[jetty-discuss] Blocking on ContextLoader.loadClass

[Aaron M. <aar...@ho...>]

Greetings,

We are facing an issue whereby many threads seem to be waiting on the 
synchronized method ContextLoader.loadClass.  We are using Hibernate, and 
typical stack dumps look like the following two excerpts:

	at org.mortbay.http.ContextLoader.loadClass(ContextLoader.java:170)
	- waiting to lock <0x152dc3e8> (a org.mortbay.http.ContextLoader)
	at org.hibernate.util.ReflectHelper.classForName(ReflectHelper.java:102)
	at 
org.hibernate.impl.SessionFactoryImpl.getImplementors(SessionFactoryImpl.java:699)


	at org.mortbay.http.ContextLoader.loadClass(ContextLoader.java:170)
	- waiting to lock <0x152dc3e8> (a org.mortbay.http.ContextLoader)
	at antlr.ReflectHelper.classForName(ReflectHelper.java:17)
	at antlr.CharScanner.setTokenObjectClass(CharScanner.java:337)
	at org.hibernate.hql.ast.HqlLexer.setTokenObjectClass(HqlLexer.java:25)
	at antlr.CharScanner.<init>(CharScanner.java:51)
	at antlr.CharScanner.<init>(CharScanner.java:60)
	at org.hibernate.hql.antlr.HqlBaseLexer.<init>(HqlBaseLexer.java:55)


In my brief analysis, it seems as though ContextLoader.loadClass could 
simply be declared as not being syncrhonized.  I didn't see any of the 
underlying code that was not thread safe.  Also, it would seem to me that by 
convention the class loader that this method would be calling off to would 
by definition need to be thread safe.

Does anyone have any thoughts on changing this method to not be 
synchronized?  Is there something I've overlooked?

Thanks,

Aaron

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