threadtest.pas

program threadtest;

{$mode objfpc}{$H+}

uses
  //{$IFDEF UNIX}{$IFDEF UseCThreads}
  cthreads, cmem,
  //{$ENDIF}{$ENDIF}
  Classes, // TThread
  SysUtils;// Format

type
  { TMyThread }
  TMyThread = class (TThread)
  private
    fCount: word;
    fID: word;
    procedure WriteSync;
  protected
    procedure Execute; override;
  public
    constructor Create(aCreateSuspended: boolean; aID, aCountdownFrom: word);
  end;

constructor TMyThread.Create(aCreateSuspended: boolean; aID,
  aCountdownFrom: word);
begin
  fID:= aID;
  fCount := aCountdownFrom;
  inherited Create(aCreateSuspended);
end;

procedure TMyThread.WriteSync;
begin
  WriteLn(Format('Thread #%0.4d at count %0.3d', [fID, fCount]));
end;

procedure TMyThread.Execute;
begin
  while not (terminated) and (fCount <> 0) do
  begin
    Synchronize(@WriteSync);
    Dec(fCount);
  end;
end;

var
  Threads: array of TMyThread;
  i, countdownFrom: word;

function ThreadsFinished: boolean;
begin
  Result := True;
  for i:= 0 to High(Threads) do
  begin
    Result := Threads[i].Finished and Result;
  end;
end;

begin
  WriteLn('Randomizing');
  Randomize;
  SetLength(Threads, Random(1024));
  WriteLn('Thread count ', Length(Threads));
  for i:= 0 to High(Threads) do
  begin
    countdownFrom:= Random(128);
    WriteLn('Making thread #', i, ' with count ', countdownFrom);
    Threads[i]:=TMyThread.Create(false, i, countdownFrom);
    Threads[i].Start();
  end;
  while not ThreadsFinished do
  begin
    CheckSynchronize();
  end;
  for i:= 0 to High(Threads) do
    FreeAndNil(Threads[i])
end.