[fpc-pascal] Problems with GetMem

[Darius Blaszyk]

On Apr 10, 2011, at 12:24 AM, Jonas Maebe wrote:

> 
> On 10 Apr 2011, at 00:20, <dhkblaszyk at zeelandnet.nl> <dhkblaszyk at zeelandnet.nl> wrote:
> 
>> I get strange errors when using GetMem. In my
>> app I keep on allocating and freeing memory in a variable. At a certain
>> moment I do keep getting a SIGSEGV on the GetMem call when trying to
>> allocate exactly 128bytes. However allocating other sizes seems to work
>> just fine. Is there some logical explanation what could be going on
>> here?
> 
> Most likely it's memory corruption: writing into a freed memory block, writing outside the bounds of an allocated memory block, ... Compiling with -gh may help pinpoint it, and if not and you're on a Unix-based platform, you can try Valgrind.

You're right that there seems to be a memleak somewhere, but it's something strange, heaptrc reports 1 unfreed block and 0bytes unfreed. Never seen this before. I will test with valgrind this afternoon to see if I can get some wiser from it.
BTW, for those interested, I ported some code that allows bitmapped freetype fonts be used in OpenGL this works a lot simpler than using the freetype support from fcl-image. If you wish you can find the code here: http://scandraid.svn.sourceforge.net/viewvc/scandraid/src/branches/font/
 
Darius

>bitmappedglfont
Marked memory at $0A5AF068 invalid
Wrong signature $9BC362D6 instead of D1853A22
  $0040CFBB
  $00407D08
  $00401948  KEYPRESSED,  line 80 of BitmappedGLFont.pas
  $0984E054
  $0984D5DE
  $7E418734
  $7E418816
  $7E42A013
  $7E42A039
Heap dump by heaptrc unit
11894 memory blocks allocated : 8658563/8704536
11893 memory blocks freed     : 8658563/8704536
1 unfreed memory blocks : 0
True heap size : 1146880 (160 used in System startup)
True free heap : 1146384
Should be : 1146656
Marked memory at $0A5AF068 invalid
Wrong signature $9BC362D6 instead of D1853A22
  $0040DE47
  $0040CFBB
  $00407D08
  $00401948
  $0984E054
  $0984D5DE
  $7E418734
  $7E418816
  $7E42A013
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