loki@physics.mcgill.ca (Loki Jorgenson Rm421) (08/18/90)
Hey ho..... I have been suffering with symptoms which I can't trace to an algorithmic error. I am wondering if it isn't a system bug of some strange sort. On a 4D/25 running IRIXv3.2.1, I have been running a simple program which reads in a 2D array of values, +1/-1, opens a window and draws the rectangular array by coloring a pixel if +1 and leaving it black if -1. Strangely enough, I have been encountering a problem wherein the program crashes, reporting a graphics error #2 OUTMEM (and a couple of #75 NOWINOPEN after that) and leaving a core. Dbx shows the reason for the crash to be a segmentation fault. This may seem obvious to many but the hitch is this: This only happens on certain size arrays, typically my smaller ones! For example, 72x72 sized systems. For larger systems, like 192x192, I have no problems. Dbx has narrowed the offending subrountine down to my call "ortho2()" and eventually to the internal graphics call "i_ortho2()". Repeated examinations of the core, the code and the results have yielded very little consistent info upon which to define the source of the problem. I have used edge to trace the program and check variable values but nothing has appeared to be amiss. Note that there are a couple of malloc()'s in my program but I have no reason to suspect that there is actually a shortage of memory; the machine has 16M and the cores are actually quite small.... about 30k. Has anyone had any similar experiences? Thanks, Loki Jorgenson node: loki@physics.mcgill.ca Physics, McGill University fax: (514) 398-3733 Montreal Quebec CANADA phone: (514) 398-6531 << If I only had a brain >>