Hi,

I noticed crashing in dotosg wrappers when try to use osgDB::readNodeFile from 
multiple threads.
Crash occurs when I try to load .osg file from two threads.

For example callstack of crashed thread:
osg80_osgDB!concrete_wrapper::matches+0x4
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readObjectOfType+0x527
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readObjectOfType+0x28
osgdb_deprecated_osg!Drawable_readLocalData+0xa1
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readObject+0x8fb
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readDrawable+0xe1
osgdb_deprecated_osg!Geode_readLocalData+0x90
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readObject+0x8fb
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readNode+0xe1
osgdb_deprecated_osg!Group_readLocalData+0x71
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readObject+0x8fb
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readNode+0xe1
osgdb_deprecated_osg!Group_readLocalData+0x71
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readObject+0x8fb
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readNode+0xe1
osgdb_osg!OSGReaderWriter::readNode+0xfe
osgdb_osg!OSGReaderWriter::readNode+0x31c
osg80_osgDB!osgDB::Registry::ReadNodeFunctor::doRead+0x28
osg80_osgDB!osgDB::Registry::read+0x5e4
osg80_osgDB!osgDB::Registry::readImplementation+0x34c
osg80_osgDB!osgDB::Registry::readNodeImplementation+0x6a
osg80_osgDB!osgDB::Registry::readNode+0xfc
osg80_osgDB!osgDB::readNodeFile+0x4e
[...]

second thread callstack:
msvcp90!std::basic_istream<char,std::char_traits<char>
msvcp90!std::basic_istream<char,std::char_traits<char>
osg80_osgDB!osgDB::FieldReader::_readField+0x3f8
osg80_osgDB!osgDB::FieldReaderIterator::field+0x19d
osgdb_deprecated_osg!Array_readLocalData+0xbfb
osgdb_deprecated_osg!Geometry_readLocalData+0x991
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readObject+0x8fb
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readDrawable+0xe1
osgdb_deprecated_osg!Geode_readLocalData+0x90
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readObject+0x8fb
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readNode+0xe1
osgdb_deprecated_osg!Group_readLocalData+0x71
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readObject+0x8fb
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readNode+0xe1
osgdb_deprecated_osg!Group_readLocalData+0x9a
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readObject+0x8fb
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readNode+0xe1
osgdb_deprecated_osg!Group_readLocalData+0x9a
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readObject+0x8fb
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readNode+0xe1
osgdb_deprecated_osg!Group_readLocalData+0x71
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readObject+0x8fb
osg80_osgDB!osgDB::DeprecatedDotOsgWrapperManager::readNode+0xe1
osgdb_osg!OSGReaderWriter::readNode+0xfe
osgdb_osg!OSGReaderWriter::readNode+0x31c
osg80_osgDB!osgDB::Registry::ReadNodeFunctor::doRead+0x28
osg80_osgDB!osgDB::Registry::read+0x5e4
osg80_osgDB!osgDB::Registry::readImplementation+0x34c
osg80_osgDB!osgDB::Registry::readNodeImplementation+0x6a
osg80_osgDB!osgDB::Registry::readNode+0xfc
osg80_osgDB!osgDB::readNodeFile+0x4e
[...]

code:
struct concrete_wrapper: basic_type_wrapper
{
    virtual ~concrete_wrapper() {}
    concrete_wrapper(const osg::Object *myobj) : myobj_(myobj) {}
    bool matches(const osg::Object *proto) const
    {
        return myobj_->isSameKindAs(proto);  <<<<<<<<<<<<<<<<<CRASH HERE<<<<<<<
    }
    const osg::Object *myobj_;
};

crash occurs because myobj_ is NULL.

myobj_ passed from osgdb_deprecated_osg!Drawable_readLocalData as s_drawstate

bool Drawable_readLocalData(Object& obj, Input& fr)
{
    bool iteratorAdvanced = false;

    Drawable& drawable = static_cast<Drawable&>(obj);

    static ref_ptr<StateSet> s_drawstate = new osg::StateSet;
    if (StateSet* readState = 
static_cast<StateSet*>(fr.readObjectOfType(*s_drawstate)))
    {
        drawable.setStateSet(readState);
        iteratorAdvanced = true;
    }
[...]


so problem is in
    static ref_ptr<StateSet> s_drawstate = new osg::StateSet;

MSVC 2008 x64 compiler (maybe gcc too) generate this code as:

static bool s_drawstate_init = false;
static ref_ptr<StateSet> s_drawstate = NULL;

bool Drawable_readLocalData(Object& obj, Input& fr)
{
    bool iteratorAdvanced = false;

    Drawable& drawable = static_cast<Drawable&>(obj);

    if(!s_drawstate_init)
    {
        s_drawstate_init = true;
        s_drawstate = new osg::StateSet;
    }

    if (StateSet* readState = 
static_cast<StateSet*>(fr.readObjectOfType(*s_drawstate)))
    {
        drawable.setStateSet(readState);
        iteratorAdvanced = true;
    }
[...]


and this code is not thread safe as you can see.

Possible solution is to move static variables to global scope to avoid lazy 
initialization.


Mikhail.
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