[click] userlevel multi-threads

Hi All,

I am new to click. I want to use multi-threading in userlevel. I enabled
and put -j 2 in command line, and am using test.click. However, thread_id=0
always calls run_task and processes the packets, but thread_id=1 appears in
RouterThread, but then is not called at all from run_task in
infinitesource. thread_id=1 even disappeared after calling twice. This is
consistent. I could not figure out why thread_id=1 disappeared. There is no
signal delivered to the thread (checked), it seems naturally gone.

Can anybody help?

Thank you,

Jinho