Multithreading (Access Violation)

[exchange]

Hallo,
danke für die Infos. Hat aber leider nichts gebracht. Der Fehler entsteht wenn ich die Verbindung aufbauen will.

Folgende Fehler erscheinen:
Zugriffsverletzung bei Adresse 008BC0B5 in Modul 'ServiceTool.exe'. Lesen von Adresse 0000000C
ODER
DBVerbindung Fehler
Exception message = Zu wenig Arbeitsspeicher

Ohne das ich Parameter ändere, sind die Fehler nur manchmal. Sobald ich hingehe und die Threads zeitversetzt starte (z.B. 500 ms) erhalte ich keine Fehler.

Anbei mal den gesamten Quellcode von dem Beispiel.

Delphi-Quellcode:

unit main;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, BMDThread, cxGraphics, cxLookAndFeels,
  cxLookAndFeelPainters, Vcl.Menus, dxSkinsCore, dxSkinBlack, dxSkinBlue,
  dxSkinBlueprint, dxSkinCaramel, dxSkinCoffee, dxSkinDarkRoom, dxSkinDarkSide,
  dxSkinDevExpressDarkStyle, dxSkinDevExpressStyle, dxSkinFoggy,
  dxSkinGlassOceans, dxSkinHighContrast, dxSkiniMaginary, dxSkinLilian,
  dxSkinLiquidSky, dxSkinLondonLiquidSky, dxSkinMcSkin, dxSkinMetropolis,
  dxSkinMetropolisDark, dxSkinMoneyTwins, dxSkinOffice2007Black,
  dxSkinOffice2007Blue, dxSkinOffice2007Green, dxSkinOffice2007Pink,
  dxSkinOffice2007Silver, dxSkinOffice2010Black, dxSkinOffice2010Blue,
  dxSkinOffice2010Silver, dxSkinOffice2013DarkGray, dxSkinOffice2013LightGray,
  dxSkinOffice2013White, dxSkinOffice2016Colorful, dxSkinOffice2016Dark,
  dxSkinPumpkin, dxSkinSeven, dxSkinSevenClassic, dxSkinSharp, dxSkinSharpPlus,
  dxSkinSilver, dxSkinSpringTime, dxSkinStardust, dxSkinSummer2008,
  dxSkinTheAsphaltWorld, dxSkinsDefaultPainters, dxSkinValentine,
  dxSkinVisualStudio2013Blue, dxSkinVisualStudio2013Dark,
  dxSkinVisualStudio2013Light, dxSkinVS2010, dxSkinWhiteprint,
  dxSkinXmas2008Blue, Vcl.StdCtrls, cxButtons, Vcl.ExtCtrls, cxControls,
  cxContainer, cxEdit, cxTextEdit, cxMemo, cxLabel, Uni, MySQLUniProvider,
  IdBaseComponent, IdThreadComponent, Data.DB, DBAccess;

type
  TForm_Main = class(TForm)
    cxButton1: TcxButton;
    Timer_Export_Radius_Accept: TTimer;
    Timer_Export_Radius_Deny: TTimer;
    cxMemo_Accept: TcxMemo;
    cxLabel1: TcxLabel;
    cxMemo_Deny: TcxMemo;
    cxLabel2: TcxLabel;
    idThread_Export_Radius_Accept: TIdThreadComponent;
    idThread_Export_Radius_Deny: TIdThreadComponent;
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure Timer_Export_Radius_AcceptTimer(Sender: TObject);
    procedure Timer_Export_Radius_DenyTimer(Sender: TObject);
    procedure Thread_Export_Radius_DenyTerminate(Sender: TObject;
      Thread: TBMDExecuteThread; var Data: Pointer);
    procedure Thread_Export_Radius_AcceptStart(Sender: TObject;
      Thread: TBMDExecuteThread; var Data: Pointer);
    procedure Thread_Export_Radius_DenyStart(Sender: TObject;
      Thread: TBMDExecuteThread; var Data: Pointer);
    procedure cxButton1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure idThread_Export_Radius_DenyRun(Sender: TIdThreadComponent);
    procedure idThread_Export_Radius_AcceptRun(Sender: TIdThreadComponent);
    procedure idThread_Export_Radius_AcceptTerminate(
      Sender: TIdThreadComponent);
    procedure idThread_Export_Radius_DenyTerminate(Sender: TIdThreadComponent);
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

var
  Form_Main: TForm_Main;
  MySQL: TMySQLUniProvider;

implementation

{$R *.dfm}

procedure TForm_Main.idThread_Export_Radius_AcceptRun(
  Sender: TIdThreadComponent);
var DBConnection: TUniConnection; DBQuery: TUniQuery;
begin
  cxMemo_Accept.Lines.Add(FormatDateTime('dd.mm.yyyy, hh:nn:ss', now) + ', Thread gestartet');

