SIGINT raises an exception in IBConnection.Close

[Sann-X!]

Hi,

I have created simple project included IBConnection and Button components. Also I reassigned SigAction handler.

Code: Pascal  [Select][+][-]

1. program project1;
2.  
3. {$mode objfpc}{$H+}
4.  
5. uses
6.   {$IFDEF UNIX}{$IFDEF UseCThreads}
7.   cthreads,
8.   {$ENDIF}{$ENDIF}
9.   Interfaces, // this includes the LCL widgetset
10.   Forms, Unit1, BaseUnix;
11.  
12. {$R *.res}
13.  
14. procedure DoSig(signal: longint; info: psiginfo; context: psigcontext); cdecl;
15. begin
16.   if Assigned(Application) then
17.       Application.Terminate;
18. end;
19.  
20. procedure SetSigHandler(const Sig: cint; const new, old: PSigActionRec; const Handler: SigActionHandler);
21. begin
22.   new^.sa_handler := Handler;
23.   fillchar(new^.Sa_Mask, SizeOf(new^.sa_mask), #0);
24.   new^.sa_flags := 0;
25.   {$ifdef Linux}               // Linux specific
26.   new^.Sa_Restorer := nil;
27.   {$endif}
28.   fpSigAction(Sig, new, old);
29. end;
30.  
31. var
32.   new_act_term, new_act_int, new_act_hup, old_act: SigActionRec;
33. begin
34.   SetSigHandler(SIGTERM, @new_act_term, @old_act, @DoSig);
35.   SetSigHandler(SIGINT, @new_act_int, @old_act, @DoSig);
36.   SetSigHandler(SIGHUP, @new_act_hup, @old_act, @DoSig);
37.  
38.   {$if declared(UseHeapTrace)}
39.   GlobalSkipIfNoLeaks := True; // supported as of debugger version 3.1.1
40.   {$endif}
41.  
42.   RequireDerivedFormResource := True;
43.   Application.Initialize;
44.   Application.CreateForm(TForm1, Form1);
45.   Application.Run;
46. end.
47.  

Success scenario:

• Run app
• Click button that open fb connection
• Close app

Failed scenario:

• Run app
• Click button that open fb connection
• In terminal execute command "kill -SIGINT <pid>"

Last step raises exception like as attached image. How to fix it?

DB: Firebird classic 2.5
Device: OrangePi Zero
OS: ARMBIAN 5.35 user-built Ubuntu 16.04.3 LTS 3.4.113-sun8i

[Sann-X!]

Test project sources

[sash]

Why do you ever need to kill your application from outside?
If you don't like "how it is dying", use try..except.

[Sann-X!]

Why do you ever need to kill your application from outside?

See here

If you don't like "how it is dying", use try..except.

Try..except don't help. I suppose that stack is corrupted. But why? I don't know.

[DonAlfredo]

I am trying to run your program on Linux Mint.
But Mint latest has FB 3.0.2.
I have patched FPC to work with this version, but your employee-file is not accepted by 3.0.2 (wrong version).
If you can help me get things running, I can try to help you with your sig-problem.

[Sann-X!]

But Mint latest has FB 3.0.2.
..If you can help me get things running..

I can't. My OS device supports Firebird 2.5 only.

[Sann-X!]

I am trying to run your program on Linux Mint.
But Mint latest has FB 3.0.2.

You can install fb2.5 manually. See here. After this do following:

• cp /opt/firebird/misc/firebird.init.d.debian /etc/init.d/firebird2.5
• chmod +x /etc/init.d/firebird2.5
• update-rc.d firebird2.5 defaults
• sudo /etc/init.d/firebird2.5 reload

[sash]

I can't. My OS device supports Firebird 2.5 only.

There's virtualbox, vmware. You can install any linux there, and test if problem is specific for arm architecture or not.

[DonAlfredo]

I would appreciate if you can design an app that does not depend on a pre-loaded database file. So, something that starts empty and creates an entry on startup or something similar.

[Sann-X!]

I posted similar question on other forum (ru lang). FB developers say that fbclient set its SIG* handler in other thread. Workaround is set my own SIG* handler AFTER firebird unit/library initialization.

[sash]

My own test:

- Ubuntu 18.04 bionic Kernel: x86_64 Linux 4.15.0-38-generic
- FB3
- Simple default Application compiled with cthreads enabled, without any termination handlers.
 

Code: Pascal  [Select][+][-]

1.   {$IFDEF UNIX}
2.     cthreads,
3.     {$ENDIF}
4.  

- Functionality: connect to database and open select query (and stay connected) on button click.
Result:
  Is being killed  by SIGINT or SIGTERM without any messages, just as it should be.

[Sann-X!]

My own test:

- Ubuntu 18.04 bionic Kernel: x86_64 Linux 4.15.0-38-generic
- FB3
- Simple default Application compiled with cthreads enabled, without any termination handlers.
 

Code: Pascal  [Select][+][-]

1.   {$IFDEF UNIX}
2.     cthreads,
3.     {$ENDIF}
4.  

- Functionality: connect to database and open select query (and stay connected) on button click.
Result:
  Is being killed  by SIGINT or SIGTERM without any messages, just as it should be.

If you can, please try another minimal program for test from here (first message under spoiler).

[sash]

If you can, please try another minimal program for test from here (first message under spoiler).

project1.lpr(130,18) Error: Illegal expression

[Sann-X!]

project1.lpr(130,18) Error: Illegal expression

Code: Pascal  [Select][+][-]

1. const
2.   OS_USER_NAME = ;

You have to specify a username for a valid path to the EMPLOYEE.FDB file. This file is attached to the archive in the second post of this topic.