Example #1
0
kern_return_t
semaphore_timedwait_signal_trap_internal(
	mach_port_name_t wait_name,
	mach_port_name_t signal_name,
	unsigned int sec,
	clock_res_t nsec,
	void (*caller_cont)(kern_return_t))
{
	semaphore_t wait_semaphore;
	semaphore_t signal_semaphore;
	mach_timespec_t wait_time;
	kern_return_t kr;

	wait_time.tv_sec = sec;
	wait_time.tv_nsec = nsec;
	if(BAD_MACH_TIMESPEC(&wait_time))
		return KERN_INVALID_VALUE;
	
	kr = port_name_to_semaphore(signal_name, &signal_semaphore);
	if (kr == KERN_SUCCESS) {
		kr = port_name_to_semaphore(wait_name, &wait_semaphore);
		if (kr == KERN_SUCCESS) {
			kr = semaphore_wait_internal(wait_semaphore,
					signal_semaphore,
					&wait_time,
					caller_cont);
			semaphore_dereference(wait_semaphore);
		}
		semaphore_dereference(signal_semaphore);
	}
	return kr;
}
Example #2
0
/*
 *	Routine:	semaphore_destroy
 *
 *	Destroys a semaphore and consume the caller's reference on the
 *	semaphore.
 */
kern_return_t
semaphore_destroy(
	task_t			task,
	semaphore_t		semaphore)
{
	spl_t spl_level;

	if (semaphore == SEMAPHORE_NULL)
		return KERN_INVALID_ARGUMENT;

	if (task == TASK_NULL) {
		semaphore_dereference(semaphore);
		return KERN_INVALID_ARGUMENT;
	}

	task_lock(task);
	spl_level = splsched();
	semaphore_lock(semaphore);

	if (semaphore->owner != task) {
		semaphore_unlock(semaphore);
		splx(spl_level);
		task_unlock(task);
		return KERN_INVALID_ARGUMENT;
	}
			
	semaphore_destroy_internal(task, semaphore);
	/* semaphore unlocked */

	splx(spl_level);
	task_unlock(task);

	semaphore_dereference(semaphore);
	return KERN_SUCCESS;
}
Example #3
0
/*
 *	Routine:	semaphore_wait_continue
 *
 *	Common continuation routine after waiting on a semphore.
 *	It returns directly to user space.
 */
void
semaphore_wait_continue(void)
{
	thread_t self = current_thread();
	int wait_result = self->wait_result;
	void (*caller_cont)(kern_return_t) = self->sth_continuation;

	assert(self->sth_waitsemaphore != SEMAPHORE_NULL);
	semaphore_dereference(self->sth_waitsemaphore);
	if (self->sth_signalsemaphore != SEMAPHORE_NULL)
		semaphore_dereference(self->sth_signalsemaphore);

	assert(caller_cont != (void (*)(kern_return_t))0);
	(*caller_cont)(semaphore_convert_wait_result(wait_result));
}
Example #4
0
/*
 *	Routine:	semaphore_signal_thread_trap
 *
 *	Trap interface to the semaphore_signal_thread function.
 */
kern_return_t
semaphore_signal_thread_trap(
	struct semaphore_signal_thread_trap_args *args)
{
	mach_port_name_t sema_name = args->signal_name;
	mach_port_name_t thread_name = args->thread_name;
	semaphore_t	semaphore;
	thread_t	thread;
	kern_return_t	kr;

