[AXIS-2909] ConcurrentModificationException when running under Java 1.8.0_20 or later

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 1.4
• Fix Version/s: 1.4.1
• Component/s: Serialization/Deserialization
• Environment: java full version "1.8.0_20-b26"
• Flags: Patch
• Assignee: Andreas Veithen
• Reporter: Kim Albertsson
• Created: 08/May/15 15:34
• Updated: 31/Mar/22 14:26
• Resolved: 04/Jul/15 10:20

Description

Java 8u20 introduced a change in how Collections.sort is implemented. See http://bugs.java.com/view_bug.do?bug_id=8032636 and http://bugs.java.com/view_bug.do?bug_id=8030848.

The sorting is now deferred to the specific list implementation which can operate directly on the underlying data structure without making a defensive copy beforehand. This can cause a java.util.ConcurrentModificationException to occur.

The error can be reproduced by compiling axis-1.4.1-SNAPSHOT using java 1.8.0_20 or later and running the maven test suite (mvn test). The error does not manifest every single run, but I have never had to run the tests more than 3 times to reproduce. The test that fails is test.concurrency.TestApplicationScope.

The issue originates in org.apache.axis.description.JavaServiceDesc.getOperationsByQName where an unsynchronized call to Collections.sort is made. Synchronizing over the sorted array resolves the issue.

A working patch that has been tested in the test suite is appended in diff.txt.

The stack trace from the axis test-suite is appended below. Do note however that this stack trace does not show the actual error (The original error is caught and rethrown). To get the stack trace where the Collections.sort call is made you can run the specific test and attach the jdb configured to catch all java.util.ConcurrentModificationExceptions.

The stack trace from my jdb session is appended as axis-concurrent-mod.stack-trace. It was generated from an apache tomcat instance running a webservice relying on axis.

AxisFault
faultCode:

{http://schemas.xmlsoap.org/soap/envelope/}

Server.userException
faultSubcode:
faultString: java.util.ConcurrentModificationException
faultActor:
faultNode:
faultDetail:

{http://xml.apache.org/axis/}

stackTrace:java.util.ConcurrentModificationException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at java.lang.Class.newInstance(Class.java:442)
at org.apache.axis.encoding.ser.BeanDeserializer.<init>(BeanDeserializer.java:104)
at org.apache.axis.encoding.ser.BeanDeserializerFactory.getGeneralPurpose(BeanDeserializerFactory.java:89)
at org.apache.axis.encoding.ser.BaseDeserializerFactory.getDeserializerAs(BaseDeserializerFactory.java:89)
at org.apache.axis.encoding.DeserializationContext.getDeserializer(DeserializationContext.java:484)
at org.apache.axis.encoding.DeserializationContext.getDeserializerForType(DeserializationContext.java:567)
at org.apache.axis.message.SOAPFaultDetailsBuilder.onStartChild(SOAPFaultDetailsBuilder.java:157)
at org.apache.axis.encoding.DeserializationContext.startElement(DeserializationContext.java:1052)
at org.apache.xerces.parsers.AbstractSAXParser.startElement(Unknown Source)
at org.apache.xerces.parsers.AbstractXMLDocumentParser.emptyElement(Unknown Source)
at org.apache.xerces.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
at org.apache.axis.encoding.DeserializationContext.parse(DeserializationContext.java:241)
at org.apache.axis.SOAPPart.getAsSOAPEnvelope(SOAPPart.java:696)
at org.apache.axis.Message.getSOAPEnvelope(Message.java:435)
at org.apache.axis.handlers.soap.MustUnderstandChecker.invoke(MustUnderstandChecker.java:62)
at org.apache.axis.client.AxisClient.invoke(AxisClient.java:206)
at org.apache.axis.client.Call.invokeEngine(Call.java:2782)
at org.apache.axis.client.Call.invoke(Call.java:2765)
at org.apache.axis.client.Call.invoke(Call.java:2443)
at org.apache.axis.client.Call.invoke(Call.java:2366)
at org.apache.axis.client.Call.invoke(Call.java:2391)
at test.concurrency.TestApplicationScope$TestRunnable.run(TestApplicationScope.java:80)
at java.lang.Thread.run(Thread.java:745)