2018-07-17 6:18 GMT+02:00 Radim Řehůřek <ra...@rare-technologies.com>: > one of our Python projects calls for pretty heavy, low-level optimizations. > > We went down the rabbit hole and determined that having access to > PyList_GET_ITEM(list), PyInt_AS_LONG(int) and PyDict_GetItem(dict, unicode) > on Python objects **outside of GIL** might be a good-enough solution. The > Python objects in question are guaranteed to live and not be mutated > externally in any way. They're "frozen" and read-only.
IMHO it's a great path to introduce very tricky race conditions in multithreaded applications! :-) At the C level, even immutable Python objects are mutable: str, tuple, etc. IMHO you need a different approach to implement optimizations. For example, use your objects which don't rely on the GIL to be consistent. Sadly, I have no experience with that and so cannot provide any example. Python releases the GIL *often* and pass pointers to buffers to C functions. For example, os.stat() writes into a memory block allocated by Python. But it's a raw memory block, it's much simpler than a Python object like a tuple. Victor _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
