Steve Holden <[EMAIL PROTECTED]> writes: > You write as though the GIL was invented to get in the programmer's > way, which is quite wrong. It's there to avoid deep problems with > thread interaction. Languages that haven't bitten that bullet can bite > you in quite nasty ways when you write threaded applications.
And yet, Java programmers manage to write threaded applications all day long without getting bitten (once they're used to the issues), despite usually being less skilled than Python programmers ;-). > Contrary to your apparent opinion, the GIL has nothing to do with > reference-counting. I think it does, i.e. one of the GIL's motivations was to protect the management of reference counts in CPython, which otherwise wasn't thread-safe. The obvious implementation of Py_INCREF has a race condition, for example. The GIL documentation at http://docs.python.org/api/threads.html describes this in its very first paragraph. > > Will the madness never end? > > This reveals an opinion of the development team that's altogether too > low. I believe the GIL was introduced for good reasons. The GIL was an acceptable tradeoff when it was first created in the previous century. First of all, it gave a way to add threads to the existing, non-threadsafe CPython implementation without having to rework the old code too much. Second, Python was at that time considered a "scripting language" and there was less concern about writing complex apps in it, especially multiprocessing apps. Third, multiprocessor computers were themselves exotic, so people who wanted to program them probably had exotic problems that they were willing to jump through hoops to solve. These days, even semi-entry-level consumer laptop computers have dual core CPU's, and quad Opteron boxes (8-way multiprocessing using X2 processors) are quite affordable for midrange servers or engineering workstations, and there's endless desire to write fancy server apps completely in Python. There is no point paying for all that multiprocessor hardware if your programming language won't let you use it. So, Python must punt the GIL if it doesn't want to keep presenting undue obstacles to writing serious apps on modern hardware. -- http://mail.python.org/mailman/listinfo/python-list
