Pig does not use multiple threads for executing the udf (at least in
versions so far, and i haven't seen any proposals to change that).
So you don't need to deal with synchronization issues. But if you are
using a static variables, remember that there can be multiple instances
of the udf - one for each place in the pig-latin script where you use
the udf.
-Thejas
On 12/20/11 3:32 PM, Rohini U wrote:
Hi,
I am using a static HashMap in EvalUDF which needs configuration, so I am
initializing it in exec method checking if it is null
@Override
public String exec(Tuple input) throws IOException {
if(dict== null){
dict=MyDictionary.getInstance(UDFContext.getUDFContext().getJobConf());
}
// Other piece of code here
}
Now, in the getInstance method, do I have to take care of any thread
synchronization issues? Is there a chance that multiple threads access it?
Thanks,
-Rohini
