diff --git a/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs b/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs index 2c5ad85432..1e6927fadf 100644 --- a/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs +++ b/OpenSim/Region/ClientStack/LindenUDP/LLUDPServer.cs @@ -87,7 +87,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP /// The LLUDP server for a region. This handles incoming and outgoing /// packets for all UDP connections to the region /// - public class LLUDPServer : UDPBase + public class LLUDPServer : OpenSimUDPBase { private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType); diff --git a/OpenSim/Region/ClientStack/LindenUDP/OpenSimUDPBase.cs b/OpenSim/Region/ClientStack/LindenUDP/OpenSimUDPBase.cs new file mode 100644 index 0000000000..aaefbc6ce3 --- /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(); + } + } +}