/* GNU Objective C Runtime Thread Implementation   Copyright (C) 1996, 1997 Free Software Foundation, Inc.   Contributed by Galen C. Hunt (gchunt@cs.rochester.edu)   Modified for Mach threads by Bill Bumgarner <bbum@friday.com>   Condition functions added by Mircea Oancea <mircea@first.elcom.pub.ro>This file is part of GNU CC.GNU CC is free software; you can redistribute it and/or modify it under theterms of the GNU General Public License as published by the Free SoftwareFoundation; either version 2, or (at your option) any later version.GNU CC is distributed in the hope that it will be useful, but WITHOUT ANYWARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESSFOR A PARTICULAR PURPOSE.  See the GNU General Public License for moredetails.You should have received a copy of the GNU General Public Licensealong with GNU CC; see the file COPYING.  If not, write tothe 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 <mach/mach.h>#include <mach/cthreads.h>#include <objc/thr.h>#include "runtime.h"/*  Obtain the maximum thread priority that can set for t.  Under the  mach threading model, it is possible for the developer to adjust the  maximum priority downward only-- cannot be raised without superuser  privileges.  Once lowered, it cannot be raised.  */static int __mach_get_max_thread_priority(cthread_t t, int *base){  thread_t threadP;  kern_return_t error;  struct thread_sched_info info;  unsigned int info_count=THREAD_SCHED_INFO_COUNT;      if (t == NULL)    return -1;  threadP  = cthread_thread(t); 	/* get thread underlying */  error=thread_info(threadP, THREAD_SCHED_INFO, 		    (thread_info_t)&info, &info_count);  if (error != KERN_SUCCESS)    return -1;  if (base != NULL)    *base = info.base_priority;  return info.max_priority;}	/* Backend initialization functions *//* Initialize the threads subsystem. */int__objc_init_thread_system(void){  return 0;}/* 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;  cthread_t new_thread_handle;  /* create thread */  new_thread_handle = cthread_fork((cthread_fn_t)func, arg);  if(new_thread_handle)    {      /* this is not terribly portable */      thread_id = *(objc_thread_t *)&new_thread_handle;       cthread_detach(new_thread_handle);    }  else    thread_id = NULL;    return thread_id;}/* Set the current thread's priority. */int__objc_thread_set_priority(int priority){  objc_thread_t *t = objc_thread_id();  cthread_t cT = (cthread_t) t;   int maxPriority = __mach_get_max_thread_priority(cT, NULL);  int sys_priority = 0;  if (maxPriority == -1)    return -1;  switch (priority)    {    case OBJC_THREAD_INTERACTIVE_PRIORITY:      sys_priority = maxPriority;      break;    case OBJC_THREAD_BACKGROUND_PRIORITY:      sys_priority = (maxPriority * 2) / 3;      break;    case OBJC_THREAD_LOW_PRIORITY:      sys_priority = maxPriority / 3;      break;    default:      return -1;    }  if (sys_priority == 0)    return -1;  /* Change the priority */  if (cthread_priority(cT, sys_priority, 0) == KERN_SUCCESS)    return 0;  else    return -1;}/* Return the current thread's priority. */int__objc_thread_get_priority(void){  objc_thread_t *t = objc_thread_id();  cthread_t cT = (cthread_t) t; /* see objc_thread_id() */  int basePriority;  int maxPriority;  int sys_priority = 0;  int interactiveT, backgroundT, lowT; /* thresholds */  maxPriority = __mach_get_max_thread_priority(cT, &basePriority);  if(maxPriority == -1)    return -1;  if (basePriority > ( (maxPriority * 2) / 3))    return OBJC_THREAD_INTERACTIVE_PRIORITY;  if (basePriority > ( maxPriority / 3))    return OBJC_THREAD_BACKGROUND_PRIORITY;  return OBJC_THREAD_LOW_PRIORITY;}/* Yield our process time to another thread. */void__objc_thread_yield(void){  cthread_yield();}/* Terminate the current thread. */int__objc_thread_exit(void){  /* exit the thread */  cthread_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){  cthread_t self = cthread_self();  return *(objc_thread_t *)&self;}/* Sets the thread's local storage pointer. */int__objc_thread_set_data(void *value){  cthread_set_data(cthread_self(), (any_t) value);  return 0;}/* Returns the thread's local storage pointer. */void *__objc_thread_get_data(void){  return (void *) cthread_data(cthread_self());}/* Backend mutex functions *//* Allocate a mutex. */int__objc_mutex_allocate(objc_mutex_t mutex){  int err = 0;  mutex->backend = objc_malloc(sizeof(struct mutex));  err = mutex_init((mutex_t)(mutex->backend));  if (err != 0)    {      objc_free(mutex->backend);      return -1;    }  else    return 0;}/* Deallocate a mutex. */int__objc_mutex_deallocate(objc_mutex_t mutex){  mutex_clear((mutex_t)(mutex->backend));  objc_free(mutex->backend);  mutex->backend = NULL;  return 0;}/* Grab a lock on a mutex. */int__objc_mutex_lock(objc_mutex_t mutex){  mutex_lock((mutex_t)(mutex->backend));  return 0;}/* Try to grab a lock on a mutex. */int__objc_mutex_trylock(objc_mutex_t mutex){  if (mutex_try_lock((mutex_t)(mutex->backend)) == 0)    return -1;  else    return 0;}/* Unlock the mutex */int__objc_mutex_unlock(objc_mutex_t mutex){  mutex_unlock((mutex_t)(mutex->backend));  return 0;}/* Backend condition mutex functions *//* Allocate a condition. */int__objc_condition_allocate(objc_condition_t condition){  condition->backend = objc_malloc(sizeof(struct condition));  condition_init((condition_t)(condition->backend));  return 0;}/* Deallocate a condition. */int__objc_condition_deallocate(objc_condition_t condition){  condition_clear((condition_t)(condition->backend));  objc_free(condition->backend);  condition->backend = NULL;  return 0;}/* Wait on the condition */int__objc_condition_wait(objc_condition_t condition, objc_mutex_t mutex){  condition_wait((condition_t)(condition->backend),		 (mutex_t)(mutex->backend));  return 0;}/* Wake up all threads waiting on this condition. */int__objc_condition_broadcast(objc_condition_t condition){  condition_broadcast((condition_t)(condition->backend));  return 0;}/* Wake up one thread waiting on this condition. */int__objc_condition_signal(objc_condition_t condition){  condition_signal((condition_t)(condition->backend));  return 0;}/* End of File */