- From: Kenneth Jacker <khj_at_be.cs.appstate.edu>
- Date: Thu, 28 Oct 2004 12:30:11 -0400
As long time members of these list know, I have used RTAI (RTLinux at first) and COMEDI for many years in my undergraduate/graduate "real-time systems" course. Though I and some graduate students have "experimented" with LXRT, most of our projects have used RTAI, kernel modules and Tcl/Tk -- *not* LXRT. Next semester I am considering using LXRT and COMEDI with Java as the GUI front end instead of Tcl/Tk. I know Java works using the "kernel modules approach" where multiple threads interact with RT FIFOs (to avoid blocking "issues") and the RT side is written in C. However, Paolo and others are encouraging the use of LXRT over the deprecated "kernel modules approach" for reasons that have been stated many times on the RTAI list. It appears that the LXRT/Java approach would require me and my students to write Java-callable routines in C for the actual, time- critical RT code. These "methods" themselves would invoke rt_make_hard_real_time(), rt_make_soft_real_time(), etc., and have to be written following the JNI (Java Native Interface). Compared to using the multiple thread/kernel modules approach described above, this would be a *lot* of work (unless someone else has already done it) and require learning JNI. Also, I'm not sure there wouldn't be problems (scheduling, timing, etc) with the JNI "RT methods" interacting with the Java virtual machine. Have others used LXRT, COMEDI and Java *without* kernel modules? I am *most* interested in hearing others' experiences, thoughts, suggestions, and/or comments ... Thanks! -- Prof Kenneth H Jacker khj_at_cs.appstate.edu Computer Science Dept www.cs.appstate.edu/~khj Appalachian State Univ Boone, NC 28608 USA
Received on 2004-10-28Z15:30:11