flat assembler - FASMW.ASM - memory leak (?) Tomasz ?

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ouadji

Joined: 24 Dec 2008
Posts: 1080
Location: Belgium

ouadji 19 Jan 2011, 00:49

Tomasz, I think there is a small problem here (?)

Code:

FASMW.ASM

save_file_as:
      .....
       .....
       mov     eax,[ei.pszpath]
    or      eax,eax
     jnz     alloc_ok
    invoke  VirtualAlloc,0,0C000000h,MEM_COMMIT,PAGE_READWRITE   ;1000h
 mov     [ei.pszpath],eax
      alloc_ok:
     mov     [lparam],eax
        mov     [ofn.lpstrFile],eax
 mov     [ofn.lpstrFilter],asm_filter
        mov     [ofn.Flags],OFN_EXPLORER+OFN_HIDEREADONLY+OFN_OVERWRITEPROMPT
       invoke  GetSaveFileName,ofn
 or      eax,eax
     jz      save_cancelled
      mov     eax,[ei.pszpath]
    .....
       .....

save_cancelled:

        mov     eax,[lparam]
        xchg    eax,[ei.pszpath]
    cmp     eax,[ei.pszpath]
    je      finish
      invoke  VirtualFree,eax,0,MEM_RELEASE
       .....
       .....

GetSaveFileName ==> Cancel ==> eax=0
save_cancelled: ... save is not canceled !
[lparam] == [ei.pszpath] always ! ... then "je finish".

I checked it with my debugger and also with the Windows Task Manager ...
(with 200MB of memory allocation to be sure of the result )
results: "VirtualAlloc" is not canceled.
if I repeat the operation, "save as - cancel - save as - cancel ..."
my memory allocation rises to 400, 600, 800 MB ...

after "cancel" I think It would be nice to clear [ei.pszpath] too.
Probably not necessary but "aesthetically" more correct.

to solve this problem, maybe something like this (?)

Code:

  mov     eax,[ei.pszpath]
    or      eax,eax
     mov     [lparam],eax ;<--- here
  jnz     alloc_ok
    invoke  VirtualAlloc,0,1000h,MEM_COMMIT,PAGE_READWRITE 
     mov     [ei.pszpath],eax
alloc_ok:
;  mov     [lparam],eax

_________________
I am not young enough to know everything (Oscar Wilde)-

19 Jan 2011, 00:49

ouadji

Joined: 24 Dec 2008
Posts: 1080
Location: Belgium

ouadji 20 Jan 2011, 20:41

Code:

"0.95.05"

      save_cancelled:
     ;mov    eax,[lparam]
        ;xchg   eax,[ei.pszpath]
    ;cmp    eax,[ei.pszpath]
    ;je     finish
      ;invoke VirtualFree,eax,0,MEM_RELEASE
       invoke  SendMessage,[hwnd_tabctrl],TCM_GETCURSEL,0,0
        invoke  SendMessage,[hwnd_tabctrl],TCM_SETITEM,eax,ei
       jmp     finish

thank you Tomasz for this fix.

Your solution is another way of looking at things,
but I checked it, everything works correctly.

_________________
I am not young enough to know everything (Oscar Wilde)-

20 Jan 2011, 20:41

ouadji

Joined: 24 Dec 2008
Posts: 1080
Location: Belgium

ouadji 21 Jan 2011, 01:25

Code:

fmsave:
      mov     [ei.header.mask],TCIF_PARAM
 invoke  SendMessage,[hwnd_tabctrl],TCM_GETITEM,[wparam],ei
  or      eax,eax
     jz      failed
      mov     eax,[ei.pszpath] ;eax != 0, but *eax="" => CreateFile fail!
    or      eax,eax
     jz      failed
      invoke  CreateFile,eax,GENERIC_WRITE,0,0,CREATE_ALWAYS,0,0

but with your solution, the path is empty,
*[ei.pszpath] == "" and CreateFile fail.
Yes ...it does not matter! (but this is not aesthetic)
I think my solution was better.

_________________
I am not young enough to know everything (Oscar Wilde)-

21 Jan 2011, 01:25

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8434
Location: Kraków, Poland

Tomasz Grysztar 21 Jan 2011, 05:06

Yes, I now leave the memory block allocated but unused (until the next time). It may appear a bit "dirty"... But, on the other hand, if you then do "save" once again, the memory is already allocated -why allocate it two times?

21 Jan 2011, 05:06

ouadji

Joined: 24 Dec 2008
Posts: 1080
Location: Belgium

ouadji 21 Jan 2011, 09:37

Quote:

"It may appear a bit "dirty"..."

relax, just a little bit Wink

Quote:

"why allocate it two times?"

yes, ok, good idea
but in this case, the string "path" is empty
and in "fmsave", this is not :

Code:

mov     eax,[ei.pszpath]
or      eax,eax
jz      failed ;-----> out

but

Code:

invoke   CreateFile
cmp       eax,-1
je    failed ;-----> here out

and that ... it's a bit "dirty".
sorry, I'm a perfectionist ... (only with code Wink

)

then, maybe this ? (to be politically perfect Wink

)

Code:

mov       eax,[ei.pszpath]
or  eax,eax
jz   failed
mov   ebx,[eax]       ;+
or        ebx,ebx         ;+ Memory allocated by VirtualAlloc 
jz      failed          ;+ is automatically initialized to zero
invoke       CreateFile

have a good day Tomasz, and thank you for your reply.

_________________
I am not young enough to know everything (Oscar Wilde)-

21 Jan 2011, 09:37

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