From a0dd9f4bb4c1a88c2692066c54923c7f91429df5 Mon Sep 17 00:00:00 2001
From: Melanie
Date: Thu, 8 Oct 2009 22:25:14 +0100
Subject: Fork UDPBase from libOMV into opensim
---
.../Region/ClientStack/LindenUDP/OpenSimUDPBase.cs | 340 +++++++++++++++++++++
1 file changed, 340 insertions(+)
create mode 100644 OpenSim/Region/ClientStack/LindenUDP/OpenSimUDPBase.cs
(limited to 'OpenSim/Region/ClientStack/LindenUDP/OpenSimUDPBase.cs')
diff --git a/OpenSim/Region/ClientStack/LindenUDP/OpenSimUDPBase.cs b/OpenSim/Region/ClientStack/LindenUDP/OpenSimUDPBase.cs
new file mode 100644
index 0000000..aaefbc6
--- /dev/null
+++ b/OpenSim/Region/ClientStack/LindenUDP/OpenSimUDPBase.cs
@@ -0,0 +1,340 @@
+/*
+ * Copyright (c) 2006, Clutch, Inc.
+ * Original Author: Jeff Cesnik
+ * All rights reserved.
+ *
+ * - Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ * - Neither the name of the openmetaverse.org nor the names
+ * of its contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+using System.Net;
+using System.Net.Sockets;
+using System.Threading;
+using OpenMetaverse;
+
+namespace OpenSim.Region.ClientStack.LindenUDP
+{
+ ///
+ ///
+ ///
+ public abstract class OpenSimUDPBase
+ {
+ // these abstract methods must be implemented in a derived class to actually do
+ // something with the packets that are sent and received.
+ protected abstract void PacketReceived(UDPPacketBuffer buffer);
+ protected abstract void PacketSent(UDPPacketBuffer buffer, int bytesSent);
+
+ // the port to listen on
+ internal int udpPort;
+
+ // the UDP socket
+ private Socket udpSocket;
+
+ // the ReaderWriterLock is used solely for the purposes of shutdown (Stop()).
+ // since there are potentially many "reader" threads in the internal .NET IOCP
+ // thread pool, this is a cheaper synchronization primitive than using
+ // a Mutex object. This allows many UDP socket "reads" concurrently - when
+ // Stop() is called, it attempts to obtain a writer lock which will then
+ // wait until all outstanding operations are completed before shutting down.
+ // this avoids the problem of closing the socket with outstanding operations
+ // and trying to catch the inevitable ObjectDisposedException.
+ private ReaderWriterLock rwLock = new ReaderWriterLock();
+
+ // number of outstanding operations. This is a reference count
+ // which we use to ensure that the threads exit cleanly. Note that
+ // we need this because the threads will potentially still need to process
+ // data even after the socket is closed.
+ private int rwOperationCount = 0;
+
+ // the all important shutdownFlag. This is synchronized through the ReaderWriterLock.
+ private volatile bool shutdownFlag = true;
+
+ // the remote endpoint to communicate with
+ protected IPEndPoint remoteEndPoint = null;
+
+
+ ///
+ /// Initialize the UDP packet handler in server mode
+ ///
+ /// Port to listening for incoming UDP packets on
+ public OpenSimUDPBase(int port)
+ {
+ udpPort = port;
+ }
+
+ ///
+ /// Initialize the UDP packet handler in client mode
+ ///
+ /// Remote UDP server to connect to
+ public OpenSimUDPBase(IPEndPoint endPoint)
+ {
+ remoteEndPoint = endPoint;
+ udpPort = 0;
+ }
+
+ ///
+ ///
+ ///
+ public void Start()
+ {
+ if (shutdownFlag)
+ {
+ if (remoteEndPoint == null)
+ {
+ // Server mode
+
+ // create and bind the socket
+ IPEndPoint ipep = new IPEndPoint(Settings.BIND_ADDR, udpPort);
+ udpSocket = new Socket(
+ AddressFamily.InterNetwork,
+ SocketType.Dgram,
+ ProtocolType.Udp);
+ udpSocket.Bind(ipep);
+ }
+ else
+ {
+ // Client mode
+ IPEndPoint ipep = new IPEndPoint(Settings.BIND_ADDR, udpPort);
+ udpSocket = new Socket(
+ AddressFamily.InterNetwork,
+ SocketType.Dgram,
+ ProtocolType.Udp);
+ udpSocket.Bind(ipep);
+ //udpSocket.Connect(remoteEndPoint);
+ }
+
+ // we're not shutting down, we're starting up
+ shutdownFlag = false;
+
+ // kick off an async receive. The Start() method will return, the
+ // actual receives will occur asynchronously and will be caught in
+ // AsyncEndRecieve().
+ AsyncBeginReceive();
+ }
+ }
+
+ ///
+ ///
+ ///
+ public void Stop()
+ {
+ if (!shutdownFlag)
+ {
+ // wait indefinitely for a writer lock. Once this is called, the .NET runtime
+ // will deny any more reader locks, in effect blocking all other send/receive
+ // threads. Once we have the lock, we set shutdownFlag to inform the other
+ // threads that the socket is closed.
+ rwLock.AcquireWriterLock(-1);
+ shutdownFlag = true;
+ udpSocket.Close();
+ rwLock.ReleaseWriterLock();
+
+ // wait for any pending operations to complete on other
+ // threads before exiting.
