API Proposal: Check Disposed Socket #54

chronoxor · Mar 31, 2020 · 710500a · 710500a
1 parent d35c2e4
commit 710500a
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Showing 10 changed files with 249 additions and 35 deletions.
diff --git a/.appveyor.yml b/.appveyor.yml
@@ -1,5 +1,5 @@
 # Specify version format
-version: "3.0.7.{build}"
+version: "3.0.8.{build}"
 
 # Image to use
 image: Visual Studio 2019

diff --git a/source/NetCoreServer/NetCoreServer.csproj b/source/NetCoreServer/NetCoreServer.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <TargetFramework>netstandard2.1</TargetFramework>
-    <Version>3.0.7</Version>
+    <Version>3.0.8</Version>
     <Authors>Ivan Shynkarenka</Authors>
     <Copyright>Copyright (c) 2019-2020 Ivan Shynkarenka</Copyright>
     <RepositoryUrl>https://github.com/chronoxor/NetCoreServer</RepositoryUrl>

diff --git a/source/NetCoreServer/SslClient.cs b/source/NetCoreServer/SslClient.cs
@@ -1,5 +1,4 @@
 using System;
-using System.IO;
 using System.Net;
 using System.Net.Security;
 using System.Net.Sockets;
@@ -200,12 +199,20 @@ public virtual bool Connect()
             }
             catch (SocketException ex)
             {
+                // Close the client socket
+                Socket.Close();
+                // Dispose the client socket
+                Socket.Dispose();
+
                 // Call the client disconnected handler
                 SendError(ex.SocketErrorCode);
                 OnDisconnected();
                 return false;
             }
 
+            // Update the client socket disposed flag
+            IsSocketDisposed = false;
+
             // Apply the option: keep alive
             if (OptionKeepAlive)
                 Socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.KeepAlive, true);
@@ -310,6 +317,9 @@ public virtual bool Disconnect()
 
                 // Dispose the client socket
                 Socket.Dispose();
+
+                // Update the client socket disposed flag
+                IsSocketDisposed = true;
             }
             catch (ObjectDisposedException) {}
 
@@ -978,8 +988,15 @@ private void SendError(SocketError error)
 
         #region IDisposable implementation
 
-        // Disposed flag.
-        private bool _disposed;
+        /// <summary>
+        /// Disposed flag
+        /// </summary>
+        public bool IsDisposed { get; private set; }
+
+        /// <summary>
+        /// Client socket disposed flag
+        /// </summary>
+        public bool IsSocketDisposed { get; private set; } = true;
 
         // Implement IDisposable.
         public void Dispose()
@@ -1002,7 +1019,7 @@ protected virtual void Dispose(bool disposingManagedResources)
             // refer to reference type fields because those objects may
             // have already been finalized."
 
-            if (!_disposed)
+            if (!IsDisposed)
             {
                 if (disposingManagedResources)
                 {
@@ -1015,7 +1032,7 @@ protected virtual void Dispose(bool disposingManagedResources)
                 // Set large fields to null here...
 
                 // Mark as disposed.
-                _disposed = true;
+                IsDisposed = true;
             }
         }
 

diff --git a/source/NetCoreServer/SslServer.cs b/source/NetCoreServer/SslServer.cs
@@ -145,6 +145,9 @@ public virtual bool Start()
             // Create a new acceptor socket
             _acceptorSocket = new Socket(Endpoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
 
+            // Update the acceptor socket disposed flag
+            IsSocketDisposed = false;
+
             // Apply the option: reuse address
             _acceptorSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, OptionReuseAddress);
             // Apply the option: exclusive address use
@@ -197,6 +200,9 @@ public virtual bool Stop()
             // Dispose the acceptor socket
             _acceptorSocket.Dispose();
 
+            // Update the acceptor socket disposed flag
+            IsSocketDisposed = true;
+
             // Disconnect all sessions
             DisconnectAll();
 
@@ -442,8 +448,15 @@ private void SendError(SocketError error)
 
         #region IDisposable implementation
 
-        // Disposed flag.
-        private bool _disposed;
+        /// <summary>
+        /// Disposed flag
+        /// </summary>
+        public bool IsDisposed { get; private set; }
+
+        /// <summary>
+        /// Acceptor socket disposed flag
+        /// </summary>
+        public bool IsSocketDisposed { get; private set; } = true;
 
         // Implement IDisposable.
         public void Dispose()
@@ -466,7 +479,7 @@ protected virtual void Dispose(bool disposingManagedResources)
             // refer to reference type fields because those objects may
             // have already been finalized."
 
-            if (!_disposed)
+            if (!IsDisposed)
             {
                 if (disposingManagedResources)
                 {
@@ -479,7 +492,7 @@ protected virtual void Dispose(bool disposingManagedResources)
                 // Set large fields to null here...
 
                 // Mark as disposed.
-                _disposed = true;
+                IsDisposed = true;
             }
         }
 

diff --git a/source/NetCoreServer/SslSession.cs b/source/NetCoreServer/SslSession.cs
@@ -1,5 +1,4 @@
 using System;
-using System.IO;
 using System.Net.Security;
 using System.Net.Sockets;
 using System.Text;
@@ -12,7 +11,7 @@ namespace NetCoreServer
     /// SSL session is used to read and write data from the connected SSL client
     /// </summary>
     /// <remarks>Thread-safe</remarks>
-    public class SslSession
+    public class SslSession : IDisposable
     {
         /// <summary>
         /// Initialize the session with a given server
@@ -125,6 +124,9 @@ internal void Connect(Socket socket)
         {
             Socket = socket;
 
+            // Update the session socket disposed flag
+            IsSocketDisposed = false;
+
             // Setup buffers
             _receiveBuffer = new Buffer();
             _sendBufferMain = new Buffer();
@@ -213,6 +215,9 @@ public virtual bool Disconnect()
 
