source: trunk/kernel/syscalls/sys_thread_exit.c @ 16

/*
 * kern/sys_thread_exit.c - terminates the execution of current thread
 * 
 * Copyright (c) 2008,2009,2010,2011,2012 Ghassan Almaless
 * Copyright (c) 2011,2012 UPMC Sorbonne Universites
 *
 * This file is part of ALMOS-kernel.
 *
 * ALMOS-kernel is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2.0 of the License.
 *
 * ALMOS-kernel is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with ALMOS-kernel; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <list.h>
#include <thread.h>
#include <scheduler.h>
#include <wait_queue.h>
#include <cluster.h>
#include <dqdt.h>
#include <process.h>

///////////////////////////////////////
int sys_thread_exit ( void * exit_val )
{
        thread_t  * this = CURRENT_THREAD;
    core_t    * core = this->core;
        bool_t      isEmpty;
        bool_t      isReleased;
    uint32_t    irq_state;

        // update DQDT TODO must be done by thread destroy 
        if(this->process->pid != 1) dqdt_local_update_threads( -1 );

        spinlock_lock( &this->lock );

        if(!(thread_isJoinable(this)))
        {
                goto exit_dead;
        }

        // Check if there's a thread waiting the end of calling thread
        isEmpty = wait_queue_isEmpty(&this->info.wait_queue);

        if(isEmpty)
        {
                this->info.exit_value = exit_val;
                wait_on(&this->info.wait_queue, WAIT_ANY);
                spinlock_unlock_nosched(&this->lock);
                sched_sleep(this);
        }
        else
        {
                this->info.join->info.exit_value = exit_val;
                wakeup_one(&this->info.wait_queue, WAIT_ANY);
                spinlock_unlock_nosched(&this->lock);
        }

exit_dead:

        isReleased = false;

        // Release FPU if required
        hal_disable_irq( &irq_state );
        if(core->fpu_owner == this)
        {
                core->fpu_owner = NULL;
                isReleased = true;
        }
        hal_restore_irq( irq_state );

        if(isReleased)
        {
                thread_dmsg(1, "INFO: Thread %x has released FPU on CPU %d\n",
                       this, 
                       current_cpu->gid);
        }

        sched_exit(this);

        PANIC ("Thread %x, CPU %d must never return", this, current_cpu->gid);
        return -1;              /* Fake return ! */
}