Network/SocketPoller: Makes it possible to watch read and write states

include/Nazara/Network/Enums.hpp

@@ -7,7 +7,7 @@
 #ifndef NAZARA_ENUMS_NETWORK_HPP
 #define NAZARA_ENUMS_NETWORK_HPP
 
-#include <Nazara/Prerequesites.hpp>
+#include <Nazara/Core/Flags.hpp>
 
 namespace Nz
 {
@@ -91,6 +91,23 @@ namespace Nz
 		SocketError_Max = SocketError_UnreachableHost
 	};
 
+	enum SocketPollEvent
+	{
+		SocketPollEvent_Read,  //< One or more sockets is ready for a read operation
+		SocketPollEvent_Write, //< One or more sockets is ready for a write operation
+
+		SocketPollEvent_Max = SocketPollEvent_Write
+	};
+
+	template<>
+	struct EnumAsFlags<SocketPollEvent>
+	{
+		static constexpr bool value = true;
+		static constexpr int  max = SocketPollEvent_Max;
+	};
+
+	using SocketPollEventFlags = Flags<SocketPollEvent>;
+
 	enum SocketState
 	{
 		SocketState_Bound,        //< The socket is currently bound

include/Nazara/Network/SocketPoller.hpp

@@ -24,10 +24,11 @@ namespace Nz
 
 			void Clear();
 
-			bool IsReady(const AbstractSocket& socket) const;
+			bool IsReadyToRead(const AbstractSocket& socket) const;
+			bool IsReadyToWrite(const AbstractSocket& socket) const;
 			bool IsRegistered(const AbstractSocket& socket) const;
 
-			bool RegisterSocket(AbstractSocket& socket);
+			bool RegisterSocket(AbstractSocket& socket, SocketPollEventFlags eventFlags);
 			void UnregisterSocket(AbstractSocket& socket);
 
 			bool Wait(UInt64 msTimeout);

src/Nazara/Network/Linux/SocketPollerImpl.cpp

@@ -23,13 +23,19 @@ namespace Nz
 
 	void SocketPollerImpl::Clear()
 	{
-		m_activeSockets.clear();
+		m_readyToReadSockets.clear();
+		m_readyToWriteSockets.clear();
 		m_sockets.clear();
 	}
 
-	bool SocketPollerImpl::IsReady(SocketHandle socket) const
+	bool SocketPollerImpl::IsReadyToRead(SocketHandle socket) const
 	{
-		return m_activeSockets.count(socket) != 0;
+		return m_readyToReadSockets.count(socket) != 0;
+	}
+
+	bool SocketPollerImpl::IsReadyToWrite(SocketHandle socket) const
+	{
+		return m_readyToWriteSockets.count(socket) != 0;
 	}
 
 	bool SocketPollerImpl::IsRegistered(SocketHandle socket) const
@@ -37,15 +43,21 @@ namespace Nz
 		return m_sockets.count(socket) != 0;
 	}
 
-	bool SocketPollerImpl::RegisterSocket(SocketHandle socket)
+	bool SocketPollerImpl::RegisterSocket(SocketHandle socket, SocketPollEventFlags eventFlags)
 	{
 		NazaraAssert(!IsRegistered(socket), "Socket is already registered");
 
-		epoll_event event;
+		epoll_event entry;
-		event.events = EPOLLIN;
+		entry.events = 0;
-		event.data.fd = socket;
+		entry.data.fd = socket;
 
-		if (epoll_ctl(m_handle, EPOLL_CTL_ADD, socket, &event) != 0)
+		if (eventFlags & SocketPollEvent_Read)
+			entry.events |= EPOLLIN;
+
+		if (eventFlags & SocketPollEvent_Write)
+			entry.events |= EPOLLOUT;
+
+		if (epoll_ctl(m_handle, EPOLL_CTL_ADD, socket, &entry) != 0)
 		{
 			NazaraError("Failed to add socket to epoll structure (errno " + String::Number(errno) + ": " + Error::GetLastSystemError() + ')');
 			return false;
@@ -60,7 +72,8 @@ namespace Nz
 	{
 		NazaraAssert(IsRegistered(socket), "Socket is not registered");
 
