Delphi DBXPool在连接失败时损坏内存

当

TSQLConnection

上的

DelegateConnection

使用

DBXPool

时，如果调用

TSQLConnection.Open

方法时SQLServer不可用，它将第一次超时。但是如果您随后再次调用

Open

，它将行为不端。在我的生产服务中，它会在没有任何警告的情况下终止进程——不会引发任何异常，什么都不会。这个过程就消失了。。。在我为测试

DBXPool

而创建的一个简单应用程序中，它认为

TSQLConnection

已连接，即使它未连接

是否有人在使用

DBXPool

作为可以提供任何建议的

DelegateConnection

时遇到过问题

谢谢

>

我使用下面edit#1中的代码来跟踪DBX框架。仅当使用DBXPool时才调用以下方法：

（DBXDelegate单元）

。。。调用以下方法，无论是否使用DBXPool，都会调用该方法：

（单位：DBXCommon）

注意这个评论。当发生异常（例如，错误的用户名或超时等）时，仅当未使用DBXPool时才会调用以下代码

（单位：DBXCommon）

因为使用DBXPool时，

FOpen

不会被设置回

False

，它会导致在下次调用

DerivedOpen

时不应该执行的代码，这会导致访问冲突和内存损坏。有时RTL捕捉到它，有时它没有（例如，我的生产服务被Windows杀死）。我还不能更深入地跟踪DBXDelegate，以确定它为什么不能捕获异常并调用

TDBXConnection.Close

>

根据肯的建议，我附上了简单的示例应用程序。我的服务应用程序刚刚死掉。此应用程序在dbxmss.dll（今天）中显示访问冲突。昨天，它在第二次单击时没有引发异常，只是返回“Connected”为True。对我来说似乎是记忆的堕落

在具有或不具有SQLServer的计算机上构建并运行应用程序。单击每个按钮几次。两者在第一次单击时都返回一个错误。“With DBXPool”会认为它从第二次单击开始就连接好了。如果幸运的话，你可能会看到AV。“W/O DBXPool”按钮每次都会失败，这是正确的

项目1.dpr

program Project1;

uses
  Forms,
  Unit1 in 'Unit1.pas' {Form1};

{$R *.res}

begin
  Application.Initialize;
  Application.MainFormOnTaskbar := True;
  Application.CreateForm(TForm1, Form1);
  Application.Run;
end.

单元1.dfm

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 301
  ClientWidth = 562
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  OnCreate = FormCreate
  PixelsPerInch = 96
  TextHeight = 13
  object Button1: TButton
    Left = 40
    Top = 8
    Width = 75
    Height = 25
    Caption = 'With DBXPool'
    TabOrder = 0
    OnClick = Button1Click
  end
  object Button2: TButton
    Left = 40
    Top = 39
    Width = 75
    Height = 25
    Caption = 'W/O DBXPool'
    TabOrder = 1
    OnClick = Button2Click
  end
  object SQLConnection1: TSQLConnection
    DriverName = 'MSSQL'
    GetDriverFunc = 'getSQLDriverMSSQL'
    LibraryName = 'dbxmss.dll'
    LoginPrompt = False
    Params.Strings = (
      'DriverUnit=DBXMSSQL'

        'DriverPackageLoader=TDBXDynalinkDriverLoader,DBXCommonDriver150.' +
        'bpl'

        'DriverAssemblyLoader=Borland.Data.TDBXDynalinkDriverLoader,Borla' +
        'nd.Data.DbxCommonDriver,Version=15.0.0.0,Culture=neutral,PublicK' +
        'eyToken=91d62ebb5b0d1b1b'

        'MetaDataPackageLoader=TDBXMsSqlMetaDataCommandFactory,DbxMSSQLDr' +
        'iver150.bpl'

        'MetaDataAssemblyLoader=Borland.Data.TDBXMsSqlMetaDataCommandFact' +
        'ory,Borland.Data.DbxMSSQLDriver,Version=15.0.0.0,Culture=neutral' +
        ',PublicKeyToken=91d62ebb5b0d1b1b'
      'GetDriverFunc=getSQLDriverMSSQL'
      'LibraryName=dbxmss.dll'
      'VendorLib=sqlncli10.dll'
      'MaxBlobSize=-1'
      'OSAuthentication=False'
      'PrepareSQL=True'
      'ErrorResourceFile='
      'drivername=MSSQL'
      'schemaoverride=%.dbo'
      'HostName=127.0.0.1'
      'Database=database'
      'User_Name=username'
      'Password=password'
      'blobsize=-1'
      'localecode=0000'
      'isolationlevel=ReadCommitted'
      'os authentication=False'
      'prepare sql=False'
      'DelegateConnection=DBXPool'
      'DBXPool.MaxConnections=20'
      'DBXPool.MinConnections=1'
      'DBXPool.ConnectTimeout=1000'
      'DBXPool.DriverUnit=DBXPool'
      'DBXPool.DelegateDriver=True'
      'DBXPool.DBXPool.MaxConnections=20'
      'DBXPool.DBXPool.MinConnections=1'
      'DBXPool.DBXPool.ConnectTimeout=1000'
      'DBXPool.DBXPool.DriverUnit=DBXPool'
      'DBXPool.DBXPool.DelegateDriver=True'
      'DBXPool.DBXPool.DriverName=DBXPool'
      'DBXPool.DriverName=DBXPool')
    VendorLib = 'sqlncli10.dll'
    Left = 8
    Top = 8
  end
  object SQLConnection2: TSQLConnection
    DriverName = 'MSSQL'
    GetDriverFunc = 'getSQLDriverMSSQL'
    LibraryName = 'dbxmss.dll'
    LoginPrompt = False
    Params.Strings = (
      'DriverUnit=DBXMSSQL'

