I have a thread. Inside of them, i have a loop to send UDP packet. In this loop i need wait the UDP response of the device (that received the previous packet [if OK or not]) before send the next message. If OK i send the next message of the StringList, if error i stop the thread. How to make it? And i need more: I need implement a timeout of the 3 seconds if the software doesn't receive the response of the device.
I'm using the TIdUDPServer to listen the udp packages.
Here is my code:
TEnvioFirmware = class(TThread)
private
I: integer;
Lock: TCriticalSection;
mMac: string;
mVersao: integer;
mProduto: integer;
_max: integer;
_min: integer;
mIP: string;
firmware_string: TStringList;
idpclnt: TIdUDPClient;
progress: TProgressBar;
lbPorc: TLabel;
bAck: Boolean;
procedure Executar;
procedure OnVerificarTimeOut(Sender: TObject);
public
tmrTimeout: TTimer;
bContinua: Boolean;
procedure Execute; override;
constructor Create(CreateSuspended: Boolean; firmware_string: TStringList;
edtIP: string; idpclnt: TIdUDPClient; max, atual: integer;
var pb: TProgressBar; var lblPorcentagem: TLabel; abAck: Boolean);
end;
procedure TEnvioFirmware.Execute;
begin
inherited;
// Synchronize(Executar);
Executar;
end;
procedure TEnvioFirmware.Executar;
var
I, J: integer;
X: pacote;
Y: String;
B: String;
B2: String;
msgCount: integer;
Buffer: TBytes;
// array[0..5] of Byte;
max, atual: integer;
BufferSend: TBytes;
begin
SetLength(Buffer, 6);
idpclnt.Host := mIP;
idpclnt.Active := true;
msgCount := firmware_string.Count;
max := msgCount - 1; // Progress Bar
// pb.Max := max;
self.progress.Min := 0;
self.progress.max := max;
B := '12345';
B2 := '0';
if bAck then
begin //trying to make timeout
tmrTimeout := TTimer.Create(nil);
tmrTimeout.Interval := 3000;
tmrTimeout.OnTimer := OnVerificarTimeOut;
end;
bContinua := True;
for I := 0 to msgCount - 1 do
begin
B[1] := chr(15);
B[2] := chr(0);
B[3] := chr(2);
B[4] := chr((I) mod 256);
B[5] := chr((I) div 256);
B2[1] := chr(255);
Y := B + firmware_string.Strings[I] + B2;
SetLength(BufferSend, Length(Y));
for J := 0 to Length(BufferSend) - 1 do
begin
BufferSend[J] := Ord(Y[J + 1]);
end;
if bContinua then
idpclnt.SendBuffer(BufferSend); //after send the device will response
if not bAck then
begin
Sleep(200);
bContinua := true;
progress.Position := I + 1;
lbPorc.Caption :=
IntToStr(Round((100 * progress.Position) / progress.max));
atual := I;
end
else
begin
tmrTimeout.Enabled := True;
end;
end;
Buffer[0] := $0F;
Buffer[1] := 00;
Buffer[2] := 03;
Buffer[3] := (msgCount) mod 256;
Buffer[4] := (msgCount) div 256;
Buffer[5] := 255;
idpclnt.SendBuffer(Buffer);
Sleep(150);
end;
On UDPRead
if (AData[0] = 15) and (AData[1] = 1) and (AData[2] = 2) and (Count = 5)
then
begin
if AData[3] = 0 then
begin
MainEstrutura.objFirmwareUpdater.bContinua := true;
MainEstrutura.objFirmwareUpdater.tmrTimeout.Enabled := false;
end
else
begin
MainEstrutura.objFirmwareUpdater.bContinua := false;
MainEstrutura.objFirmwareUpdater.tmrTimeout.Enabled := false;
end;
end;
Since you need to serialize your packets, you should use a TIdUDPClient inside the thread instead of using a TIdUDPServer outside of the thread. Then you don't have to deal with synchronizing the OnUDPRead event or using a timer at all. Simply have the thread SendBuffer() an outgoing packet, then immediately ReceiveBuffer() the inbound response with a timeout specified, and continue looping as needed until finished. If the timeout elapses, either re-sent the outbound packet, or terminate the thread, depending on your needs.
The only reason to use a TIdUDPServer in this situation is if you have multiple firmware threads running at the same time and they all respond to the same IP/Port, in which case it would make sense to have a single TIdUDPServer receiving all of those responses and delgating them to each appropriate firmware thread as needed.