ObjFW  Artifact [3ad5dffb1b]

Artifact 3ad5dffb1bfc71df539767a5dfb649c18b9ff4e8667dd6845eaf7a990b1118d1:

• File src/OFKernelEventObserver_kqueue.m — part of check-in [e9b4700cb6] at 2015-12-29 21:33:07 on branch trunk — Refactor OFKernelEventObserver

  This moves the locked queue for actions to
  OFKernelEventObserver_LockedQueue, which is now used for select and
  poll, but skipped for kqueue and epoll, as they natively support changes
  from another thread.

  This fixes the problem that removing an object is delayed until the next
  observe call - at which point it might have already been closed, meaning
  the fd is no longer available. This was mainly a problem with kqueue, as
  closing the fd already removed it from the kqueue, which then resulted
  in an error being returned when trying to manually remove the fd from
  the kqueue. (user: js, size: 5123) [annotate] [blame] [check-ins using]

/*
 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015
 *   Jonathan Schleifer <js@webkeks.org>
 *
 * All rights reserved.
 *
 * This file is part of ObjFW. It may be distributed under the terms of the
 * Q Public License 1.0, which can be found in the file LICENSE.QPL included in
 * the packaging of this file.
 *
 * Alternatively, it may be distributed under the terms of the GNU General
 * Public License, either version 2 or 3, which can be found in the file
 * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
 * file.
 */

#include "config.h"

#include <assert.h>
#include <errno.h>
#include <math.h>

#include <fcntl.h>
#include <unistd.h>

#include <sys/types.h>
#include <sys/event.h>
#include <sys/time.h>

#import "OFKernelEventObserver.h"
#import "OFKernelEventObserver+Private.h"
#import "OFKernelEventObserver_kqueue.h"
#import "OFDataArray.h"
#import "OFArray.h"

#import "OFInitializationFailedException.h"
#import "OFObserveFailedException.h"
#import "OFOutOfRangeException.h"

#define EVENTLIST_SIZE 64

@implementation OFKernelEventObserver_kqueue
- init
{
	self = [super init];

	@try {
		struct kevent event;

#ifdef HAVE_KQUEUE1
		if ((_kernelQueue = kqueue1(O_CLOEXEC)) == -1)
			@throw [OFInitializationFailedException
			    exceptionWithClass: [self class]];
#else
		int flags;

		if ((_kernelQueue = kqueue()) == -1)
			@throw [OFInitializationFailedException
			    exceptionWithClass: [self class]];

		if ((flags = fcntl(_kernelQueue, F_GETFD, 0)) != -1)
			fcntl(_kernelQueue, F_SETFD, flags | FD_CLOEXEC);
#endif

		EV_SET(&event, _cancelFD[0], EVFILT_READ, EV_ADD, 0, 0, 0);

		if (kevent(_kernelQueue, &event, 1, NULL, 0, NULL) != 0)
			@throw [OFInitializationFailedException
			    exceptionWithClass: [self class]];
	} @catch (id e) {
		[self release];
		@throw e;
	}

	return self;
}

- (void)dealloc
{
	close(_kernelQueue);

	[super dealloc];
}

- (void)addObjectForReading: (id <OFReadyForReadingObserving>)object
{
	struct kevent event;

	memset(&event, 0, sizeof(event));
	event.ident = [object fileDescriptorForReading];
	event.filter = EVFILT_READ;
	event.flags = EV_ADD;
#ifndef OF_NETBSD
	event.udata = object;
#else
	event.udata = (intptr_t)object;
#endif

	if (kevent(_kernelQueue, &event, 1, NULL, 0, NULL) != 0)
		@throw [OFObserveFailedException
		    exceptionWithObserver: self
				    errNo: errno];
}

- (void)addObjectForWriting: (id <OFReadyForWritingObserving>)object
{
	struct kevent event;

	memset(&event, 0, sizeof(event));
	event.ident = [object fileDescriptorForWriting];
	event.filter = EVFILT_WRITE;
	event.flags = EV_ADD;
#ifndef OF_NETBSD
	event.udata = object;
#else
	event.udata = (intptr_t)object;
#endif

	if (kevent(_kernelQueue, &event, 1, NULL, 0, NULL) != 0)
		@throw [OFObserveFailedException
		    exceptionWithObserver: self
				    errNo: errno];
}

- (void)removeObjectForReading: (id <OFReadyForReadingObserving>)object
{
	struct kevent event;

	memset(&event, 0, sizeof(event));
	event.ident = [object fileDescriptorForReading];
	event.filter = EVFILT_READ;
	event.flags = EV_DELETE;

	if (kevent(_kernelQueue, &event, 1, NULL, 0, NULL) != 0)
		@throw [OFObserveFailedException
		    exceptionWithObserver: self
				    errNo: errno];
}

- (void)removeObjectForWriting: (id <OFReadyForWritingObserving>)object
{
	struct kevent event;

	memset(&event, 0, sizeof(event));
	event.ident = [object fileDescriptorForWriting];
	event.filter = EVFILT_WRITE;
	event.flags = EV_DELETE;

	if (kevent(_kernelQueue, &event, 1, NULL, 0, NULL) != 0)
		@throw [OFObserveFailedException
		    exceptionWithObserver: self
				    errNo: errno];
}

- (void)observeForTimeInterval: (of_time_interval_t)timeInterval
{
	void *pool = objc_autoreleasePoolPush();
	struct timespec timeout;
	struct kevent eventList[EVENTLIST_SIZE];
	int i, events;

	timeout.tv_sec = (time_t)timeInterval;
	timeout.tv_nsec = lrint((timeInterval - timeout.tv_sec) * 1000000000);

	[self OF_processReadBuffers];

	objc_autoreleasePoolPop(pool);

	events = kevent(_kernelQueue, NULL, 0, eventList, EVENTLIST_SIZE,
	    (timeInterval != -1 ? &timeout : NULL));

	if (events < 0)
		@throw [OFObserveFailedException exceptionWithObserver: self
								 errNo: errno];

	for (i = 0; i < events; i++) {
		if (eventList[i].flags & EV_ERROR)
			@throw [OFObserveFailedException
			    exceptionWithObserver: self
					    errNo: (int)eventList[i].data];

		if (eventList[i].ident == _cancelFD[0]) {
			char buffer;

			assert(eventList[i].filter == EVFILT_READ);
			OF_ENSURE(read(_cancelFD[0], &buffer, 1) == 1);

			continue;
		}

		pool = objc_autoreleasePoolPush();

		switch (eventList[i].filter) {
		case EVFILT_READ:
			if ([_delegate respondsToSelector:
			    @selector(objectIsReadyForReading:)])
				[_delegate objectIsReadyForReading:
				    (id)eventList[i].udata];
			break;
		case EVFILT_WRITE:
			if ([_delegate respondsToSelector:
			    @selector(objectIsReadyForWriting:)])
				[_delegate objectIsReadyForWriting:
				    (id)eventList[i].udata];
			break;
		default:
			assert(0);
		}

		objc_autoreleasePoolPop(pool);
	}
}
@end