Re: org.apache.bcel.classfile.ClassFormatException: Invalid method signature...

Juozas Baliuka wrote:
> Are you sure this generator is thread safe ?
> 
> ----- Original Message -----
> From: "Neeme Praks" <[email protected]>
> To: "bcel-dev" <[email protected]>
> Sent: Tuesday, June 03, 2003 9:54 AM
> Subject: org.apache.bcel.classfile.ClassFormatException: Invalid method
> signature...
> 
> 
> 
>>Does anyone have any idea, under what circumstances the following error
>>could happen?
>>
>>Unable to create new instance
>>org.apache.bcel.classfile.ClassFormatException: Invalid method
>>signature:
>>
> 
> java/lang/Long;Ljava/lang/Long;Lcom/inpoc/srv/parameters/ServiceParameters;)
> V
> 
>>        at
>>org.apache.bcel.classfile.Utility.typeOfSignature(Utility.java:1024)


> org.apache.avalon.fortress.impl.handler.ThreadSafeComponentHandler.doPrepare
> (ThreadSafeComponentHandler.java:72)

I'm not familiar with Avalon, but BCEL really is not thread safe. Some 
of the methods in Utility use static variables. If two parts of a 
program both use BCEL (using the same ClassLoader context) then they'll 
have to coordinate amongst themselves not to use it at the same time.

>>The actual signature should be:
>>
> 
> (Lcom/inpoc/srv/messages/RequestMessage;Ljava/lang/Long;Ljava/lang/Long;Lcom
> /inpoc/srv/parameters/ServiceParameters;)V
> 
>>And the error is not really 100% reproduceable, sometimes it shows up,
>>sometimes not...

Certain sounds like a thread problem.

I have a large patch somewhere to fix BCELs static variable problems 
(amongst other things). When I work out how, I'll post it some time... 
In the mean time a quick synchronized around affected methods in BCEL 
should fix it.

Tom Hawtin
-- 
http://www.tackline.demon.co.uk/
Unemployed Java Developer of Central London.