                 // Dispose the session socket
                 Socket.Dispose();
+
+                // Update the session socket disposed flag
+                IsSocketDisposed = true;
             }
             catch (ObjectDisposedException) {}
 
@@ -751,5 +756,64 @@ private void SendError(SocketError error)
         }
 
         #endregion
+
+        #region IDisposable implementation
+
+        /// <summary>
+        /// Disposed flag
+        /// </summary>
+        public bool IsDisposed { get; private set; }
+
+        /// <summary>
+        /// Session socket disposed flag
+        /// </summary>
+        public bool IsSocketDisposed { get; private set; } = true;
+
+        // Implement IDisposable.
+        public void Dispose()
+        {
+            Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        protected virtual void Dispose(bool disposingManagedResources)
+        {
+            // The idea here is that Dispose(Boolean) knows whether it is
+            // being called to do explicit cleanup (the Boolean is true)
+            // versus being called due to a garbage collection (the Boolean
+            // is false). This distinction is useful because, when being
+            // disposed explicitly, the Dispose(Boolean) method can safely
+            // execute code using reference type fields that refer to other
+            // objects knowing for sure that these other objects have not been
+            // finalized or disposed of yet. When the Boolean is false,
+            // the Dispose(Boolean) method should not execute code that
+            // refer to reference type fields because those objects may
+            // have already been finalized."
+
+            if (!IsDisposed)
+            {
+                if (disposingManagedResources)
+                {
+                    // Dispose managed resources here...
+                    Disconnect();
+                }
+
+                // Dispose unmanaged resources here...
+
+                // Set large fields to null here...
+
+                // Mark as disposed.
+                IsDisposed = true;
+            }
+        }
+
+        // Use C# destructor syntax for finalization code.
+        ~SslSession()
+        {
+            // Simply call Dispose(false).
+            Dispose(false);
+        }
+
+        #endregion
     }
 }
diff --git a/source/NetCoreServer/TcpClient.cs b/source/NetCoreServer/TcpClient.cs
@@ -177,12 +177,20 @@ public virtual bool Connect()
             }
             catch (SocketException ex)
             {
+                // Close the client socket
+                Socket.Close();
+                // Dispose the client socket
+                Socket.Dispose();
+
                 // Call the client disconnected handler
                 SendError(ex.SocketErrorCode);
                 OnDisconnected();
                 return false;
             }
 
+            // Update the client socket disposed flag
+            IsSocketDisposed = false;
+
             // Apply the option: keep alive
             if (OptionKeepAlive)
                 Socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.KeepAlive, true);
@@ -246,6 +254,9 @@ public virtual bool Disconnect()
 
                 // Dispose the client socket
                 Socket.Dispose();
+
+                // Update the client socket disposed flag
+                IsSocketDisposed = true;
             }
             catch (ObjectDisposedException) {}
 
@@ -858,8 +869,15 @@ private void SendError(SocketError error)
 
         #region IDisposable implementation
 
-        // Disposed flag.
-        private bool _disposed;
+        /// <summary>
+        /// Disposed flag
+        /// </summary>
+        public bool IsDisposed { get; private set; }
+
+        /// <summary>
+        /// Client socket disposed flag
+        /// </summary>
+        public bool IsSocketDisposed { get; private set; } = true;
 
         // Implement IDisposable.
         public void Dispose()
@@ -882,7 +900,7 @@ protected virtual void Dispose(bool disposingManagedResources)
             // refer to reference type fields because those objects may
             // have already been finalized."
 
-            if (!_disposed)
+            if (!IsDisposed)
             {
                 if (disposingManagedResources)
                 {
@@ -895,7 +913,7 @@ protected virtual void Dispose(bool disposingManagedResources)
                 // Set large fields to null here...
 
                 // Mark as disposed.
-                _disposed = true;
+                IsDisposed = true;
             }
         }
 

diff --git a/source/NetCoreServer/TcpServer.cs b/source/NetCoreServer/TcpServer.cs
@@ -136,6 +136,9 @@ public virtual bool Start()
             // Create a new acceptor socket
             _acceptorSocket = new Socket(Endpoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
 
+            // Update the acceptor socket disposed flag
+            IsSocketDisposed = false;
+
             // Apply the option: reuse address
             _acceptorSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, OptionReuseAddress);
             // Apply the option: exclusive address use
@@ -188,6 +191,9 @@ public virtual bool Stop()
             // Dispose the acceptor socket
             _acceptorSocket.Dispose();
 
+            // Update the acceptor socket disposed flag
+            IsSocketDisposed = true;
+
             // Disconnect all sessions
             DisconnectAll();
 
@@ -427,8 +433,15 @@ private void SendError(SocketError error)
 
         #region IDisposable implementation
 
-        // Disposed flag.
-        private bool _disposed;
+        /// <summary>
+        /// Disposed flag
+        /// </summary>
+        public bool IsDisposed { get; private set; }
+
+        /// <summary>
+        /// Acceptor socket disposed flag
+        /// </summary>
+        public bool IsSocketDisposed { get; private set; } = true;
 
         // Implement IDisposable.
         public void Dispose()
@@ -451,7 +464,7 @@ protected virtual void Dispose(bool disposingManagedResources)
             // refer to reference type fields because those objects may
             // have already been finalized."
 
-            if (!_disposed)
+            if (!IsDisposed)
             {
                 if (disposingManagedResources)
                 {
@@ -464,7 +477,7 @@ protected virtual void Dispose(bool disposingManagedResources)
                 // Set large fields to null here...
 
                 // Mark as disposed.
-                _disposed = true;
+                IsDisposed = true;
             }
         }