/* GNU Objective C Runtime Thread Interface
   Copyright (C) 1996, 1997, 2009 Free Software Foundation, Inc.
   Contributed by Galen C. Hunt (gchunt@cs.rochester.edu)
   Conditions added by Mircea Oancea (mircea@first.elcom.pub.ro)
      
This file is part of GCC.

GCC 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; either version 3, or (at your option) any later version.

GCC 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.

Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.

You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
<http://www.gnu.org/licenses/>.  */


#include "objc/thr.h"
#include "objc/runtime.h"

#include <thread.h>
#include <synch.h>
#include <errno.h>

/* Key structure for maintaining thread specific storage */
static thread_key_t     __objc_thread_data_key;

/* Backend initialization functions */

/* Initialize the threads subsystem. */
int
__objc_init_thread_system(void)
{
  /* Initialize the thread storage key */
  if (thr_keycreate(&__objc_thread_data_key, NULL) == 0)
    return 0;
  else
    return -1;
}

/* Close the threads subsystem. */
int
__objc_close_thread_system(void)
{
  return 0;
}

/* Backend thread functions */

/* Create a new thread of execution. */
objc_thread_t
__objc_thread_detach(void (*func)(void *arg), void *arg)
{
  objc_thread_t thread_id;
  thread_t new_thread_id = 0;

  if (thr_create(NULL, 0, (void *)func, arg,
                 THR_DETACHED | THR_NEW_LWP,
                 &new_thread_id) == 0)
    thread_id = *(objc_thread_t *)&new_thread_id;
  else
    thread_id = NULL;
  
  return thread_id;
}

/* Set the current thread's priority. */
int
__objc_thread_set_priority(int priority)
{
  int sys_priority = 0;

  switch (priority)
    {
    case OBJC_THREAD_INTERACTIVE_PRIORITY:
      sys_priority = 300;
      break;
    default:
    case OBJC_THREAD_BACKGROUND_PRIORITY:
      sys_priority = 200;
      break;
    case OBJC_THREAD_LOW_PRIORITY:
      sys_priority = 1000;
      break;
    }

  /* Change priority */
  if (thr_setprio(thr_self(), sys_priority) == 0)
    return 0;
  else
    return -1;
}

/* Return the current thread's priority. */
int
__objc_thread_get_priority(void)
{
  int sys_priority;
                                                   
  if (thr_getprio(thr_self(), &sys_priority) == 0)
    {
      if (sys_priority >= 250)
	return OBJC_THREAD_INTERACTIVE_PRIORITY;
      else if (sys_priority >= 150)
	return OBJC_THREAD_BACKGROUND_PRIORITY;
      return OBJC_THREAD_LOW_PRIORITY;
    }

  /* Couldn't get priority. */
  return -1;
}

/* Yield our process time to another thread. */
void
__objc_thread_yield(void)
{
  thr_yield();
}

/* Terminate the current thread. */
int
__objc_thread_exit(void)
{
  /* exit the thread */
  thr_exit(&__objc_thread_exit_status);

  /* Failed if we reached here */
  return -1;
}

/* Returns an integer value which uniquely describes a thread. */
objc_thread_t
__objc_thread_id(void)
{
  return (objc_thread_t)thr_self();
}

/* Sets the thread's local storage pointer. */
int
__objc_thread_set_data(void *value)
{
  if (thr_setspecific(__objc_thread_data_key, value) == 0)
    return 0;
  else
    return -1;
}

/* Returns the thread's local storage pointer. */
void *
__objc_thread_get_data(void)
{
  void *value = NULL;

  if (thr_getspecific(__objc_thread_data_key, &value) == 0)
    return value;

  return NULL;
}

/* Backend mutex functions */

/* Allocate a mutex. */
int
__objc_mutex_allocate(objc_mutex_t mutex)
{
  if (mutex_init( (mutex_t *)(&(mutex->backend)), USYNC_THREAD, 0))
    return -1;
  else
    return 0;
}


/* Deallocate a mutex. */
int
__objc_mutex_deallocate(objc_mutex_t mutex)
{
  mutex_destroy((mutex_t *)(&(mutex->backend)));
  return 0;
}

/* Grab a lock on a mutex. */
int
__objc_mutex_lock(objc_mutex_t mutex)
{
  if (mutex_lock((mutex_t *)(&(mutex->backend))) != 0)
    return -1;
  else
    return 0;
}

/* Try to grab a lock on a mutex. */
int
__objc_mutex_trylock(objc_mutex_t mutex)
{
  if (mutex_trylock((mutex_t *)(&(mutex->backend))) != 0)
    return -1;
  else
    return 0;
}

/* Unlock the mutex */
int
__objc_mutex_unlock(objc_mutex_t mutex)
{
  if (mutex_unlock((mutex_t *)(&(mutex->backend))) != 0)
    return -1;
  else
    return 0;
}

/* Backend condition mutex functions */

/* Allocate a condition. */
int
__objc_condition_allocate(objc_condition_t condition)
{
  return cond_init((cond_t *)(&(condition->backend)), USYNC_THREAD, NULL);
}

/* Deallocate a condition. */
int
__objc_condition_deallocate(objc_condition_t condition)
{
  return cond_destroy((cond_t *)(&(condition->backend)));
}

/* Wait on the condition */
int
__objc_condition_wait(objc_condition_t condition, objc_mutex_t mutex)
{
  return cond_wait((cond_t *)(&(condition->backend)),
		   (mutex_t *)(&(mutex->backend)));
}

/* Wake up all threads waiting on this condition. */
int
__objc_condition_broadcast(objc_condition_t condition)
{
  return cond_broadcast((cond_t *)(&(condition->backend)));
}

/* Wake up one thread waiting on this condition. */
int
__objc_condition_signal(objc_condition_t condition)
{
  return cond_signal((cond_t *)(&(condition->backend)));
}

/* End of File */