[OpenJDK 2D-Dev] Thoughts about font implementation

[Roman Kennke]

Hi Igor,

> >> Quick tests are: run Font2DTest on system that has some really large 
> >> ttf/ttc files.
> >>
> >> Write simple test that iterates through all available fonts and draw
> >> one 
> >> or all glyphs to bufferedimage.
> >>     
> >
> > I wrote a simple test program that gets an array of all fonts and gets
> > the baseline for all 0-0xffff characters. (Drawing stuff to BI didn't
> > work due to NPE, see stacktrace below. BTW, this makes everything, e.g.
> > SwingSet2, kindof unstable, is this a known bug?)
> >
> > 10 runs of this program with my patch take: 4338ms
> > 10 runs of this program w/o  my patch take: 4492ms
> >   
> 
> Can you check process size stats at the end of program?
> Guess you can simply exec "ps | grep" and print out result

Ok, it took me a while to figure out a way to measure process size of a
program that only runs for a second or so. I am using top -b -d0.1 |grep
java to measure memory consumption. Without my patch, the output looks
like:

637m 5936 2912 S   37  0.3   0:00.04 java              
644m  11m 5408 S   90  0.6   0:00.14 java              
645m  12m 5900 S   96  0.6   0:00.24 java              
645m  12m 5900 S   95  0.6   0:00.34 java              
648m  15m 6224 S  135  0.8   0:00.48 java              
648m  17m 6380 S  163  0.9   0:00.65 java              
648m  20m 6716 S  145  1.0   0:00.80 java              
650m  22m 6908 S  146  1.1   0:00.95 java              
650m  24m 7016 S  106  1.2   0:01.06 java              
653m  26m 7304 S  152  1.3   0:01.22 java              
653m  26m 7324 S  125  1.3   0:01.35 java              
654m  26m 7340 S   86  1.3   0:01.44 java              
654m  26m 7340 S    0  1.3   0:01.44 java              
654m  26m 7340 S    0  1.3   0:01.44 java           

The first 3 fields here are of interest: virtual memory, resident
memory, and shared memory.

Typical output of the same program with my patch:

637m 6288 3008 S   37  0.3   0:00.04 java              
645m  10m 4676 S   90  0.5   0:00.14 java              
645m  10m 4680 S  114  0.5   0:00.26 java              
645m  10m 4680 S   95  0.5   0:00.36 java              
647m  15m 6224 S  129  0.8   0:00.50 java              
648m  17m 6384 S  176  0.9   0:00.69 java              
648m  20m 6816 S  111  1.0   0:00.81 java              
720m  24m 8620 S  162  1.2   0:00.98 java              
894m  26m  10m S  144  1.3   0:01.13 java              
806m  26m 9748 S  125  1.3   0:01.26 java              
806m  26m 9756 S  115  1.3   0:01.38 java              
807m  26m 9760 S   19  1.3   0:01.40 java              
807m  26m 9760 S    0  1.3   0:01.40 java              
807m  26m 9760 S    0  1.3   0:01.40 java              

It appears that the programs virtual memory usage grows a little more
than w/o my patch :-( However, the actual resident memory stays more or
less the same (compared to the version w/o the patch). Also interesting
is the short spike in shared memory usage (maybe a font that is already
mmapped by the desktop?). This can be explained: when mapping a file
into memory, it 'uses' virtual memory of the size of the file, but
doesn't actually consume any resident memory as long as the memory is
not accessed. So the VM consumtion is growing, but the RM stays the
same. Don't know if that is a concern.

> > One interesting note here: Everytime this program is run, it shows a
> > different number of fonts (around 285-302 fonts). On an OpenJDK6 system
> > it constantly shows 360 fonts.
> >   
> This is weird.
> I suggest to print out font names and find what is different. Perhaps we 
> do have bug somethere in 7.
> -Dsun.java2d.debugfonts=true may also provide some details on files 
> being opened.

I'll have a look at this later.

Cheers, Roman

-- 
Dipl.-Inform. (FH) Roman Kennke, Software Engineer, http://kennke.org
aicas Allerton Interworks Computer Automated Systems GmbH
Haid-und-Neu-Straße 18 * D-76131 Karlsruhe * Germany
http://www.aicas.com   * Tel: +49-721-663 968-48
USt-Id: DE216375633, Handelsregister HRB 109481, AG Karlsruhe
Geschäftsführer: Dr. James J. Hunt