#129 pix_image assertion fail crashes pd

[Winfried Ritsch]

using pd0.43-test4 and Gem latest trunk of today pix_image crashes on loading an image
using imagemagick-dev:

#0 0xb7fe2424 in __kernel_vsyscall ()
#1 0xb7d75751 in *__GI_raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#2 0xb7d78b82 in *__GI_abort () at abort.c:92
#3 0xb7d6e8b8 in *__GI___assert_fail (assertion=0xb6e5f680 "semaphore_info != (SemaphoreInfo *) ((void *)0)", file=0xb6e5f66c "magick/semaphore.c", line=525,
function=0xb6e5f751 "LockSemaphoreInfo") at assert.c:81
#4 0xb6d0be5c in LockSemaphoreInfo () from /usr/lib/libGraphicsMagick.so.3
#5 0xb6cd809e in GetMagickInfo () from /usr/lib/libGraphicsMagick.so.3
#6 0xb6cd3e1b in SetImageInfo () from /usr/lib/libGraphicsMagick.so.3
#7 0xb6c8cc5a in ReadImage () from /usr/lib/libGraphicsMagick.so.3
#8 0xb6f62ee6 in Magick::Image::read(std::string const&) () from /usr/lib/libGraphicsMagick++.so.3
#9 0xb71940b0 in magickImage2mem (filename=0xb474320c "/usr/local/lib/pd/extra/Gem/somefile.jpg") at GemPixImageLoad.cpp:738
#10 0xb71942ef in image2mem (filename=0x85c1db0 "/usr/local/lib/pd/extra/Gem/somefile.jpg") at GemPixImageLoad.cpp:128
#11 0xb7248a1d in pix_image::openThread (you=0x85c1820) at pix_image.cpp:165
#12 0xb7eb8955 in start_thread (arg=0xb4743b70) at pthread_create.c:300
#13 0xb7e16e7e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:130

OS: i386 squeeze stable Debian (just updated)

Used pix_image-help patch.

mfg winfried

[Winfried Ritsch]

compiling Gem with --without-ImageMagick doesnt crash so it is definitily ImageMagick with cloned process.

image.read( filename );

so library is not thread save.

[IOhannes m zmölnig]

this is really weird, as i never experienced anything like this.
i'm pretty sure that ImageMagick _is_ thread safe, and i'm using libmagick++-dev (8:6.6.0.4-3) all the time without problems (seems like the same version is in squeeze-wheezy-sid right now)

does it help if you use [thread 0, open <myimage>( ?