问题
I have a Xtext grammar which throws following exception when I try to generate Xtext artifacts (It starts and in the end it throws the exception(s)).
My Outline (first few lines):
0 [main] INFO lipse.emf.mwe.utils.StandaloneSetup - Registering platform uri 'C:\Users\Robert Adam\Documents\eclipse.luna\workspace'
451 [main] INFO lipse.emf.mwe.utils.StandaloneSetup - Adding generated EPackage 'org.eclipse.xtext.xbase.XbasePackage'
701 [main] INFO clipse.emf.mwe.utils.GenModelHelper - Registered GenModel 'http://www.eclipse.org/Xtext/Xbase/XAnnotations' from 'platform:/resource/org.eclipse.xtext.xbase/model/Xbase.genmodel'
701 [main] INFO clipse.emf.mwe.utils.GenModelHelper - Registered GenModel 'http://www.eclipse.org/xtext/xbase/Xtype' from 'platform:/resource/org.eclipse.xtext.xbase/model/Xbase.genmodel'
717 [main] INFO clipse.emf.mwe.utils.GenModelHelper - Registered GenModel 'http://www.eclipse.org/xtext/xbase/Xbase' from 'platform:/resource/org.eclipse.xtext.xbase/model/Xbase.genmodel'
717 [main] INFO clipse.emf.mwe.utils.GenModelHelper - Registered GenModel 'http://www.eclipse.org/xtext/common/JavaVMTypes' from 'platform:/resource/org.eclipse.xtext.common.types/model/JavaVMTypes.genmodel'
1904 [main] INFO lipse.emf.mwe.utils.StandaloneSetup - Adding generated EPackage 'org.eclipse.xtext.common.types.TypesPackage'
1916 [main] INFO ipse.emf.mwe.utils.DirectoryCleaner - Cleaning C:\Users\Robert Adam\Documents\eclipse.luna\workspace\raven.sqf\..\raven.sqf\src-gen
2076 [main] INFO ipse.emf.mwe.utils.DirectoryCleaner - Cleaning C:\Users\Robert Adam\Documents\eclipse.luna\workspace\raven.sqf\..\raven.sqf\model\generated
2077 [main] INFO ipse.emf.mwe.utils.DirectoryCleaner - Cleaning C:\Users\Robert Adam\Documents\eclipse.luna\workspace\raven.sqf\..\raven.sqf.ui\src-gen
2081 [main] INFO ipse.emf.mwe.utils.DirectoryCleaner - Cleaning C:\Users\Robert Adam\Documents\eclipse.luna\workspace\raven.sqf\..\raven.sqf.tests\src-gen
8449 [main] INFO clipse.emf.mwe.utils.GenModelHelper - Registered GenModel 'http://www.SQF.raven' from 'platform:/resource/raven.sqf/model/generated/SQF.genmodel'
164592 [main] INFO text.generator.junit.Junit4Fragment - generating Junit4 Test support classes
164692 [main] INFO text.generator.junit.Junit4Fragment - generating Compare Framework infrastructure
164707 [main] ERROR mf.mwe2.launch.runtime.Mwe2Launcher - Problems running workflow raven.GenerateSQF:
[ERROR]: GeneratorException: (Element: -UNKNOWN-; Reported by: Generator)
org.eclipse.emf.common.util.WrappedException: java.lang.reflect.InvocationTargetException
at org.eclipse.xtext.generator.parser.antlr.AntlrToolFacade.runWithEncodingAndParams(AntlrToolFacade.java:183)
at org.eclipse.xtext.generator.parser.antlr.XtextAntlrGeneratorFragment.generate(XtextAntlrGeneratorFragment.java:48)
at org.eclipse.xtext.generator.DefaultGeneratorFragment.generate(DefaultGeneratorFragment.java:167)
at org.eclipse.xtext.generator.CompositeGeneratorFragment.generate(CompositeGeneratorFragment.java:163)
at org.eclipse.xtext.generator.Generator.generate(Generator.java:555)
at org.eclipse.xtext.generator.Generator.invokeInternal(Generator.java:172)
at org.eclipse.emf.mwe.core.lib.AbstractWorkflowComponent.invoke(AbstractWorkflowComponent.java:126)
at org.eclipse.emf.mwe.core.lib.Mwe2Bridge.invoke(Mwe2Bridge.java:34)
at org.eclipse.emf.mwe.core.lib.AbstractWorkflowComponent.invoke(AbstractWorkflowComponent.java:201)
at org.eclipse.emf.mwe2.runtime.workflow.AbstractCompositeWorkflowComponent.invoke(AbstractCompositeWorkflowComponent.java:35)
at org.eclipse.emf.mwe2.runtime.workflow.Workflow.run(Workflow.java:19)
at org.eclipse.emf.mwe2.launch.runtime.Mwe2Runner.run(Mwe2Runner.java:102)
at org.eclipse.emf.mwe2.launch.runtime.Mwe2Runner.run(Mwe2Runner.java:62)
at org.eclipse.emf.mwe2.launch.runtime.Mwe2Runner.run(Mwe2Runner.java:52)
at org.eclipse.emf.mwe2.launch.runtime.Mwe2Launcher.run(Mwe2Launcher.java:78)
at org.eclipse.emf.mwe2.launch.runtime.Mwe2Launcher.main(Mwe2Launcher.java:36)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.xtext.generator.parser.antlr.AntlrToolFacade.runWithEncodingAndParams(AntlrToolFacade.java:173)
... 15 more
Caused by: java.lang.OutOfMemoryError: GC overhead limit exceeded
at java.util.HashMap.newTreeNode(Unknown Source)
at java.util.HashMap$TreeNode.putTreeVal(Unknown Source)
at java.util.HashMap.putVal(Unknown Source)
at java.util.HashMap.put(Unknown Source)
at java.util.HashSet.add(Unknown Source)
at org.antlr.misc.OrderedHashSet.add(OrderedHashSet.java:63)
at org.antlr.analysis.DFAState.addNFAConfiguration(DFAState.java:226)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:633)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:683)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:765)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:683)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:683)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:765)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:765)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:765)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:683)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
at org.antlr.analysis.NFAToDFAConverter.closure(NFAToDFAConverter.java:709)
My guess is that the problem is caused by an issue with the memory...Is this correct? And if so how can I avoid this?
Best regards Raven
回答1:
The GC throws this exception when too much time is spent in garbage collection for too little return, eg. 98% of CPU time is spent on GC and less than 2% of heap is recovered.
This feature is designed to prevent applications from running for an extended period of time while making little or no progress because the heap is too small.
You can either try to increase the size of the heap with -Xmx1g (sets the heap to 1 gigabyte)
Or you can just turn this off with the command line option -XX:-UseGCOverheadLimit which hides the symptom, but does not fix the problem.
This feature is detailed on here: http://www.oracle.com/technetwork/java/javase/gc-tuning-6-140523.html#par_gc.oom
来源：https://stackoverflow.com/questions/32022966/xtext-what-does-this-exception-mean