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Re: [PROGRAMMERING] Hvad koster en malloc og free



On Fri, Oct 14, 2005 at 09:48:17AM +0200, Lars Riisgaard Ribe wrote:
> Jeg sidder og arbejder på noget C-kode, og i den forbindelse har jeg
> en funktion, hvor jeg er nødt til at oprette et midlertidigt array af
> størrelsen 8-12 floats – oprettelsen (og nedlæggelsen) sker med
> malloc og free. 
> 
> Funktionen kaldes adskillige tusinde gange under program-eksekvering,
> så jeg kom pludselig til at tænke på, om jeg kan få
> hukommelsesfragmentering af dette, eller om så mange oprettelser og
> nedlæggelser er en flaskehals?
> 
> Er det bedre, at man giver det midlertidige array som argument til
> funktionen og så kun opretter det en gang for alle i main? (jeg synes
> bare det er så grim kode, når man skal sende midlertidige variable
> med).

Har du konstateret en flaskehals siden du kaster dig ud i den slags
optimeringer? Som Donald Knuth siger:

        "Premature optimization is the root of all evil"

-- 
Med venlig hilsen
- Jacob Atzen


 
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