Memory Leak in Windows 10 TNotification in Delphi Seattle?

Question

I'm implementing Windows 10 Notification in my application. However, the code below (which runs fine) apparently give a memo leak of 1 TNotification object and 2 strings, yet I free the object at the end of the block:

aNotification := NotificationCenter.CreateNotification;

//-- If not assigned then must be Win 8.1 or below
if not assigned(aNotification) then
  exit;

try
  aNotification.Title := AlignMixVersionName + ' License';
  aNotification.AlertBody := aText;

  NotificationCenter.PresentNotification(aNotification);

finally
  aNotification.Free;
end;

Am I doing something stupid or is there a memory leak in the implementation of Notifications?

Steve

what is the value of `aNotification` after `NotificationCenter.PresentNotification(aNotification)` ? — Hugh Jones, Mar 30 '16 at 14:19
@HughJones `aNotification` is still assigned after `PresentNotification` - so strange. — Steve Maughan, Mar 30 '16 at 15:00
I did Delphi many moons ago and remember setting things to nil ... aNotification := nil; — KornMuffin, Apr 20 '16 at 12:17
There was an issue opened for this mem leak in RAD Studio's issue tracker: https://quality.embarcadero.com/browse/RSP-17660 — Joachim Marder, May 02 '17 at 12:04

score 8 · Accepted Answer · answered Mar 30 '16 at 15:01

8

It is indeed a leak caused by TNotificationCenterDelegateActivated. In its Create a copy of the TNotification parameter is created, but never freed.

Seems like some developers responsible for this code are not that proficient with non-ARC environments.

answered Mar 30 '16 at 15:01

Uwe Raabe

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Thanks for confirming. – Steve Maughan Mar 30 '16 at 15:06
Would be great to QC this at Emba. – J... Mar 30 '16 at 16:26
3

Naively one might expect Emba to have tests for their libraries that would flush out leaks. How hard could it be? – David Heffernan Mar 30 '16 at 17:37
2

@DavidHeffernan Naively one might expect they have a simple app to test and the very first line of written code is `ReportMemoryLeaksOnShutdown := true;`. – Sir Rufo Mar 30 '16 at 17:54
@UweRaabe - does that mean we have very little hope of a positive result? – Hugh Jones Mar 31 '16 at 11:15
@HughJones, No - merely the opposite. – Uwe Raabe Mar 31 '16 at 11:17
@UweRaabe - what does 'ARC' stand for? – Hugh Jones Mar 31 '16 at 11:22
@HughJones, ARC = Automated Reference Counting. It is a new feature of the Delphi mobile compilers. Sometimes features are developed for mobile first and then ported to Win32 and Win64. That is where such errors creep in. – Uwe Raabe Mar 31 '16 at 11:25
@UweRaabe - so is it the same as 'Garbage Collection'? (not to worry - I found this : http://blog.marcocantu.com/blog/automatic_reference_counting_for_delphi.html) – Hugh Jones Mar 31 '16 at 11:30
1

@Hugh No it is different from garbage collection – David Heffernan Mar 31 '16 at 20:05

Memory Leak in Windows 10 TNotification in Delphi Seattle?

1 Answers1