OpenJDK: Java application Startup

[Andrew Haley]

Sandeep Konchady writes:
 > 
 > As Roman mentioned, there is some activity around improving performance 
 > of Java through Java Kernel project. This forum on java.net has some 
 > interesting information, in case you have not already seen it.
 > 
 > http://forums.java.net/jive/thread.jspa?threadID=22378&tstart=0
 > 
 > As for creating .exe from Java program, it has already been done by gcj, 
 > but I have not seen or heard about significant performance gain or 
 > startup improvements by doing this.

There is a startup time improvement with gcj, but this tends somewhat
to be masked by the large time spent by the shared library loader
doing fixups.  Prelinking helps this, though:


zorro:tmp $ gcj Hello.java --main=Hello -o Hello
zorro:tmp $ time ./Hello
Hello, World!

real    0m0.074s
user    0m0.037s
sys     0m0.038s
zorro:tmp $ sudo prelink Hello
zorro:tmp $ time ./Hello
Hello, World!

real    0m0.045s
user    0m0.017s
sys     0m0.028s
zorro:tmp $ time java Hello
Hello, World!

real    0m0.131s
user    0m0.052s
sys     0m0.043s

Andrew.

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