Hi all,

DBISAM 4.24b1 on client & server, Delphi 7, FastMM v4.76.
Multithreaded app getting Invalid Pointer Operation whenever I close
Here are both the server log and Delphi 7 event logs
I don't have DBISAM source code (I know! When I order EDB, I'll get it
with source!)
Has anyone encountered the Invalid or Unknown Request to engine problem?
What does REQUEST_FREESTMNT do?
Any help would be greatly appreciated,

Jason Lee




v4.24 on both server and client - server log
================================

1/24/2007 9:26:47 AM Starting admin server on all addresses and port
12006 [Server Version: 4.24]
1/24/2007 9:26:47 AM Starting server on all addresses and port 12005
[Server Version: 4.24]
1/24/2007 9:56:06 AM Connection accepted [Client Version: 4.24 User
Name:  Address: 192.168.18.129 Encrypted: No Thread: 896 Session: 21825544]
1/24/2007 9:56:06 AM Login [Client Version: 4.24 User Name: CTWIN_USR
Address: 192.168.18.129 Encrypted: No Thread: 896 Session: 21825544]
1/24/2007 9:56:11 AM Connection accepted [Client Version: 4.24 User
Name:  Address: 192.168.18.129 Encrypted: No Thread: 396 Session: 21856264]
1/24/2007 9:56:11 AM Login [Client Version: 4.24 User Name: CTWIN_USR
Address: 192.168.18.129 Encrypted: No Thread: 396 Session: 21856264]
1/24/2007 9:56:50 AM Connection accepted [Client Version: 4.24 User
Name:  Address: 192.168.18.129 Encrypted: No Thread: 1356 Session: 21952520]
1/24/2007 9:56:50 AM Login [Client Version: 4.24 User Name: CTWIN_USR
Address: 192.168.18.129 Encrypted: No Thread: 1356 Session: 21952520]
1/24/2007 9:56:50 AM Logout [Client Version: 4.24 User Name: CTWIN_USR
Address: 192.168.18.129 Encrypted: No Thread: 1356 Session: 21952520]
1/24/2007 9:56:50 AM Connection closed [Client Version: 4.24 User Name:
 Address: 192.168.18.129 Encrypted: No Thread: 1356 Session: 0]
1/24/2007 9:57:01 AM Logout [Client Version: 4.24 User Name: CTWIN_USR
Address: 192.168.18.129 Encrypted: No Thread: 896 Session: 21825544]
1/24/2007 9:57:01 AM Connection closed [Client Version: 4.24 User Name:
 Address: 192.168.18.129 Encrypted: No Thread: 896 Session: 0]
1/24/2007 9:57:01 AM [ERROR] Engine error [DBISAM Engine Error # 11308
An invalid or unknown request was made to the database server at '']
[Client Version: 4.24 User Name: CTWIN_USR Address: 192.168.18.129
Encrypted: No Request: REQUEST_FREESTMT Thread: 396 Session: 21856264]
1/24/2007 9:57:30 AM Connection accepted [Client Version: 4.24 User
Name:  Address: 192.168.18.129 Encrypted: No Thread: 896 Session: 22059016]
1/24/2007 9:57:30 AM Login [Client Version: 4.24 User Name: CTWIN_USR
Address: 192.168.18.129 Encrypted: No Thread: 896 Session: 22059016]
1/24/2007 9:57:52 AM Connection closed [Client Version: 4.24 User Name:
CTWIN_USR Address: 192.168.18.129 Encrypted: No Thread: 896 Session:
22059016]
<snip>
no problems
</snip>
1/24/2007 10:13:51 AM Login [Client Version: 4.24 User Name: CTWIN_USR
Address: 192.168.18.129 Encrypted: No Thread: 896 Session: 22218760]
1/24/2007 10:14:44 AM Connection accepted [Client Version: 4.24 User
Name:  Address: 192.168.18.129 Encrypted: No Thread: 396 Session: 22231048]
1/24/2007 10:14:44 AM Login [Client Version: 4.24 User Name: CTWIN_USR
Address: 192.168.18.129 Encrypted: No Thread: 396 Session: 22231048]
1/24/2007 10:19:31 AM Logout [Client Version: 4.24 User Name: CTWIN_USR
Address: 192.168.18.129 Encrypted: No Thread: 896 Session: 22218760]
1/24/2007 10:19:31 AM Connection closed [Client Version: 4.24 User Name:
 Address: 192.168.18.129 Encrypted: No Thread: 896 Session: 0]
1/24/2007 10:19:31 AM [ERROR] Engine error [DBISAM Engine Error # 11308
An invalid or unknown request was made to the database server at '']
[Client Version: 4.24 User Name: CTWIN_USR Address: 192.168.18.129
Encrypted: No Request: REQUEST_FREESTMT Thread: 396 Session: 22231048]
1/24/2007 10:20:04 AM Connection accepted [Client Version: 4.24 User
Name:  Address: 192.168.18.129 Encrypted: No Thread: 896 Session: 22112264]
1/24/2007 10:20:04 AM Login [Client Version: 4.24 User Name: CTWIN_USR
Address: 192.168.18.129 Encrypted: No Thread: 896 Session: 22112264]
1/24/2007 10:20:10 AM Connection closed [Client Version: 4.24 User Name:
CTWIN_USR Address: 192.168.18.129 Encrypted: No Thread: 396 Session:
22231048]
1/24/2007 10:20:10 AM Connection closed [Client Version: 4.24 User Name:
CTWIN_USR Address: 192.168.18.129 Encrypted: No Thread: 896 Session:
22112264]


