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| -rw-r--r-- | Doc/whatsnew/3.3.rst | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/Doc/whatsnew/3.3.rst b/Doc/whatsnew/3.3.rst index 6fb60af..fe1a84a 100644 --- a/Doc/whatsnew/3.3.rst +++ b/Doc/whatsnew/3.3.rst @@ -573,6 +573,23 @@ Some smaller changes made to the core Python language are: .. XXX mention new error messages for passing wrong number of arguments to functions +A Finer-Grained Import Lock +=========================== + +Previous versions of CPython have always relied on a global import lock. +This led to unexpected annoyances, such as deadlocks when importing a module +would trigger code execution in a different thread as a side-effect. +Clumsy workarounds were sometimes employed, such as the +:c:func:`PyImport_ImportModuleNoBlock` C API function. + +In Python 3.3, importing a module takes a per-module lock. This correctly +serializes importation of a given module from multiple threads (preventing +the exposure of incompletely initialized modules), while eliminating the +aforementioned annoyances. + +(contributed by Antoine Pitrou in :issue:`9260`.) + + New and Improved Modules ======================== |