C++ EventableDescriptor::ShouldDelete方法代码示例

bool EventMachine_t::_RunKqueueOnce()
{
	#ifdef HAVE_KQUEUE
	assert (kqfd != -1);
	const int maxKevents = 2000;
	struct kevent Karray [maxKevents];
	struct timespec ts = {0, 10000000}; // Too frequent. Use blocking_region

	int k = kevent (kqfd, NULL, 0, Karray, maxKevents, &ts);
	struct kevent *ke = Karray;
	while (k > 0) {
		EventableDescriptor *ed = (EventableDescriptor*) (ke->udata);
		assert (ed);

		if (ke->filter == EVFILT_READ)
			ed->Read();
		else if (ke->filter == EVFILT_WRITE)
			ed->Write();
		else
			cerr << "Discarding unknown kqueue event " << ke->filter << endl;

		--k;
		++ke;
	}

	{ // cleanup dying sockets
		// vector::pop_back works in constant time.
		// TODO, rip this out and only delete the descriptors we know have died,
		// rather than traversing the whole list.
		// In kqueue, closing a descriptor automatically removes its event filters.

		int i, j;
		int nSockets = Descriptors.size();
		for (i=0, j=0; i < nSockets; i++) {
			EventableDescriptor *ed = Descriptors[i];
			assert (ed);
			if (ed->ShouldDelete()) {
				ModifiedDescriptors.erase (ed);
				delete ed;
			}
			else
				Descriptors [j++] = ed;
		}
		while ((size_t)j < Descriptors.size())
			Descriptors.pop_back();

	}

	{ // dispatch heartbeats
		if (gCurrentLoopTime >= NextHeartbeatTime) {
			NextHeartbeatTime = gCurrentLoopTime + HeartbeatInterval;

			for (int i=0; i < Descriptors.size(); i++) {
				EventableDescriptor *ed = Descriptors[i];
				assert (ed);
				ed->Heartbeat();
			}
		}
	}


	// TODO, replace this with rb_thread_blocking_region for 1.9 builds.
	timeval tv = {0,0};
	EmSelect (0, NULL, NULL, NULL, &tv);

	return true;
	#else
	throw std::runtime_error ("kqueue is not implemented on this platform");
	#endif
}

//.........这里部分代码省略.........
	// Windows has a version of the Unix pipe() library function, but it doesn't
	// give you back descriptors that are selectable.
	FD_SET (LoopBreakerReader, &(SelectData.fdreads));
	if (SelectData.maxsocket < LoopBreakerReader)
		SelectData.maxsocket = LoopBreakerReader;

	// prepare the sockets for reading and writing
	size_t i;
	for (i = 0; i < Descriptors.size(); i++) {
		EventableDescriptor *ed = Descriptors[i];
		assert (ed);
		int sd = ed->GetSocket();
		assert (sd != INVALID_SOCKET);

		if (ed->SelectForRead())
			FD_SET (sd, &(SelectData.fdreads));
		if (ed->SelectForWrite())
			FD_SET (sd, &(SelectData.fdwrites));

		if (SelectData.maxsocket < sd)
			SelectData.maxsocket = sd;
	}


	{ // read and write the sockets
		//timeval tv = {1, 0}; // Solaris fails if the microseconds member is >= 1000000.
		//timeval tv = Quantum;
		SelectData.tv = Quantum;
		int s = SelectData._Select();
		//rb_thread_blocking_region(xxx,(void*)&SelectData,RB_UBF_DFL,0);
		//int s = EmSelect (SelectData.maxsocket+1, &(SelectData.fdreads), &(SelectData.fdwrites), NULL, &(SelectData.tv));
		//int s = SelectData.nSockets;
		if (s > 0) {
			/* Changed 01Jun07. We used to handle the Loop-breaker right here.
			 * Now we do it AFTER all the regular descriptors. There's an
			 * incredibly important and subtle reason for this. Code on
			 * loop breakers is sometimes used to cause the reactor core to
			 * cycle (for example, to allow outbound network buffers to drain).
			 * If a loop-breaker handler reschedules itself (say, after determining
			 * that the write buffers are still too full), then it will execute
			 * IMMEDIATELY if _ReadLoopBreaker is done here instead of after
			 * the other descriptors are processed. That defeats the whole purpose.
			 */
			for (i=0; i < Descriptors.size(); i++) {
				EventableDescriptor *ed = Descriptors[i];
				assert (ed);
				int sd = ed->GetSocket();
				assert (sd != INVALID_SOCKET);

				if (FD_ISSET (sd, &(SelectData.fdwrites)))
					ed->Write();
				if (FD_ISSET (sd, &(SelectData.fdreads)))
					ed->Read();
			}

			if (FD_ISSET (LoopBreakerReader, &(SelectData.fdreads)))
				_ReadLoopBreaker();
		}
		else if (s < 0) {
			// select can fail on error in a handful of ways.
			// If this happens, then wait for a little while to avoid busy-looping.
			// If the error was EINTR, we probably caught SIGCHLD or something,
			// so keep the wait short.
			timeval tv = {0, ((errno == EINTR) ? 5 : 50) * 1000};
			EmSelect (0, NULL, NULL, NULL, &tv);
		}
	}


