Feature Requests item #1497532, was opened at 2006-05-30 14:58 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=355470&aid=1497532&group_id=5470
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Extension Modules Group: None Status: Open Resolution: None Priority: 5 Submitted By: Martin Gfeller (gfe) Assigned to: Nobody/Anonymous (nobody) Summary: C API to retain GIL during Python Callback Initial Comment: [Split off from closed 1453341, which desired a Python- level API. This request is for a C API, to be used in C extensions that call back into Python.] I think it would be very useful to have an API that would tell Python not to release the GIL during call backs to Python code, until it is told again (back in C code) that it is ok to do so. I'd like to quote Tim Peters, who explains it better than me (private conversation, June 2005): ---------- It would be more feasible to patch Python, introducing a way to tell the interpreter not to allow other _Python_ threads to run. It has such a mechanism already (the GIL -- the global interpreter lock), but as soon as C code calls back into Python, the interpreter may release the GIL and give ownership of it to a different thread. I think it would be pretty easy to introduce a Python C API to say "don't allow other Python threads to run until I tell you otherwise". ---------- The Use Case arose with a multi-threading problem in ZODB's Connection, where the C code must ensure that no other thread runs Python code accessing an object BUT the own thread needs to call back into Python. Any other mechanism that came to my mind would either require to halt *all* others threads, or run into race conditions. Best regards, Martin Gfeller ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=355470&aid=1497532&group_id=5470 _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
