What are these processes doing?

[Ken Teague]

I have two processes running on a Linux box that are consuming quite a
lot of CPU time.  I ran strace -p on the main program itself and it shows:
  futex(0x9fd7ef8, FUTEX_WAIT, 1, NULL

The main program also uses java, so I ran strace -p on the java process
ID and see:
futex(0xb7f88bd8, FUTEX_WAIT, 2352, NULL

Is this enough information to see what they're doing?  It's been like
this since last night.  I'm confused, but that's probably because I
don't know enough about this type of output. :-(

- Ken