Details
Improvement
Closed
Major
Description
com.thoughtworks.xstream.core.util.ClassLoaderReference is referring another ClassLoader and does not add any restriction itself.
As such, it should call java.lang.ClassLoader.registerAsParallelCapable() in its static initializer to mark itself as parallel capable, which allows the VM to use it concurrently.
This is new with Java7 and not calling the method introduces an unneeded performance loss.
See ClassLoader's Javadoc for more background info.
Activity
For staying source-compatible with Java6 and earlier, you can use this:
static { // see http://www.cs.duke.edu/csed/java/jdk1.7/technotes/guides/lang/cl-mt.html // TODO as soon as we compile with Java7 use this: ClassLoader.registerAsParallelCapable(); // until then: workaround: try { Method m = ClassLoader.class.getDeclaredMethod("registerAsParallelCapable"); m.setAccessible(true); m.invoke(null); } catch (Throwable t) { // ignore for older runtime environments } }
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Rico Neubauer
added a comment - - edited For staying source-compatible with Java6 and earlier, you can use this:
static
{
// see http://www.cs.duke.edu/csed/java/jdk1.7/technotes/guides/lang/cl-mt.html
// TODO as soon as we compile with Java7 use this : ClassLoader .registerAsParallelCapable();
// until then: workaround:
try
{
Method m = ClassLoader .class.getDeclaredMethod( "registerAsParallelCapable" );
m.setAccessible( true );
m.invoke( null );
}
catch (Throwable t)
{
// ignore for older runtime environments
}
}
Rico Neubauer
added a comment - - edited For staying source-compatible with Java6 and earlier, you can use this:
static
{
// see http://www.cs.duke.edu/csed/java/jdk1.7/technotes/guides/lang/cl-mt.html
// TODO as soon as we compile with Java7 use this : ClassLoader .registerAsParallelCapable();
// until then: workaround:
try
{
Method m = ClassLoader .class.getDeclaredMethod( "registerAsParallelCapable" );
m.setAccessible( true );
m.invoke( null );
}
catch (Throwable t)
{
// ignore for older runtime environments
}
}
Thanks for the pointer. Applied in trunk.
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Jörg Schaible
added a comment - Thanks for the pointer. Applied in trunk.
Jörg Schaible
added a comment - Thanks for the pointer. Applied in trunk. 
For trunk, ClassLoaderReference does not extend ClassLoader anymore, so this is OK.
But the issue is true for com.thoughtworks.xstream.core.util.CompositeClassLoader