C#•3mo ago

SignalR Blocking Issue: Infinite Wait When Calling a Method from Client

Hello here is a Hub I implemented, the goal is to make a board game turn system, the most important part is in the method LaunchGame. I ask in the while loop two question "PiocheRequest" and "CoordRequest". The functions works well for the first 2 player in the loop. But at the third, the client send it successfully but the server is blocked and don't trigger PiocheResponse. What I tried: Using locks, mutexes because I think it's a threading problem but it didn't gave me a different result. Many thanks in advance,

message.txt

5 Replies

Mehdi•3mo ago

You have the full code of. my lobby if you want to try in local Here is how I call from client the methods in general: (Here PiocheRequest)

_connection.On<string, string>("PiocheRequest", async (request, requestId) =>
        {      
                Console.WriteLine(request);
                try{
                var coords = Console.ReadLine();
                var task = _connection.SendAsync("PiocheResponse", requestId, coords);
                await task;
                if(task.IsCompletedSuccessfully){
                        Console.WriteLine("Ok le message a ete envoye");
                } else {
                        Console.WriteLine("On a des problemes a envoyer la tuile a piocher.");
                }
                } catch (Exception e){
                        throw;
                }
        });

_connection.On<string, string>("PiocheRequest", async (request, requestId) =>
        {      
                Console.WriteLine(request);
                try{
                var coords = Console.ReadLine();
                var task = _connection.SendAsync("PiocheResponse", requestId, coords);
                await task;
                if(task.IsCompletedSuccessfully){
                        Console.WriteLine("Ok le message a ete envoye");
                } else {
                        Console.WriteLine("On a des problemes a envoyer la tuile a piocher.");
                }
                } catch (Exception e){
                        throw;
                }
        });

graph TD
    A[Client] -->|Connects| B((OkeyHub))
    B -->|Sends lobby list| C((Client))
    C -->|Chooses lobby| B
    B -->|Joins lobby| D((Room))
    B -->|Starts game| E((Jeu))
    E -->|Distributes tiles| B
    B -->|Sends game start message| C
    C -->|Receives game start message| A
    E -->|Requests player turn| B
    B -->|Requests tile discard coordinates| A
    A -->|Sends coordinates| B
    B -->|Processes discard| E
    E -->|Requests tile draw choice| B
    B -->|Requests tile draw choice| A
    A -->|Sends draw choice| B
    B -->|Processes draw choice| E
    E -->|Checks game end| B
    B -->|Continues game loop| E
    E -->|Game ends| B
    B -->|Sends game end message| C
    C -->|Receives game end message| A
    A -->|Disconnects| B
    B -->|Handles disconnection| D
    D -->|Updates room status| B

graph TD
    A[Client] -->|Connects| B((OkeyHub))
    B -->|Sends lobby list| C((Client))
    C -->|Chooses lobby| B
    B -->|Joins lobby| D((Room))
    B -->|Starts game| E((Jeu))
    E -->|Distributes tiles| B
    B -->|Sends game start message| C
    C -->|Receives game start message| A
    E -->|Requests player turn| B
    B -->|Requests tile discard coordinates| A
    A -->|Sends coordinates| B
    B -->|Processes discard| E
    E -->|Requests tile draw choice| B
    B -->|Requests tile draw choice| A
    A -->|Sends draw choice| B
    B -->|Processes draw choice| E
    E -->|Checks game end| B
    B -->|Continues game loop| E
    E -->|Game ends| B
    B -->|Sends game end message| C
    C -->|Receives game end message| A
    A -->|Disconnects| B
    B -->|Handles disconnection| D
    D -->|Updates room status| B

Here is a mermaid diagram of the logic I really need

Mehdi•3mo ago

Ok, I did an update of my code, with advice of @TeBeCo I used a Singleton and DI approach so here is my code re-written: But I need to order the sendings of request to the client. I thought about a Queue is this a good approach ?

message.txt

Mehdi•3mo ago

Ok I have added the logic and at the third turn during my PiocheRequest the server is blocked:

message.txt

Mehdi•3mo ago

I don't understand why it's only happening at the third turn Ok I found the blocking issue:

public async Task<string> PiocheRequest(string connectionId)
        {
            var requestId = Guid.NewGuid().ToString();
            var tcs = new TaskCompletionSource<string>();
            await this._responsesLock.WaitAsync();
            try
            {
                _responses[requestId] = tcs;
            }
            finally
            {
                this._responsesLock.Release();
            }
            await this._hubContext.Clients.Client(connectionId).SendAsync("PiocheRequest", "Veuillez choisir la tuile à piocher (Centre ou Defausse)", requestId);
            await this._responsesLock.WaitAsync();
            try
            {
                var response = await _responses[requestId].Task;
                _responses.TryRemove(requestId, out _);
                return response;
            }
            finally
            {
                this._responsesLock.Release();
            }
        }

        public async Task PiocheResponse(string requestId, string response)
        {
            await this._responsesLock.WaitAsync();
            try
            {
                if (_responses.TryGetValue(requestId, out var responseTask))
                {
                    responseTask.SetResult(response);
                }
            }
            finally
            {
                this._responsesLock.Release();
            }

        }

public async Task<string> PiocheRequest(string connectionId)
        {
            var requestId = Guid.NewGuid().ToString();
            var tcs = new TaskCompletionSource<string>();
            await this._responsesLock.WaitAsync();
            try
            {
                _responses[requestId] = tcs;
            }
            finally
            {
                this._responsesLock.Release();
            }
            await this._hubContext.Clients.Client(connectionId).SendAsync("PiocheRequest", "Veuillez choisir la tuile à piocher (Centre ou Defausse)", requestId);
            await this._responsesLock.WaitAsync();
            try
            {
                var response = await _responses[requestId].Task;
                _responses.TryRemove(requestId, out _);
                return response;
            }
            finally
            {
                this._responsesLock.Release();
            }
        }

        public async Task PiocheResponse(string requestId, string response)
        {
            await this._responsesLock.WaitAsync();
            try
            {
                if (_responses.TryGetValue(requestId, out var responseTask))
                {
                    responseTask.SetResult(response);
                }
            }
            finally
            {
                this._responsesLock.Release();
            }

        }

I have a blocking problem here After the

await this._hubContext.Clients.Client(connectionId).SendAsync("PiocheRequest", "Veuillez choisir la tuile à piocher (Centre ou Defausse)", requestId);

it's blocking

Mehdi•3mo ago

Here is my new code in a github repo: https://github.com/mehdi-arch/okeygameserver

GitHub

GitHub - mehdi-arch/okeygameserver

Contribute to mehdi-arch/okeygameserver development by creating an account on GitHub.

Gaming

Programming

SignalR Blocking Issue: Infinite Wait When Calling a Method from Client