	/* 
	 * MACH_PORT_NULL is not an error. It means that we want to
	 * select any one thread that is already waiting, but not to
	 * pre-post the semaphore.
	 */
	if (thread_name != MACH_PORT_NULL) {
		thread = port_name_to_thread(thread_name);
		if (thread == THREAD_NULL)
			return KERN_INVALID_ARGUMENT;
	} else
		thread = THREAD_NULL;

	kr = port_name_to_semaphore(sema_name, &semaphore);
	if (kr == KERN_SUCCESS) {
		kr = semaphore_signal_internal(semaphore,
				thread,
				SEMAPHORE_OPTION_NONE);
		semaphore_dereference(semaphore);
	}
	if (thread != THREAD_NULL) {
		thread_deallocate(thread);
	}
	return kr;
}
Example #5
0
/*
 *	Routine:	semaphore_destroy
 *
 *	Destroys a semaphore.  This call will only succeed if the
 *	specified task is the SAME task name specified at the semaphore's
 *	creation.
 *
 *	All threads currently blocked on the semaphore are awoken.  These
 *	threads will return with the KERN_TERMINATED error.
 */
kern_return_t
semaphore_destroy(
	task_t			task,
	semaphore_t		semaphore)
{
	int				old_count;
	spl_t			spl_level;


	if (task == TASK_NULL || semaphore == SEMAPHORE_NULL)
		return KERN_INVALID_ARGUMENT;

	/*
	 *  Disown semaphore
	 */
	task_lock(task);
	if (semaphore->owner != task) {
		task_unlock(task);
		return KERN_INVALID_ARGUMENT;
	}
	remqueue(&task->semaphore_list, (queue_entry_t) semaphore);
	semaphore->owner = TASK_NULL;
	task->semaphores_owned--;
	task_unlock(task);

	spl_level = splsched();
	semaphore_lock(semaphore);

	/*
	 *  Deactivate semaphore
	 */
	assert(semaphore->active);
	semaphore->active = FALSE;

	/*
	 *  Wakeup blocked threads  
	 */
	old_count = semaphore->count;
	semaphore->count = 0;

	if (old_count < 0) {
		wait_queue_wakeup64_all_locked(&semaphore->wait_queue,
					     SEMAPHORE_EVENT,
					     THREAD_RESTART,
					     TRUE);		/* unlock? */
	} else {
		semaphore_unlock(semaphore);
	}
	splx(spl_level);

	/*
	 *  Deallocate
	 *
	 *  Drop the semaphore reference, which in turn deallocates the
	 *  semaphore structure if the reference count goes to zero.
	 */
	ipc_port_dealloc_kernel(semaphore->port);
	semaphore_dereference(semaphore);
	return KERN_SUCCESS;
}
Example #6
0
kern_return_t
semaphore_timedwait_trap_internal(
	mach_port_name_t name,
	unsigned int            sec,
	clock_res_t             nsec,
	void (*caller_cont)(kern_return_t))
{
	semaphore_t semaphore;
	mach_timespec_t wait_time;
	kern_return_t kr;

	wait_time.tv_sec = sec;
	wait_time.tv_nsec = nsec;
	if(BAD_MACH_TIMESPEC(&wait_time))
		return KERN_INVALID_VALUE;
	
	kr = port_name_to_semaphore(name, &semaphore);
	if (kr == KERN_SUCCESS) {
		int				option = SEMAPHORE_OPTION_NONE;
		uint64_t		deadline = 0;

		if (sec == 0 && nsec == 0)
			option = SEMAPHORE_TIMEOUT_NOBLOCK;
		else
			deadline = semaphore_deadline(sec, nsec);

		kr = semaphore_wait_internal(semaphore,
				SEMAPHORE_NULL,
				deadline, option,
				caller_cont);
		semaphore_dereference(semaphore);
	}
	return kr;
}
Example #7
0
/*
 *	Routine:	semaphore_create
 *
 *	Creates a semaphore.
 *	The port representing the semaphore is returned as a parameter.
 */
kern_return_t
semaphore_create(
	task_t			task,
	semaphore_t		*new_semaphore,
	int				policy,
	int				value)
{
	semaphore_t		 s = SEMAPHORE_NULL;



	if (task == TASK_NULL || value < 0 || policy > SYNC_POLICY_MAX) {
		*new_semaphore = SEMAPHORE_NULL;
		return KERN_INVALID_ARGUMENT;
	}

	s = (semaphore_t) zalloc (semaphore_zone);

	if (s == SEMAPHORE_NULL) {
		*new_semaphore = SEMAPHORE_NULL;
		return KERN_RESOURCE_SHORTAGE; 
	}

	wait_queue_init(&s->wait_queue, policy); /* also inits lock */
	s->count = value;
	s->ref_count = 1;

