ObjFW  Artifact [b099b55bf8]

Artifact b099b55bf83d04ed5dfb576c824acb23b462672af471f5585d2abaa83c34dc1a:

• File src/OFKernelEventObserver.m — part of check-in [220513a3f5] at 2015-05-09 18:13:19 on branch trunk — More OFKernelEventObserver refactoring

  This was necessary because select(), poll() and kevent() on FreeBSD and
  OS X would sometimes return 0 events, even if there are some, and
  sometimes return the correct number of events that were pending, meaning
  the number of events returned is unreliable. To make things worse,
  whether it returns 0 or the number of events that were pending is
  completely non-deterministic on both FreeBSD and OS X (running the same
  tests multiple times in a row would make it sometimes work and sometimes
  fail).

  In order to prevent code from depending on the return value of
  -[observeForTimeInterval:] (which would depend on select(), poll() and
  kevent() returning the correct number), OFKernelObserver no longer
  returns whether there were pending events. It is expected that
  -[observe] or -[observeForTimeInterval:] is just called in a loop as
  long as events should be handled.

  The tests have been changed as well to reflect this. What they do now is
  set a deadline and call -[observeForTimeInterval:] with a small timeout
  in a loop until the deadline is reached or all events have been handled.

  Note: DragonFlyBSD has not been tested, but will most likely behave like
  FreeBSD and OS X. (user: js, size: 7927) [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.
 */

#define __NO_EXT_QNX

#include "config.h"

#include <assert.h>

#import "OFKernelEventObserver.h"
#import "OFKernelEventObserver+Private.h"
#import "OFArray.h"
#import "OFDictionary.h"
#import "OFStream.h"
#import "OFStream+Private.h"
#import "OFDataArray.h"
#ifndef OF_HAVE_PIPE
# import "OFStreamSocket.h"
#endif
#ifdef OF_HAVE_THREADS
# import "OFMutex.h"
#endif
#import "OFDate.h"

#ifdef HAVE_KQUEUE
# import "OFKernelEventObserver_kqueue.h"
#endif
#ifdef HAVE_EPOLL
# import "OFKernelEventObserver_epoll.h"
#endif
#if defined(HAVE_POLL_H) || defined(__wii__)
# import "OFKernelEventObserver_poll.h"
#endif
#if defined(HAVE_SYS_SELECT_H) || defined(_WIN32)
# import "OFKernelEventObserver_select.h"
#endif

#import "OFInitializationFailedException.h"
#import "OFInvalidArgumentException.h"
#import "OFOutOfRangeException.h"

#import "socket.h"
#import "socket_helpers.h"

enum {
	QUEUE_ADD = 0,
	QUEUE_REMOVE = 1,
	QUEUE_READ = 0,
	QUEUE_WRITE = 2
};
#define QUEUE_ACTION (QUEUE_ADD | QUEUE_REMOVE)

@implementation OFKernelEventObserver
+ (void)initialize
{
	if (self != [OFKernelEventObserver class])
		return;

	if (!of_socket_init())
		@throw [OFInitializationFailedException
		    exceptionWithClass: self];
}

+ (instancetype)observer
{
	return [[[self alloc] init] autorelease];
}

+ alloc
{
	if (self == [OFKernelEventObserver class])
#if defined(HAVE_KQUEUE)
		return [OFKernelEventObserver_kqueue alloc];
#elif defined(HAVE_EPOLL)
		return [OFKernelEventObserver_epoll alloc];
#elif defined(HAVE_POLL_H) || defined(__wii__)
		return [OFKernelEventObserver_poll alloc];
#elif defined(HAVE_SYS_SELECT_H) || defined(_WIN32)
		return [OFKernelEventObserver_select alloc];
#else
# error No kqueue / epoll / poll / select found!
#endif

	return [super alloc];
}

- init
{
	self = [super init];

	@try {
#if !defined(OF_HAVE_PIPE) && !defined(__wii__)
		socklen_t cancelAddrLen;
#endif

		_readObjects = [[OFMutableArray alloc] init];
		_writeObjects = [[OFMutableArray alloc] init];
		_queue = [[OFMutableArray alloc] init];
		_queueActions = [[OFDataArray alloc]
		    initWithItemSize: sizeof(int)];

#ifdef OF_HAVE_PIPE
		if (pipe(_cancelFD))
			@throw [OFInitializationFailedException
			    exceptionWithClass: [self class]];
#else
		_cancelFD[0] = _cancelFD[1] = socket(AF_INET, SOCK_DGRAM, 0);

		if (_cancelFD[0] == INVALID_SOCKET)
			@throw [OFInitializationFailedException
			    exceptionWithClass: [self class]];

		_cancelAddr.sin_family = AF_INET;
		_cancelAddr.sin_port = 0;
		_cancelAddr.sin_addr.s_addr = inet_addr("127.0.0.1");

# ifdef __wii__
		/* The Wii does not accept port 0 as "choose any free port" */
		_cancelAddr.sin_port = 65535;
# endif

		if (bind(_cancelFD[0], (struct sockaddr*)&_cancelAddr,
		    sizeof(_cancelAddr)))
			@throw [OFInitializationFailedException
			    exceptionWithClass: [self class]];

# ifndef __wii__
		cancelAddrLen = sizeof(_cancelAddr);
		if (of_getsockname(_cancelFD[0], (struct sockaddr*)&_cancelAddr,
		    &cancelAddrLen) != 0)
			@throw [OFInitializationFailedException
			    exceptionWithClass: [self class]];
# endif
#endif

