#31 Implementing the PingServer method in the TZFirebirdConnection, like such in the TZInterbase6Connection

[Vladimir Lomov]

It would be nice to implement the PingServer method in the TZFirebirdConnection, like such in the TZInterbase6Connection.

Now the TZAbstractDbcConnection.PingServer function is called, which throws the EZUnsupportedException exception:

[code]
Raise EZUnsupportedException.Create(SUnsupportedOperation);
[/code]

[code]
/ TZInterbase6Connection - has overrided method PingServer: Integer; override;
TZAbstractDbcConnection <-- TZInterbaseFirebirdConnection
\ TZFirebirdConnection - no PingServer method
unit ZDbcConnection

declared
TZAbstractDbcConnection = class...
function PingServer: Integer; virtual;
[/code]

[Vladimir Lomov]

Link to the forum topic:
https://zeoslib.sourceforge.io/viewtopic.php?f=50&t=138544

[EgonHugeist]

Hello Vladimir,

PingSetver added by r7464 on trunk.
Please close if OK.
Regards, Michael

[Vladimir Lomov]

Hello, Michael!

I am not sure what is the problem, but after I call the PingServer after restarting the Firebird server, an error occurrs.

I use mORMot2 and ZeosLib last trunk versions.
Debian 5.10.28-1 (2021-04-09) x86_64 GNU/Linux
FPC/Lazarus

That's what I'm doing:

1. connect to the database;
2. query a database - OK;
3. execute PingServer - OK;

4. query a database - OK;

5. restart the Firebird server:
   sudo systemctl restart firebird

6. execute PingServer - an error occurs:

7. in the TZFirebirdConnection.PingServer() function, the FAttachment.Ping(FStatus) function is calling (Fstatus);
8. in the ZPLainFireBird unit, IAttachment.ping(status: IStatus) procedure is executed;

9. in the IAttachment.ping() procedure, the AttachmentVTable(vTable).ping(Self, status) is called, and at this moment there is an exception:

   Project Test Application Server raised exception class 'External: SIGSEGV'.
   In file '../../src/plain/ZPlainFirebird.pas' at line 4114:
   ReferenceCountedVTable(vTable).addRef(Self);

   OK
   F9

   Project Test Application Server raised exception class 'RunError(216)' with message:
   General Protection Fault
   In file '../../src/plain/ZPlainFirebird.pas' at line 4114:
   ReferenceCountedVTable(vTable).addRef(Self);

   Continue

   Project Test Application Server raised exception class 'EAccessViolation' with message:
   Access violation
   In file '../../src/plain/ZPlainFirebird.pas' at line 4114:
   ReferenceCountedVTable(vTable).addRef(Self);

   Best regards, Vladimir