        'DriverPackageLoader=TDBXDynalinkDriverLoader,DBXCommonDriver150.' +
        'bpl'

        'DriverAssemblyLoader=Borland.Data.TDBXDynalinkDriverLoader,Borla' +
        'nd.Data.DbxCommonDriver,Version=15.0.0.0,Culture=neutral,PublicK' +
        'eyToken=91d62ebb5b0d1b1b'

        'MetaDataPackageLoader=TDBXMsSqlMetaDataCommandFactory,DbxMSSQLDr' +
        'iver150.bpl'

        'MetaDataAssemblyLoader=Borland.Data.TDBXMsSqlMetaDataCommandFact' +
        'ory,Borland.Data.DbxMSSQLDriver,Version=15.0.0.0,Culture=neutral' +
        ',PublicKeyToken=91d62ebb5b0d1b1b'
      'GetDriverFunc=getSQLDriverMSSQL'
      'LibraryName=dbxmss.dll'
      'VendorLib=sqlncli10.dll'
      'MaxBlobSize=-1'
      'OSAuthentication=False'
      'PrepareSQL=True'
      'ErrorResourceFile='
      'drivername=MSSQL'
      'schemaoverride=%.dbo'
      'HostName=127.0.0.1'
      'Database=database'
      'User_Name=username'
      'Password=password'
      'blobsize=-1'
      'localecode=0000'
      'isolationlevel=ReadCommitted'
      'os authentication=False'
      'prepare sql=False')
    VendorLib = 'sqlncli10.dll'
    Left = 8
    Top = 39
  end
end

单元1.pas

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, DBXMSSQL, StdCtrls, DB, SqlExpr, DBXPool;

type
  TForm1 = class(TForm)
    Button1: TButton;
    SQLConnection1: TSQLConnection;
    SQLConnection2: TSQLConnection;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

uses
  DBXCommon;

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  SQLConnection1.Close;
  SQLConnection1.Open;
  if SQLConnection1.Connected then
    MessageDlg('connected connection 1', mtInformation, [mbOK], 0);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  SQLConnection2.Close;
  SQLConnection2.Open;
  if SQLConnection2.Connected then
    MessageDlg('connected connection 2', mtInformation, [mbOK], 0);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  // for testing purposes, shorten the timeout so that the timeout occurs quickly
  SQLConnection1.Params.Values[TDBXPropertyNames.ConnectTimeout] := '1';
  SQLConnection2.Params.Values[TDBXPropertyNames.ConnectTimeout] := '1';
end;

end.

---

Embarcadero支持部门今天通知我，此问题已得到解决，将在下一个通用版本（如XE2）中提供。

此处没有任何信息可以回答您的问题。你没有发布任何代码。如果进程“在没有任何警告的情况下被终止”，则意味着触发了Delphi的RTL无法处理的异常，Windows终止了该进程。然而，由于没有可供审查的来源，任何人都不可能做任何事情来帮助您解决问题。如果您需要帮助解决问题，请编辑您的帖子以包含您正在使用的导致问题的代码。Embarcadero现在有两个QC项目，分别为#96506和#90347。我为Embarcadero打开了一张支持票，以便进行调查，或者修复这个bug，或者提供一个解决方案。希望我们能在不久的将来得到答案。他们最初的反应是DBXPool是一个可扩展的框架。他们的支持团队应该很快让我知道。。。

program Project1;

uses
  Forms,
  Unit1 in 'Unit1.pas' {Form1};

{$R *.res}

begin
  Application.Initialize;
  Application.MainFormOnTaskbar := True;
  Application.CreateForm(TForm1, Form1);
  Application.Run;
end.

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 301
  ClientWidth = 562
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  OnCreate = FormCreate
  PixelsPerInch = 96
  TextHeight = 13
  object Button1: TButton
    Left = 40
    Top = 8
    Width = 75
    Height = 25
    Caption = 'With DBXPool'
    TabOrder = 0
    OnClick = Button1Click
  end
  object Button2: TButton
    Left = 40
    Top = 39
    Width = 75
    Height = 25
    Caption = 'W/O DBXPool'
    TabOrder = 1
    OnClick = Button2Click
  end
  object SQLConnection1: TSQLConnection
    DriverName = 'MSSQL'
    GetDriverFunc = 'getSQLDriverMSSQL'
    LibraryName = 'dbxmss.dll'
    LoginPrompt = False
    Params.Strings = (
      'DriverUnit=DBXMSSQL'

