From d210a39249a6f5e172d0f5c119f2a90b959f735a Mon Sep 17 00:00:00 2001
From: Eugen Wissner <Eugen Wissner>
Date: Sat, 18 Feb 2017 14:10:54 +0100
Subject: [PATCH] Implement IOCPTransport.close and isClosing

---
 source/tanya/async/event/iocp.d | 81 +++++++++++++++++++++++----------
 1 file changed, 58 insertions(+), 23 deletions(-)

diff --git a/source/tanya/async/event/iocp.d b/source/tanya/async/event/iocp.d
index 8dc6f2d..26678e1 100644
--- a/source/tanya/async/event/iocp.d
+++ b/source/tanya/async/event/iocp.d
@@ -39,6 +39,8 @@ final class StreamTransport : SocketWatcher, DuplexTransport, SocketTransport
 
 	private Protocol protocol_;
 
+	private bool closing;
+
 	/**
 	 * Creates new completion port transport.
 	 *
@@ -70,6 +72,24 @@ final class StreamTransport : SocketWatcher, DuplexTransport, SocketTransport
 		return cast(OverlappedConnectedSocket) socket_;
 	}
 
+	/**
+	 * Returns $(D_PARAM true) if the transport is closing or closed.
+	 */
+	bool isClosing() const pure nothrow @safe @nogc
+	{
+		return closing;
+	}
+
+	/**
+	 * Close the transport.
+	 *
+	 * Buffered data will be flushed.  No more data will be received.
+	 */
+	void close() pure nothrow @safe @nogc
+	{
+		closing = true;
+	}
+
 	/**
 	 * Write some data to the transport.
 	 *
@@ -78,22 +98,7 @@ final class StreamTransport : SocketWatcher, DuplexTransport, SocketTransport
 	 */
 	void write(ubyte[] data) @nogc
 	{
-		immutable empty = input.length == 0;
 		input ~= data;
-		if (empty)
-		{
-			SocketState overlapped;
-			try
-			{
-				overlapped = MmapPool.instance.make!SocketState;
-				socket.beginSend(input[], overlapped);
-			}
-			catch (SocketException e)
-			{
-				MmapPool.instance.dispose(overlapped);
-				MmapPool.instance.dispose(e);
-			}
-		}
 	}
 
 	/**
@@ -132,8 +137,23 @@ final class StreamTransport : SocketWatcher, DuplexTransport, SocketTransport
 	{
 		if (output.length)
 		{
+			immutable empty = input.length == 0;
 			protocol.received(output[0 .. $]);
 			output.clear();
+			if (empty)
+			{
+				SocketState overlapped;
+				try
+				{
+					overlapped = MmapPool.instance.make!SocketState;
+					socket.beginSend(input[], overlapped);
+				}
+				catch (SocketException e)
+				{
+					MmapPool.instance.dispose(overlapped);
+					MmapPool.instance.dispose(e);
+				}
+			}
 		}
 		else
 		{
@@ -239,6 +259,20 @@ final class IOCPLoop : Loop
 		return true;
 	}
 
+	private void kill(StreamTransport transport,
+	                  SocketException exception = null) @nogc
+	in
+	{
+		assert(transport !is null);
+	}
+	body
+	{
+		transport.socket.shutdown();
+		defaultAllocator.dispose(transport.socket);
+		transport.exception = exception;
+		pendings.enqueue(transport);
+	}
+
 	/**
 	 * Does the actual polling.
 	 */
@@ -308,19 +342,16 @@ final class IOCPLoop : Loop
 				}
 				if (transport.socket.disconnected)
 				{
-					// We want to get one last notification to destroy the watcher
+					// We want to get one last notification to destroy the watcher.
 					transport.socket.beginReceive(transport.output[], overlapped);
-					transport.socket.shutdown();
-					defaultAllocator.dispose(transport.socket);
-					transport.exception = exception;
-					pendings.enqueue(transport);
+					kill(transport, exception);
 				}
 				else if (received > 0)
 				{
 					immutable full = transport.output.free == received;
 
 					transport.output += received;
-					// Receive was interrupted because the buffer is full. We have to continue
+					// Receive was interrupted because the buffer is full. We have to continue.
 					if (full)
 					{
 						transport.socket.beginReceive(transport.output[], overlapped);
@@ -333,17 +364,21 @@ final class IOCPLoop : Loop
 				assert(transport !is null);
 
 				transport.input += transport.socket.endSend(overlapped);
-				if (transport.input.length)
+				if (transport.input.length > 0)
 				{
 					transport.socket.beginSend(transport.input[], overlapped);
 				}
 				else
 				{
 					transport.socket.beginReceive(transport.output[], overlapped);
+					if (transport.isClosing())
+					{
+						kill(transport);
+					}
 				}
 				break;
 			default:
 				assert(false, "Unknown event");
 		}
 	}
-}
+}
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