Thread safety issue in LoggingEvent (1.3 code)

[Paul Smith <ps...@aconex.com>]

Umm, am I missing something or is this thread unsafe in LoggingEvent?

  static final Integer[] PARAM_ARRAY = new Integer[1];

....
in readLevel(ObjectInputStream){.
....
         PARAM_ARRAY[0] = new Integer(p);
         level = (Level)m.invoke(null, (Object[]) PARAM_ARRAY);

Is there some synchronization done here?  If not, wouldn't the  
PARAM_ARRAY be shared?  If this was the case and one had multiple  
Receivers reading data from multiple sources, then there is a  
possibility of data corruption?

Thoughts?

Paul

Re: Thread safety issue in LoggingEvent (1.3 code)

[Curt Arnold <ca...@apache.org>]

Looks like it to me, also appears in the 1.2 branch.

Is className typically null, resulting in the offending path only  
taken with a custom level?  If not, could checks for  
"org.apache.log4j.Level" and "org.apache.log4j.Priority" avoiding the  
reflection overhead except where really needed?

I've got to think the cost of a "new Integer[1]" in anything later  
than JDK 1.1 has got to be trivial compared to the method invocation  
overhead.  Unfortunately, you can't eliminate PARAM_ARRAY since it  
wasn't declared private, but you aren't required to use it.  You  
should mark it deprecated however.


On Dec 1, 2005, at 11:39 PM, Paul Smith wrote:

> Umm, am I missing something or is this thread unsafe in LoggingEvent?
>
>  static final Integer[] PARAM_ARRAY = new Integer[1];
>
> ....
> in readLevel(ObjectInputStream){.
> ....
>         PARAM_ARRAY[0] = new Integer(p);
>         level = (Level)m.invoke(null, (Object[]) PARAM_ARRAY);
>
> Is there some synchronization done here?  If not, wouldn't the  
> PARAM_ARRAY be shared?  If this was the case and one had multiple  
> Receivers reading data from multiple sources, then there is a  
> possibility of data corruption?
>
> Thoughts?
>
> Paul


---------------------------------------------------------------------
To unsubscribe, e-mail: log4j-dev-unsubscribe@logging.apache.org
For additional commands, e-mail: log4j-dev-help@logging.apache.org