ObjFW  Artifact [83e01ba01e]

Artifact 83e01ba01e236ac9866d1e61bf44de866eadbed10f4671943f9727db3edf70f0:

• File src/OFKernelEventObserver.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: 9076) [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
#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_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];
}

#if defined(HAVE_KQUEUE)
+ alloc
{
	if (self == [OFKernelEventObserver class])
		return [OFKernelEventObserver_kqueue alloc];

	return [super alloc];
}
#elif defined(HAVE_POLL_H) || defined(__wii__)
+ alloc
{
	if (self == [OFKernelEventObserver class])
		return [OFKernelEventObserver_poll alloc];

	return [super alloc];
}
#elif defined(HAVE_SYS_SELECT_H) || defined(_WIN32)
+ alloc
{
	if (self == [OFKernelEventObserver class])
		return [OFKernelEventObserver_select alloc];

	return [super alloc];
}
#endif

- 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];
		_queueInfo = [[OFDataArray alloc]
		    initWithItemSize: sizeof(int)];
		_queueFDs = [[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 (getsockname(_cancelFD[0], (struct sockaddr*)&_cancelAddr,
		    &cancelAddrLen))
			@throw [OFInitializationFailedException
			    exceptionWithClass: [self class]];
# endif
#endif

		_maxFD = _cancelFD[0];
		_FDToObject = [self allocMemoryWithSize: sizeof(id)
						  count: _maxFD + 1];
		_FDToObject[_cancelFD[0]] = nil;

#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];
	[_queueInfo release];
	[_queueFDs 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;
		int fd = [object fileDescriptorForReading];

		[_queue addObject: object];
		[_queueInfo addItem: &qi];
		[_queueFDs addItem: &fd];
	} @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;
		int fd = [object fileDescriptorForWriting];

		[_queue addObject: object];
		[_queueInfo addItem: &qi];
		[_queueFDs addItem: &fd];
	} @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;
		int fd = [object fileDescriptorForReading];

		[_queue addObject: object];
		[_queueInfo addItem: &qi];
		[_queueFDs addItem: &fd];
	} @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;
		int fd = [object fileDescriptorForWriting];

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

	[self cancel];
}

- (void)OF_addFileDescriptorForReading: (int)fd
{
	OF_UNRECOGNIZED_SELECTOR
}

- (void)OF_addFileDescriptorForWriting: (int)fd
{
	OF_UNRECOGNIZED_SELECTOR
}

- (void)OF_removeFileDescriptorForReading: (int)fd
{
	OF_UNRECOGNIZED_SELECTOR
}

- (void)OF_removeFileDescriptorForWriting: (int)fd
{
	OF_UNRECOGNIZED_SELECTOR
}

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

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

			if ((action & QUEUE_ACTION) == QUEUE_ADD) {
				if (fd > _maxFD) {
					_maxFD = fd;
					_FDToObject = [self
					    resizeMemory: _FDToObject
						    size: sizeof(id)
						   count: _maxFD + 1];
				}

				_FDToObject[fd] = object;
			}

			if ((action & QUEUE_ACTION) == QUEUE_REMOVE) {
				/* FIXME: Maybe downsize? */
				_FDToObject[fd] = nil;
			}

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

				[self OF_addFileDescriptorForReading: fd];

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

				[self OF_addFileDescriptorForWriting: fd];

				break;
			case QUEUE_REMOVE | QUEUE_READ:
				[self OF_removeFileDescriptorForReading: fd];

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

				break;
			case QUEUE_REMOVE | QUEUE_WRITE:
				[self OF_removeFileDescriptorForWriting: fd];

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

				break;
			default:
				assert(0);
			}
		}

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

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

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

- (bool)observeUntilDate: (OFDate*)date
{
	return [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
}

- (bool)OF_processCache
{
	id const *objects = [_readObjects objects];
	size_t i, count = [_readObjects count];
	bool foundInCache = false;

	for (i = 0; i < count; i++) {
		if ([objects[i] isKindOfClass: [OFStream class]] &&
		    [objects[i] hasDataInReadBuffer] &&
		    ![objects[i] OF_isWaitingForDelimiter]) {
			void *pool = objc_autoreleasePoolPush();

			if ([_delegate respondsToSelector:
			    @selector(objectIsReadyForReading:)])
				[_delegate objectIsReadyForReading: objects[i]];

			foundInCache = true;

			objc_autoreleasePoolPop(pool);
		}
	}

	/*
	 * As long as we have data in the cache for any stream, we don't want
	 * to block.
	 */
	if (foundInCache)
		return true;

	return false;
}
@end