	{ // dispatch heartbeats
		if (gCurrentLoopTime >= NextHeartbeatTime) {
			NextHeartbeatTime = gCurrentLoopTime + HeartbeatInterval;

			for (i=0; i < Descriptors.size(); i++) {
				EventableDescriptor *ed = Descriptors[i];
				assert (ed);
				ed->Heartbeat();
			}
		}
	}

	{ // cleanup dying sockets
		// vector::pop_back works in constant time.
		int i, j;
		int nSockets = Descriptors.size();
		for (i=0, j=0; i < nSockets; i++) {
			EventableDescriptor *ed = Descriptors[i];
			assert (ed);
			if (ed->ShouldDelete())
				delete ed;
			else
				Descriptors [j++] = ed;
		}
		while ((size_t)j < Descriptors.size())
			Descriptors.pop_back();

	}

	return true;
}

bool EventMachine_t::_RunEpollOnce()
{
	#ifdef HAVE_EPOLL
	assert (epfd != -1);
	struct epoll_event ev [MaxEpollDescriptors];
	int s = epoll_wait (epfd, ev, MaxEpollDescriptors, 50);
	if (s > 0) {
		for (int i=0; i < s; i++) {
			EventableDescriptor *ed = (EventableDescriptor*) ev[i].data.ptr;

			if (ev[i].events & (EPOLLERR | EPOLLHUP))
				ed->ScheduleClose (false);
			if (ev[i].events & EPOLLIN)
				ed->Read();
			if (ev[i].events & EPOLLOUT) {
				ed->Write();
				epoll_ctl (epfd, EPOLL_CTL_MOD, ed->GetSocket(), ed->GetEpollEvent());
				// Ignoring return value
			}
		}
	}
	else if (s < 0) {
		// epoll_wait can fail on error in a handful of ways.
		// If this happens, then wait for a little while to avoid busy-looping.
		// If the error was EINTR, we probably caught SIGCHLD or something,
		// so keep the wait short.
		timeval tv = {0, ((errno == EINTR) ? 5 : 50) * 1000};
		EmSelect (0, NULL, NULL, NULL, &tv);
	}

	{ // cleanup dying sockets
		// vector::pop_back works in constant time.
		// TODO, rip this out and only delete the descriptors we know have died,
		// rather than traversing the whole list.
		//  Modified 05Jan08 per suggestions by Chris Heath. It's possible that
		//  an EventableDescriptor will have a descriptor value of -1. That will
		//  happen if EventableDescriptor::Close was called on it. In that case,
		//  don't call epoll_ctl to remove the socket's filters from the epoll set.
		//  According to the epoll docs, this happens automatically when the
		//  descriptor is closed anyway. This is different from the case where
		//  the socket has already been closed but the descriptor in the ED object
		//  hasn't yet been set to INVALID_SOCKET.
		int i, j;
		int nSockets = Descriptors.size();
		for (i=0, j=0; i < nSockets; i++) {
			EventableDescriptor *ed = Descriptors[i];
			assert (ed);
			if (ed->ShouldDelete()) {
				if (ed->GetSocket() != INVALID_SOCKET) {
					assert (bEpoll); // wouldn't be in this method otherwise.
					assert (epfd != -1);
					int e = epoll_ctl (epfd, EPOLL_CTL_DEL, ed->GetSocket(), ed->GetEpollEvent());
					// ENOENT or EBADF are not errors because the socket may be already closed when we get here.
					if (e && (errno != ENOENT) && (errno != EBADF)) {
						char buf [200];
						snprintf (buf, sizeof(buf)-1, "unable to delete epoll event: %s", strerror(errno));
						throw std::runtime_error (buf);
					}
				}

				ModifiedDescriptors.erase (ed);
				delete ed;
			}
			else
				Descriptors [j++] = ed;
		}
		while ((size_t)j < Descriptors.size())
			Descriptors.pop_back();

	}

	// TODO, heartbeats.
	// Added 14Sep07, its absence was noted by Brian Candler. But the comment was here, indicated
	// that this got thought about and not done when EPOLL was originally written. Was there a reason
	// not to do it, or was it an oversight? Certainly, running a heartbeat on 50,000 connections every
	// two seconds can get to be a real bear, especially if all we're doing is timing out dead ones.
	// Maybe there's a better way to do this. (Or maybe it's not that expensive after all.)
	//
	{ // dispatch heartbeats
		if (gCurrentLoopTime >= NextHeartbeatTime) {
			NextHeartbeatTime = gCurrentLoopTime + HeartbeatInterval;

			for (int i=0; i < Descriptors.size(); i++) {
				EventableDescriptor *ed = Descriptors[i];
				assert (ed);
				ed->Heartbeat();
			}
		}
	}

	timeval tv = {0,0};
	EmSelect (0, NULL, NULL, NULL, &tv);

	return true;
	#else
	throw std::runtime_error ("epoll is not implemented on this platform");
	#endif
}