GlobalAlloc, HeapAlloc, and LocalAlloc

[nidud]

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[dedndave]

XP MCE2005 (pro) SP3, prescott w/htt

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Intel(R) Pentium(R) 4 CPU 3.00GHz (SSE3)
------------------------------------------------------
475699  cycles - LocalAlloc
477340  cycles - LocalAlloc
477033  cycles - LocalAlloc

14662124        cycles - HeapAlloc
14741803        cycles - HeapAlloc
14678539        cycles - HeapAlloc

15614816        cycles - GlobalAlloc
15559706        cycles - GlobalAlloc
15559654        cycles - GlobalAlloc

[jj2007]

Interesting :t
So the question is, why do the others need so many cycles?
BTW the thread title is misleading; LocalAlloc is a Win32 function, you are creating something different...

[dedndave]

you don't have to use a linker option - you can probe the stack down
it doesn't take many cycles because you get 4 Kb per loop pass
and - in some cases, the stack has been previously probed down part of the way

by the way - it does no good to time it more than one call per process instance 
once the stack is probed down to some address - subsequent calls don't need to loop

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;*****************************************************************************************************

        OPTION  PROLOGUE:None
        OPTION  EPILOGUE:None

ProbeStack PROC    uSize:UINT

;Probe Stack to Bytes Requested
;Copyright Dedndave 6-2012
;
;  Returns: EAX = probed-to stack pointer
;           ECX = bytes requested
;           EDX = top of stack

;---------------------------------------------------

        ASSUME  FS:Nothing

        mov     eax,esp
        mov     ecx,[esp+4]
        add     eax,8
        push    ebp
        sub     eax,ecx
        mov     ebp,esp
        and     al,-16                    ;must be 4-aligned, 16-aligned optional (shown)

Probe0: push    ecx
        mov     esp,fs:[8]
        cmp     eax,esp
        jb      Probe0

        mov     edx,esp
        leave
        ret     4

        ASSUME  FS:ERROR

ProbeStack ENDP

        OPTION  PROLOGUE:PrologueDef
        OPTION  EPILOGUE:EpilogueDef

;*****************************************************************************************************

that's an older version - don't know if i have an updated one   :P

[nidud]

deleted

[hutch--]

Different strategies do different things, a high count of small allocations is always better done by allocating a single block and allocating pointers to parts of it as it is always a lot faster. It has to do with how the system allocates blocks of memory and what is the minimum size when a small block is allocated. For variable length strings the system has OLE strings which are part of the OLE string pool, if you need large blocks that can be swapped out to virtual memory, VirtualAlloc() is the right technique, most of the others interface with the same lower level function to provide memory so its more a choice of interface than performance.

LOCAL and GLOBAL Alloc are the same function as LocalAlloc() is a compatibility left over from Win16, GlobalAlloc() is required for a few old functions, the clipboard is one of them but it is only useful as a general purpose allocation strategy if you use the GMEM_FIXED flag and forget about GlobalLock() as it has assumptions from the Win16 days in its design.

[Gunther]

Hi nidud,

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Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz (SSE4)
------------------------------------------------------
1824805 cycles - GlobalAlloc
1872796 cycles - GlobalAlloc
1863379 cycles - GlobalAlloc

1483367 cycles - HeapAlloc
1558823 cycles - HeapAlloc
1545215 cycles - HeapAlloc

227101  cycles - LocalAlloc
228995  cycles - LocalAlloc
227467  cycles - LocalAlloc


Gunther

[nidud]

deleted

[RuiLoureiro]

nidud,
           something seems to be wrong, it doesnt work.
           

[nidud]

deleted

[jj2007]

It works (XP SP3):
memory: 67108840
memory: 66708832
memory: 40308832

[dedndave]

XP SP3 prescott w/htt

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memory: 67108840
memory: 66708832
memory: 40308832

i'm confused   

[nidud]

deleted

[dedndave]

i know - the registers should be preserved before EBP is set, not after
that's because of the way LEAVE works on exit
i often write my own stack frame to get what i want...

http://masm32.com/board/index.php?topic=3326.msg35052#msg35052

[nidud]

deleted