SimpleIPC problem
lazarus / 21-General

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simsee · 2021-02-09 15:10

I want to communicate two programs that run locally. This is the code:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i program
prog1;uses  SimpleIpc; type   { TIpcHelper }   TIpcHelper=class   
 class procedure SimpleIPCServerMessageQueued(Sender: TObject); 
end; var  Prog1Client: TSimpleIPCClient;  Prog1Server:
TSimpleIPCServer;  Msg : string;  Line : string; { TIpcHelper } class
procedure TIpcHelper.SimpleIPCServerMessageQueued(Sender:
TObject);begin  Prog1Server.ReadMessage; 
Msg:=Prog1Server.StringMessage;  writeln('Received:',Msg);end; begin 
Prog1Server:=TSimpleIPCServer.Create(nil); 
Prog1Server.ServerID:='1to2';  Prog1Server.Global:=True;  Prog1Server.
OnMessageQueued:=@TIpcHelper.SimpleIPCServerMessageQueued; 
Prog1Server.StartServer(False);  
Prog1Client:=TSimpleIPCClient.Create(nil); 
Prog1Client.ServerID:='2to1';   writeln('Waiting Prog2 Server'); 
repeat until Prog1Client.ServerRunning;  Prog1Client.Connect;  
repeat    write('Send:');    readln(Line);   
Prog1Client.SendStringMessage(Line);  until (Line='');  
Prog1Client.Free;  Prog1Server.Free;end. 
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i program
prog2;uses  SimpleIpc; type   { TIpcHelper }   TIpcHelper=class   
 class procedure SimpleIPCServerMessageQueued(Sender: TObject); 
end; var  Prog2Client: TSimpleIPCClient;  Prog2Server:
TSimpleIPCServer;  Msg : string;  Line : string; { TIpcHelper } class
procedure TIpcHelper.SimpleIPCServerMessageQueued(Sender:
TObject);begin  Prog2Server.ReadMessage; 
Msg:=Prog2Server.StringMessage;  writeln('Received:',Msg);end; begin 
Prog2Server:=TSimpleIPCServer.Create(nil); 
Prog2Server.ServerID:='2to1';  Prog2Server.Global:=True;  Prog2Server.
OnMessageQueued:=@TIpcHelper.SimpleIPCServerMessageQueued; 
Prog2Server.StartServer(False);  
Prog2Client:=TSimpleIPCClient.Create(nil); 
Prog2Client.ServerID:='1to2';    writeln('Waiting Prog1 Server'); 
repeat until Prog2Client.ServerRunning;  Prog2Client.Connect;  
repeat    write('Send:');    readln(Line);   
Prog2Client.SendStringMessage(Line);  until (Line='');  
Prog2Client.Free;  Prog2Server.Free;end. 
The expected behavior is that when you type a string from the 'prompt'
of either program, it is transmitted and received by the other and
displayed. What happens instead is that the string sent from the first
program to the second is displayed only after the second sends a
string to the first. How can this problem be solved?

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simsee · 2021-02-10 08:47

I solved the problem: the readln statement prevent the output of
received message. A working gui version is attached. In the demo two
programs exchange messages. This is simple example of two-way local
comunication between two running programs.