Hi Robert, Unfortunately serializing the access to getenv() is not likely to solve the issue. The problem is not that OSG calls several getenv() in parallel, the problem is that getenv() should not be called *at all* in DllMain().
Serializing getenv() in OSG does not guarantee that another C function will not be called in another thread unrelated to OSG. In fact, this is exactly what is happening to us. Wrt to Daniel's suggestion, it's a variant of the double checked locking, which is unfortunately subtly broken (cf. previous post). Regards, Tanguy -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Robert Osfield Sent: 06 August 2009 12:48 To: OpenSceneGraph Users Subject: Re: [osg-users] Deadlock when loading osg.dll, singletons are evil Hi Tanguy, I was wondering about the possibility of wrapping up the access to the sensitive C functions using a Mutex. We couldn't do it in local code, but would need to do it via a single custom getenv() etc. function implementation, otherwise we'd still end up with multiple functions potentially accessing standard C functions like getenv in a parallel. Like Daniel's suggestion of moving the Mutex into the getenv init avoiding the overuse of the locking the mutex, doing the lock in central function would also achieve this aim. So perhaps we co do something like: static Mutex s_mutex; const char* serialized_getenv(const char* str) { ScopedLock lock(s_mutex); return getenv(str); } void* serialized_otherSensitiveCFunction(...) { ScopedLock lock(s_mutex); return otherSensitiveCFunction(...); } Then all the init code would call these methods. Note the implementations would all be in the .cpp's. Thoughts? Robert. _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.or g _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
