BUG: Placing Icons in Picture Object Causes Memory Leak

MORE INFORMATION

Steps to Reproduce Behavior

WARNING: Running the code below causes a low memory situation on the computer. This condition may cause the operating system to become unstable. Close all open applications and save your data before using this procedure. In Microsoft Windows 95 and Microsoft Windows NT, press the CTRL+ALT+DEL keys simultaneously to invoke the Close Dialog window or the Task Manager, respectively.

Create and run a program that contains the following code:

   LOCAL ARRAY laIcons[1,1]
   LOCAL loForm, lnI, lnFile, lnFiles

   loForm = CREATEOBJECT('Form')
   loForm.HEIGHT = 600
   loForm.WIDTH = 200

   FOR lnI = 1 TO 10
   loForm.ADDOBJECT('imgObject' + ALLTRIM(STR(lnI)), 'Image')
   WITH loForm.CONTROLS[lnI]
   .LEFT    = 10
   .TOP     = 10 + (lnI ) * 50
   .WIDTH   = 25
   .HEIGHT  = 25
   .VISIBLE = .T.
   ENDWITH
   ENDFOR

   loForm.ADDOBJECT('lblCounter', 'Label')
   loForm.lblCounter.TOP      = 1
   loForm.lblCounter.LEFT     = 1
   loForm.lblCounter.AUTOSIZE = .T.
   loForm.lblCounter.VISIBLE  = .T.
   loForm.SHOW()
   lnFiles = ADIR(laIcons, HOME() ;
   + 'SAMPLES\GRAPHICS\ICONS\COMPUTER\*.ICO')

   FOR lnI = 1 TO 1000
   loForm.lblCounter.CAPTION = 'Loop :' + PADL(lnI, 4)
   FOR lnFile = 1 TO lnFiles - 10
   loForm.CONTROLS[ 1].PICTURE = ;
   HOME() + 'SAMPLES\GRAPHICS\ICONS\COMPUTER\' + laIcons[lnFile , 1]
   loForm.CONTROLS[ 2].PICTURE = ;
   HOME() + 'SAMPLES\GRAPHICS\ICONS\COMPUTER\' + laIcons[lnFile+1, 1]
   loForm.CONTROLS[ 3].PICTURE = ;
   HOME() + 'SAMPLES\GRAPHICS\ICONS\COMPUTER\'+ laIcons[lnFile+2, 1]
   loForm.CONTROLS[ 4].PICTURE = ;
   HOME() + 'SAMPLES\GRAPHICS\ICONS\COMPUTER\'+laIcons[lnFile + 3, 1]
   loForm.CONTROLS[ 5].PICTURE = ;
   HOME() + 'SAMPLES\GRAPHICS\ICONS\COMPUTER\'+laIcons[lnFile + 4, 1]
   loForm.CONTROLS[ 6].PICTURE = ;
   HOME() + 'SAMPLES\GRAPHICS\ICONS\COMPUTER\'+laIcons[lnFile + 5, 1]
   loForm.CONTROLS[ 7].PICTURE = ;
   HOME() + 'SAMPLES\GRAPHICS\ICONS\COMPUTER\'+laIcons[lnFile + 6, 1]
   loForm.CONTROLS[ 8].PICTURE = ;
   HOME() + 'SAMPLES\GRAPHICS\ICONS\COMPUTER\' + laIcons[lnFile+7, 1]
   loForm.CONTROLS[ 9].PICTURE = ;
   HOME()+'SAMPLES\GRAPHICS\ICONS\COMPUTER\' + laIcons[lnFile + 8, 1]
   loForm.CONTROLS[10].PICTURE = ;
   HOME()+'SAMPLES\GRAPHICS\ICONS\COMPUTER\' + laIcons[lnFile + 9, 1]
   IF INKEY(0.001, 'HM') = 27
   CANCEL
   ENDIF
   ENDFOR
   ENDFOR
				

The first indication of a memory problem appears when the icons no longer appear in the individual image objects. The number of iterations before this symptom appears depends on the amount of physical RAM installed on the computer. Once the memory leak consumes all the physical RAM, Visual FoxPro begins using virtual memory. At this point, performance suffers greatly and the operating system may lock.