-		m_activeSockets.erase(socket);
+		m_readyToReadSockets.erase(socket);
+		m_readyToWriteSockets.erase(socket);
 		m_sockets.erase(socket);
 
 		if (epoll_ctl(m_handle, EPOLL_CTL_DEL, socket, nullptr) != 0)
@@ -84,21 +97,27 @@ namespace Nz
 			return 0;
 		}
 
-		m_activeSockets.clear();
+		m_readyToReadSockets.clear();
+		m_readyToWriteSockets.clear();
 		if (activeSockets > 0)
 		{
 			int socketCount = activeSockets;
 			for (int i = 0; i < socketCount; ++i)
 			{
-				if (m_events[i].events & (EPOLLIN | EPOLLHUP | EPOLLERR))
+				if (m_events[i].events & (EPOLLIN | EPOLLOUT | EPOLLHUP | EPOLLERR))
 				{
-					m_activeSockets.insert(m_events[i].data.fd);
+					if (m_events[i].events & (EPOLLIN | EPOLLHUP | EPOLLERR))
+						m_readyToReadSockets.insert(m_events[i].data.fd);
+
+					if (m_events[i].events & (EPOLLOUT | EPOLLERR))
+						m_readyToWriteSockets.insert(m_events[i].data.fd);
+
 					if (m_events[i].events & EPOLLERR)
 						NazaraWarning("Descriptor " + String::Number(m_events[i].data.fd) + " was returned by epoll with EPOLLERR status");
 				}
 				else
 				{
-					NazaraWarning("Descriptor " + String::Number(m_events[i].data.fd) + " was returned by epoll without EPOLLIN (events: 0x" + String::Number(m_events[i].events, 16) + ')');
+					NazaraWarning("Descriptor " + String::Number(m_events[i].data.fd) + " was returned by epoll without EPOLLIN nor EPOLLOUT flags (events: 0x" + String::Number(m_events[i].events, 16) + ')');
 					activeSockets--;
 				}
 			}

src/Nazara/Network/Linux/SocketPollerImpl.hpp

@@ -23,16 +23,18 @@ namespace Nz
 
 			void Clear();
 
-			bool IsReady(SocketHandle socket) const;
+			bool IsReadyToRead(SocketHandle socket) const;
+			bool IsReadyToWrite(SocketHandle socket) const;
 			bool IsRegistered(SocketHandle socket) const;
 
-			bool RegisterSocket(SocketHandle socket);
+			bool RegisterSocket(SocketHandle socket, SocketPollEventFlags eventFlags);
 			void UnregisterSocket(SocketHandle socket);
 
 			int Wait(UInt64 msTimeout, SocketError* error);
 
 		private:
-			std::unordered_set<SocketHandle> m_activeSockets;
+			std::unordered_set<SocketHandle> m_readyToReadSockets;
+			std::unordered_set<SocketHandle> m_readyToWriteSockets;
 			std::unordered_set<SocketHandle> m_sockets;
 			std::vector<epoll_event> m_events;
 			int m_handle;

src/Nazara/Network/Posix/SocketPollerImpl.cpp

@@ -10,14 +10,20 @@ namespace Nz
 {
 	void SocketPollerImpl::Clear()
 	{
-		m_activeSockets.clear();
+		m_readyToReadSockets.clear();
+		m_readyToWriteSockets.clear();
 		m_allSockets.clear();
 		m_sockets.clear();
 	}
 
-	bool SocketPollerImpl::IsReady(SocketHandle socket) const
+	bool SocketPollerImpl::IsReadyToRead(SocketHandle socket) const
 	{
-		return m_activeSockets.count(socket) != 0;
+		return m_readyToReadSockets.count(socket) != 0;
+	}
+
+	bool SocketPollerImpl::IsReadyToWrite(SocketHandle socket) const
+	{
+		return m_readyToWriteSockets.count(socket) != 0;
 	}
 
 	bool SocketPollerImpl::IsRegistered(SocketHandle socket) const
@@ -25,16 +31,22 @@ namespace Nz
 		return m_allSockets.count(socket) != 0;
 	}
 
