ObjFW  Artifact [d49b28d198]

Artifact d49b28d1980cbd377f44d1d970b065623fedbdbf468ff17aa141b61f9ae78cbb:

• File src/OFKernelEventObserver_kqueue.m — part of check-in [62e2de30b9] at 2015-02-16 08:39:17 on branch trunk — Explicitly pass errno to exceptions

  The old behaviour where the exception would access errno directly on
  creation of the exception was very fragile. The two main problems with
  it were that sometimes it would pick up an errno even though none had
  been set and in other cases that when the exception was created errno
  had already been overridden.

  This also greatly increases errno handling on Win32, especially in
  conjunction with sockets. It can still be improved further, though. (user: js, size: 4432) [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 <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 "OFOutOfMemoryException.h"
#import "OFOutOfRangeException.h"

#import "socket_helpers.h"

#define EVENTLIST_SIZE 64

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

	@try {
#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

		_changeList = [[OFDataArray alloc] initWithItemSize:
		    sizeof(struct kevent)];
		_removedArray = [[OFMutableArray alloc] init];

		[self OF_addFileDescriptorForReading: _cancelFD[0]];
	} @catch (id e) {
		[self release];
		@throw e;
	}

	return self;
}

- (void)dealloc
{
	close(_kernelQueue);

	[_changeList release];
	[_removedArray release];

	[super dealloc];
}

- (void)OF_addFileDescriptorForReading: (int)fd
{
	struct kevent event;

	if ([_changeList count] >= INT_MAX)
		@throw [OFOutOfRangeException exception];

	EV_SET(&event, fd, EVFILT_READ, EV_ADD, 0, 0, 0);
	[_changeList addItem: &event];
}

- (void)OF_addFileDescriptorForWriting: (int)fd
{
	struct kevent event;

	if ([_changeList count] >= INT_MAX)
		@throw [OFOutOfRangeException exception];

	EV_SET(&event, fd, EVFILT_WRITE, EV_ADD, 0, 0, 0);
	[_changeList addItem: &event];
}

- (void)OF_removeFileDescriptorForReading: (int)fd
{
	struct kevent event;

	EV_SET(&event, fd, EVFILT_READ, EV_DELETE, 0, 0, 0);
	[_changeList addItem: &event];
}

- (void)OF_removeFileDescriptorForWriting: (int)fd
{
	struct kevent event;

	EV_SET(&event, fd, EVFILT_WRITE, EV_DELETE, 0, 0, 0);
	[_changeList addItem: &event];
}

- (bool)observeForTimeInterval: (of_time_interval_t)timeInterval
{
	void *pool = objc_autoreleasePoolPush();
	struct timespec timeout;
	struct kevent eventList[EVENTLIST_SIZE];
	int i, events, realEvents = 0;

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

	/*
	 * Make sure to keep the streams retained and thus the file descriptors
	 * valid until the actual change has been performed.
	 */
	[self OF_processQueueAndStoreRemovedIn: _removedArray];

	if ([self OF_processCache]) {
		objc_autoreleasePoolPop(pool);
		return true;
	}

	objc_autoreleasePoolPop(pool);

	events = kevent(_kernelQueue, [_changeList items],
	    (int)[_changeList count], eventList, EVENTLIST_SIZE,
	    (timeInterval == -1 ? NULL : &timeout));

	[_removedArray removeAllObjects];

	if (events < 0)
		return false;

	[_changeList removeAllItems];

	if (events == 0)
		return false;

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

			OF_ENSURE(read(_cancelFD[0], &buffer, 1) > 0);

			continue;
		}

		realEvents++;

		pool = objc_autoreleasePoolPush();

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

		objc_autoreleasePoolPop(pool);
	}

	if (realEvents == 0)
		return false;

	return true;
}
@end