gcc/libobjc/thr-mach.c

313 lines
6.9 KiB
C

/* GNU Objective C Runtime Thread Implementation
Copyright (C) 1996, 1997, 2002, 2009 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 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 <mach/mach.h>
#include <mach/cthreads.h>
#include "objc/thr.h"
#include "objc/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 */