Implement support for epoll

refs #11014

lib/base/socketevents.cpp

@@ -23,17 +23,26 @@
 #include <boost/thread/once.hpp>
 #include <boost/foreach.hpp>
 #include <map>
+#ifdef __linux__
+#	include <sys/epoll.h>
+#endif /* __linux__ */
 
 using namespace icinga;
 
 struct SocketEventDescriptor
 {
+#ifndef __linux__
 	int Events;
+#endif /* __linux__ */
 	SocketEvents *EventInterface;
 	Object *LifesupportObject;
 
 	SocketEventDescriptor(void)
-		: Events(0), EventInterface(NULL), LifesupportObject(NULL)
+		:
+#ifndef __linux__
+		Events(POLLIN),
+#endif /* __linux__ */
+		EventInterface(NULL), LifesupportObject(NULL)
 	{ }
 };
 
@@ -48,19 +57,24 @@ struct EventDescription
 
 static boost::once_flag l_SocketIOOnceFlag = BOOST_ONCE_INIT;
 static boost::thread l_SocketIOThreads[IOTHREADS];
+#ifdef __linux__
+static SOCKET l_SocketIOPollFDs[IOTHREADS];
+#endif /* __linux__ */
 static SOCKET l_SocketIOEventFDs[IOTHREADS][2];
+static bool l_SocketIOFDChanged[IOTHREADS];
 static boost::mutex l_SocketIOMutex[IOTHREADS];
 static boost::condition_variable l_SocketIOCV[IOTHREADS];
-static bool l_SocketIOFDChanged[IOTHREADS];
 static std::map<SOCKET, SocketEventDescriptor> l_SocketIOSockets[IOTHREADS];
-static std::map<SOCKET, int> l_SocketIOEventChanges[IOTHREADS];
 
 int SocketEvents::m_NextID = 0;
 
 void SocketEvents::InitializeThread(void)
 {
-
 	for (int i = 0; i < IOTHREADS; i++) {
+#ifdef __linux__
+		l_SocketIOPollFDs[i] = epoll_create1(EPOLL_CLOEXEC);
+#endif /* __linux__ */
+
 		Socket::SocketPair(l_SocketIOEventFDs[i]);
 
 		Utility::SetNonBlockingSocket(l_SocketIOEventFDs[i][0]);
@@ -72,27 +86,68 @@ void SocketEvents::InitializeThread(void)
 #endif /* _WIN32 */
 
 		SocketEventDescriptor sed;
+#ifndef __linux__
 		sed.Events = POLLIN;
+#endif /* __linux__ */
 
 		l_SocketIOSockets[i][l_SocketIOEventFDs[i][0]] = sed;
 		l_SocketIOFDChanged[i] = true;
 
+#ifdef __linux__
+		epoll_event event;
+		memset(&event, 0, sizeof(event));
+		event.data.fd = l_SocketIOEventFDs[i][0];
+		event.events = EPOLLIN;
+		epoll_ctl(l_SocketIOPollFDs[i], EPOLL_CTL_ADD, l_SocketIOEventFDs[i][0], &event);
+#endif /* __linux__ */
+
 		l_SocketIOThreads[i] = boost::thread(&SocketEvents::ThreadProc, i);
 	}
 }
 
+#ifdef __linux__
+int SocketEvents::PollToEpoll(int events)
+{
+	int result = 0;
+
+	if (events & POLLIN)
+		result |= EPOLLIN;
+
+	if (events & POLLOUT)
+		result |= EPOLLOUT;
+
+	return events;
+}
+
+int SocketEvents::EpollToPoll(int events)
+{
+	int result = 0;
+
+	if (events & EPOLLIN)
+		result |= POLLIN;
+
+	if (events & EPOLLOUT)
+		result |= POLLOUT;
+
+	return events;
+}
+#endif /* __linux__ */
+
 void SocketEvents::ThreadProc(int tid)
 {
 	Utility::SetThreadName("SocketIO");
 
+#ifndef __linux__
 	std::vector<pollfd> pfds;
 	std::vector<SocketEventDescriptor> descriptors;
+#endif /* __linux__ */
 
 	for (;;) {
 		{
 			boost::mutex::scoped_lock lock(l_SocketIOMutex[tid]);
 
 			if (l_SocketIOFDChanged[tid]) {
+#ifndef __linux__
 				pfds.resize(l_SocketIOSockets[tid].size());
 				descriptors.resize(l_SocketIOSockets[tid].size());
 
@@ -110,15 +165,21 @@ void SocketEvents::ThreadProc(int tid)
 
 					i++;
 				}
+#endif /* __linux__ */
 
 				l_SocketIOFDChanged[tid] = false;
 				l_SocketIOCV[tid].notify_all();
 			}
 		}
 
+#ifndef __linux__
 		ASSERT(!pfds.empty());
+#endif /* __linux__ */
 
-#ifdef _WIN32
+#ifdef __linux__
+		epoll_event pevents[64];
+		int ready = epoll_wait(l_SocketIOPollFDs[tid], pevents, sizeof(pevents) / sizeof(pevents[0]), -1);
+#elif _WIN32
 		(void) WSAPoll(&pfds[0], pfds.size(), -1);
 #else /* _WIN32 */
 		(void) poll(&pfds[0], pfds.size(), -1);
@@ -129,9 +190,36 @@ void SocketEvents::ThreadProc(int tid)
 		{
 			boost::mutex::scoped_lock lock(l_SocketIOMutex[tid]);
 
-			if (l_SocketIOFDChanged[tid])
+			if (l_SocketIOFDChanged[tid]) {
-				continue;
+#ifdef __linux__
+				l_SocketIOFDChanged[tid] = false;
+#endif /* __linux__ */
 
