MemoryLeak in nxQuery?

[Andreas Schachtner]

Since a great Refactoring-Session and Update to NEXUSDB 3.1004 i get MemoryLeaks (ReportMemoryLeaksOnShutDown:=true) in my App.
I use only the embedded Mode of the NexusDb and
i can reproduce this with a little App like this....

unit Unit3;

interface

uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, nxseAutoComponent,
nxsrSqlEngineBase, nxsqlEngine, nxsdServerEngine, nxsrServerEngine, nxdb,
nxllComponent;

type
TForm3 = class(TForm)
nxDatabase1: TnxDatabase;
nxSession1: TnxSession;
nxServerEngine1: TnxServerEngine;
nxSqlEngine1: TnxSqlEngine;
nxseAllEngines1: TnxseAllEngines;
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private-Deklarationen }
public
{ Public-Deklarationen }
end;

var
Form3: TForm3;

implementation

{$R *.dfm}

procedure TForm3.Button1Click(Sender: TObject);
var LQ : TnxQuery;
begin
Lq:=TnxQuery.Create(self);
try
LQ.Database:=nxDatabase1;
LQ.SQL.Text:='Select * from Plan_Kulturen';
LQ.Open;
ShowMessage (intToStr(LQ.RecordCount));
LQ.Close;
finally
LQ.Free;
end;
end;

end.


The leaks all come from Unicode Strings. Any suggestions ?

On 25/03/2012 12:20 PM, Andreas Schachtner wrote:
> Since a great Refactoring-Session _*and*_ Update to NEXUSDB 3.1004 i get
> MemoryLeaks (ReportMemoryLeaksOnShutDown:=true) in my App.
> I use only the embedded Mode of the NexusDb and
> i can reproduce this with a little App like this....

> procedure TForm3.Button1Click(Sender: TObject);
> var LQ : TnxQuery;
> begin
> Lq:=TnxQuery.Create(self);
> try
> LQ.Database:=nxDatabase1;
> LQ.SQL.Text:='Select * from Plan_Kulturen';
> LQ.Open;
> ShowMessage (intToStr(LQ.RecordCount));
> LQ.Close;
> finally
> LQ.Free;

Not sure if this is the source of the leak but either:

Create(self) with no Free (let the parent handle it).
OR
Create(nil) with the Free;

I usually do the second for any non-visual components and
the first for visual components.Long article on various reasons
to not do Create(self) with Free:
http://delphi.about.com/od/kbcurt/ss...createno_3.htm

--
Brian Evans [NDX]
Ottawa, ON, CANADA
GMT-5

[Andreas Schachtner]

Usally i use TnxQuery.Create (nil). Only in this snipped i try self for some reason.

But, for me same error with Create(nil) and Free;

> The leaks all come from Unicode Strings. Any suggestions ?

Please, tell us how many, and the size? Does it depend on the number of
queries run, or is it always the same?

--
Eivind Bakkestuen [NDD]

Eivind Bakkestuen [NDD] wrote:

> > The leaks all come from Unicode Strings. Any suggestions ?
>
> Please, tell us how many, and the size? Does it depend on the number
> of queries run, or is it always the same?

Hello Eivind,

I have been getting this leak. I need to do more testing and change
some timing to see if there is only ever 1 string, but I think that is
all I've seen.

I'm not sure if it is related to Andreas' leaks, but maybe it can help.

