pthread_cancelable.c   [plain text]

/*
 * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * Copyright 1996 1995 by Open Software Foundation, Inc. 1997 1996 1995 1994 1993 1992 1991  
 *              All Rights Reserved 
 *  
 * Permission to use, copy, modify, and distribute this software and 
 * its documentation for any purpose and without fee is hereby granted, 
 * provided that the above copyright notice appears in all copies and 
 * that both the copyright notice and this permission notice appear in 
 * supporting documentation. 
 *  
 * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE 
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
 * FOR A PARTICULAR PURPOSE. 
 *  
 * IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR 
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT, 
 * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION 
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 
 * 
 */
/*
 * MkLinux
 */

/*
 * POSIX Pthread Library
 */

#include "internal.h"

#include <stdio.h>	/* For printf(). */
#include <stdlib.h>
#include <errno.h>	/* For __mach_errno_addr() prototype. */
#include <signal.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/sysctl.h>
#include <sys/queue.h>
#include <machine/vmparam.h>
#include <mach/vm_statistics.h>

extern int __unix_conforming;
extern int _pthread_setcancelstate_internal(int state, int *oldstate, int conforming);
extern void _pthread_testcancel(pthread_t thread, int isconforming);
extern int _pthread_cond_wait(pthread_cond_t *cond,
			pthread_mutex_t *mutex,
			const struct timespec *abstime,
			int isRelative,
			int isconforming);
extern int __sigwait(const sigset_t *set, int *sig);
extern int __pthread_sigmask(int, const sigset_t *, sigset_t *);
extern int __pthread_markcancel(int);

#ifdef VARIANT_CANCELABLE
extern int __semwait_signal(int cond_sem, int mutex_sem, int timeout, int relative, __int64_t tv_sec, __int32_t tv_nsec);
#else
extern int __semwait_signal(int cond_sem, int mutex_sem, int timeout, int relative, __int64_t tv_sec, __int32_t tv_nsec)  __asm__("___semwait_signal_nocancel");
#endif

#ifndef VARIANT_CANCELABLE

/*
 * Cancel a thread
 */
int
pthread_cancel(pthread_t thread)
{
#if __DARWIN_UNIX03
	if (__unix_conforming == 0)
		__unix_conforming = 1;
#endif /* __DARWIN_UNIX03 */

	if (_pthread_lookup_thread(thread, NULL, 0) != 0)
		return(ESRCH);

	/* if the thread is a workqueue thread, then return error */
	if (thread->wqthread != 0) {
		return(ENOTSUP);
	}
#if __DARWIN_UNIX03
	int state;

	LOCK(thread->lock);
	state = thread->cancel_state |= _PTHREAD_CANCEL_PENDING;
	UNLOCK(thread->lock);
	if (state & PTHREAD_CANCEL_ENABLE)
		__pthread_markcancel(_pthread_kernel_thread(thread));
#else /* __DARWIN_UNIX03 */
	thread->cancel_state |= _PTHREAD_CANCEL_PENDING;
#endif /* __DARWIN_UNIX03 */
	return (0);
}

void
pthread_testcancel(void)
{
	pthread_t self = pthread_self();

#if __DARWIN_UNIX03
	if (__unix_conforming == 0)
		__unix_conforming = 1;
	_pthread_testcancel(self, 1);
#else /* __DARWIN_UNIX03 */
	_pthread_testcancel(self, 0);
#endif /* __DARWIN_UNIX03 */
}

/*
 * Query/update the cancelability 'state' of a thread
 */
int
pthread_setcancelstate(int state, int *oldstate)
{
#if __DARWIN_UNIX03
	if (__unix_conforming == 0) {
		__unix_conforming = 1;
	}
	return (_pthread_setcancelstate_internal(state, oldstate, 1));
#else /* __DARWIN_UNIX03 */
	return (_pthread_setcancelstate_internal(state, oldstate, 0));
#endif /* __DARWIN_UNIX03 */
}

/*
 * Query/update the cancelability 'type' of a thread
 */
int
pthread_setcanceltype(int type, int *oldtype)
{
	pthread_t self;

#if __DARWIN_UNIX03
	if (__unix_conforming == 0)
		__unix_conforming = 1;
#endif /* __DARWIN_UNIX03 */

	if ((type != PTHREAD_CANCEL_DEFERRED) &&
	    (type != PTHREAD_CANCEL_ASYNCHRONOUS))
		return EINVAL;
	self = pthread_self();
	LOCK(self->lock);
	if (oldtype)
		*oldtype = self->cancel_state & _PTHREAD_CANCEL_TYPE_MASK;
	self->cancel_state &= ~_PTHREAD_CANCEL_TYPE_MASK;
	self->cancel_state |= type;
	UNLOCK(self->lock);
#if !__DARWIN_UNIX03
	_pthread_testcancel(self, 0);  /* See if we need to 'die' now... */
#endif /* __DARWIN_UNIX03 */
	return (0);
}

int
pthread_sigmask(int how, const sigset_t * set, sigset_t * oset)
{
#if __DARWIN_UNIX03
	int err = 0;

	if (__pthread_sigmask(how, set, oset) == -1) {
		err = errno;
	}
	return(err);
#else /* __DARWIN_UNIX03 */
	return(__pthread_sigmask(how, set, oset));
#endif /* __DARWIN_UNIX03 */
}

#endif /* VARIANT_CANCELABLE */

#if __DARWIN_UNIX03

static void
__posix_join_cleanup(void *arg)
{
	pthread_t thread = (pthread_t)arg;

