[XGC-120] java.util.ConcurrentModificationException in ImageImplregistry iterator

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 2.3
• Environment: Ubuntu
• Assignee: Unassigned
• Reporter: Allan Andersen
• Created: 28/May/19 07:39
• Updated: 03/Apr/24 08:20
• Resolved: 03/Apr/24 08:20

Description

I get this ConcurrentModificationException when running a multithreaded testcase. 

The problem is related to the preloaders (ArrayList) in ImageImplRegistry which isn't threadsafe. Using CopyOnWriteArrayList is a quick solution to the issue.

The other lists/maps are using the same non-threadsafe implementations. CopyOnWriteArrayList and ConcurrentHashMap works better.

Stacktrace:

Caused by: java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:909)
at java.util.ArrayList$Itr.next(ArrayList.java:859)
at org.apache.xmlgraphics.image.loader.spi.ImageImplRegistry$MyIterator.next(ImageImplRegistry.java:267)
at org.apache.xmlgraphics.image.loader.ImageManager.preloadImage(ImageManager.java:175)
at org.apache.xmlgraphics.image.loader.cache.ImageCache.needImageInfo(ImageCache.java:127)
at org.apache.xmlgraphics.image.loader.ImageManager.getImageInfo(ImageManager.java:123)
at org.apache.fop.fo.flow.ExternalGraphic.bind(ExternalGraphic.java:81)
at org.apache.fop.fo.FObj.processNode(FObj.java:126)
at org.apache.fop.fo.FOTreeBuilder$MainFOHandler.startElement(FOTreeBuilder.java:291)
at org.apache.fop.fo.FOTreeBuilder.startElement(FOTreeBuilder.java:179)
at org.apache.xalan.transformer.TransformerIdentityImpl.startElement(TransformerIdentityImpl.java:1073)
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.xalan.transformer.TransformerIdentityImpl.transform(TransformerIdentityImpl.java:485)