synapse and thread socket creation error 'winsock not initialized' 10093

[alogrep 0]

Hello. This is a hard one for me to understand/solve.

Using synapse on delphi 11.

 I have a main form that starts a thread (TTCPHttpDaemon) defined in a used Unit;

     TTCPHttpDaemon.create;

The initialization section of the the blcksock.pas of sinapse, runs at the very beginning

of the App seems to successfully create the socket

    synsock.WSAStartup(WinsockLevel, WsaDataOnce);

I create the thread (log_it() is a function to log messages).

TTCPHttpDaemon.Create;
 TRY
   inherited create(false);
   sock:=TTCPBlockSocket.create;
  FreeOnTerminate:=true;

 except
        on E:SysUtils.Exception do begin
           log_it('TTCPHttpDaemon.Create  '+e.message);
       end;
 end;
end;

No errors. Then right here i get the  inexplicable behaviour  

procedure TTCPHttpDaemon.Execute;
begin
  with sock do begin
  try
    CreateSocket;
  except
        on E:SysUtils.Exception do begin
         log_it(e.message);
       end;
  end;
   bind(serverip,PORTNUMBER); //portno
   listen;
   repeat
     try
        b:= canread (1000);  RIGHT HERE!!!!!
       except
         on E:SysUtils.Exception do begin
              log_it('****** Canread error: '+e.message);
          end;
       end;
       if b then 
           ClientSock:=sock.accept;
    ...................

on the canread() function the error is 'winsock not initialized' code:10093

And the main form is  destroyed, by-passing the except block.

What goes wrong, where?

This happened suddenly without any change to the App that I could tell. Could it be one of the lates windows 10 updates?

 

[Fr0sT.Brutal 897]

Probably you have the port occupied. You're not catching errors that could rise inside .listen

[Remy Lebeau 1260]

16 hours ago, alogrep said:

No errors. Then right here i get the  inexplicable behaviour  

...

on the canread() function the error is 'winsock not initialized' code:10093

The WinSock library is reference-counted internally.  WSAStartup() increments the refcount, and WSACleanup() decrements it.  The library internals are initialized only on the 1st call to WSAStartup(), and cleaned up only on the last call to WSACleanup().   So, every successful call to WSAStartup() must be balanced with a call to WSACleanup().

 

The code you have shown looks fine (well, mostly ... your error handling needs work), which means that what you have described can occur only if SOME OTHER THREAD is making an unbalanced call to WSACleanup(), thus decrementing the refcount too much and unloading the library even though you are still using it.  That is not the fault of the code you have shown, the problem is elsewhere in your project.  What else is your project doing that uses WinSock outside of this TTCPHttpDaemon class?

16 hours ago, alogrep said:

And the main form is  destroyed, by-passing the except block.

What do you mean?

16 hours ago, alogrep said:

This happened suddenly without any change to the App that I could tell.

Something had to have changed, behavior like this doesn't just change for no reason.  Unless, this bug was likely always present in your project to begin with, and you just never happened to hit on it until now.

16 hours ago, alogrep said:

Could it be one of the lates windows 10 updates?

Doubtful.

[Remy Lebeau 1260]

9 hours ago, Fr0sT.Brutal said:

Probably you have the port occupied. You're not catching errors that could rise inside .listen

That would not cause error 10093 (WSANOTINITIALISED).  That error can only happen if a WinSock function is called either before the 1st call to WSAStartup() or after the last call to WSACleanup().  If bind() or listen() failed, they should be raising their own exception, which would terminate the daemon thread before it reaches the marked line of code, since it is not catching them.

Edited May 2, 2023 by Remy Lebeau

[alogrep 0]

Thanlks Remy.

Ah! Fool that I am!.

I caused the problem. It is true that the App had not changed at all when this started to happen.

But the condition of the data that the app reads had changed in these last few occasions.

In short, I have a check function that if the result is negative it  goes 

    Application.terminate.

This a couple of lines before the Thread>create();

Obviously the app continued for a few microseconds and the thread was created

BUT when it got to the Execute part the application was terminated and the socket was closed.

I rewrote the lines 

  if not checked then begin

     Application.terminate;

     exit;

end;

[Fr0sT.Brutal 897]

18 hours ago, Remy Lebeau said:

That would not cause error 10093 (WSANOTINITIALISED).  That error can only happen if a WinSock function is called either before the 1st call to WSAStartup() or after the last call to WSACleanup().  If bind() or listen() failed, they should be raising their own exception, which would terminate the daemon thread before it reaches the marked line of code, since it is not catching them.

Yeah, you're right. I misread the message as 'socket not initialized'