Regards
Sue



--------------------------------2012/3/26
20:14:43--------------------------------
A memory block has been leaked. The size is: 52

This block was allocated by thread 0xB48, and the stack trace (return
addresses) at the time was:
404ACE [System][@GetMem]
4079F7 [System][@NewUnicodeString]
408CBF [System][@UStrSetLength]
40BD5B [System][UTF8ToUnicodeString]
40BDC7 [System][UTF8ToString]
405E32 [System][TObject.ClassName]
59802C [nxllThread.pas][nxllThread][TnxThread.Create][409]
5A084E
[nxllKeepAliveService.pas][nxllKeepAliveService][TnxKeepAliveThread.Crea
te][134]
5A07CD
[nxllKeepAliveService.pas][nxllKeepAliveService][TnxKeepAliveQueue.Creat
e][119]
5A074B
[nxllKeepAliveService.pas][nxllKeepAliveService][nxAddKeepAlive][104]
5A41E3 [nxrpChannel.pas][nxrpChannel][TnxChannelExit.Create][203]

The block is currently used for an object of class: UnicodeString

The allocation number is: 6866

Current memory dump of 256 bytes starting at pointer address 7EE79640:
B0 04 02 00 01 00 00 00 12 00 00 00 54 00 6E 00 78 00 4B 00 65 00 65 00
70 00 41 00 6C 00 69 00
76 00 65 00 54 00 68 00 72 00 65 00 61 00 64 00 00 00 9E 1D 59 7A 80 80
00 00 00 00 C1 92 E7 7E
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 9E 1C 00 00 CE 4A 40 00
F7 79 40 00 2E 8E 40 00
C3 99 42 00 62 9F 57 00 66 9E 57 00 92 E3 5C 00 70 36 43 00 64 72 64 00
13 81 64 00 09 76 64 00
A8 08 00 00 48 0B 00 00 B1 7A 40 00 81 95 40 00 C9 94 40 00 C9 95 40 00
C9 94 40 00 A3 5F 40 00
E6 5E 40 00 AD 64 40 00 26 5F 40 00 33 5F 40 00 03 A0 57 00 26 00 00 00
B0 04 02 00 03 CB 46 85
60 62 95 00 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80
80 80 80 80 80 80 80 80
80 80 80 80 80 80 FC 34 B9 7A 80 80 80 80 80 80 80 80 80 80 80 80 80 80
00 00 00 00 01 98 E7 7E
° . . . . . . . . . . . T . n . x . K . e . e .
p . A . l . i .
v . e . T . h . r . e . a . d . . . ž . Y z € €
.. . . . Á ’ ç ~
.. . . . . . . . . . . . . . . . ž . . . Î J @ .
÷ y @ . . Ž @ .
à ™ B . b Ÿ W . f ž W . ’ ã \ . p 6 C . d r d .
.. � d . . v d .
¨ . . . H . . . ± z @ . � • @ . É ” @ . É • @ .
É ” @ . £ _ @ .
æ ^ @ . * d @ . & _ @ . 3 _ @ . . * W . & . . .
° . . . . Ë F …
` b • . € € € € € € € € € € € € € € € € € € € €
€ € € € € € € €
€ € € € € € ü 4 ¹ z € € € € € € € € € € € € € €
.. . . . . ˜ ç ~

--------------------------------2012/3/26
20:14:43--------------------------------
This application has leaked memory. The small block leaks are
(excluding expected leaks registered by pointer):

37 - 52 bytes: UnicodeString x 1
--

[Andreas Schachtner]

With the little App from my previous post i get for each ExecSQL

45-52 Byte Leak from UnicodeString x 2.

In my MainApp i get 37560 x 45-100 Byte from UnicodeString for a full Calculation. Not good.....

> With the little App from my previous post i get for each ExecSQL

Can you please log the issue in our tracker, including the source of
your testapp and database table?

--
Eivind Bakkestuen [NDD]

[Andreas Schachtner]

done!

