On Tue, Apr 20, 2010 at 3:48 PM, Jean-Baptiste Quenot <[email protected]> wrote: > Hi there, > > First, thanks for the great piece of software! > > I am a happy user of Shapely since a few years, but since I upgraded > my server to Ubuntu 9.10 I notice the following message everytime I my > Python application ends: > > *** glibc detected *** python: double free or corruption (!prev): > 0x00000000018839b0 *** > > Also, the process hangs and never completes. This problem is > particularly painful when Python is run as a CGI within Apache, as > HTTP requests will never complete. Otherwise on the command-line, I > just issue a CTRL-C to stop it. > > Software that has changed during the Ubuntu upgrade includes: > > * Python, from 2.6.2 to 2.6.4 > * Libgeos, from 3.0.0 to 3.1.0 > > I tried to upgrade shapely from 1.0.11 to 1.0.14 with no luck. > > Note that I also use python-mapscript, the package that comes with > mapserver, also using libgeos. I verified that only one version of > libgeos is installed and used. > > Here is the gdb backtrace during the hang: > > #0 __lll_lock_wait_private () at > ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:97 > #1 0x00007f238c6c7b11 in _L_lock_9274 () from /lib/libc.so.6 > #2 0x00007f238c6c5741 in *__GI___libc_free (mem=0x7f238c9b5e40) at > malloc.c:3714 > #3 0x00007f238d48ab32 in _dl_scope_free (old=0xf6e5b0) at dl-open.c:175 > #4 0x00007f238d485035 in _dl_map_object_deps (map=0x7f238d697530, > preloads=<value optimized out>, npreloads=<value optimized out>, > trace_mode=<value optimized out>, open_mode=<value optimized out>) at > dl-deps.c:668 > #5 0x00007f238d48ada3 in dl_open_worker (a=<value optimized out>) at > dl-open.c:326 > #6 0x00007f238d486386 in _dl_catch_error (objname=<value optimized > out>, errstring=<value optimized out>, mallocedp=<value optimized > out>, operate=<value optimized out>, args=<value optimized out>) at > dl-error.c:178 > #7 0x00007f238d48a6c7 in _dl_open (file=0x7f238c77e2ae > "libgcc_s.so.1", mode=-2147483647, caller_dlopen=0x0, nsid=-2, argc=1, > argv=0x18, env=0xafed90) at dl-open.c:615 > #8 0x00007f238c767c00 in do_dlopen (ptr=0x7ffff3913b10) at dl-libc.c:86 > #9 0x00007f238d486386 in _dl_catch_error (objname=<value optimized > out>, errstring=<value optimized out>, mallocedp=<value optimized > out>, operate=<value optimized out>, args=<value optimized out>) at > dl-error.c:178 > #10 0x00007f238c767d57 in dlerror_run (name=<value optimized out>, > mode=<value optimized out>) at dl-libc.c:47 > #11 *__GI___libc_dlopen_mode (name=<value optimized out>, mode=<value > optimized out>) at dl-libc.c:160 > #12 0x00007f238c7426e5 in init () at ../sysdeps/x86_64/../ia64/backtrace.c:41 > #13 0x00007f238d2687a3 in pthread_once () at > ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_once.S:94 > #14 0x00007f238c7427e4 in *__GI___backtrace (array=<value optimized > out>, size=64) at ../sysdeps/x86_64/../ia64/backtrace.c:79 > #15 0x00007f238c6b6cab in __libc_message (do_abort=<value optimized > out>, fmt=<value optimized out>) at > ../sysdeps/unix/sysv/linux/libc_fatal.c:168 > #16 0x00007f238c6c0dd6 in malloc_printerr (action=3, > str=0x7f238c7827b0 "double free or corruption (!prev)", ptr=<value > optimized out>) at malloc.c:6217 > #17 0x00007f238c6c574c in *__GI___libc_free (mem=<value optimized > out>) at malloc.c:3716 > #18 0x00007f2384a5130b in msGEOSCleanup () from > /usr/lib/python2.6/dist-packages/_mapscript.so > #19 0x00007f2384969fda in msCleanup () from > /usr/lib/python2.6/dist-packages/_mapscript.so > #20 0x00000000004c2cc2 in call_ll_exitfuncs () at ../Python/pythonrun.c:1705 > #21 Py_Finalize () at ../Python/pythonrun.c:534 > #22 0x00000000004185c2 in Py_Main (argc=<value optimized out>, > argv=<value optimized out>) at ../Modules/main.c:625 > #23 0x00007f238c669abd in __libc_start_main (main=<value optimized > out>, argc=<value optimized out>, ubp_av=<value optimized out>, > init=<value optimized out>, fini=<value optimized out>, > rtld_fini=<value optimized out>, stack_end=0x7ffff3914738) at > libc-start.c:220 > #24 0x0000000000417ca9 in _start () at ../sysdeps/x86_64/elf/start.S:113 > > I have no clue where the problem comes from, however, when I edit the > installed python2.6/shapely/geos.py module and comment the cleanup > code, Python does not crash anymore: > > def cleanup(): > if lgeos is not None: > pass > #lgeos.finishGEOS() > > Any idea? Your help will be much appreciated.
Hi Jean-Baptiste, I suspect at-exit cleanup collision: mapscript's msCleanup is freeing some memory allocated by libgeos and when Shapely exits, cleanup() attempts to free that same memory. I've created a ticket in the tracker: http://trac.gispython.org/lab/ticket/217 If you've anything to add, please register and do so. In the meanwhile, do not use Shapely with mapscript. Mapscript provides most of the functionality if not such a handy API. Cheers, -- Sean _______________________________________________ Community mailing list [email protected] http://lists.gispython.org/mailman/listinfo/community
