Delphi DLL

Async Accept Socket Connection

See more Socket/SSL/TLS Examples

Demonstrates how to get the connected client socket after accepting a connection asynchronously. Delphi DLL

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Task, Socket;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
listenSocket: HCkSocket;
maxWaitMs: Integer;
acceptTask: HCkTask;
connectedClient: HCkSocket;

begin
success := False;

// This example assumes the Chilkat Socket API to have been previously unlocked.
// See Socket Unlock Sample for sample code.

listenSocket := CkSocket_Create();

// Bind to a port and listen.
// This example will listen at port 5555 and allows for a backlog
// of 25 pending connection requests.
success := CkSocket_BindAndListen(listenSocket,5555,25);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkSocket__lastErrorText(listenSocket));
    Exit;
  end;

// Start a background task to accept an incoming connection ...
maxWaitMs := 20000;
acceptTask := CkSocket_AcceptNextConnectionAsync(listenSocket,maxWaitMs);
CkTask_Run(acceptTask);

// ...
// ...
// ...

// Imagine at this point the task has completed successfully,
// and a connection was accepted.  Here's how to get the connected socket...
connectedClient := CkSocket_Create();
success := CkSocket_LoadTaskResult(connectedClient,acceptTask);

// Here's how it works:  The AcceptNextConnection method would normally
// return a socket object when called synchronously.  When called asynchronously,
// it cannot do so because it returns the task object.  When the async method
// (running in a background thread) completes, the socket object that is the client
// connection is contained within the task object.
// 
// This can be generalized for any case where a Chilkat method returns an object.
// The async version of that method is such that the object returned in the background
// thread is contained within the task object.

// To get the result object, we create a new object instance of that type.
// In this case, we create a socket object (connectedClient).  There is a LoadTaskResult
// method in all Chilkat classes that can be a return value of an async method call.
// The LoadTaskResult method transfers the returned object from the task to the caller.

CkSocket_Dispose(listenSocket);
CkSocket_Dispose(connectedClient);

end;