OutOfMemoryError: Java heap space

[Rafael Angarita]

Hello everybody,

I'm writing a code generator as an Eclipse plugin using the framework Xtext for developing my DSL. My test project consist of 15000 source files. After doing some optimization specific to Xtext, I keep running into java.lang.OutOfMemoryError: Java heap space when I iterate over the objects representing my source files.

I'm learnig about GC and its related JVM parameters. Im trying this run configuration:

-Dosgi.requiredJavaVersion=1.5
-Xms2000m
-Xmx2000m
-verbosegc
-XX:+PrintGCDetails 
-XX:+HeapDumpOnOutOfMemoryError 
-XX:+UseConcMarkSweepGC
-XX:+CMSIncrementalMode
-XX:+CMSIncrementalPacing
-XX:CMSInitiatingOccupancyFraction=5
-XX:MaxTenuringThreshold=150 
-XX:+UseCMSInitiatingOccupancyOnly

At first, It seems to go very well with an acceptable speed, but after awhile I get:

[GC [ParNew (promotion failed): 29504K->29504K(29504K), 0.1049370 secs]
[CMS[CMS-concurrent-abortable-preclean: 0.048/0.218 secs]
[Times: user=0.17 sys=0.01, real=0.21 secs] 
 (concurrent mode failure)[Unloading class sun.reflect.GeneratedConstructorAccessor16]
[Unloading class sun.reflect.GeneratedMethodAccessor9]
[Unloading class sun.reflect.GeneratedMethodAccessor2]
[Unloading class sun.reflect.GeneratedConstructorAccessor20]
[Unloading class sun.reflect.GeneratedMethodAccessor4]
[Unloading class sun.reflect.GeneratedConstructorAccessor5]
[Unloading class sun.reflect.GeneratedMethodAccessor19]
[Unloading class sun.reflect.GeneratedConstructorAccessor15]
[Unloading class sun.reflect.GeneratedConstructorAccessor14]
[Unloading class sun.reflect.GeneratedMethodAccessor15]
[Unloading class sun.reflect.GeneratedConstructorAccessor12]
[Unloading class sun.reflect.GeneratedMethodAccessor8]
[Unloading class sun.reflect.GeneratedMethodAccessor17]
[Unloading class sun.reflect.GeneratedConstructorAccessor10]
[Unloading class sun.reflect.GeneratedConstructorAccessor18]
[Unloading class sun.reflect.GeneratedMethodAccessor3]
[Unloading class sun.reflect.GeneratedConstructorAccessor26]
[Unloading class sun.reflect.GeneratedConstructorAccessor7]
[Unloading class sun.reflect.GeneratedConstructorAccessor28]
[Unloading class sun.reflect.GeneratedConstructorAccessor9]
[Unloading class sun.reflect.GeneratedConstructorAccessor17]
[Unloading class sun.reflect.GeneratedMethodAccessor16]
[Unloading class sun.reflect.GeneratedConstructorAccessor29]
[Unloading class sun.reflect.GeneratedConstructorAccessor25]
[Unloading class sun.reflect.GeneratedConstructorAccessor27]
[Unloading class sun.reflect.GeneratedConstructorAccessor6]
[Unloading class sun.reflect.GeneratedConstructorAccessor19]
[Unloading class sun.reflect.GeneratedConstructorAccessor24]
[Unloading class sun.reflect.GeneratedConstructorAccessor11]
[Unloading class sun.reflect.GeneratedMethodAccessor18]
[Unloading class sun.reflect.GeneratedConstructorAccessor8]

After it, the application gets really slow, and eventually I get:

 (concurrent mode failure): 2015231K->2015214K(2015232K), 26.9962260 secs] 2044735K->2043623K(2044736K), 
[CMS Perm : 50571K->50571K(85880K)] icms_dc=100 , 26.9963260 secs] 
[Times: user=26.92 sys=0.07, real=27.00 secs] 
java.lang.OutOfMemoryError: Java heap space
	at org.eclipse.core.internal.jobs.JobListeners.newEvent(JobListeners.java:66)
	at org.eclipse.core.internal.jobs.JobListeners.aboutToRun(JobListeners.java:142)
	at org.eclipse.core.internal.jobs.JobManager.startJob(JobManager.java:1466)
	at org.eclipse.core.internal.jobs.WorkerPool.startJob(WorkerPool.java:218)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:50)
Exception in thread "State Data Manager" java.lang.OutOfMemoryError: Java heap space
	at org.eclipse.osgi.internal.resolver.StateImpl.getBundles(StateImpl.java:222)
	at org.eclipse.osgi.internal.resolver.StateImpl.unloadLazyData(StateImpl.java:890)
	at org.eclipse.osgi.internal.baseadaptor.StateManager.run(StateManager.java:326)
	at java.lang.Thread.run(Thread.java:636)

I know "promotion failed" has to do with the generations of living objects, but I have experimented with different parameters for the Run Congifuration with no success.

I would really appreciate your help!

Thank you very much.

[Ramon Anger]

Hi Rafael,

which JVM and which OS do you use?

Ramon