getting some information from activity monitor in mac pro
The CPU% value shows how much CPU load a process generates. A value of 100% means that the process uses one CPU core fully. As all modern Macs use multi-core CPUs you can even see processes with more than 100% CPU load sometimes (requires the process to be written in a way to make use of several cores at once of course).

So in your case the process is running happily. What Activity Monitor doesn't show you though is whether the process just runs in an endless loop or whether it actually processes its data as you expect.