Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!asuvax!ncar!gatech!mcnc!uvaarpa!polaris.cv.nrao.edu!polaris.cv.nrao.edu!dwells From: dwells@fits.cx.nrao.edu (Don Wells) Newsgroups: comp.realtime Subject: Re: Summary of opinions and info on realtime kernels (long) Message-ID: Date: 12 Jun 91 04:12:04 GMT References: <577@ceco.ceco.com> Sender: news@polaris.cv.nrao.edu (News Manager) Organization: National Radio Astronomy Observatory, Charlottesville, VA Lines: 36 In-Reply-To: sung@ceco.ceco.com's message of 10 Jun 91 18: 32:16 GMT In article <577@ceco.ceco.com> sung@ceco.ceco.com (Sung Han) writes: ... Good point - multitask debugging is a strong point of RTSource. XRAY+ and VxGDB normally follow a single task at a time, and don't offer any multiprocessor debugging features (I think)... I have done multitask debugging under vxWorks. I have used the dbxWorks package, as sold by Sun Consulting, under SunView. With dbxWorks it is trivial to do multitask debugging. The manuals never talk about it, because it is obvious! Just pop open a window with another instance of dbxtool (yes, the standard SunOS windowed source-level debugger) and connect it to the second task running under vxWorks (the dbxWorks package hacks dbx to support remote debugging). If the tasks interact in a critical region you can walk both of them up to the region, and then walk them through it, issueing commands to the respective tasks and debuggers by simply moving the mouse from one window to the other, and watching the results of the interaction in the respective windows. I have not yet done this with two tasks in two different processors, but I can't see any reason at all why it shouldn't work in exactly the same way. I have not yet examined vxGDB, but I expect that the same considerations will apply to it. GDB is not yet an X-windowed tool, but dbxWorks gives lots of hints about what the developers should do... In summary, in 1991 with windows on every desk, why should we bother to build multi-task capability into a single-task debugger when we can just pop open another window and run a completely independent instance of the debugger? -- Donald C. Wells Associate Scientist dwells@nrao.edu National Radio Astronomy Observatory +1-804-296-0277 Edgemont Road Fax= +1-804-296-0278 Charlottesville, Virginia 22903-2475 USA 78:31.1W, 38:02.2N