Character decoding could be 3 times faster !

Ulf Zibis Ulf.Zibis at
Wed May 21 16:24:22 UTC 2008

Hi Alan,

thanks for your interest, and your hints.

- Yes, I'm on Windows.
- I did my tests in default (-client) mode with 100 loops on 190k file. 
In my experience I didn't recognize any significant difference for 500 
or 1000 loops, so IMO 100 loops should be enough. On the other hand I 
had significant differences (up to 3 times) on different runs of 
SpeedTest at different times, but regardless of 100 or 1000 loops. I 
assume, that other running windows tasks are the cause for this. So I 
did up to 40 runs, and then valued the minimum of those results.
- Now I also tried some tests with the -server option. The improvement 
is ~10 % for 100 loops, but ~30 % for 1000 loops.


Am 19.05.2008 13:16, Alan Bateman schrieb:
> Your scripts are DOS batch files so I assume you are on Windows. As 
> the scripts don't specify the -client or -server option then I assume 
> you are testing only with the Client VM (is that right?). If you are 
> only testing with the Client VM then switching to the Server VM should 
> make a significant difference to this test. Another comment is that 
> the input file is only 190k so you'll probably need to decode it 
> several thousand times to get to a steady-state and get reasonable 
> results.
> One other thing - it looks like you are using the jdk6 sources with 
> the JRL license rather than OpenJDK sources. If you do improve the 
> performance of the decode loop for this class of decoder then it would 
> be best to post a patch against the OpenJDK sources.
> -Alan.

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