  DBConnection:=TUniConnection.Create(nil);
  DBConnection.Server:='172.16.6.50';
  DBConnection.Port:=3306;
  DBConnection.Username:='root_copy';
  DBConnection.Password:='password';
  DBConnection.ProviderName:='MySQL';
  DBConnection.Database:='xxx';
  DBConnection.LoginPrompt:=false;
  DBConnection.Pooling:=true;

  try
    DBConnection.Connect;
  except
    on E : Exception do
    begin
      cxMemo_Accept.Lines.Add('DBVerbindung Fehler');
      cxMemo_Accept.Lines.Add('Exception message = '+E.Message);
    end;
  end;

  if DBConnection.Connected then
  begin
    try
      DBQuery:=TUniQuery.Create(nil);
      DBQuery.Connection:=DBConnection;
      DBQuery.SQL.Text:='SELECT * FROM hotspotstatistik h LIMIT 100;';
      DBQuery.Active:=true;
      cxMemo_Accept.Lines.Add(inttostr(DBQuery.RecordCount));
      DBQuery.Active:=false;
      DBQuery.Free;
    except
    on E : Exception do
    begin
      cxMemo_Accept.Lines.Add('Query Fehler');
      cxMemo_Accept.Lines.Add('Exception message = '+E.Message);
    end;
    end;
    DBConnection.Close;
  end;

  DBConnection.Free;

  Sender.Stop;
end;

procedure TForm_Main.idThread_Export_Radius_AcceptTerminate(
  Sender: TIdThreadComponent);
begin
  cxMemo_Accept.Lines.Add(FormatDateTime('dd.mm.yyyy, hh:nn:ss', now) + ', Thread beendet');
  Timer_Export_Radius_Accept.Enabled:=true;
end;

procedure TForm_Main.Thread_Export_Radius_AcceptStart(Sender: TObject;
  Thread: TBMDExecuteThread; var Data: Pointer);
begin
  cxMemo_Accept.Lines.Add('Thread Start');
end;

procedure TForm_Main.Thread_Export_Radius_DenyStart(Sender: TObject;
  Thread: TBMDExecuteThread; var Data: Pointer);
begin
  cxMemo_Deny.Lines.Add('Thread Start');
end;

procedure TForm_Main.Thread_Export_Radius_DenyTerminate(Sender: TObject;
  Thread: TBMDExecuteThread; var Data: Pointer);
begin
  cxMemo_Deny.Lines.Add('Thread Ende');
  Timer_Export_Radius_Deny.Enabled:=true;
end;

procedure TForm_Main.Timer_Export_Radius_AcceptTimer(Sender: TObject);
begin
  Timer_Export_Radius_Accept.Enabled:=false;
  idThread_Export_Radius_Accept.Start();
end;

procedure TForm_Main.Timer_Export_Radius_DenyTimer(Sender: TObject);
begin
  Timer_Export_Radius_Deny.Enabled:=false;
  idThread_Export_Radius_Deny.Start();
end;

procedure TForm_Main.cxButton1Click(Sender: TObject);
begin
  cxButton1.Enabled:=false;
  Timer_Export_Radius_Accept.Enabled:=true;
  Timer_Export_Radius_Deny.Enabled:=true;
end;

procedure TForm_Main.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  idThread_Export_Radius_Accept.OnTerminate := NIL;
  idThread_Export_Radius_Accept.Stop();

  idThread_Export_Radius_Deny.OnTerminate := NIL;
  idThread_Export_Radius_Deny.Stop();

  MySQL.Free;
end;

procedure TForm_Main.FormCreate(Sender: TObject);
begin
  MySQL:=TMySQLUniProvider.Create(nil);
end;

procedure TForm_Main.idThread_Export_Radius_DenyRun(Sender: TIdThreadComponent);
var DBConnection: TUniConnection; DBQuery: TUniQuery;
begin
  cxMemo_Deny.Lines.Add(FormatDateTime('dd.mm.yyyy, hh:nn:ss', now) + ', Thread gestartet');
  DBConnection:=TUniConnection.Create(nil);
  DBConnection.Server:='172.16.6.50';
  DBConnection.Port:=3306;
  DBConnection.Username:='root_copy';
  DBConnection.Password:='password';
  DBConnection.Database:='xxx';
  DBConnection.ProviderName:='MySQL';
  DBConnection.LoginPrompt:=false;
  DBConnection.Pooling:=true;

  try
    DBConnection.Connect;
  except
    on E : Exception do
    begin
      cxMemo_Deny.Lines.Add('DBVerbindung Fehler');
      cxMemo_Deny.Lines.Add('Exception message = '+E.Message);
    end;
  end;

  if DBConnection.Connected then
  begin
    try
      DBQuery:=TUniQuery.Create(nil);
      DBQuery.Connection:=DBConnection;
      DBQuery.SQL.Text:='SELECT * FROM hotspotstatistik h LIMIT 100;';
      DBQuery.Active:=true;
      cxMemo_Deny.Lines.Add(inttostr(DBQuery.RecordCount));
      DBQuery.Active:=false;
      DBQuery.Free;
    except
    on E : Exception do
    begin
      cxMemo_Deny.Lines.Add('Query Fehler');
      cxMemo_Deny.Lines.Add('Exception message = '+E.Message);
    end;
    end;
    DBConnection.Close;
  end;

  DBConnection.Free;
  Sender.Stop;
end;

procedure TForm_Main.idThread_Export_Radius_DenyTerminate(
  Sender: TIdThreadComponent);
begin
  cxMemo_Deny.Lines.Add(FormatDateTime('dd.mm.yyyy, hh:nn:ss', now) + ', Thread beendet');
  Timer_Export_Radius_Deny.Enabled:=true;
end;

end.

MFG