached. */
        PANIC("Thread has resumed after exit");
}