There's one thing we didn't foresee from the beginning, which is apparently TLS is only available in OSX starting from version 10.7, and we still do support of 10.6. After recent Brecht's changes about locked viewport while initializing BI render this TLS is not needed in trunk anymore. So reverting this chunk of base iteration to use static variable. But leaving all the other static variables warped into context still, it should help a bit in the future refactor. Real fix would be to have some kind of graph context evaluation structure which would be passing to update routines (which will solve threaded mballs update) and making depsgraph responsible for getting a motherball. But this is all for GSoC project.