	/*
	 *  Create and initialize the semaphore port
	 */
	s->port	= ipc_port_alloc_kernel();
	if (s->port == IP_NULL) {	
		/* This will deallocate the semaphore */	
		semaphore_dereference(s);
		*new_semaphore = SEMAPHORE_NULL;
		return KERN_RESOURCE_SHORTAGE; 
	}

	ipc_kobject_set (s->port, (ipc_kobject_t) s, IKOT_SEMAPHORE);

	/*
	 *  Associate the new semaphore with the task by adding
	 *  the new semaphore to the task's semaphore list.
	 *
	 *  Associate the task with the new semaphore by having the
	 *  semaphores task pointer point to the owning task's structure.
	 */
	task_lock(task);
	enqueue_head(&task->semaphore_list, (queue_entry_t) s);
	task->semaphores_owned++;
	s->owner = task;
	s->active = TRUE;
	task_unlock(task);

	*new_semaphore = s;

	return KERN_SUCCESS;
}		  
Example #8
0
/*
 * Routine:	semaphore_notify
 * Purpose:
 *	Called whenever the Mach port system detects no-senders
 *	on the semaphore port.
 *
 *	When a send-right is first created, a no-senders
 *	notification is armed (and a semaphore reference is donated).
 *
 *	A no-senders notification will be posted when no one else holds a
 *	send-right (reference) to the semaphore's port. This notification function
 *	will consume the semaphore reference donated to the extant collection of
 *	send-rights.
 */
void
semaphore_notify(mach_msg_header_t *msg)
{
	mach_no_senders_notification_t *notification = (void *)msg;
	ipc_port_t port = notification->not_header.msgh_remote_port;
	semaphore_t semaphore;

	assert(ip_active(port));
	assert(IKOT_SEMAPHORE == ip_kotype(port));
	semaphore = (semaphore_t)port->ip_kobject;

	semaphore_dereference(semaphore);
}
Example #9
0
kern_return_t
semaphore_wait_signal_trap_internal(
	mach_port_name_t wait_name,
	mach_port_name_t signal_name,
	void (*caller_cont)(kern_return_t))
{
	semaphore_t wait_semaphore;
	semaphore_t signal_semaphore;
	kern_return_t kr;

	kr = port_name_to_semaphore(signal_name, &signal_semaphore);
	if (kr == KERN_SUCCESS) {
		kr = port_name_to_semaphore(wait_name, &wait_semaphore);
		if (kr == KERN_SUCCESS) {
			kr = semaphore_wait_internal(wait_semaphore,
					signal_semaphore,
					(mach_timespec_t *)0,
					caller_cont);
			semaphore_dereference(wait_semaphore);
		}
		semaphore_dereference(signal_semaphore);
	}
	return kr;
}
Example #10
0
kern_return_t
semaphore_wait_signal_trap_internal(
	mach_port_name_t wait_name,
	mach_port_name_t signal_name,
	void (*caller_cont)(kern_return_t))
{
	semaphore_t wait_semaphore;
	semaphore_t signal_semaphore;
	kern_return_t kr;

	kr = port_name_to_semaphore(signal_name, &signal_semaphore);
	if (kr == KERN_SUCCESS) {
		kr = port_name_to_semaphore(wait_name, &wait_semaphore);
		if (kr == KERN_SUCCESS) {
			kr = semaphore_wait_internal(wait_semaphore,
					signal_semaphore,
					0ULL, SEMAPHORE_OPTION_NONE,
					caller_cont);
			semaphore_dereference(wait_semaphore);
		}
		semaphore_dereference(signal_semaphore);
	}
	return kr;
}
Example #11
0
kern_return_t
semaphore_signal_internal_trap(mach_port_name_t sema_name)
{
	semaphore_t	semaphore;
	kern_return_t kr;

