用Delphi开发语言实现的对网络链路层的连续ARQ协议的仿真。
源代码在线查看： sender.~pas
unit sender;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, Sockets, ComCtrls, ExtCtrls, Spin;
type
TForm1 = class(TForm)
ListBox1: TListBox;
TcpClient1: TTcpClient;
TcpServer1: TTcpServer;
Button1: TButton;
Button2: TButton;
Memo1: TMemo;
StatusBar1: TStatusBar;
Button3: TButton;
Timer0: TTimer;
SpinEdit1: TSpinEdit;
Label1: TLabel;
Timer1: TTimer;
Timer2: TTimer;
Timer3: TTimer;
Timer4: TTimer;
Timer5: TTimer;
Timer6: TTimer;
OpenDialog1: TOpenDialog;
procedure Button2Click(Sender: TObject);
procedure Sendframe;
procedure Button1Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure Timer0Timer(Sender: TObject);
procedure Button3Click(Sender: TObject);
procedure TcpServer1Accept(Sender: TObject;
ClientSocket: TCustomIpClient);
procedure Timer1Timer(Sender: TObject);
procedure Timer2Timer(Sender: TObject);
procedure Timer3Timer(Sender: TObject);
procedure Timer4Timer(Sender: TObject);
procedure Timer5Timer(Sender: TObject);
procedure Timer6Timer(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
sends,gets,k:integer;
send:boolean;
t1,t2,t3,t4,t5,t6:integer;
implementation
{$R *.dfm}
function checksum(x:integer):integer;
var
t,y:integer;
begin
t:= x div 999;
y:= x-t*999;
x:=x*1000;
result:=x+y;
end;
procedure TForm1.Sendframe;
var
sor:integer;
info:string;
begin
if sends>0 then
ListBox1.Selected[sends-1]:=false;
sor:=strtoint(Listbox1.Items.Strings[sends]);
info:=inttostr(checksum(sor))+inttostr(sends);
TcpClient1.Connect;
TcpClient1.Sendln(info);
TcpClient1.Disconnect;
ListBox1.Selected[sends]:=true;
SpinEdit2.Value:=sends;
sends:=sends+1;
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
Timer0.Enabled:=true;
Button2.Enabled:=false;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
jiange:integer;
begin
if Button1.Caption='启动' then begin
TcpClient1.Active:=true;
Timer0.Interval:= SpinEdit1.Value *1000;
TcpServer1.Active:=true;
Button1.Caption:='暂停发送';
jiange:=20;
timer1.Interval:=jiange*1000;
timer2.Interval:=jiange*1000;
timer3.Interval:=jiange*1000;
timer4.Interval:=jiange*1000;
timer5.Interval:=jiange*1000;
timer6.Interval:=jiange*1000;
if sends>0 then Timer0.Enabled:=true;
end
else begin
Timer0.Enabled:=false;
timer1.Enabled:=false;
timer2.Enabled:=false;
timer3.Enabled:=false;
timer4.Enabled:=false;
timer5.Enabled:=false;
timer6.Enabled:=false;
TcpClient1.Active:=false;
Button1.Caption:='启动'
end;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
sends:=0;
gets:=0;
end;
procedure TForm1.Timer0Timer(Sender: TObject);
begin
if sends-gets case (sends mod 6) of
0:begin
t6:=sends;
Timer6.Enabled:=true;
end;
1:begin
t1:=sends;
Timer1.Enabled:=true;
end;
2:begin
t2:=sends;
Timer2.Enabled:=true;
end;
3:begin
t3:=sends;
Timer3.Enabled:=true;
end;
4:begin
t4:=sends;
Timer4.Enabled:=true;
end;
5:begin
t5:=sends;
Timer5.Enabled:=true;
end;
end;
Sendframe;
end
else memo1.lines.Append('网络时延过大，发送窗口已满');
end;
procedure TForm1.Button3Click(Sender: TObject);
begin
close;
end;
procedure TForm1.TcpServer1Accept(Sender: TObject;
ClientSocket: TCustomIpClient);
var
temp:string;
m:integer;
begin
temp:= ClientSocket.Receiveln;
delete(temp,1,3);
m:=strtoint(temp);
m:=m mod 6;
memo1.Lines.Add('收到ACK'+inttostr(m));
if temp=inttostr(gets) then begin
case (gets mod 6)of
0:begin
Timer6.Enabled:=false;
end;
1:begin
Timer1.Enabled:=false;
end;
2:begin
Timer2.Enabled:=false;
end;
3:begin
Timer3.Enabled:=false;
end;
4:begin
Timer4.Enabled:=false;
end;
5:begin
Timer5.Enabled:=false;
end;
end;
if gets>0 then ListBox1.Selected[gets-1]:=false;
ListBox1.Selected[gets]:=true;
gets:=gets+1;
end;
end;
procedure TForm1.Timer1Timer(Sender: TObject);
begin
ListBox1.Selected[sends-1]:=false;
memo1.Lines.Append('超时重发第'+inttostr(t1)+'帧');
sends:=t1;
sendframe;
end;
procedure TForm1.Timer2Timer(Sender: TObject);
begin
ListBox1.Selected[sends-1]:=false;
memo1.Lines.Append('超时重发第'+inttostr(t2)+'帧');
sends:=t2;
sendframe;
end;
procedure TForm1.Timer3Timer(Sender: TObject);
begin
ListBox1.Selected[sends-1]:=false;
memo1.Lines.Append('超时重发第'+inttostr(t3)+'帧');
sends:=t3;
sendframe;
end;
procedure TForm1.Timer4Timer(Sender: TObject);
begin
ListBox1.Selected[sends-1]:=false;
memo1.Lines.Append('超时重发第'+inttostr(t4)+'帧');
sends:=t4;
sendframe;
end;
procedure TForm1.Timer5Timer(Sender: TObject);
begin
ListBox1.Selected[sends-1]:=false;
memo1.Lines.Append('超时重发第'+inttostr(t5)+'帧');
sends:=t5;
sendframe;
end;
procedure TForm1.Timer6Timer(Sender: TObject);
begin
ListBox1.Selected[sends-1]:=false;
memo1.Lines.Append('超时重发第'+inttostr(t6)+'帧');
sends:=t6;
sendframe;
end;
end.
