From ba8cd46e4cdb6585c230dd2666bcf8ea62d57e31 Mon Sep 17 00:00:00 2001
From: Koen <koen@pop-os.localdomain>
Date: Thu, 22 Feb 2024 11:37:52 +0100
Subject: [PATCH] Added write/read semaphores.

---
 .../FCastClient.Cli/FCastClient.Cli.csproj    |  2 +-
 .../FCastClient.Cli/Program.cs                |  2 +
 .../FCastClient/FCastClient.csproj            |  2 +-
 .../FCastClient/FCastSession.cs               | 74 +++++++++++++------
 4 files changed, 56 insertions(+), 24 deletions(-)

diff --git a/clients/terminal-dotnet/FCastClient.Cli/FCastClient.Cli.csproj b/clients/terminal-dotnet/FCastClient.Cli/FCastClient.Cli.csproj
index eb806fe..79059af 100644
--- a/clients/terminal-dotnet/FCastClient.Cli/FCastClient.Cli.csproj
+++ b/clients/terminal-dotnet/FCastClient.Cli/FCastClient.Cli.csproj
@@ -10,7 +10,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
diff --git a/clients/terminal-dotnet/FCastClient.Cli/Program.cs b/clients/terminal-dotnet/FCastClient.Cli/Program.cs
index 74a84fe..bed8183 100644
--- a/clients/terminal-dotnet/FCastClient.Cli/Program.cs
+++ b/clients/terminal-dotnet/FCastClient.Cli/Program.cs
@@ -121,6 +121,8 @@ internal class Program
             .Build();
 
         CommandMatches matches = rootCommand.Parse(args);
+        Console.WriteLine(matches.ToString());
+
         var host = matches.Value("host")!;
         var connectionType = matches.Value("connection_type")!;
 
diff --git a/clients/terminal-dotnet/FCastClient/FCastClient.csproj b/clients/terminal-dotnet/FCastClient/FCastClient.csproj
index 4658cbf..1d2b313 100644
--- a/clients/terminal-dotnet/FCastClient/FCastClient.csproj
+++ b/clients/terminal-dotnet/FCastClient/FCastClient.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
diff --git a/clients/terminal-dotnet/FCastClient/FCastSession.cs b/clients/terminal-dotnet/FCastClient/FCastSession.cs
index 28d9c78..f84a402 100644
--- a/clients/terminal-dotnet/FCastClient/FCastSession.cs
+++ b/clients/terminal-dotnet/FCastClient/FCastSession.cs
@@ -41,6 +41,8 @@ public class FCastSession : IDisposable
     private int _bytesRead;
     private int _packetLength;
     private Stream _stream;
+    private SemaphoreSlim _writerSemaphore = new SemaphoreSlim(1);
+    private SemaphoreSlim _readerSemaphore = new SemaphoreSlim(1);
     private SessionState _state;
 
     public FCastSession(Stream stream)
@@ -51,30 +53,48 @@ public class FCastSession : IDisposable
 
     public async Task SendMessageAsync(Opcode opcode, CancellationToken cancellationToken)
     {
-        int size = 1;
-        byte[] header = new byte[LengthBytes + 1];
-        Array.Copy(BitConverter.GetBytes(size), header, LengthBytes);
-        header[LengthBytes] = (byte)opcode;
+        await _writerSemaphore.WaitAsync();
 
-        Console.WriteLine($"Sent {header.Length} bytes with (opcode: {opcode}, header size: {header.Length}, no body).");
-        await _stream.WriteAsync(header, cancellationToken);
+        try
+        {
+            int size = 1;
+            byte[] header = new byte[LengthBytes + 1];
+            Array.Copy(BitConverter.GetBytes(size), header, LengthBytes);
+            header[LengthBytes] = (byte)opcode;
+
+            Console.WriteLine($"Sent {header.Length} bytes with (opcode: {opcode}, header size: {header.Length}, no body).");
+            await _stream.WriteAsync(header, cancellationToken);
+        }
+        finally
+        {
+            _writerSemaphore.Release();
+        }
     }
 
     public async Task SendMessageAsync<T>(Opcode opcode, T message, CancellationToken cancellationToken) where T : class
     {
-        string json = JsonSerializer.Serialize(message);
-        byte[] data = Encoding.UTF8.GetBytes(json);
-        int size = 1 + data.Length;
-        byte[] header = new byte[LengthBytes + 1];
-        Array.Copy(BitConverter.GetBytes(size), header, LengthBytes);
-        header[LengthBytes] = (byte)opcode;
+        await _writerSemaphore.WaitAsync();
 
-        byte[] packet = new byte[header.Length + data.Length];
-        header.CopyTo(packet, 0);
-        data.CopyTo(packet, header.Length);
+        try
+        {
+            string json = JsonSerializer.Serialize(message);
+            byte[] data = Encoding.UTF8.GetBytes(json);
+            int size = 1 + data.Length;
+            byte[] header = new byte[LengthBytes + 1];
+            Array.Copy(BitConverter.GetBytes(size), header, LengthBytes);
+            header[LengthBytes] = (byte)opcode;
 
-        Console.WriteLine($"Sent {packet.Length} bytes with (opcode: {opcode}, header size: {header.Length}, body size: {data.Length}, body: {json}).");
-        await _stream.WriteAsync(packet, cancellationToken);
+            byte[] packet = new byte[header.Length + data.Length];
+            header.CopyTo(packet, 0);
+            data.CopyTo(packet, header.Length);
+
+            Console.WriteLine($"Sent {packet.Length} bytes with (opcode: {opcode}, header size: {header.Length}, body size: {data.Length}, body: {json}).");
+            await _stream.WriteAsync(packet, cancellationToken);
+        }
+        finally
+        {
+            _writerSemaphore.Release();
+        }
     }
 
     public async Task ReceiveLoopAsync(CancellationToken cancellationToken)
@@ -85,12 +105,22 @@ public class FCastSession : IDisposable
         byte[] buffer = new byte[1024];
         while (!cancellationToken.IsCancellationRequested)
         {
-            int bytesRead = await _stream.ReadAsync(buffer, cancellationToken);
-            if (bytesRead == 0)
+            await _readerSemaphore.WaitAsync();
+
+            int bytesRead;
+            try
             {
-                Console.WriteLine("Connection shutdown gracefully.");
-                Dispose();
-                break;
+                bytesRead = await _stream.ReadAsync(buffer, cancellationToken);
+                if (bytesRead == 0)
+                {
+                    Console.WriteLine("Connection shutdown gracefully.");
+                    Dispose();
+                    break;
+                }
+            }
+            finally
+            {
+                _readerSemaphore.Release();
             }
 
             await ProcessBytesAsync(buffer, bytesRead, cancellationToken);