	kr = port_name_to_semaphore(sema_name, &semaphore);
	if (kr == KERN_SUCCESS) {
		kr = semaphore_signal_internal(semaphore, 
				THREAD_NULL, 
				SEMAPHORE_SIGNAL_PREPOST);
		semaphore_dereference(semaphore);
		if (kr == KERN_NOT_WAITING)
			kr = KERN_SUCCESS;
	}
	return kr;
}
Example #12
0
kern_return_t
semaphore_wait_trap_internal(
	mach_port_name_t name, 
	void (*caller_cont)(kern_return_t))
{	
	semaphore_t	semaphore;
	kern_return_t kr;

	kr = port_name_to_semaphore(name, &semaphore);
	if (kr == KERN_SUCCESS) {
		kr = semaphore_wait_internal(semaphore,
				SEMAPHORE_NULL,
				(mach_timespec_t *)0,
				caller_cont);
		semaphore_dereference(semaphore);
	}
	return kr;
}
Example #13
0
/*
 *	Routine:	convert_semaphore_to_port
 *	Purpose:
 *		Convert a semaphore reference to a send right to a
 *		semaphore port.
 *
 *		Consumes the semaphore reference.  If the semaphore
 *		port currently has no send rights (or doesn't exist
 *		yet), the reference is donated to the port to represent
 *		all extant send rights collectively.
 */
ipc_port_t
convert_semaphore_to_port (semaphore_t semaphore)
{
	ipc_port_t port, send;

	if (semaphore == SEMAPHORE_NULL)
		return (IP_NULL);

	/* caller is donating a reference */
	port = semaphore->port;

	if (!IP_VALID(port)) {
		port = ipc_port_alloc_kernel();
		assert(IP_VALID(port));
		ipc_kobject_set_atomically(port, (ipc_kobject_t) semaphore, IKOT_SEMAPHORE);

		/* If we lose the race, deallocate and pick up the other guy's port */
		if (!OSCompareAndSwapPtr(IP_NULL, port, &semaphore->port)) {
			ipc_port_dealloc_kernel(port);
			port = semaphore->port;
			assert(ip_kotype(port) == IKOT_SEMAPHORE);
			assert(port->ip_kobject == (ipc_kobject_t)semaphore);
		}
	}

	ip_lock(port);
	assert(ip_active(port));
	send = ipc_port_make_send_locked(port);

	if (1 == port->ip_srights) {
		ipc_port_t old_notify;

		/* transfer our ref to the port, and arm the no-senders notification */
		assert(IP_NULL == port->ip_nsrequest);
		ipc_port_nsrequest(port, port->ip_mscount, ipc_port_make_sonce_locked(port), &old_notify);
		/* port unlocked */
		assert(IP_NULL == old_notify);
	} else {
		/* piggyback on the existing port reference, so consume ours */
		ip_unlock(port);
		semaphore_dereference(semaphore);
	}
	return (send);
}
Example #14
0
/*
 *	Routine:	semaphore_signal_all_trap
 *
 *	Trap interface to the semaphore_signal_all function.
 */
kern_return_t
semaphore_signal_all_trap(
	struct semaphore_signal_all_trap_args *args)
{
	mach_port_name_t sema_name = args->signal_name;
	semaphore_t	semaphore;
	kern_return_t kr;

	kr = port_name_to_semaphore(sema_name, &semaphore);
	if (kr == KERN_SUCCESS) {
		kr = semaphore_signal_internal(semaphore,
				THREAD_NULL, 
				SEMAPHORE_SIGNAL_ALL);
		semaphore_dereference(semaphore);
		if (kr == KERN_NOT_WAITING)
			kr = KERN_SUCCESS;
	}
	return kr;
}