Hi Christian, Do you come across any discussion online about thread safety of libtiff? Have you got any further in resolving this issue?
I have lots of stuff in intray to deal with so can't personally chase up the issue right away so would appreciate if you can make some headway on. Cheers, Robert. On 3 December 2011 15:16, Christian Ehrlicher <ch.ehrlic...@gmx.de> wrote: > Hello, > > I'm experiencing crashes when I try to read tiff images / textures with osg. > When I use other image formats all seems to work fine. Since I'm using a lot > of threads I came to the conclusion that there's maybe a threading problem > inside ReaderWriterTIFF.cpp. So I wrote a small testcase (see attachment, > needs Qt) and valgrind --tool=helgrind gives me thisi answer: > > Code: > > ==20491== Possible data race during read of size 4 at 0x128e6270 by thread #4 > ==20491== at 0x126E2518: simage_tiff_load(std::istream&, int&, int&, int&, > unsigned short&) (ReaderWriterTIFF.cpp:748) > ==20491== by 0x126E3BF4: ReaderWriterTIFF::readImage(std::string const&, > osgDB::Options const*) const (ReaderWriterTIFF.cpp:793) > ==20491== by 0x4EEB3DD: > osgDB::Registry::ReadImageFunctor::doRead(osgDB::ReaderWriter&) const > (Registry.cpp:908) > ==20491== by 0x4EE67C8: osgDB::Registry::read(osgDB::Registry::ReadFunctor > const&) (Registry.cpp:1103) > ==20491== by 0x4EE76CA: > osgDB::Registry::readImplementation(osgDB::Registry::ReadFunctor const&, > osgDB::Options::CacheHintOptions) (Registry.cpp:1277) > ==20491== by 0x4EE7D44: > osgDB::Registry::readImageImplementation(std::string const&, osgDB::Options > const*) (Registry.cpp:1355) > ==20491== by 0x4EDBA30: osgDB::readImageFile(std::string const&, > osgDB::Options const*) (Registry:231) > ==20491== by 0x4019AB: MyThread::run() (in > /home/chehrlic/tds/osg-build-desktop-Qt_aus_PATH_Release/osg) > ==20491== by 0x68FC024: QThreadPrivate::start(void*) (qthread_unix.cpp:331) > ==20491== by 0x4C2A63D: ??? (in > /usr/lib64/valgrind/vgpreload_helgrind-amd64-linux.so) > ==20491== by 0x6D1BF04: start_thread (in /lib64/libpthread-2.14.1.so) > ==20491== by 0x778153C: clone (in /lib64/libc-2.14.1.so) > ==20491== This conflicts with a previous write of size 4 by thread #2 > ==20491== at 0x126E21E1: simage_tiff_load(std::istream&, int&, int&, int&, > unsigned short&) (ReaderWriterTIFF.cpp:652) > ==20491== by 0x126E3BF4: ReaderWriterTIFF::readImage(std::string const&, > osgDB::Options const*) const (ReaderWriterTIFF.cpp:793) > ==20491== by 0x4EEB3DD: > osgDB::Registry::ReadImageFunctor::doRead(osgDB::ReaderWriter&) const > (Registry.cpp:908) > ==20491== by 0x4EE67C8: osgDB::Registry::read(osgDB::Registry::ReadFunctor > const&) (Registry.cpp:1103) > ==20491== by 0x4EE76CA: > osgDB::Registry::readImplementation(osgDB::Registry::ReadFunctor const&, > osgDB::Options::CacheHintOptions) (Registry.cpp:1277) > ==20491== by 0x4EE7D44: > osgDB::Registry::readImageImplementation(std::string const&, osgDB::Options > const*) (Registry.cpp:1355) > ==20491== by 0x4EDBA30: osgDB::readImageFile(std::string const&, > osgDB::Options const*) (Registry:231) > ==20491== by 0x4019AB: MyThread::run() (in > /home/chehrlic/tds/osg-build-desktop-Qt_aus_PATH_Release/osg) > ==20491== > > > > The related piece of code is > > Code: > > currPtr = buffer + (h-1)*w*format; > > tifferror = ERR_NO_ERROR; // line 526 > > switch (pack(photometric, config)) > > > > And tifferror is a static variable which is accessed without a mutex (which > would also be wrong - the variable needs to be in the TLS). > > Is my observation correct? And If so - can someone fix it for me? ;-) > > /add > Looks like TiffSetError/WarningHandler needs also a mutex (Line 526 + 527) - > at least valgrind complains about a problem there too (inside tiff library). > > ------------------ > Read this topic online here: > http://forum.openscenegraph.org/viewtopic.php?p=44204#44204 > > > > > Attachments: > http://forum.openscenegraph.org//files/osg_tifftar_197.gz > > > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
