/*
 * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
 * Copyright (c) 2003 Daniel M. Eischen <deischen@gdeb.com>
 * 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.
 *
 * 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.
 *
 * $FreeBSD: src/lib/libpthread/thread/thr_create.c,v 1.58 2004/10/23 23:28:36 davidxu Exp $
 */

#include "namespace.h"
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <stddef.h>
#include <sys/time.h>
#include <machine/reg.h>
#include <machine/tls.h>
#include <pthread.h>
#include <sys/signalvar.h>
#include <sys/lwp.h>
#include "un-namespace.h"

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

static int  create_stack(pthread_attr_t pattr);
static void thread_start(void *);

int
_pthread_create(pthread_t * __restrict thread,
    const pthread_attr_t * __restrict attr, void *(*start_routine) (void *),
    void * __restrict arg)
{
        struct lwp_params create_params;
        void *stack;
        sigset_t sigmask, oldsigmask;
        pthread_t curthread, new_thread;
        const cpu_set_t *cpumask = NULL;
        int ret = 0, locked;

        _thr_check_init();

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

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

        if (attr == NULL || *attr == NULL) {
                /* Use the default thread attributes: */
                new_thread->attr = _pthread_attr_default;
        } else {
                new_thread->attr = *(*attr);
        }
        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;
                /*
                 * scheduling policy and scheduling parameters will be
                 * inherited in following code.
                 */
        }
        if (new_thread->attr.flags & THR_CPUMASK)
                cpumask = &new_thread->attr.cpumask;

        if (create_stack(&new_thread->attr) != 0) {
                /* Insufficient memory to create a stack: */
                new_thread->terminated = 1;
                _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->cancelflags = PTHREAD_CANCEL_ENABLE |
            PTHREAD_CANCEL_DEFERRED;
        /*
         * Check if this thread is to inherit the scheduling
         * attributes from its parent:
         */
        if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
                /*
                 * Copy the scheduling attributes. Lock the scheduling
                 * lock to get consistent scheduling parameters.
                 */
                THR_LOCK(curthread);
                new_thread->base_priority = curthread->base_priority;
                new_thread->attr.prio = curthread->attr.prio;
                new_thread->attr.sched_policy = curthread->attr.sched_policy;
                THR_UNLOCK(curthread);
        } else {
                /*
                 * Use just the thread priority, leaving the
                 * other scheduling attributes as their
                 * default values:
                 */
                new_thread->base_priority = new_thread->attr.prio;
        }
        new_thread->active_priority = new_thread->base_priority;

        /* Initialize the mutex queue: */
        TAILQ_INIT(&new_thread->mutexq);

        /* Initialise hooks in the thread structure: */
        if (new_thread->attr.suspend == THR_CREATE_SUSPENDED)
                new_thread->flags = THR_FLAGS_NEED_SUSPEND;

        new_thread->state = PS_RUNNING;

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

        /* Add the new thread. */
        new_thread->refcount = 1;
        _thr_link(curthread, new_thread);
        /* Return thread pointer eariler so that new thread can use it. */
        (*thread) = new_thread;
        if (SHOULD_REPORT_EVENT(curthread, TD_CREATE)) {
                THR_THREAD_LOCK(curthread, new_thread);
                locked = 1;
        } else
                locked = 0;
        /* Schedule the new thread. */
        stack = (char *)new_thread->attr.stackaddr_attr +
                        new_thread->attr.stacksize_attr;
        bzero(&create_params, sizeof(create_params));
        create_params.lwp_func = thread_start;
        create_params.lwp_arg = new_thread;
        create_params.lwp_stack = stack;
        create_params.lwp_tid1 = &new_thread->tid;
        /*
         * Thread created by thr_create() inherits currrent thread
         * sigmask, however, before new thread setup itself correctly,
         * it can not handle signal, so we should mask all signals here.
         * We do this at the very last moment, so that we don't run
         * into problems while we have all signals disabled.
         */
        SIGFILLSET(sigmask);
        __sys_sigprocmask(SIG_SETMASK, &sigmask, &oldsigmask);
        new_thread->sigmask = oldsigmask;
        ret = lwp_create2(&create_params, cpumask);
        __sys_sigprocmask(SIG_SETMASK, &oldsigmask, NULL);
        if (ret != 0) {
                if (!locked)
                        THR_THREAD_LOCK(curthread, new_thread);
                new_thread->state = PS_DEAD;
                new_thread->terminated = 1;
                if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
                        new_thread->cycle++;
                        _thr_umtx_wake(&new_thread->cycle, 0);
                }
                THR_THREAD_UNLOCK(curthread, new_thread);
                THREAD_LIST_LOCK(curthread);
                _thread_active_threads--;
                new_thread->tlflags |= TLFLAGS_DETACHED;
                _thr_ref_delete_unlocked(curthread, new_thread);
                THREAD_LIST_UNLOCK(curthread);
                (*thread) = NULL;
                ret = EAGAIN;
        } else if (locked) {
                _thr_report_creation(curthread, new_thread);
                THR_THREAD_UNLOCK(curthread, new_thread);
        }
        return (ret);
}

static int
create_stack(pthread_attr_t 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(void *arg)
{
        pthread_t curthread = (pthread_t)arg;

        tls_set_tcb(curthread->tcb);

        /* Thread was created with all signals blocked, unblock them. */
        __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL);

        THR_LOCK(curthread);
        THR_UNLOCK(curthread);

        if (curthread->flags & THR_FLAGS_NEED_SUSPEND)
                _thr_suspend_check(curthread);
        _libc_thr_init();

        /* 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");
}

__strong_reference(_pthread_create, pthread_create);