Problem binding a TCP Client to a specified port Topic is solved

[Guido]

I have this problem trying to make a TCP Client (it's a wxSocketClient) that binds itself to a specified port with:

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sock_cl->Connect(addr_server,addr_client,false);

The first connection works perfectly. But if the Client disconnects and then tries to reconnect using the same port the connection fails (the Server doesn't even get the connection request).
Trying to correct this error I found a lot of strange things:
This is the function that close the connection with the server:

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void ClientTCPFrm::DisconnectClick(wxCommandEvent& event)
{
  sock_cl->Close();
}

After sock_cl->Close(); if i put sock_cl->Ok(); it returns a true value, but that should mean that the client is still connected (the documentation here says that For wxSocketClient, Ok won't return true unless the client is connected to a server), right?
But if in the same place I put sock_cl->IsDisconnect(); that returns true!!!
So at the same time for Ok() the client is connected to a server but for IsDisconnect() that's not true ... very confusing

I tried to destroy the socket and rebuild it after the connection is closed:

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void ClientTCPFrm::DisconnectClick(wxCommandEvent& event)
{
  sock_cl->Close();
  sock_cl->Destroy();
  sock_cl = new wxSocketClient();
  sock_cl->SetEventHandler(*this, ID_CLIENT);
  sock_cl->SetNotify(wxSOCKET_CONNECTION_FLAG | wxSOCKET_INPUT_FLAG | wxSOCKET_LOST_FLAG);
  sock_cl->Notify(true); 
}

But even like this the successive connection attempt fails.

I tried to save the socket state before the first connection and then restoring it after the disconnection like this:

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...
  sock_cl->SaveState()
  sock_cl->Connect(addr_server,addr_client,false);
...

void ClientTCPFrm::DisconnectClick(wxCommandEvent& event)
{
  sock_cl->Close();
  sock_cl->RestoreState();
}

But nothing changes

I looked for errors with sock_cl->Error(); after sock_cl->Connect(addr_server,addr_client,false); and after
sock_cl->Close();, but in both cases it returns false.

Is it possible that it's a bug, that when it close the connection is closed the port binded to the client is not made available again?
Please help me beacuse this thing is driving me mad ^^'

[tan]

Hi,
i don't sure exactly, but try use flag wxSOCKET_REUSEADDR in the client ctor.

[Guido]

i don't sure exactly, but try use flag wxSOCKET_REUSEADDR in the client ctor

I just tried it, but it doesn't work
Anyway, thank you for your suggestion

[tan]

Hi,
did you look at wxDIR/samples/sockets ?
It works just fine with client connect/disconnect.

[Guido]

Hi,
did you look at wxDIR/samples/sockets ?
It works just fine with client connect/disconnect.

Yes I looked at it. That Client works but it doesn't binds itself to a specified port, it connects with:

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sock_cl->Connect(addr_server,false);

So it lets the OS choose the port.
In my case I want to be able to choose a specified port for the Client.

[tan]

Yes I looked at it. That Client works but it doesn't binds itself to a specified port, it connects with:

Code: Select all

sock_cl->Connect(addr_server,false);

So it lets the OS choose the port.
In my case I want to be able to choose a specified port for the Client.

Does it make any sense for the client side???

[Guido]

Yes I looked at it. That Client works but it doesn't binds itself to a specified port, it connects with:

Code: Select all

sock_cl->Connect(addr_server,false);

So it lets the OS choose the port.
In my case I want to be able to choose a specified port for the Client.

Does it make any sense for the client side???

Well instead of letting the OS decide the port in my case the user can set a specified port for the Client. I don't think that's a problem for the Client. And also that's made possible by the Connect(addr_server,addr_client,boolean); function of wxClientSocket so if there's an appropriate function for it I think it makes sense ^^'

[Guido]

Problem solved: it's possible for the Client to reconnect using the same port but to do that it must wait at least 120 seconds after closing the previous connection on that port