PEP 419: update from Paul.

pep-0419.txt

@@ -310,6 +310,9 @@ cleanup handlers, be prepared to handle ``InterruptedError``
 explicitly.  An example of such code might be a file-based lock
 implementation.
 
+:func:`signal.pthread_sigmask` can be used to block signals inside
+cleanup handlers which can be interrupted with ``EINTR``.
+
 
 Setting Interruption Context Inside Finally Itself
 --------------------------------------------------
@@ -500,6 +503,9 @@ References
 .. [4] Original discussion
    http://mail.python.org/pipermail/python-ideas/2012-April/014705.html
 
+.. [5] Issue #14730: Implementation of the PEP 419
+   http://bugs.python.org/issue14730
+
 
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