Delphi 7 Event Log
===================
First chance exception at $7C81EB33. Exception class EDBISAMEngineError
with message 'DBISAM Engine Error # 11308 An invalid or unknown request
was made to the database server at '192.168.18.129''. Process Ctwin.exe
(1852)
First chance exception at $7C81EB33. Exception class EInvalidPointer
with message 'Invalid pointer operation'. Process Ctwin.exe (1852)
First chance exception at $7C81EB33. Exception class EAccessViolation
with message 'Access violation at address 004C8F5F in module
'Ctwin.exe'. Read of address 000002F4'. Process Ctwin.exe (1852)

Jason,

<< DBISAM 4.24b1 on client & server, Delphi 7, FastMM v4.76. Multithreaded
app getting Invalid Pointer Operation whenever I close
Here are both the server log and Delphi 7 event logs I don't have DBISAM
source code (I know! When I order EDB, I'll get it  with source!)
Has anyone encountered the Invalid or Unknown Request to engine problem?
What does REQUEST_FREESTMNT do? Any help would be greatly appreciated, >>

It means that you're not doing the multi-threading properly on the client.
The "invalid request" error is raised in 3 situations:

1) DBISAM gets a request from a valid session that it doesn't recognize
(very rare and means a bug in DBISAM).
2) DBISAM gets a request from a valid session that isn't logged in (also
very rare but could be caused the same as 3)).
3) DBISAM gets a request from a session that doesn't exist or isn't a valid
session ID (probably the case here).

Most likely, somewhere in your client code you're stepping on a session
component (or some other DBISAM component) that is already being used by
another thread.

--
Tim Young
Elevate Software
www.elevatesoft.com

Thanks for the help, I'll try to nail it down. It's strange, I've got
anywhere from 2 to 4 threads involving DBISAM at any given time in the
app and haven't had any problems with the others. I'll let you know when
I find out.

Regards,

Jason Lee



Tim Young [Elevate Software] wrote:
> Jason,
>
> << DBISAM 4.24b1 on client & server, Delphi 7, FastMM v4.76. Multithreaded
> app getting Invalid Pointer Operation whenever I close
>  Here are both the server log and Delphi 7 event logs I don't have DBISAM
> source code (I know! When I order EDB, I'll get it  with source!)
>  Has anyone encountered the Invalid or Unknown Request to engine problem?
> What does REQUEST_FREESTMNT do? Any help would be greatly appreciated, >>
>
> It means that you're not doing the multi-threading properly on the client.
> The "invalid request" error is raised in 3 situations:
>
> 1) DBISAM gets a request from a valid session that it doesn't recognize
> (very rare and means a bug in DBISAM).
> 2) DBISAM gets a request from a valid session that isn't logged in (also
> very rare but could be caused the same as 3)).
> 3) DBISAM gets a request from a session that doesn't exist or isn't a valid
> session ID (probably the case here).
>
> Most likely, somewhere in your client code you're stepping on a session
> component (or some other DBISAM component) that is already being used by
> another thread.
>