| Subject: | InlineJavaPerlInterpreter.eval() hangs when called from another thread |
InlineJavaPerlInterpreter.eval() hangs if called from a thread different from the one where InlineJavaPerlInterpreter.create() was called.
Program reproducing the bug:
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import org.perl.inline.java.*;
class PerlEvalBug extends Thread
{
InlineJavaPerlInterpreter pi;
PerlEvalBug() throws InlineJavaPerlException, InlineJavaException
{
pi = InlineJavaPerlInterpreter.create();
// if I call print without newline in the end,
// nothing happens until a newline is output later
pi.eval("print \"called from the constructor\\n\";");
}
public void run()
{
try
// this hangs!
{pi.eval("print \"called from the second thread\\n\";");}
catch(Exception e)
{e.printStackTrace();}
}
public void call() throws InlineJavaPerlException, InlineJavaException
{
// this works
pi.eval("print \"called from the main thread\\n\";");
}
public void finalize()
{
pi.destroy();
}
public static void main(String[] args) throws InlineJavaPerlException, InlineJavaException
{
PerlEvalBug bug = new PerlEvalBug();
bug.call();
bug.start();
}
}
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Output (with debug level 10):
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[java][2] creating temporary JNI InlineJavaServer
[java][2] temporary JNI InlineJavaServer created
[java][2] creating InlineJavaPerlInterpreter
[java][2] loading shared library /usr/lib/perl5/site_perl/5.8.7/i586-linux-thread-multi/auto/Inline/Java/PerlInterpreter/PerlInterpreter.so
[java][2] shared library /usr/lib/perl5/site_perl/5.8.7/i586-linux-thread-multi/auto/Inline/Java/PerlInterpreter/PerlInterpreter.so loaded
[java][2] constructing perl interpreter
[java][2] perl interpreter constructed
called from the constructor
called from the main thread
(hangs...)
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Configuration:
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avatar:~/.cpan/build/Inline-Java-0.50 # perl Makefile.PL
Welcome to the Inline::Java installation procedure.
Default J2SDK for Inline::Java will be '/usr/lib/jvm/java-1.4.2-sun/'.
See module documentation for information on how to use a different J2SDK
or change this default value.
Inline::Java can use a JNI extension that allows the Java Virtual Machine
(JVM) to be dynamically linked with Perl instead of running as a separate
process. The use of this extension is optional, and building it still
allows Inline::Java to run the JVM in the default (separate process)
fashion.
Note: You need a C compiler to build the extension.
Note: You must build the extension if you wish to use PerlNatives or
PerlInterpreter.
Do you wish to build the JNI extension? [y] y
Building JNI extension.
1) /usr/lib/jvm/java-1.4.2-sun/jre/lib/i386/server
2) /usr/lib/jvm/java-1.4.2-sun/jre/lib/i386/client
Please select from the above list which 'libjvm.so' to use: [2] 1
Building with:
/usr/lib/jvm/java-1.4.2-sun/include/jni.h
/usr/lib/jvm/java-1.4.2-sun/include/linux/jni_md.h
/usr/lib/jvm/java-1.4.2-sun/jre/lib/i386/server/libjvm.so
Note: In order for Inline::Java to use the JNI extension, you will need to
use the JNI configuration option or set the PERL_INLINE_JAVA_JNI environment
variable to a true value. You will also need to add the following directories
to your LD_LIBRARY_PATH environment variable:
/usr/lib/jvm/java-1.4.2-sun/jre/lib/i386/server
/usr/lib/jvm/java-1.4.2-sun/jre/lib/i386/native_threads
/usr/lib/jvm/java-1.4.2-sun/jre/lib/i386
See README.JNI for more information.
The PerlNatives extension allows for callbacks to be defined as native
Java methods. It is still EXPERIMENTAL and may not build or work properly
on all platforms. See documentation for more details.
Note: PerlNatives requires J2SDK 1.4 or greater.
Do you wish to build the PerlNatives extension? [n] y
The PerlInterpreter extension allows Inline::Java to be loaded directly from
Java using an embedded Perl interpreter. It is still EXPERIMENTAL and
may not build or work properly on all platforms. See documentation for
more details.
Do you wish to build the PerlInterpreter extension? [n] y
Writing Makefile for Inline::Java::PerlNatives
Writing Makefile for Inline::Java::PerlInterpreter
Writing Makefile for Inline::Java::JNI
Writing Makefile for Inline::Java
You can continue the installation with the following commands:
% make java
% make
% make test
% make install
=======================================================================
Regards,
Misha