        'DriverPackageLoader=TDBXDynalinkDriverLoader,DBXCommonDriver150.' +
        'bpl'

        'DriverAssemblyLoader=Borland.Data.TDBXDynalinkDriverLoader,Borla' +
        'nd.Data.DbxCommonDriver,Version=15.0.0.0,Culture=neutral,PublicK' +
        'eyToken=91d62ebb5b0d1b1b'

        'MetaDataPackageLoader=TDBXMsSqlMetaDataCommandFactory,DbxMSSQLDr' +
        'iver150.bpl'

        'MetaDataAssemblyLoader=Borland.Data.TDBXMsSqlMetaDataCommandFact' +
        'ory,Borland.Data.DbxMSSQLDriver,Version=15.0.0.0,Culture=neutral' +
        ',PublicKeyToken=91d62ebb5b0d1b1b'
      'GetDriverFunc=getSQLDriverMSSQL'
      'LibraryName=dbxmss.dll'
      'VendorLib=sqlncli10.dll'
      'MaxBlobSize=-1'
      'OSAuthentication=False'
      'PrepareSQL=True'
      'ErrorResourceFile='
      'drivername=MSSQL'
      'schemaoverride=%.dbo'
      'HostName=127.0.0.1'
      'Database=database'
      'User_Name=username'
      'Password=password'
      'blobsize=-1'
      'localecode=0000'
      'isolationlevel=ReadCommitted'
      'os authentication=False'
      'prepare sql=False'
      'DelegateConnection=DBXPool'
      'DBXPool.MaxConnections=20'
      'DBXPool.MinConnections=1'
      'DBXPool.ConnectTimeout=1000'
      'DBXPool.DriverUnit=DBXPool'
      'DBXPool.DelegateDriver=True'
      'DBXPool.DBXPool.MaxConnections=20'
      'DBXPool.DBXPool.MinConnections=1'
      'DBXPool.DBXPool.ConnectTimeout=1000'
      'DBXPool.DBXPool.DriverUnit=DBXPool'
      'DBXPool.DBXPool.DelegateDriver=True'
      'DBXPool.DBXPool.DriverName=DBXPool'
      'DBXPool.DriverName=DBXPool')
    VendorLib = 'sqlncli10.dll'
    Left = 8
    Top = 8
  end
  object SQLConnection2: TSQLConnection
    DriverName = 'MSSQL'
    GetDriverFunc = 'getSQLDriverMSSQL'
    LibraryName = 'dbxmss.dll'
    LoginPrompt = False
    Params.Strings = (
      'DriverUnit=DBXMSSQL'

        'DriverPackageLoader=TDBXDynalinkDriverLoader,DBXCommonDriver150.' +
        'bpl'

        'DriverAssemblyLoader=Borland.Data.TDBXDynalinkDriverLoader,Borla' +
        'nd.Data.DbxCommonDriver,Version=15.0.0.0,Culture=neutral,PublicK' +
        'eyToken=91d62ebb5b0d1b1b'

        'MetaDataPackageLoader=TDBXMsSqlMetaDataCommandFactory,DbxMSSQLDr' +
        'iver150.bpl'

        'MetaDataAssemblyLoader=Borland.Data.TDBXMsSqlMetaDataCommandFact' +
        'ory,Borland.Data.DbxMSSQLDriver,Version=15.0.0.0,Culture=neutral' +
        ',PublicKeyToken=91d62ebb5b0d1b1b'
      'GetDriverFunc=getSQLDriverMSSQL'
      'LibraryName=dbxmss.dll'
      'VendorLib=sqlncli10.dll'
      'MaxBlobSize=-1'
      'OSAuthentication=False'
      'PrepareSQL=True'
      'ErrorResourceFile='
      'drivername=MSSQL'
      'schemaoverride=%.dbo'
      'HostName=127.0.0.1'
      'Database=database'
      'User_Name=username'
      'Password=password'
      'blobsize=-1'
      'localecode=0000'
      'isolationlevel=ReadCommitted'
      'os authentication=False'
      'prepare sql=False')
    VendorLib = 'sqlncli10.dll'
    Left = 8
    Top = 39
  end
end

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, DBXMSSQL, StdCtrls, DB, SqlExpr, DBXPool;

type
  TForm1 = class(TForm)
    Button1: TButton;
    SQLConnection1: TSQLConnection;
    SQLConnection2: TSQLConnection;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

uses
  DBXCommon;

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  SQLConnection1.Close;
  SQLConnection1.Open;
  if SQLConnection1.Connected then
    MessageDlg('connected connection 1', mtInformation, [mbOK], 0);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  SQLConnection2.Close;
  SQLConnection2.Open;
  if SQLConnection2.Connected then
    MessageDlg('connected connection 2', mtInformation, [mbOK], 0);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  // for testing purposes, shorten the timeout so that the timeout occurs quickly
  SQLConnection1.Params.Values[TDBXPropertyNames.ConnectTimeout] := '1';
  SQLConnection2.Params.Values[TDBXPropertyNames.ConnectTimeout] := '1';
end;

end.