[fpc-pascal] Stuck in TMSSQLConnection.Execute

[Luca Olivetti]

Hello,

I encountered a strange problem in an application, that's been running 
for over a year now.
The application is quite convoluted with hundred of threads, one 
(actually more than one) of those threads connects to an ms sql server 
and now it blocks inside TMSSQLConnection.Execute, but not always


procedure TMSSQLConnection.Execute(const cmd: string);
begin
   DBErrorStr:='';
   DBMsgStr  :='';
   CheckError( dbcmd(FDBProc, PAnsiChar(cmd)) );
   CheckError( dbsqlexec(FDBProc) );  <--- this doesn't return
   CheckError( dbresults(FDBProc) );
end;


However when I terminate the application and before the destroy method 
of the thread is called, dbsqlexec returns and the rest of the thread 
goes on as nothing happened.

As an experiment I wrapped the method in synchronize but that only 
freezes the gui when it happens.

I don't know it if is relevant but I have a note in my program that I 
have to initialize the sql server libraries in the main thread, 
otherwise doing it in another thread eventually causes a sigsev.

I got the dlls (almost 2 years ago) following the instructions here

https://forum.lazarus.freepascal.org/index.php/topic,55037.msg409167.html#msg409167

using Environment: PLAT=Win32, WIDTH=32, VS_VERSION=2017, TDSVER=7.3
(though older artifacts are deleted after a month)

This is on windows 32 bits, fpc 3.2.2, any hint on how to debug it further?

Bye
-- 
Luca