[Lazarus] Simple ipc server fatal error on start - 0xc000007b

[Giuliano Colla]

Among the internet examples of Delphi 7 you should find a small app named netchat, which provides a basic IPC. It’s quite simple and bullet-proof. I’ve converted to Lazarus on Linux, and used as a base for my needs of IPC. But converting on the same Windows environment should be very simple, just using the Lazarus facilities. You may test it just as it is, and then adapt it to your needs. 
Giuliano 

Inviato da iPhone

> Il giorno 31 mar 2023, alle ore 18:39, Bo Berglund via lazarus <lazarus at lists.lazarus-ide.org> ha scritto:
> 
> I am investigating the possibilities to use IPC between a Lazarus and a Delphi7
> application running on Windows. I was discussing this on the Lazarus forum where
> I got a tip to use SimpleIPC, which apparently is delivered with the Fpc
> compiler itself.
> 
> The tip was given in this post:
> https://forum.lazarus.freepascal.org/index.php/topic,62867.msg475663.html#msg475663
> 
> In that post is a link to a GitHub project which simplifies ipc usage by
> creating a dll packaging everything needed so that the dll could be used from
> other applications developed in other languages too. Sounds good to me.
> Here is the GitHub project url:
> https://github.com/z505/SimpleIPC-lib
> 
> So I downloaded this and using Lazarus 2.2.4 and Fpc 3.2.2 on Windows 10 x64 I
> did this:
> 1) opened the dll project and compiled the dll itself.
> 2) Opened the demo-lazarus\ipcclient project and compiled it
> 3) Opened the demo-lazarus\ipcserver project and compiled it
> 
> So now I could start the ipcclient app and it shows its form with a button to
> send data to the server. When I used it there was an error message about "not
> finding the server". To be expected, since I had not started the server...
> 
> So I next tried to start the server app, but it immediately shows an error box
> with the text:
> -------------------
> Application error
> The application was unable to start correctly (0xc000007b).
> Click OK to close the application.
>       [OK]
> -------------------
> 
> I have tried various things like changing target for the dll and both
> applications to win32 (I have the cross for Win32 installed), but the exact same
> happens.
> 
> And I have no idea whatsoever on where to look for a reason for this to happen.
> 
> I have even put a breakpoint into the server code at the earliest point I could
> find and started it from Lazarus, but get the same error dialog and no
> breakpoint reached...
> 
> I tried reading https://wiki.freepascal.org/SimpleIPC but got no idea from that
> either...
> 
> What to do now?
> I am not clever enough to figure out if there is some error in the GitHub
> project. Not used to windows communications at all.
> 
> 
> What I want to do is to create an ipc link to a Delphi7 server app from a
> Lazarus/fpc client app to use the D7 app to read a hardware device on command
> and send the data to the Lazarus app.
> It is not possible to compile the D7 app on Lazarus because there is a device
> manufacturer's obj file involved and it is apparently of the wrong format for
> Lazarus/Fpc to use. It can be linked to in Delphi7 but not in Lazarus/Fpc.
> 
> Hence the D7<=ipc=>Lazarus IPC communication...
> 
> I really do hope this can be fixed so I can get the ipc comm line to the D7
> interfacing app working!
> 
> 
> -- 
> Bo Berglund
> Developer in Sweden
> 
> -- 
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