Sue King wrote:

Sorry, this is 3.1003

> Eivind Bakkestuen [NDD] wrote:
>
> > > The leaks all come from Unicode Strings. Any suggestions ?
> >
> > Please, tell us how many, and the size? Does it depend on the number
> > of queries run, or is it always the same?
>
> Hello Eivind,
>
> I have been getting this leak. I need to do more testing and change
> some timing to see if there is only ever 1 string, but I think that is
> all I've seen.
>
> I'm not sure if it is related to Andreas' leaks, but maybe it can
> help.
>
> Regards
> Sue
>
>
>
> --------------------------------2012/3/26
> 20:14:43--------------------------------
> A memory block has been leaked. The size is: 52
>
> This block was allocated by thread 0xB48, and the stack trace (return
> addresses) at the time was:
> 404ACE [System][@GetMem]
> 4079F7 [System][@NewUnicodeString]
> 408CBF [System][@UStrSetLength]
> 40BD5B [System][UTF8ToUnicodeString]
> 40BDC7 [System][UTF8ToString]
> 405E32 [System][TObject.ClassName]
> 59802C [nxllThread.pas][nxllThread][TnxThread.Create][409]
> 5A084E
> [nxllKeepAliveService.pas][nxllKeepAliveService][TnxKeepAliveThread.Cr
> ea te][134]
> 5A07CD
> [nxllKeepAliveService.pas][nxllKeepAliveService][TnxKeepAliveQueue.Cre
> at e][119]
> 5A074B
> [nxllKeepAliveService.pas][nxllKeepAliveService][nxAddKeepAlive][104]
> 5A41E3 [nxrpChannel.pas][nxrpChannel][TnxChannelExit.Create][203]
>
> The block is currently used for an object of class: UnicodeString
>
> The allocation number is: 6866
>
> Current memory dump of 256 bytes starting at pointer address 7EE79640:
> B0 04 02 00 01 00 00 00 12 00 00 00 54 00 6E 00 78 00 4B 00 65 00 65
> 00 70 00 41 00 6C 00 69 00
> 76 00 65 00 54 00 68 00 72 00 65 00 61 00 64 00 00 00 9E 1D 59 7A 80
> 80 00 00 00 00 C1 92 E7 7E
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 9E 1C 00 00 CE 4A 40
> 00 F7 79 40 00 2E 8E 40 00
> C3 99 42 00 62 9F 57 00 66 9E 57 00 92 E3 5C 00 70 36 43 00 64 72 64
> 00 13 81 64 00 09 76 64 00
> A8 08 00 00 48 0B 00 00 B1 7A 40 00 81 95 40 00 C9 94 40 00 C9 95 40
> 00 C9 94 40 00 A3 5F 40 00
> E6 5E 40 00 AD 64 40 00 26 5F 40 00 33 5F 40 00 03 A0 57 00 26 00 00
> 00 B0 04 02 00 03 CB 46 85
> 60 62 95 00 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80
> 80 80 80 80 80 80 80 80 80
> 80 80 80 80 80 80 FC 34 B9 7A 80 80 80 80 80 80 80 80 80 80 80 80 80
> 80 00 00 00 00 01 98 E7 7E
> ° . . . . . . . . . . . T . n . x . K . e . e .
> p . A . l . i .
> v . e . T . h . r . e . a . d . . . ž . Y z € €
> . . . . Á ’ ç ~
> . . . . . . . . . . . . . . . . ž . . . Î J @ .
> ÷ y @ . . Ž @ .
> Ã ™ B . b Ÿ W . f ž W . ’ ã \ . p 6 C . d r d .
> . � d . . v d .
> ¨ . . . H . . . ± z @ . � • @ . É ” @ . É • @ .
> É ” @ . £ _ @ .
> æ ^ @ . * d @ . & _ @ . 3 _ @ . . * W . & . . .
> ° . . . . Ë F …
> ` b • . € € € € € € € € € € € € € € € € € € € €
> € € € € € € € €
> € € € € € € ü 4 ¹ z € € € € € € € € € € € € € €
> . . . . . ˜ ç ~
>
> --------------------------------2012/3/26
> 20:14:43--------------------------------
> This application has leaked memory. The small block leaks are
> (excluding expected leaks registered by pointer):
>
> 37 - 52 bytes: UnicodeString x 1



--