Message-ID: <39B28CA5.14799CC8@user.rose.com> From: April X-Mailer: Mozilla 4.7 [en]C-CCK-MCD {TLC;RETAIL} (Win95; U) X-Accept-Language: en MIME-Version: 1.0 Newsgroups: comp.os.msdos.djgpp Subject: tracking an elusive crash Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 40 Date: Sun, 03 Sep 2000 12:38:46 -0500 NNTP-Posting-Host: 205.189.215.4 X-Trace: client 967998751 205.189.215.4 (Sun, 03 Sep 2000 12:32:31 EDT) NNTP-Posting-Date: Sun, 03 Sep 2000 12:32:31 EDT Path: news.mv.net!newspeer.phoen-x.net!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed.skycache.com!Cidera!portc01.blue.aol.com!peerfeed.news.psi.net!psinr!client!not-for-mail Xref: news.mv.net comp.os.msdos.djgpp:103134 I am working with btree code based on a text book. I get an elusive crash that I cannot track down nor get any useful info post-crash. djgpp gcc version 2.95.2 19991024 win95 The worst crash reboots the computer, the second worst gives a fatal error 'you program has commited an illegal instruction'. Obviously in both cases there is no call stack to symify. I use a configuration file page size, and this is what makes the crash elusive. If I use 512 bytes or 2048 bytes, the program can add about 17000 words to the tree (with duplicates ignored), and then delete 16999 (I leave one for testing), without a problem. If I use a page size of 1024 (or just recently tried, 4096), I get the fatal crash during the delete test, several 100 (maybe a 1000 or more) words later. I have tried to run the program in dos mode (ie. booted to dos), but the GPF gives no callstack, and if I can believe the IP address, when I locate it in the map file I finaly created, it is inside libc.a(exceptn.o). I have tried to increase my internal buffer that corresponds to the page buffer, but too no avail; I tried to allocate larger memory blocks and put an indicator before/after and check for those upon release, too no avail. I tried to put an indicator at the start of all of my file blocks and verify this upon any read process, to no avail. HELP! What can I try? I though it might be from redirecting a large file for input and producing a large redirected stdout output, so I replaced the input with a direct file read - it still crashed. Suggestions? April