ObjFW  Artifact [fea66ded56]

Artifact fea66ded567272aa718821bdc9817fadb204a7b8b9b32a0cfcacf284d20e34fa:

• File src/OFStreamObserver_kqueue.m — part of check-in [e1e7ffa903] at 2011-09-22 23:25:42 on branch trunk — Exceptions are now autoreleased.

  This is safe as an "exception loop" can't happen, since if allocating
  an exception fails, it throws an OFAllocFailedException which is
  preallocated and can always be thrown.

  So, the worst case would be that an autorelease of an exception fails,
  triggering an OFOutOfMemoryException for which there is no memory,
  resulting in an OFAllocFailedException to be thrown. (user: js, size: 3197) [annotate] [blame] [check-ins using]

/*
 * Copyright (c) 2008, 2009, 2010, 2011
 *   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 <unistd.h>
#include <errno.h>

#include <assert.h>

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

#import "OFStreamObserver_kqueue.h"
#import "OFDataArray.h"

#import "OFInitializationFailedException.h"
#import "OFOutOfMemoryException.h"

#define EVENTLIST_SIZE 64

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

	@try {
		if ((kernelQueue = kqueue()) == -1)
			@throw [OFInitializationFailedException
			    exceptionWithClass: isa];

		changeList = [[OFDataArray alloc] initWithItemSize:
		    sizeof(struct kevent)];

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

	return self;
}

- (void)dealloc
{
	close(kernelQueue);
	[changeList release];

	[super dealloc];
}

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

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

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

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

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

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

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

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

- (BOOL)observeWithTimeout: (int)timeout
{
	struct timespec timespec = { timeout, 0 };
	struct kevent eventList[EVENTLIST_SIZE];
	int i, events;

	[self _processQueue];

	if ([self _processCache])
		return YES;

	events = kevent(kernelQueue, [changeList cArray],
	    (int)[changeList count], eventList, EVENTLIST_SIZE,
	    (timeout == -1 ? NULL : &timespec));

	if (events == -1) {
		switch (errno) {
		case EINTR:
			return NO;
		case ENOMEM:
			@throw [OFOutOfMemoryException exceptionWithClass: isa];
		default:
			assert(0);
		}
	}

	[changeList removeNItems: [changeList count]];

	if (events == 0)
		return NO;

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

			assert(read(cancelFD[0], &buffer, 1) > 0);

			continue;
		}

		if (eventList[i].flags & EV_ERROR) {
			[delegate streamDidReceiveException:
			    FDToStream[eventList[i].ident]];
			continue;
		}

		switch (eventList[i].filter) {
		case EVFILT_READ:
			[delegate streamIsReadyForReading:
			    FDToStream[eventList[i].ident]];
			break;
		case EVFILT_WRITE:
			[delegate streamIsReadyForWriting:
			    FDToStream[eventList[i].ident]];
		default:
			assert(0);
		}
	}

	return YES;
}
@end