	LOCK(thread->lock);
	/* leave another thread to join */
	thread->joiner = (struct _pthread *)NULL;
	UNLOCK(thread->lock);
}

#endif /* __DARWIN_UNIX03 */

/*
 * Wait for a thread to terminate and obtain its exit value.
 */
int       
pthread_join(pthread_t thread, 
	     void **value_ptr)
{
	int res = 0;
	pthread_t self = pthread_self();
	mach_port_t kthport;
	int conforming = 0;
#if !__DARWIN_UNIX03
	kern_return_t kern_res;
#endif

#if __DARWIN_UNIX03
	if (__unix_conforming == 0)
		__unix_conforming = 1;

#ifdef VARIANT_CANCELABLE
	_pthread_testcancel(self, 1);
#endif /* VARIANT_CANCELABLE */
#endif /* __DARWIN_UNIX03 */

	if ((res = _pthread_lookup_thread(thread, &kthport, 1)) != 0)
		return(res);

	if (thread->sig == _PTHREAD_SIG) {
		semaphore_t death = SEMAPHORE_NULL; /* in case we need it */
		semaphore_t joinsem = SEMAPHORE_NULL;

		if (thread->joiner_notify == SEMAPHORE_NULL) {
			death = (semaphore_t)os_get_cached_semaphore();
		}

		LOCK(thread->lock);
		if ((thread->detached & PTHREAD_CREATE_JOINABLE) &&
				(thread->joiner == NULL)) {
			PTHREAD_ASSERT(_pthread_kernel_thread(thread) == kthport);
			if (thread != self && (self == NULL || self->joiner != thread)) {
				if (thread->joiner_notify == SEMAPHORE_NULL) {
					thread->joiner_notify = death;
					death = SEMAPHORE_NULL;
				} 
				joinsem = thread->joiner_notify;
				thread->joiner = self;
				UNLOCK(thread->lock);

				if (death != SEMAPHORE_NULL) {
					os_put_cached_semaphore((os_semaphore_t)death);
					death = SEMAPHORE_NULL;
				}
#if __DARWIN_UNIX03
				/* Wait for it to signal... */ 
				pthread_cleanup_push(__posix_join_cleanup, (void *)thread);
				do {
					res = __semwait_signal(joinsem, 0, 0, 0, (int64_t)0, (int32_t)0);
				} while ((res < 0) && (errno == EINTR));
				pthread_cleanup_pop(0);
#else /* __DARWIN_UNIX03 */
				/* Wait for it to signal... */ 
				do {
					kern_res = semaphore_wait(joinsem);
				} while (kern_res != KERN_SUCCESS);
#endif /* __DARWIN_UNIX03 */

				os_put_cached_semaphore((os_semaphore_t)joinsem);
				res = _pthread_join_cleanup(thread, value_ptr, conforming);
			} else {
				UNLOCK(thread->lock);
				res = EDEADLK;
			}
		} else {
			UNLOCK(thread->lock);
			res = EINVAL;
		}
		if (death != SEMAPHORE_NULL) {
			os_put_cached_semaphore((os_semaphore_t)death);
		}
		return res;
	}
	return ESRCH;
}

int       
pthread_cond_wait(pthread_cond_t *cond, 
		  pthread_mutex_t *mutex)
{
	int conforming;
#if __DARWIN_UNIX03

	if (__unix_conforming == 0)
		__unix_conforming = 1;

#ifdef VARIANT_CANCELABLE
	conforming = 1;
#else /* !VARIANT_CANCELABLE */
	conforming = -1;
#endif /* VARIANT_CANCELABLE */
#else /* __DARWIN_UNIX03 */
	conforming = 0;
#endif /* __DARWIN_UNIX03 */
	return (_pthread_cond_wait(cond, mutex, (struct timespec *)NULL, 0, conforming));
}

int       
pthread_cond_timedwait(pthread_cond_t *cond, 
		       pthread_mutex_t *mutex,
		       const struct timespec *abstime)
{
	int conforming;
#if __DARWIN_UNIX03
	if (__unix_conforming == 0)
		__unix_conforming = 1;

#ifdef VARIANT_CANCELABLE
	conforming = 1;
#else /* !VARIANT_CANCELABLE */
	conforming = -1;
#endif /* VARIANT_CANCELABLE */
#else /* __DARWIN_UNIX03 */
        conforming = 0;
#endif /* __DARWIN_UNIX03 */

	return (_pthread_cond_wait(cond, mutex, abstime, 0, conforming));
}

int
sigwait(const sigset_t * set, int * sig)
{
#if __DARWIN_UNIX03
	int err = 0;

	if (__unix_conforming == 0)
		__unix_conforming = 1;

#ifdef VARIANT_CANCELABLE
	_pthread_testcancel(pthread_self(), 1);
#endif /* VARIANT_CANCELABLE */

	if (__sigwait(set, sig) == -1) {
		err = errno;

#ifdef VARIANT_CANCELABLE
		_pthread_testcancel(pthread_self(), 1);
#endif /* VARIANT_CANCELABLE */
		
		/* 
		 * EINTR that isn't a result of pthread_cancel()
		 * is translated to 0.
		 */
		if (err == EINTR) {
			err = 0;
		}
	}
	return(err);
#else /* __DARWIN_UNIX03 */
	if (__sigwait(set, sig) == -1) {
		/* 
		 * EINTR that isn't a result of pthread_cancel()
		 * is translated to 0.
		 */
		if (errno != EINTR) {
			return -1;
		}
	}

	return 0;
#endif /* __DARWIN_UNIX03 */
}