[nylug-talk] Why does "enterprise" imply "Java"?

[Tim Gales]

David Rosenstrauch wrote:
> Michael Bacarella wrote:
>> Yes, we've all heard how theoretically awesome this HotSpot technology 
>> is, but
>> apparantly it still has a ways to go because even the antiquated old-news
>> barbarian GNU C Compiler was smart enough to see:
>>
>>     for (i = 0; i < 1000000000; i++)
>>         ;
>>
>> and figure out it was a long winded way of saying:
>>
>>     i = 1000000000;
>>
>> Whereas the JRE chewed through that loop a billion times, although I'm 
>> assured
>> that thanks to advanced HotSpot JIT magic that has never really been 
>> explained,
>> it happened as efficiently as possible.
> 
> 
> Again, you're comparing apples to oranges.
> 
> You ran your benchmark using the (default) client-side version of the VM 
> which doesn't perform that optimization.  The server-side version does:
> 
> 
> [darose at davidrlin classes]$ time java -showversion -cp . stillslow
> java version "1.4.2_06"
> Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_06-b03)
> Java HotSpot(TM) Client VM (build 1.4.2_06-b03, mixed mode)
> 
> 
> real    0m1.361s
> user    0m1.292s
> sys     0m0.004s
> 
> 
> [darose at davidrlin classes]$ time java -showversion -server -cp . stillslow
> java version "1.4.2_06"
> Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_06-b03)
> Java HotSpot(TM) Server VM (build 1.4.2_06-b03, mixed mode)
> 
> 
> real    0m0.261s
> user    0m0.184s
> sys     0m0.000s
> 
Is the server-side VM free from the following defect:
(six years ago is pretty long time in 'computer years' -- so
  may be its fixed by now, tho its still marked as open)

4329831
Votes  29
Synopsis  HotSpot violates Memory Model in the Java Language Specification
Category  java:specification
Reported Against  2.0_beta
Release Fixed
State  In progress, bug
Related Bugs  4242244
Submit Date  12-APR-2000

Java HotSpot(TM) Client VM (build 1.3.0rc1-S, mixed mode)


All known JVM's perform optimizations that violate
chapter 17 of the Java Language Specification, which describes.
the model for how threads can interact through shared memory. This
includes all versions of Sun HotSpot JVM.

This is a duplicate of bug 4242244, which was incorrectly closed by
someone who thought that it only applied to pre-HotSpot JVM's, even though
bug 4242244 clearly mentions that the bug occurs in HotSpot...

http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4329831



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