Lots of RUNNABLE threads in java.lang.Class.getEnclosingMethod0(Native Method)
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I've been taking thread dumps of our system to troubleshoot various problems, and one thing I've noticed is that in good times and bad, we have a lot of things like this in the thread dump:

    "TP-Processor59" - Thread t@915
       java.lang.Thread.State: RUNNABLE
    	at java.lang.Class.getEnclosingMethod0(Native Method)
    	at java.lang.Class.getEnclosingMethodInfo(Class.java:929)
    	at java.lang.Class.getEnclosingClass(Class.java:1081)
    	at java.lang.Class.getSimpleBinaryName(Class.java:1220)
    	at java.lang.Class.getSimpleName(Class.java:1112)

Now, we do make a lot of calls to getSimpleName(), which our config system relies on.  But my question is why do they always get caught in this particular method?  This is a Windows JVM, 1.6.0_29, 64-bit.

I feel like getSimpleName() should in general be a very fast call.  Is this most likely getEnclosingMethod0() is somehow very slow, or is it possible that that native method is somehow blocking on something (which would, of course, not show up in the JVM thread dump)?