+				continue;
+			}
+
+#ifdef __linux__
+			for (int i = 0; i < ready; i++) {
+				if (pevents[i].data.fd == l_SocketIOEventFDs[tid][0]) {
+					char buffer[512];
+					if (recv(l_SocketIOEventFDs[tid][0], buffer, sizeof(buffer), 0) < 0)
+						Log(LogCritical, "SocketEvents", "Read from event FD failed.");
+
+					continue;
+				}
+
+				if ((pevents[i].events & (EPOLLIN | EPOLLOUT | EPOLLHUP | EPOLLERR)) == 0)
+					continue;
+
+				EventDescription event;
+				event.REvents = EpollToPoll(pevents[i].events);
+				event.Descriptor = l_SocketIOSockets[tid][pevents[i].data.fd];
+				event.LifesupportReference = event.Descriptor.LifesupportObject;
+				VERIFY(event.LifesupportReference);
+
+				events.push_back(event);
+			}
+#else /* __linux__ */
 			for (int i = 0; i < pfds.size(); i++) {
 				if ((pfds[i].revents & (POLLIN | POLLOUT | POLLHUP | POLLERR)) == 0)
 					continue;
@@ -152,6 +240,7 @@ void SocketEvents::ThreadProc(int tid)
 
 				events.push_back(event);
 			}
+#endif /* __linux__ */
 		}
 
 		BOOST_FOREACH(const EventDescription& event, events) {
@@ -195,7 +284,10 @@ void SocketEvents::WakeUpThread(bool wait)
  * Constructor for the SocketEvents class.
  */
 SocketEvents::SocketEvents(const Socket::Ptr& socket, Object *lifesupportObject)
-	: m_ID(m_NextID++), m_FD(socket->GetFD()), m_PFD(NULL)
+	: m_ID(m_NextID++), m_FD(socket->GetFD())
+#ifndef __linux__
+	  , m_PFD(NULL)
+#endif /* __linux__ */
 {
 	boost::call_once(l_SocketIOOnceFlag, &SocketEvents::InitializeThread);
 
@@ -217,19 +309,32 @@ void SocketEvents::Register(Object *lifesupportObject)
 		VERIFY(m_FD != INVALID_SOCKET);
 
 		SocketEventDescriptor desc;
+#ifndef __linux__
 		desc.Events = 0;
+#endif /* __linux__ */
 		desc.EventInterface = this;
 		desc.LifesupportObject = lifesupportObject;
 
 		VERIFY(l_SocketIOSockets[tid].find(m_FD) == l_SocketIOSockets[tid].end());
 
 		l_SocketIOSockets[tid][m_FD] = desc;
+
+#ifdef __linux__
+		epoll_event event;
+		memset(&event, 0, sizeof(event));
+		event.data.fd = m_FD;
+		event.events = 0;
+		epoll_ctl(l_SocketIOPollFDs[tid], EPOLL_CTL_ADD, m_FD, &event);
+#else /* __linux__ */
 		l_SocketIOFDChanged[tid] = true;
+#endif /* __linux__ */
 
 		m_Events = true;
 	}
 
+#ifndef __linux__
 	WakeUpThread(true);
+#endif /* __linux__ */
 }
 
 void SocketEvents::Unregister(void)
@@ -245,9 +350,12 @@ void SocketEvents::Unregister(void)
 		l_SocketIOSockets[tid].erase(m_FD);
 		l_SocketIOFDChanged[tid] = true;
 
+#ifdef __linux__
+		epoll_ctl(l_SocketIOPollFDs[tid], EPOLL_CTL_DEL, m_FD, NULL);
+#endif /* __linux__ */
+
 		m_FD = INVALID_SOCKET;
 		m_Events = false;
-
 	}
 
 	WakeUpThread(true);
@@ -255,14 +363,21 @@ void SocketEvents::Unregister(void)
 
 void SocketEvents::ChangeEvents(int events)
 {
+	if (m_FD == INVALID_SOCKET)
+		BOOST_THROW_EXCEPTION(std::runtime_error("Tried to read/write from a closed socket."));
+
 	int tid = m_ID % IOTHREADS;
 
+#ifdef __linux__
+	epoll_event event;
+	memset(&event, 0, sizeof(event));
+	event.data.fd = m_FD;
+	event.events = PollToEpoll(events);
+	epoll_ctl(l_SocketIOPollFDs[tid], EPOLL_CTL_MOD, m_FD, &event);
+#else /* __linux__ */
 	{
 		boost::mutex::scoped_lock lock(l_SocketIOMutex[tid]);
 
-		if (m_FD == INVALID_SOCKET)
-			BOOST_THROW_EXCEPTION(std::runtime_error("Tried to read/write from a closed socket."));
-
 		std::map<SOCKET, SocketEventDescriptor>::iterator it = l_SocketIOSockets[tid].find(m_FD);
 
 		if (it == l_SocketIOSockets[tid].end())
@@ -280,6 +395,7 @@ void SocketEvents::ChangeEvents(int events)
 	}
 
 	WakeUpThread();
+#endif /* __linux__ */
 }
 
 bool SocketEvents::IsHandlingEvents(void) const

lib/base/socketevents.hpp

@@ -55,7 +55,9 @@ private:
 	int m_ID;
 	SOCKET m_FD;
 	bool m_Events;
+#ifndef __linux__
 	pollfd *m_PFD;
+#endif /* __linux__ */
 
 	static int m_NextID;
 
@@ -67,6 +69,9 @@ private:
 	int GetPollEvents(void) const;
 
 	void Register(Object *lifesupportObject);
+
+	static int PollToEpoll(int events);
+	static int EpollToPoll(int events);
 };
 
 }