ObjFW  Artifact [3e6c82710c]

Artifact 3e6c82710c5b227497d4c1ba943ac6610f74970ef029ec29eda8848ba614d69c:

• File src/OFKernelEventObserver_epoll.m — part of check-in [85917ea0dd] at 2016-03-20 14:19:43 on branch 0.8 — Use the locked queue for kqueue and epoll as well

  _readObjects must only be changed from the thread running the observer
  and not from a thread adding or removing objects to observe. This is
  already handled by the locked queue used by poll and select, so the best
  way to solve this is to use the locked queue for kqueue and epoll as
  well. (user: js, size: 5498) [annotate] [blame] [check-ins using]

/*
 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016
 *   Jonathan Schleifer <js@heap.zone>
 *
 * 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 <fcntl.h>
#include <unistd.h>

#include <sys/epoll.h>

#import "OFKernelEventObserver.h"
#import "OFKernelEventObserver+Private.h"
#import "OFKernelEventObserver_epoll.h"
#import "OFArray.h"
#import "OFMapTable.h"
#import "OFNull.h"
#ifdef OF_HAVE_THREADS
# import "OFMutex.h"
#endif

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

#define EVENTLIST_SIZE 64

static const of_map_table_functions_t mapFunctions = { NULL };

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

	@try {
		struct epoll_event event;

#ifdef HAVE_EPOLL_CREATE1
		if ((_epfd = epoll_create1(EPOLL_CLOEXEC)) == -1)
			@throw [OFInitializationFailedException exception];
#else
		int flags;

		if ((_epfd = epoll_create(1)) == -1)
			@throw [OFInitializationFailedException exception];

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

		_FDToEvents = [[OFMapTable alloc]
		    initWithKeyFunctions: mapFunctions
			  valueFunctions: mapFunctions];

		memset(&event, 0, sizeof(event));
		event.events = EPOLLIN;
		event.data.ptr = [OFNull null];

		if (epoll_ctl(_epfd, EPOLL_CTL_ADD, _cancelFD[0], &event) == -1)
			@throw [OFInitializationFailedException exception];
	} @catch (id e) {
		[self release];
		@throw e;
	}

	return self;
}

- (void)dealloc
{
	close(_epfd);

	[_FDToEvents release];

	[super dealloc];
}

- (void)OF_addObject: (id)object
      fileDescriptor: (int)fd
	      events: (int)addEvents
{
	struct epoll_event event;
	intptr_t events;

	events = (intptr_t)[_FDToEvents valueForKey: (void*)(intptr_t)fd];

	memset(&event, 0, sizeof(event));
	event.events = (int)events | addEvents;
	event.data.ptr = object;

	if (epoll_ctl(_epfd, (events == 0 ? EPOLL_CTL_ADD : EPOLL_CTL_MOD),
	    fd, &event) == -1)
		@throw [OFObserveFailedException exceptionWithObserver: self
								 errNo: errno];

	[_FDToEvents setValue: (void*)(events | addEvents)
		       forKey: (void*)(intptr_t)fd];
}

- (void)OF_removeObject: (id)object
	 fileDescriptor: (int)fd
		 events: (int)removeEvents
{
	intptr_t events;

	events = (intptr_t)[_FDToEvents valueForKey: (void*)(intptr_t)fd];
	events &= ~removeEvents;

	if (events == 0) {
		if (epoll_ctl(_epfd, EPOLL_CTL_DEL, fd, NULL) == -1)
			@throw [OFObserveFailedException
			    exceptionWithObserver: self
					    errNo: errno];

		[_FDToEvents removeValueForKey: (void*)(intptr_t)fd];
	} else {
		struct epoll_event event;

		memset(&event, 0, sizeof(event));
		event.events = (int)events;
		event.data.ptr = object;

		if (epoll_ctl(_epfd, EPOLL_CTL_MOD, fd, &event) == -1)
			@throw [OFObserveFailedException
			    exceptionWithObserver: self
					    errNo: errno];

		[_FDToEvents setValue: (void*)events
			       forKey: (void*)(intptr_t)fd];
	}
}

- (void)OF_addObjectForReading: (id <OFReadyForReadingObserving>)object
{
	[self OF_addObject: object
	    fileDescriptor: [object fileDescriptorForReading]
		    events: EPOLLIN];
}

- (void)OF_addObjectForWriting: (id <OFReadyForWritingObserving>)object
{
	[self OF_addObject: object
	    fileDescriptor: [object fileDescriptorForWriting]
		    events: EPOLLOUT];
}

- (void)OF_removeObjectForReading: (id <OFReadyForReadingObserving>)object
{
	[self OF_removeObject: object
	       fileDescriptor: [object fileDescriptorForReading]
		       events: EPOLLIN];
}

- (void)OF_removeObjectForWriting: (id <OFReadyForWritingObserving>)object
{
	[self OF_removeObject: object
	       fileDescriptor: [object fileDescriptorForWriting]
		       events: EPOLLOUT];
}

- (void)observeForTimeInterval: (of_time_interval_t)timeInterval
{
	OFNull *nullObject = [OFNull null];
	struct epoll_event eventList[EVENTLIST_SIZE];
	int i, events;

	[self OF_processQueue];

	if ([self OF_processReadBuffers])
		return;

	events = epoll_wait(_epfd, eventList, EVENTLIST_SIZE,
	    (timeInterval != -1 ? timeInterval * 1000 : -1));

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

	for (i = 0; i < events; i++) {
		if (eventList[i].data.ptr == nullObject) {
			char buffer;

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

			continue;
		}

		if (eventList[i].events & EPOLLIN) {
			void *pool = objc_autoreleasePoolPush();

			if ([_delegate respondsToSelector:
			    @selector(objectIsReadyForReading:)])
				[_delegate objectIsReadyForReading:
				    eventList[i].data.ptr];

			objc_autoreleasePoolPop(pool);
		}

		if (eventList[i].events & EPOLLOUT) {
			void *pool = objc_autoreleasePoolPush();

			if ([_delegate respondsToSelector:
			    @selector(objectIsReadyForWriting:)])
				[_delegate objectIsReadyForWriting:
				    eventList[i].data.ptr];

			objc_autoreleasePoolPop(pool);
		}

		assert((eventList[i].events & ~(EPOLLIN | EPOLLOUT)) == 0);
	}
}
@end