-	bool SocketPollerImpl::RegisterSocket(SocketHandle socket)
+	bool SocketPollerImpl::RegisterSocket(SocketHandle socket, SocketPollEventFlags eventFlags)
 	{
 		NazaraAssert(!IsRegistered(socket), "Socket is already registered");
 
 		PollSocket entry = {
 			socket,
-			POLLRDNORM,
+			0,
 			0
 		};
 
+		if (eventFlags & SocketPollEvent_Read)
+			entry.events |= POLLRDNORM;
+
+		if (eventFlags & SocketPollEvent_Write)
+			entry.events |= POLLWRNORM;
+
 		m_allSockets[socket] = m_sockets.size();
 		m_sockets.emplace_back(entry);
 
@@ -57,10 +69,11 @@ namespace Nz
 			// Now move it properly (lastElement is invalid after the following line) and pop it
 			m_sockets[entry] = std::move(m_sockets.back());
 		}
-
 		m_sockets.pop_back();
-		m_activeSockets.erase(socket);
+
 		m_allSockets.erase(socket);
+		m_readyToReadSockets.erase(socket);
+		m_readyToWriteSockets.erase(socket);
 	}
 
 	int SocketPollerImpl::Wait(UInt64 msTimeout, SocketError* error)
@@ -68,20 +81,25 @@ namespace Nz
 		int activeSockets;
 
 		// Reset status of sockets
-		for (PollSocket& entry : m_sockets)
-			entry.revents = 0;
-
 		activeSockets = SocketImpl::Poll(m_sockets.data(), m_sockets.size(), static_cast<int>(msTimeout), error);
 
-		m_activeSockets.clear();
+		m_readyToReadSockets.clear();
-		if (activeSockets > 0)
+		m_readyToWriteSockets.clear();
+		if (activeSockets > 0U)
 		{
 			int socketRemaining = activeSockets;
 			for (PollSocket& entry : m_sockets)
 			{
-				if (entry.revents & POLLRDNORM)
+				if (entry.revents != 0)
 				{
-					m_activeSockets.insert(entry.fd);
+					if (entry.revents & POLLRDNORM)
+						m_readyToReadSockets.insert(entry.fd);
+
+					if (entry.revents & POLLWRNORM)
+						m_readyToWriteSockets.insert(entry.fd);
+
+					entry.revents = 0;
+
 					if (--socketRemaining == 0)
 						break;
 				}

src/Nazara/Network/Posix/SocketPollerImpl.hpp

@@ -27,13 +27,14 @@ namespace Nz
 			bool IsReady(SocketHandle socket) const;
 			bool IsRegistered(SocketHandle socket) const;
 
-			bool RegisterSocket(SocketHandle socket);
+			bool RegisterSocket(SocketHandle socket, SocketPollEventFlags eventFlags);
 			void UnregisterSocket(SocketHandle socket);
 
 			int Wait(UInt64 msTimeout, SocketError* error);
 
 		private:
-			std::unordered_set<SocketHandle> m_activeSockets;
+			std::unordered_set<SocketHandle> m_readyToReadSockets;
+			std::unordered_set<SocketHandle> m_readyToWriteSockets;
 			std::unordered_map<SocketHandle, std::size_t> m_allSockets;
 			std::vector<PollSocket> m_sockets;
 	};

