That could be it in my case, I am using Inline::Java to use a Java API to
access a data product in a FastCGI-like environment. I'll have to look into
it the next time I get a chance. Thanks.
On Tue, 4 Jan 2011 08:23:04 -0500, Patrick LeBoutillier
<patrick.leboutill...@gmail.com> wrote:
> Hi,
>
> If you fork you have to use reconnect_JVM, or else you will run into
> trouble eventually. What will happen is that all the processes will
> use the same socket connection the JVM, and eventually things will get
> messed up.
>
> However, Java objects created from a Perl process can't be accessed
> directly by other processes using Inline::Java. This is meant to be a
> minimal security mechanism when using SHARED_JVM mode. It helps keep
> each Perl processe's Java objects somewhat separate.
>
> If you really want to keep your current design, you will have to keep
> your objects on the Java side in an array and access them indirectly.
> That way the objects references remain in Java-land and can re-fetched
> by the different threads. Here's an example:
>
> use Inline (
> Java => 'DATA',
> SHARED_JVM => 1,
> PORT => 17891,
> ) ;
> Inline::Java::capture_JVM() ; # Kill JVM on exit
>
> my $nb = $ARGV[0] || 5 ;
> for (my $i = 0 ; $i < $nb ; $i++){
> test->make_test($i) ;
> }
>
> $starttime = time;
> for (my $i = 0 ; $i < $nb ; $i++){
> my $pid = fork;
> if (! $pid)
> {
> print "start $i\n";
> Inline::Java::reconnect_JVM() ;
> my $test = test->get_test($i) ;
> $test->sleep() ;
> print "end $i\n";
> exit;
> }
> else
> {
> push @pid, $pid;
> }
> }
>
> waitpid $_,0 for @pid;
>
> $elapsed = time-$starttime;
> print "For $nb threads it took $elapsed seconds\n";
>
> __DATA__
> __Java__
> import java.util.* ;
>
> class test {
> static ArrayList tests ;
> static {
> tests = new ArrayList() ;
> }
>
> static public void make_test (int i) { tests.add(i, new test()) ; }
> static public test get_test (int i) { return (test)tests.get(i) ; }
> private test() { }
> public void sleep() throws InterruptedException {
> Thread.sleep(1000) ;
> }
> }
>
>
> Patrick
>
>
> On Mon, Jan 3, 2011 at 3:59 PM, ant <a...@suave.net> wrote:
>>
>>
>> I made this work by turning off SHARED_JVM (because after a while it
>> seemed
>> to cause problems) and then loading the module that had Inline::Java in
>> it
>> at runtime in an eval instead because reconnect_JVM didn't seem to work
>> right at all.
>>
>> so basically I did
>> fork();
>> eval "use My::Module;";
>>
>> I'll be interested to see if you get a better solution.
>>
>> On Mon, 3 Jan 2011 12:53:37 -0600, <scott.dav...@wellsfargo.com> wrote:
>>> Hi Patrick,
>>>
>>> Thanks for writing back! I am calling from Perl to Java only. Here is a
>>> closer example to what I am doing. I want to create several objects in
>> the
>>> main process, and then execute methods in parallel in sub-processes.
>> There
>>> are several steps to what I am doing, and I want to ensure that the
>>> first
>>> step completes on all target servers before moving on to the second
>>> step,
>>> and so forth.
>>>
>>> use Inline (
>>> Java => 'DATA',
>>> SHARED_JVM => 1,
>>> PORT => 17891,
>>> ) ;
>>> Inline::Java::capture_JVM() ; # Kill JVM on exit
>>>
>>> my $nb = $ARGV[0] || 5 ;
>>> for (my $i = 0 ; $i < $nb ; $i++){
>>> $test[$i] = new test;
>>> }
>>>
>>> $starttime = time;
>>> for (my $i = 0 ; $i < $nb ; $i++){
>>> my $pid = fork;
>>> if (! $pid)
>>> {
>>> print "start $i\n";
>>> #Inline::Java::reconnect_JVM() ;
>>> $test[$i]->sleep();
>>> print "end $i\n";
>>> exit;
>>> }
>>> else
>>> {
>>> push @pid, $pid;
>>> }
>>> }
>>>
>>> waitpid $_,0 for @pid;
>>>
>>> $elapsed = time-$starttime;
>>> print "For $nb threads it took $elapsed seconds\n";
>>>
>>> __DATA__
>>> __Java__
>>> class test {
>>> public test() { }
>>> public void sleep() throws InterruptedException {
>>> Thread.sleep(1000) ;
>>> }
>>> }
>>>
>>> ---------------
>>>
>>> $ perl ptest3.pl 2
>>> start 0
>>> start 1
>>> end 0
>>> end 1
>>> For 2 threads it took 2 seconds
>>> $ perl ptest3.pl 5
>>> start 0
>>> start 1
>>> start 2
>>> start 3
>>> start 4
>>> end 0
>>> end 1
>>> end 2
>>> end 4
>>> end 3
>>> For 5 threads it took 5 seconds
>>> $ perl ptest3.pl 10
>>> start 0
>>> start 1
>>> start 2
>>> start 3
>>> start 4
>>> start 5
>>> start 6
>>> start 7
>>> start 8
>>> start 9
>>> end 0
>>> end 3
>>> end 6
>>> end 1
>>> end 8
>>> end 9
>>> end 5
>>> end 7
>>> end 2
>>> end 4
>>> For 10 threads it took 10 seconds
>>>
>>> Note that when I uncomment the reconnect_JVM() line, then I get an
error
>>> message:
>>> $ perl ptest3.pl 2
>>> start 0
>>> start 1
>>> Can't find object 1 for thread IJST-#1 at (eval 13) line 215
>>> at ptest3.pl line 24
>>> Can't find object 2 for thread IJST-#2 at (eval 13) line 215
>>> at ptest3.pl line 24
>>> For 2 threads it took 0 seconds
>>>
>>> Thanks,
>>> Scott
>>
