Message960

notice that we want the synchronization. Although it makes no strong promises about what happens
with implementations withouh the GIL, Python style is influenced by the presence of the GIL in CPython
this means that builtin types should have an "atomic" behavior.

Now the are dissenting opionions (http://effbot.org/pyfaq/what-kinds-of-global-value-mutation-are-thread-safe.htm) on this but the bottom line (because it has happened) is that if we
miss some synchronized related to some of the listed ops, someone will ends up filing a bug because some code is not behaving like on CPython. We had this kind of reports from experienced Pythoneers (for example some twisted contributors), and telling them to add more locks themself doesn't really work or scale in practice, because is too
annoying especially if the code is to run on top CPython primarely.