From: Philip J. <re...@bu...> - 2008-04-17 06:04:32
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New submission from Philip Jenvey <pj...@us...>: CPython .pyc files include the modified time of the .py file it was created from. CPython then knows that the .pyc is up to date by comparing the .py's mtime against the .pyc's stored value Jython doesn't store this value in $py.class, all it does is compare the $py.class's mtime against .py on the filesystem This doesn't seem like a big deal but it makes us incompatible with CPython I ran into a situation where this caused a hard to diagnose problem: a test would generate a sample.py file and invoke a separate process to import it. Then it would copy a different version of the same sample.py file over, and invoke another process that imported it. The first $py.class generated actually ended up having the same mtime as the second .py that was copied over. Because we only compare the mtimes of the files themselves, Jython assumed the bytecode was up to date when it wasn't, the second .py wasn't compiled/used (causing a very weird bug) In this situation in CPython, the first .pyc might have the same mtime as the second .py, like our situation above in Jython, but CPython would actually be comparing the second .py's mtime against the mtime of the first .py, which in this situation were reliably different. We need to work this way too to avoid surprises like this with code written for CPython ---------- components: Core keywords: test failure causes messages: 3157 nosy: pjenvey severity: normal status: open title: Jython $py.class bytecode doesn't include the .py's mtime type: behaviour _______________________________________ Jython tracker <re...@bu...> <http://bugs.jython.org/issue1024> _______________________________________ |