Deadlocks in Groovy shell evaluations - groovy

Question

I am using Groovy 1.7.8. and have written a Groovy DSL which I execute concurrently on different domain objects.
Of late, I have started facing deadlocks under heavy concurrency when DSLs are compiling/executing concurrently.
I am compiling/executing Groovy DSL at runtime using:
Script s = compileScript(dsl)
def binding = new Binding()
binding.setVariable("domainObj", domainObj)
s.setBinding(binding)
s.run()
def Script compileScript(String dsl) {
def scriptText = getScriptText(dsl)
def conf = new CompilerConfiguration()
conf.setScriptBaseClass(GroovyViewExecutionBase.class.getName())
new GroovyShell(conf).parse(scriptText)
}
Below is the thread dump of deadlocked threads, looking at the thread dumps I feel that Groovy is deadlocking internally when we concurrently compile/execute scripts at runtime.
Deadlock-Participant-1:
at java.beans.PropertyDescriptor.getReadMethod(PropertyDescriptor.java:158)
- waiting to lock <0x00007f41a3363960> (a java.beans.PropertyDescriptor)
at java.beans.Introspector.processPropertyDescriptors(Introspector.java:683)
at java.beans.Introspector.getTargetPropertyInfo(Introspector.java:615)
at java.beans.Introspector.getBeanInfo(Introspector.java:407)
at java.beans.Introspector.getBeanInfo(Introspector.java:164)
- locked <0x00007f41a3358c28> (a java.lang.Object)
at groovy.lang.MetaClassImpl$15.run(MetaClassImpl.java:2940)
at java.security.AccessController.doPrivileged(Native Method)
at groovy.lang.MetaClassImpl.addProperties(MetaClassImpl.java:2938)
at groovy.lang.MetaClassImpl.initialize(MetaClassImpl.java:2921)
- locked <0x00007f429f011268> (a groovy.lang.ExpandoMetaClass)
at groovy.lang.ExpandoMetaClass.initialize(ExpandoMetaClass.java:463)
- locked <0x00007f429f011268> (a groovy.lang.ExpandoMetaClass)
at org.codehaus.groovy.reflection.ClassInfo.getMetaClassUnderLock(ClassInfo.java:166)
at org.codehaus.groovy.reflection.ClassInfo.getMetaClass(ClassInfo.java:182)
at org.codehaus.groovy.runtime.metaclass.MetaClassRegistryImpl.getMetaClass(MetaClassRegistryImpl.java:210)
at org.codehaus.groovy.runtime.InvokerHelper.getMetaClass(InvokerHelper.java:751)
at groovy.lang.GroovyObjectSupport.<init>(GroovyObjectSupport.java:32)
at groovy.lang.Script.<init>(Script.java:40)
at groovy.lang.Script.<init>(Script.java:37)
at flipkart.cms.views.core.GroovyViewExecutionBase.<init>(GroovyViewExecutionBase.groovy)
at Script1.<init>(Script1.groovy)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at java.lang.Class.newInstance0(Class.java:355)
at java.lang.Class.newInstance(Class.java:308)
at org.codehaus.groovy.runtime.InvokerHelper.createScript(InvokerHelper.java:408)
at groovy.lang.GroovyShell.parse(GroovyShell.java:743)
at groovy.lang.GroovyShell.parse(GroovyShell.java:770)
at groovy.lang.GroovyShell.parse(GroovyShell.java:761)
at groovy.lang.GroovyShell$parse.call(Unknown Source)
at cms.views.core.GroovyDSLViewComputer.compileScript(GroovyDSLViewComputer.groovy:85)
==================
Deadlock-Participant-2:
at java.beans.Introspector.getPublicDeclaredMethods(Introspector.java:1277)
- waiting to lock <0x00007f41a3358c28> (a java.lang.Object)
at java.beans.Introspector.internalFindMethod(Introspector.java:1312)
at java.beans.Introspector.findMethod(Introspector.java:1383)
at java.beans.Introspector.findMethod(Introspector.java:1363)
at java.beans.PropertyDescriptor.getReadMethod(PropertyDescriptor.java:179)
- locked <0x00007f41a3363960> (a java.beans.PropertyDescriptor)
at groovy.lang.MetaClassImpl.applyPropertyDescriptors(MetaClassImpl.java:2215)
at groovy.lang.MetaClassImpl.setupProperties(MetaClassImpl.java:1995)
at groovy.lang.MetaClassImpl.addProperties(MetaClassImpl.java:2950)
at groovy.lang.MetaClassImpl.initialize(MetaClassImpl.java:2921)
- locked <0x00007f42a12972b8> (a groovy.lang.ExpandoMetaClass)
at groovy.lang.ExpandoMetaClass.initialize(ExpandoMetaClass.java:463)
- locked <0x00007f42a12972b8> (a groovy.lang.ExpandoMetaClass)
at org.codehaus.groovy.runtime.HandleMetaClass.replaceDelegate(HandleMetaClass.java:66)
at org.codehaus.groovy.runtime.HandleMetaClass.setProperty(HandleMetaClass.java:91)
at org.codehaus.groovy.runtime.InvokerHelper.setProperty(InvokerHelper.java:179)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.setProperty(ScriptBytecodeAdapter.java:483)
at flipkart.cms.views.core.GroovyViewExecutionBase.setupAttrProperties(GroovyViewExecutionBase.groovy:60)
at flipkart.cms.views.core.GroovyViewExecutionBase$setupAttrProperties$0.callCurrent(Unknown Source)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallCurrent(CallSiteArray.java:44)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:141)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:149)
at cms.views.core.GroovyViewExecutionBase.computeView(GroovyViewExecutionBase.groovy:32)
==================
Any ideas how I can fix/workaround this?

Answer 1

Posted this on groovy-user forum and looks like the deadlocks are caused because of synchronization issues in java 6's java.beans.Introspector class which apparently have been fixed in Java 7. Also received a backport of these classes for java 6 and am testing the backported classes to reproduce the deadlocks.
More details here:
http://groovy.329449.n5.nabble.com/Groovy-deadlocks-when-executing-DSL-from-GroovyShell-td5709889.html