source: branches/libc-0.6/src/gcc/libobjc/thr-posix.c@ 2777

/* GNU Objective C Runtime Thread Interface for POSIX compliant threads
   Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   Contributed by Galen C. Hunt ([email protected])
   Modified for Linux/Pthreads by Kai-Uwe Sattler ([email protected])
   Modified for posix compliance by Chris Ball ([email protected])

This file is part of GNU CC.

GNU CC 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 2, or (at your option) any later version.

GNU CC 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 GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* As a special exception, if you link this library with files compiled with
   GCC to produce an executable, this does not cause the resulting executable
   to be covered by the GNU General Public License. This exception does not
   however invalidate any other reasons why the executable file might be
   covered by the GNU General Public License.  */

#include <objc/thr.h>
#include "runtime.h"
#include <pthread.h>

/* Key structure for maintaining thread specific storage */
static pthread_key_t _objc_thread_storage;
static pthread_attr_t _objc_thread_attribs;

/* Backend initialization functions */

/* Initialize the threads subsystem. */
int
__objc_init_thread_system(void)
{
  /* Initialize the thread storage key */
  if (pthread_key_create(&_objc_thread_storage, NULL) == 0)
    {
      /*
       * The normal default detach state for threads is PTHREAD_CREATE_JOINABLE
       * which causes threads to not die when you think they should.
           */
      if (pthread_attr_init(&_objc_thread_attribs) == 0)
        {
          if (pthread_attr_setdetachstate(&_objc_thread_attribs, 
                                          PTHREAD_CREATE_DETACHED) == 0)
            return 0;
        }
    }

  return -1;
}

/* Close the threads subsystem. */
int
__objc_close_thread_system(void)
{
  if (pthread_key_delete(_objc_thread_storage) == 0)
    {
      if (pthread_attr_destroy(&_objc_thread_attribs) == 0)
        return 0;
    }

  return -1;
}

/* 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;
  pthread_t new_thread_handle;
  
  if (!(pthread_create(&new_thread_handle, &_objc_thread_attribs, 
                       (void *)func, arg)))
    thread_id = *(objc_thread_t *)&new_thread_handle;
  else
    thread_id = NULL;
  
  return thread_id;
}

/* Set the current thread's priority.
 *
 * Be aware that the default schedpolicy often disallows thread priorities.
 */
int
__objc_thread_set_priority(int priority)
{
  pthread_t thread_id = pthread_self();
  int policy;
  struct sched_param params;
  int priority_min, priority_max;

  if (pthread_getschedparam(thread_id, &policy, &params) == 0)
    {
      if ((priority_max = sched_get_priority_max(policy)) != 0)
        return -1;

      if ((priority_min = sched_get_priority_min(policy)) != 0)
        return -1;

      if (priority > priority_max)
        priority = priority_max;
      else if (priority < priority_min)
        priority = priority_min;
      params.sched_priority = priority;

      /*
       * The solaris 7 and several other man pages incorrectly state that
       * this should be a pointer to policy but pthread.h is universally
       * at odds with this.
       */
      if (pthread_setschedparam(thread_id, policy, &params) == 0)
        return 0;
    }