src/Nazara/Network/SocketPoller.cpp

@@ -57,12 +57,13 @@ namespace Nz
 	/*!
 	* \brief Checks if a specific socket is ready to read data
 	*
-	* This function allows you to read the results of the last Wait operation and if a specific socket is ready.
+	* This function allows you to read the results of the last Wait operation and if a specific socket is ready to read (has incoming data).
 	*
-	* A socket in the ready state (with the exception of TcpServer) has incoming data and can be read without blocking.
+	* A socket in the ready to read state (with the exception of TcpServer) has incoming data and can be read without blocking.
 	*
-	* \remark When used on a TcpServer socket, this function returns true if the server is ready to accept a new client.
+	* \remark You must call Wait before using this function in order to refresh the read state.
-	* \remark You must call Wait before using this function in order to refresh the state.
+	* \remark A socket must be registered with SocketPollerEvent_Read event flag for its read state to be watched
+	* \remark A TcpServer socket becomes ready to read when it is ready to accept a new client.
 	*
 	* \param socket Reference to the socket to check
 	*
@@ -70,11 +71,32 @@ namespace Nz
 	*
 	* \see Wait
 	*/
-	bool SocketPoller::IsReady(const AbstractSocket& socket) const
+	bool SocketPoller::IsReadyToRead(const AbstractSocket& socket) const
 	{
 		NazaraAssert(IsRegistered(socket), "Socket is not registered in the poller");
 
-		return m_impl->IsReady(socket.GetNativeHandle());
+		return m_impl->IsReadyToRead(socket.GetNativeHandle());
+	}
+
+	/*!
+	* \brief Checks if a specific socket is ready to write data
+	*
+	* This function allows you to read the results of the last Wait operation and if a specific socket is ready to write (can be written to without blocking).
+	*
+	* \remark You must call Wait before using this function in order to refresh the read state.
+	* \remark A socket must be registered with SocketPollerEvent_Write event flag for its read state to be watched
+	*
+	* \param socket Reference to the socket to check
+	*
+	* \return True if the socket is available for writing without blocking, false otherwise
+	*
+	* \see Wait
+	*/
+	bool SocketPoller::IsReadyToWrite(const AbstractSocket& socket) const
+	{
+		NazaraAssert(IsRegistered(socket), "Socket is not registered in the poller");
+
+		return m_impl->IsReadyToWrite(socket.GetNativeHandle());
 	}
 
 	/*!
@@ -97,7 +119,7 @@ namespace Nz
 	/*!
 	* \brief Register a socket in the SocketPoller
 	*
-	* A registered socket is part of the SocketPoller and will be checked by the next Wait operations.
+	* A registered socket is part of the SocketPoller and will be checked by the next Wait operations according to the event flags passed when registered.
 	*
 	* The SocketPoller keeps a reference to the internal handle of registered socket, which should not be freed while it is registered in the SocketPooler.
 	*
@@ -107,17 +129,18 @@ namespace Nz
 	* \remark The socket should not be freed while it is registered in the SocketPooler.
 	*
 	* \param socket Reference to the socket to register
+	* \param eventFlags Socket events to watch
 	*
 	* \return True if the socket is registered, false otherwise
 	*
 	* \see IsRegistered
 	* \see UnregisterSocket
 	*/
-	bool SocketPoller::RegisterSocket(AbstractSocket& socket)
+	bool SocketPoller::RegisterSocket(AbstractSocket& socket, SocketPollEventFlags eventFlags)
 	{
 		NazaraAssert(!IsRegistered(socket), "This socket is already registered in this SocketPoller");
 
-		return m_impl->RegisterSocket(socket.GetNativeHandle());
+		return m_impl->RegisterSocket(socket.GetNativeHandle(), eventFlags);
 	}
 
 	/*!
@@ -145,7 +168,7 @@ namespace Nz
 	* \brief Wait until any registered socket switches to a ready state.
 	*
 	* Waits a specific/undetermined amount of time until at least one socket part of the SocketPoller becomes ready.
-	* To query the ready state of the registered socket, use the IsReady function.
+	* To query the ready state of the registered socket, use the IsReadyToRead or IsReadyToWrite functions.
 	*
 	* \param msTimeout Maximum time to wait in milliseconds, 0 for infinity
 	*

