java - Xtext:这个异常是什么意思？

Question

我有一个 Xtext 语法，当我尝试生成 Xtext 工件时，它会抛出以下异常(它开始并最终抛出异常)。
我的大纲(前几行):

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)

我的猜测是该问题是由内存问题引起的...这是正确的吗？如果是这样我怎样才能避免这种情况？

最诚挚的问候乌鸦

Answer 1

当垃圾收集花费太多时间而返回太少时，GC 会抛出此异常，例如。 98% 的 CPU 时间花费在 GC 上，只有不到 2% 的堆被回收。

此功能旨在防止应用程序长时间运行，但由于堆太小而几乎没有进展。

您可以尝试使用 -Xmx1g 增加堆的大小(将堆设置为 1 GB)

或者您可以使用命令行选项 -XX:-UseGCOverheadLimit 关闭此功能，该选项会隐藏症状，但不会解决问题。

此功能的详细信息请参见:http://www.oracle.com/technetwork/java/javase/gc-tuning-6-140523.html#par_gc.oom