ObjFW  Check-in [41ca862453]

- (int)fileDescriptorForWriting;
@end

/*!
 * @brief A class that can observe multiple kernel events (e.g. streams being
 *	  ready to read) at once.
 *
 * @note Currently, Win32 can only observe TCP and UDP sockets!
 */
@interface OFKernelEventObserver: OFObject
{
	OFMutableArray *_readObjects;
	OFMutableArray *_writeObjects;
	__unsafe_unretained id *_FDToObject;
	size_t _maxFD;

- (void)observe;

/*!
 * @brief Observes all objects until an event happens on an object or the
 *	  timeout is reached.
 *
 * @param timeInterval The time to wait for an event, in seconds
 * @return A boolean whether events occurred before returning
 */
- (bool)observeForTimeInterval: (of_time_interval_t)timeInterval;

/*!
 * @brief Observes all objects until an event happens on an object or the
 *	  specified date is reached.
 *
 * @param date The until which to observe
 * @return A boolean whether events occurred before returning
 */
- (bool)observeUntilDate: (OFDate*)date;

/*!
 * @brief Cancels the currently blocking observe call.
 *
 * This is automatically done when a new object is added or removed by another

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

				[self OF_addFileDescriptorForWriting: fd];

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

				[_readObjects removeObjectIdenticalTo: object];

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

				[_writeObjects removeObjectIdenticalTo: object];

				break;
			default:
				assert(0);
			}
		}

			continue;
		}

		realEvents++;

		pool = objc_autoreleasePoolPush();

		/*
		 * If a file descriptor has been closed before it is removed
		 * from the kernel event observer, the file descriptor is not
		 * valid anymore and causes EBADF. As closing a file descriptor
		 * automatically removes it from the queue, there is nothing to
		 * do anymore.
		 *
		 * Ideally, a file descriptor should never be closed before it
		 * is removed from the kernel event observer, as in rare cases,
		 * it could result in removing the wrong object from the kernel
		 * event observer, for example if a file descriptor is closed,
		 * a new one created, added to the kernel event observer and
		 * then the old one removed, as the new one could now have the
		 * same file descriptor as the closed one had and thus the new
		 * one is removed.
		 *
		 * For other errors, call the callback like it was successful
		 * so that the read / write will generate an error and throw an
		 * exception.
		 */
		if ((eventList[i].flags & EV_ERROR) &&
		    eventList[i].data == EBADF)
			continue;

		switch (eventList[i].filter) {
		case EVFILT_READ:
			if ([_delegate respondsToSelector:
			    @selector(objectIsReadyForReading:)])
				[_delegate objectIsReadyForReading:
				    _FDToObject[eventList[i].ident]];
			break;