src/Nazara/Network/Win32/SocketPollerImpl.cpp

@@ -10,29 +10,43 @@ namespace Nz
 	SocketPollerImpl::SocketPollerImpl()
 	{
 		#if !NAZARA_NETWORK_POLL_SUPPORT
-		FD_ZERO(&m_activeSockets);
+		FD_ZERO(&m_readSockets);
-		FD_ZERO(&m_sockets);
+		FD_ZERO(&m_readyToReadSockets);
+		FD_ZERO(&m_readyToWriteSockets);
+		FD_ZERO(&m_writeSockets);
 		#endif
 	}
 
 	void SocketPollerImpl::Clear()
 	{
 		#if NAZARA_NETWORK_POLL_SUPPORT
-		m_activeSockets.clear();
 		m_allSockets.clear();
+		m_readyToReadSockets.clear();
+		m_readyToWriteSockets.clear();
 		m_sockets.clear();
 		#else
-		FD_ZERO(&m_activeSockets);
+		FD_ZERO(&m_readSockets);
-		FD_ZERO(&m_sockets);
+		FD_ZERO(&m_readyToReadSockets);
+		FD_ZERO(&m_readyToWriteSockets);
+		FD_ZERO(&m_writeSockets);
 		#endif
 	}
 
-	bool SocketPollerImpl::IsReady(SocketHandle socket) const
+	bool SocketPollerImpl::IsReadyToRead(SocketHandle socket) const
 	{
 		#if NAZARA_NETWORK_POLL_SUPPORT
-		return m_activeSockets.count(socket) != 0;
+		return m_readyToReadSockets.count(socket) != 0;
 		#else
-		return FD_ISSET(socket, &m_activeSockets) != 0;
+		return FD_ISSET(socket, &m_readyToReadSockets) != 0;
+		#endif
+	}
+
+	bool SocketPollerImpl::IsReadyToWrite(SocketHandle socket) const
+	{
+		#if NAZARA_NETWORK_POLL_SUPPORT
+		return m_readyToWriteSockets.count(socket) != 0;
+		#else
+		return FD_ISSET(socket, &m_readyToWriteSockets) != 0;
 		#endif
 	}
 
@@ -41,31 +55,45 @@ namespace Nz
 		#if NAZARA_NETWORK_POLL_SUPPORT
 		return m_allSockets.count(socket) != 0;
 		#else
-		return FD_ISSET(socket, &m_sockets) != 0;
+		return FD_ISSET(socket, &m_readSockets) != 0 ||
+		       FD_ISSET(socket, &m_writeSockets) != 0;
 		#endif
 	}
 
-	bool SocketPollerImpl::RegisterSocket(SocketHandle socket)
+	bool SocketPollerImpl::RegisterSocket(SocketHandle socket, SocketPollEventFlags eventFlags)
 	{
 		NazaraAssert(!IsRegistered(socket), "Socket is already registered");
 
 		#if NAZARA_NETWORK_POLL_SUPPORT
 		PollSocket entry = {
 			socket,
-			POLLRDNORM,
+			0,
 			0
 		};
 
+		if (eventFlags & SocketPollEvent_Read)
+			entry.events |= POLLRDNORM;
+
+		if (eventFlags & SocketPollEvent_Write)
+			entry.events |= POLLWRNORM;
+
 		m_allSockets[socket] = m_sockets.size();
 		m_sockets.emplace_back(entry);
 		#else
-		if (m_sockets.fd_count > FD_SETSIZE)
+		for (std::size_t i = 0; i < 2; ++i)
 		{
-			NazaraError("Socket count exceeding FD_SETSIZE (" + String::Number(FD_SETSIZE) + ")");
+			if (eventFlags & ((i == 0) ? SocketPollEvent_Read : SocketPollEvent_Write) == 0)
+				continue;
+
+			fd_set& targetSet = (i == 0) ? m_readSockets : m_writeSockets;
+			if (targetSet.fd_count > FD_SETSIZE)
+			{
+				NazaraError("Socket count exceeding hard-coded FD_SETSIZE (" + String::Number(FD_SETSIZE) + ")");
 				return false;
 			}
 
