Message 78952 - Python tracker

Haypo, we can probably reduce overhead by defining ENTER_HASHLIB like this:

#define ENTER_HASHLIB(obj) \
    if ((obj)->lock) { \
        if (!PyThread_acquire_lock((obj)->lock, 0)) { \
            Py_BEGIN_ALLOW_THREADS \
            PyThread_acquire_lock((obj)->lock, 1); \
            Py_END_ALLOW_THREADS \
        } \
    }