Source Code TCriticalSection Threrad Example Delphi

emailx45 · 19 Май 2020

TCriticalSection Threrad Example Delphi
Ivan Revelli - 15/May/2020

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Example on how to user a critical section in Delphi:

Delphi/Pascal

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TThreadedMsgEvent = class( TThread )
private
FLock : TCriticalSection;
FStr : TQueue<String>;
FMemo : TMemo;
function GetEvent : String;
protected
procedure Execute; override;
public
procedure AddEvent( aMsg : String );

constructor Create( AMemo: TMemo );
destructor Destroy; override;
end;
implementation

{ TThreadedMsgEvent }

procedure TThreadedMsgEvent.AddEvent(aMsg: String);
begin
FLock.Acquire;
FStr.Enqueue( FormatDateTime('DD/MM/YY HH:NN:SS.ZZZ',Now)+ ' : '+ aMsg );
FLock.Release;
end;

constructor TThreadedMsgEvent.Create(aMemo: TMemo);
begin
inherited Create(True);

FreeOnTerminate := False;
FOnMessage := ACallBack;
FStr := TQueue<String>.Create();
FLock := TCriticalSection.Create;
FMemo := aMemo;
Resume;
end;

destructor TThreadedMsgEvent.Destroy; override;
begin
FreeAndNil( FStr );
FreeAndNil( FLock );
end;

procedure TThreadedMsgEvent.Execute;
begin
while not Terminated do
begin

try
if (FStr.Count > 0) then
begin
if Assigned( aMemo ) then
begin
TThread.synchronize( procedure
begin
FMemo.Lines.Add( GetEvent );
end; );
end;

end;
except
end;
TThread.Sleep(1);
end;

end;

function TThreadedMsgEvent.GetEvent: String;
begin
FLock.Acquire;
result := FStr.Dequeue;
FLock.Release;
end;

From post found at: Как увидеть ссылки? | How to see hidden links?

In short:
How to handle Log in a Threaded manner in Delphi
Active 6 years, 10 months ago - Viewed 3k times

Delphi XE2
I have a form with a TMemo that I want to show what is going on in several services started by the application.
What I have running:

idHTTPServer running with idContext responding to requests
a Thread downloading updates from Dropbox
idUDPServer responding to UDP requests
another thread taking care of some database stuff.
the main application thread also needed to add log

Basically, I need to know how to create a standard, unified, thread safe way to channel the log messages to my TMemo and keep the user updated of what is going on.
....

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Source Code TCriticalSection Threrad Example Delphi

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