On Tue, Feb 8, 2011 at 12:59 PM, Corinna Vinschen wrote: > On Feb 7 22:38, marco atzeri wrote: >> I am testing latest release candidate for octave, and only on cygwin using >> the fltk graphics interface when we try to print through ghostscript we have: >> >> octave 4236 E:\cygwin2\bin\octave-3.3.92.exe: *** fatal error - >> Internal error: TP_NUM_C_BUFS too small: 79987540 > 10 > > This message points to a stack corruption. There's a thread-local > storage in the highest area of the thread local stack. In this TLS area > are a couple of buffer pointers which point to mallocated storage. > There are up to 10 of the "C_BUF" pointers and a counter which contains > the number of used pointers. That counter has the value 79987540, which > looks *very* wrong.
I was sure . > >> Stack trace: >> Frame Function Args >> 0022CF90 6102773B (0022CF90, 00000000, 00000000, 00000000) >> 0022D280 6102773B (6117CC60, 00008000, 00000000, 6117E997) >> 0022E2B0 61004E5B (611C978C, 04C48354, 0000000A, 0022E4E4) >> 0022E2D0 610EF554 (0022F578, 00000001, 00000000, 00000000) >> 0022F5A0 61096D4F (61208220, 0002625A, 00001000, 000BF399) >> 011AE3F4 610225C2 (6F2F6572, 76617463, 2E332F65, 32392E33) >> End of stack trace >> Hangup >> >> This is on latest cygwin snapshot, but it crash on any version release. > > So this occurs on 1.7.7 as well? any 1.7.x or snapshots that I tested in the last 6 months, since fltk 1.1.10-1 was available. This crash always happens, and it seems a specific cygwin only issue. >> I suspect the error message is a red herring. Am I right ? > > Yes, it is. The problem is that the stackdump is not very helpful > to find the cause. The information you can gather is where the problem > is encountered, but it doesn't show what overwrote the TLS area. > >> The plot is built as expected, so gs is doing its work; from strace output >> (available on http://matzeri.altervista.org/works/octave/) > > There's nothing in octave_fltk.strace which points to any kind of > problem. thanks for looking > >> I guess that gs execution is unable to return back on octave. >> >> Suggestion for debugging ? > > Build the Cygwin DLL for debugging (just -g, no -O2), build octave for > debugging, and try to find the problem. > > What I can see from the stack dump is that it happens when trying to > open a file. If you find the Cygwin call (probably, but not necessarily > open()) from octave in which the problem is encountered, you can narrow > down the problem to somewhere between this call and the previous > file-related call since all of these calls access the TLS buffers. From > there it's detective work. Maybe a watchpoint on the aforementioned > counter helps (class tls_pathbuf, member c_cnt). > > This is pretty tricky to find, I fear. Time to learn serious gdb debugging. > > > Corinna > thanks Marco -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