-		FD_SET(socket, &m_sockets);
+			FD_SET(socket, &targetSet);
+		}
 		#endif
 
 		return true;
@@ -88,13 +116,16 @@ namespace Nz
 			// Now move it properly (lastElement is invalid after the following line) and pop it
 			m_sockets[entry] = std::move(m_sockets.back());
 		}
-
 		m_sockets.pop_back();
-		m_activeSockets.erase(socket);
+
 		m_allSockets.erase(socket);
+		m_readyToReadSockets.erase(socket);
+		m_readyToWriteSockets.erase(socket);
 		#else
-		FD_CLR(socket, &m_activeSockets);
+		FD_CLR(socket, &m_readSockets);
-		FD_CLR(socket, &m_sockets);
+		FD_CLR(socket, &m_readyToReadSockets);
+		FD_CLR(socket, &m_readyToWriteSockets);
+		FD_CLR(socket, &m_writeSockets);
 		#endif
 	}
 
@@ -103,35 +134,18 @@ namespace Nz
 		int activeSockets;
 
 		#if NAZARA_NETWORK_POLL_SUPPORT
-		// Reset status of sockets
-		for (PollSocket& entry : m_sockets)
-			entry.revents = 0;
-
 		activeSockets = SocketImpl::Poll(m_sockets.data(), m_sockets.size(), static_cast<int>(msTimeout), error);
+		x
 
-		m_activeSockets.clear();
-		if (activeSockets > 0U)
-		{
-			int socketRemaining = activeSockets;
-			for (PollSocket& entry : m_sockets)
-			{
-				if (entry.revents & POLLRDNORM)
-				{
-					m_activeSockets.insert(entry.fd);
-					if (--socketRemaining == 0)
-						break;
-				}
-			}
-		}
 		#else
-
+		m_readyToReadSockets = m_readSockets;
-		m_activeSockets = m_sockets;
+		m_readyToWriteSockets = m_writeSockets;
 
 		timeval tv;
 		tv.tv_sec = static_cast<long>(msTimeout / 1000ULL);
 		tv.tv_usec = static_cast<long>((msTimeout % 1000ULL) * 1000ULL);
 
-		activeSockets = ::select(0xDEADBEEF, &m_activeSockets, nullptr, nullptr, (msTimeout > 0) ? &tv : nullptr); //< The first argument is ignored on Windows
+		activeSockets = ::select(0xDEADBEEF, &m_readyToReadSockets, &m_readyToWriteSockets, nullptr, (msTimeout > 0) ? &tv : nullptr); //< The first argument is ignored on Windows
 		if (activeSockets == SOCKET_ERROR)
 		{
 			if (error)

src/Nazara/Network/Win32/SocketPollerImpl.hpp

@@ -25,22 +25,26 @@ namespace Nz
 
 			void Clear();
 
-			bool IsReady(SocketHandle socket) const;
+			bool IsReadyToRead(SocketHandle socket) const;
+			bool IsReadyToWrite(SocketHandle socket) const;
 			bool IsRegistered(SocketHandle socket) const;
 
-			bool RegisterSocket(SocketHandle socket);
+			bool RegisterSocket(SocketHandle socket, SocketPollEventFlags eventFlags);
 			void UnregisterSocket(SocketHandle socket);
 
 			int Wait(UInt64 msTimeout, SocketError* error);
 
 		private:
 			#if NAZARA_NETWORK_POLL_SUPPORT
-			std::unordered_set<SocketHandle> m_activeSockets;
+			std::unordered_set<SocketHandle> m_readyToReadSockets;
+			std::unordered_set<SocketHandle> m_readyToWriteSockets;
 			std::unordered_map<SocketHandle, std::size_t> m_allSockets;
 			std::vector<PollSocket> m_sockets;
 			#else
-			fd_set m_sockets;
+			fd_set m_readSockets;
-			fd_set m_activeSockets;
+			fd_set m_readyToReadSockets;
+			fd_set m_readyToWriteSockets;
+			fd_set m_writeSockets;
 			#endif
 	};
 }