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Subject: Re: Restricting the memory usage of a Java program
Date: Thu, 11 Aug 2016 18:04:16 -0400
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On 8/11/2016 5:42 PM, Cecil Westerhof wrote:
> I made a little program for cropping images. When just starting it as
> a Java program the memory usage was just way to much. So I wrote the
> following script:
> #!/usr/bin/env bash
>
> declare -r CLASS=CropImage
> declare -r MIN_MEM=128M
> declare -r MAX_MEM=256M
>
> # Make sure you are in the right directory.
> # Only start the Java application when moving to the right directory was succesful.
> cd "${0%/*}" && java "-Xms${MIN_MEM}" "-Xmx${MAX_MEM}" "${CLASS}" &
>
> And now the memory consumption is much less and as far as I can see
> without negative consequences for the program.
>
> The values I use (128 MB and 256 MB) are just values I kind of
> randomly choose. Is there a way to find ‘optimal’ values?

System.gc();
Runtime rt = Runtime.getRuntime();
long actual_value = rt.totalMemory() - rt.freeMemory();
long good_value = SOME_MAGIC_FACTOR * actual_value;

Arne