Memory Limits

[raleeper]

The assembler hangs when I include, in .DATA?, the line:

   fmemt   DB   100000 DUP (?)      ;File MEMory Temp - 1 meg

although

   fmemt   DB   10000 DUP (?)      ;File MEMory Temp - 64k

works OK.

I assemble and link using a batch file:

c:\aw.bat   for debug   at g:\lfw

g:
cd lfw
g:\masm32\bin\ml /c /coff /Cp /Fl /W2 /Zi g:\lfw\lfw.asm >errs
g:\masm32\bin\link /SUBSYSTEM:WINDOWS /LIBPATH:g:\masm32\lib /DEBUG /DEBUGTYPE:CV lfw.obj >>errs
cd\
c:

I suspect that I need to add something to the link options, but so far I cannot find documentation for what.

Can anyone suggest how to get around the limit or where I might look for the answer?

Thanks.

[BogdanOntanu]

Hi,

It does not hang... it is just assembling very very very slow.

This is "well known" bug in MASM: it slows down a lot when assembling huge non-initialized data blocks.

The solution is to allocate the data buffer at runtime using VirtualAlloc or GlobalAlloc etc.

Doing so is anyway a much better programming practice for such buffers. At least at runtime you can check for an error (not enough memory for example)

[raleeper]

Hi,

It does not hang... it is just assembling very very very slow.

This is "well known" bug in MASM: it slows down a lot when assembling huge non-initialized data blocks.

The solution is to allocate the data buffer at runtime using VirtualAlloc or GlobalAlloc etc.

Doing so is anyway a much better programming practice for such buffers. At least at runtime you can check for an error (not enough memory for example)

OK. Thanks.

It looks then as if what I need, to replace the "fmemt DD 100000" is [in the initialization part of my winmain procedure]:

    invoke  VirtualAlloc, 0, 100000, MEM_COMMIT, PAGE_READWRITE
    mov     [fmemt], eax

Then instead of "mov esi, OFFSET fmemt", it is "mov esi, [fmemt]" and I have *virtually* the same thing.

It does seem a waste to initialize to zeros, since it (or all of it that matters) will be overwritten.

Thanks again.

[Tedd]

GlobalAlloc may suit you better :wink

[BogdanOntanu]

And BTW do not forget to release the allocated memory at the end of the application :D

[Vortex]

Assembling modules with large uninitialized data blocks can be done by omitting the /coff switch. OMF object modules are created more easily.

[raleeper]

GlobalAlloc may suit you better :wink

I believe you are right.  I was put off by the SDK statement:

   Note  The global functions are slower than other memory management functions and do not provide as many features. Therefore, new applications should use
   the heap functions

But until I need the extra features, I'll try GlobalAlloc.

Thanks.