#ifdef OF_HAVE_THREADS
		_mutex = [[OFMutex alloc] init];
#endif
	} @catch (id e) {
		[self release];
		@throw e;
	}

	return self;
}

- (void)dealloc
{
	close(_cancelFD[0]);
	if (_cancelFD[1] != _cancelFD[0])
		close(_cancelFD[1]);

	[_readObjects release];
	[_writeObjects release];
	[_queue release];
	[_queueActions release];
#ifdef OF_HAVE_THREADS
	[_mutex release];
#endif

	[super dealloc];
}

- (id <OFKernelEventObserverDelegate>)delegate
{
	return _delegate;
}

- (void)setDelegate: (id <OFKernelEventObserverDelegate>)delegate
{
	_delegate = delegate;
}

- (void)addObjectForReading: (id <OFReadyForReadingObserving>)object
{
#ifdef OF_HAVE_THREADS
	[_mutex lock];
#endif
	@try {
		int qi = QUEUE_ADD | QUEUE_READ;

		[_queue addObject: object];
		[_queueActions addItem: &qi];
	} @finally {
#ifdef OF_HAVE_THREADS
		[_mutex unlock];
#endif
	}

	[self cancel];
}

- (void)addObjectForWriting: (id <OFReadyForWritingObserving>)object
{
#ifdef OF_HAVE_THREADS
	[_mutex lock];
#endif
	@try {
		int qi = QUEUE_ADD | QUEUE_WRITE;

		[_queue addObject: object];
		[_queueActions addItem: &qi];
	} @finally {
#ifdef OF_HAVE_THREADS
		[_mutex unlock];
#endif
	}

	[self cancel];
}

- (void)removeObjectForReading: (id <OFReadyForReadingObserving>)object
{
#ifdef OF_HAVE_THREADS
	[_mutex lock];
#endif
	@try {
		int qi = QUEUE_REMOVE | QUEUE_READ;

		[_queue addObject: object];
		[_queueActions addItem: &qi];
	} @finally {
#ifdef OF_HAVE_THREADS
		[_mutex unlock];
#endif
	}

	[self cancel];
}

- (void)removeObjectForWriting: (id <OFReadyForWritingObserving>)object
{
#ifdef OF_HAVE_THREADS
	[_mutex lock];
#endif
	@try {
		int qi = QUEUE_REMOVE | QUEUE_WRITE;

		[_queue addObject: object];
		[_queueActions addItem: &qi];
	} @finally {
#ifdef OF_HAVE_THREADS
		[_mutex unlock];
#endif
	}

	[self cancel];
}

- (void)OF_addObjectForReading: (id)object
{
	OF_UNRECOGNIZED_SELECTOR
}

- (void)OF_addObjectForWriting: (id)object
{
	OF_UNRECOGNIZED_SELECTOR
}

- (void)OF_removeObjectForReading: (id)object
{
	OF_UNRECOGNIZED_SELECTOR
}

- (void)OF_removeObjectForWriting: (id)object
{
	OF_UNRECOGNIZED_SELECTOR
}

- (void)OF_processQueueAndStoreRemovedIn: (OFMutableArray*)removed
{
#ifdef OF_HAVE_THREADS
	[_mutex lock];
#endif
	@try {
		id const *queueObjects = [_queue objects];
		int *queueActionItems = [_queueActions items];
		size_t i, count = [_queue count];

		for (i = 0; i < count; i++) {
			id object = queueObjects[i];
			int action = queueActionItems[i];

			switch (action) {
			case QUEUE_ADD | QUEUE_READ:
				[_readObjects addObject: object];

				[self OF_addObjectForReading: object];

				break;
			case QUEUE_ADD | QUEUE_WRITE:
				[_writeObjects addObject: object];

				[self OF_addObjectForWriting: object];

				break;
			case QUEUE_REMOVE | QUEUE_READ:
				[self OF_removeObjectForReading: object];

				[removed addObject: object];
				[_readObjects removeObjectIdenticalTo: object];

				break;
			case QUEUE_REMOVE | QUEUE_WRITE:
				[self OF_removeObjectForWriting: object];

				[removed addObject: object];
				[_writeObjects removeObjectIdenticalTo: object];

				break;
			default:
				assert(0);
			}
		}

		[_queue removeAllObjects];
		[_queueActions removeAllItems];
	} @finally {
#ifdef OF_HAVE_THREADS
		[_mutex unlock];
#endif
	}
}

- (void)observe
{
	[self observeForTimeInterval: -1];
}

- (void)observeForTimeInterval: (of_time_interval_t)timeInterval
{
	OF_UNRECOGNIZED_SELECTOR
}

- (void)observeUntilDate: (OFDate*)date
{
	[self observeForTimeInterval: [date timeIntervalSinceNow]];
}

- (void)cancel
{
#ifdef OF_HAVE_PIPE
	OF_ENSURE(write(_cancelFD[1], "", 1) > 0);
#else
	OF_ENSURE(sendto(_cancelFD[1], "", 1, 0, (struct sockaddr*)&_cancelAddr,
	    sizeof(_cancelAddr)) > 0);
#endif
}

- (void)OF_processReadBuffers
{
	id const *objects = [_readObjects objects];
	size_t i, count = [_readObjects count];

	for (i = 0; i < count; i++) {
		void *pool = objc_autoreleasePoolPush();

		if ([objects[i] isKindOfClass: [OFStream class]] &&
		    [objects[i] hasDataInReadBuffer] &&
		    ![objects[i] OF_isWaitingForDelimiter] &&
		    [_delegate respondsToSelector:
		    @selector(objectIsReadyForReading:)])
			[_delegate objectIsReadyForReading: objects[i]];

		objc_autoreleasePoolPop(pool);
	}
}
@end