+ const int FORCE_STOP = 100;
+ int i = 0;
+ while (rwOperationCount > 0 && i < FORCE_STOP)
+ {
+ Thread.Sleep(10);
+ ++i;
+ }
+
+ if (i >= FORCE_STOP)
+ {
+ Logger.Log("UDPBase.Stop() forced shutdown while waiting on pending operations",
+ Helpers.LogLevel.Warning);
+ }
+ }
+ }
+
+ ///
+ ///
+ ///
+ public bool IsRunning
+ {
+ get { return !shutdownFlag; }
+ }
+
+ private void AsyncBeginReceive()
+ {
+ // this method actually kicks off the async read on the socket.
+ // we aquire a reader lock here to ensure that no other thread
+ // is trying to set shutdownFlag and close the socket.
+ rwLock.AcquireReaderLock(-1);
+
+ if (!shutdownFlag)
+ {
+ // increment the count of pending operations
+ Interlocked.Increment(ref rwOperationCount);
+
+ // allocate a packet buffer
+ //WrappedObject wrappedBuffer = Pool.CheckOut();
+ UDPPacketBuffer buf = new UDPPacketBuffer();
+
+ try
+ {
+ // kick off an async read
+ udpSocket.BeginReceiveFrom(
+ //wrappedBuffer.Instance.Data,
+ buf.Data,
+ 0,
+ UDPPacketBuffer.BUFFER_SIZE,
+ SocketFlags.None,
+ //ref wrappedBuffer.Instance.RemoteEndPoint,
+ ref buf.RemoteEndPoint,
+ new AsyncCallback(AsyncEndReceive),
+ //wrappedBuffer);
+ buf);
+ }
+ catch (SocketException)
+ {
+ // something bad happened
+ //Logger.Log(
+ // "A SocketException occurred in UDPServer.AsyncBeginReceive()",
+ // Helpers.LogLevel.Error, se);
+
+ // an error occurred, therefore the operation is void. Decrement the reference count.
+ Interlocked.Decrement(ref rwOperationCount);
+ }
+ }
+
+ // we're done with the socket for now, release the reader lock.
+ rwLock.ReleaseReaderLock();
+ }
+
+ private void AsyncEndReceive(IAsyncResult iar)
+ {
+ // Asynchronous receive operations will complete here through the call
+ // to AsyncBeginReceive
+
+ // aquire a reader lock
+ rwLock.AcquireReaderLock(-1);
+
+ if (!shutdownFlag)
+ {
+ // get the buffer that was created in AsyncBeginReceive
+ // this is the received data
+ //WrappedObject wrappedBuffer = (WrappedObject)iar.AsyncState;
+ //UDPPacketBuffer buffer = wrappedBuffer.Instance;
+ UDPPacketBuffer buffer = (UDPPacketBuffer)iar.AsyncState;
+
+ try
+ {
+ // get the length of data actually read from the socket, store it with the
+ // buffer
+ buffer.DataLength = udpSocket.EndReceiveFrom(iar, ref buffer.RemoteEndPoint);
+
+ // this operation is now complete, decrement the reference count
+ Interlocked.Decrement(ref rwOperationCount);
+
+ // we're done with the socket, release the reader lock
+ rwLock.ReleaseReaderLock();
+
+ // call the abstract method PacketReceived(), passing the buffer that
+ // has just been filled from the socket read.
+ PacketReceived(buffer);
+ }
+ catch (SocketException)
+ {
+ // an error occurred, therefore the operation is void. Decrement the reference count.
+ Interlocked.Decrement(ref rwOperationCount);
+
+ // we're done with the socket for now, release the reader lock.
+ rwLock.ReleaseReaderLock();
+ }
+ finally
+ {
+ // start another receive - this keeps the server going!
+ AsyncBeginReceive();
+
+ //wrappedBuffer.Dispose();
+ }
+ }
+ else
+ {
+ // nothing bad happened, but we are done with the operation
+ // decrement the reference count and release the reader lock
+ Interlocked.Decrement(ref rwOperationCount);
+ rwLock.ReleaseReaderLock();
+ }
+ }
+
+ public void AsyncBeginSend(UDPPacketBuffer buf)
+ {
+ rwLock.AcquireReaderLock(-1);
+
+ if (!shutdownFlag)
+ {
+ try
+ {
+ Interlocked.Increment(ref rwOperationCount);
+ udpSocket.BeginSendTo(
+ buf.Data,
+ 0,
+ buf.DataLength,
+ SocketFlags.None,
+ buf.RemoteEndPoint,
+ new AsyncCallback(AsyncEndSend),
+ buf);
+ }
+ catch (SocketException)
+ {
+ //Logger.Log(
+ // "A SocketException occurred in UDPServer.AsyncBeginSend()",
+ // Helpers.LogLevel.Error, se);
+ }
+ }
+
+ rwLock.ReleaseReaderLock();
+ }
+
+ private void AsyncEndSend(IAsyncResult iar)
+ {
+ rwLock.AcquireReaderLock(-1);
+
+ if (!shutdownFlag)
+ {
+ UDPPacketBuffer buffer = (UDPPacketBuffer)iar.AsyncState;
+
+ try
+ {
+ int bytesSent = udpSocket.EndSendTo(iar);
+
+ // note that call to the abstract PacketSent() method - we are passing the number
+ // of bytes sent in a separate parameter, since we can't use buffer.DataLength which
+ // is the number of bytes to send (or bytes received depending upon whether this
+ // buffer was part of a send or a receive).
+ PacketSent(buffer, bytesSent);
+ }
+ catch (SocketException)
+ {
+ //Logger.Log(
+ // "A SocketException occurred in UDPServer.AsyncEndSend()",
+ // Helpers.LogLevel.Error, se);
+ }
+ }
+
+ Interlocked.Decrement(ref rwOperationCount);
+ rwLock.ReleaseReaderLock();
+ }
+ }
+}
--
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