Mercurial > hg
view mercurial/help/hgrc.5.txt @ 31956:c13ff31818b0
ui: add special-purpose atexit functionality
In spite of its longstanding use, Python's built-in atexit code is
not suitable for Mercurial's purposes, for several reasons:
* Handlers run after application code has finished.
* Because of this, the code that runs handlers swallows exceptions
(since there's no possible stacktrace to associate errors with).
If we're lucky, we'll get something spat out to stderr (if stderr
still works), which of course isn't any use in a big deployment
where it's important that exceptions get logged and aggregated.
* Mercurial's current atexit handlers make unfortunate assumptions
about process state (specifically stdio) that, coupled with the
above problems, make it impossible to deal with certain categories
of error (try "hg status > /dev/full" on a Linux box).
* In Python 3, the atexit implementation is completely hidden, so
we can't hijack the platform's atexit code to run handlers at a
time of our choosing.
As a result, here's a perfectly cromulent atexit-like implementation
over which we have control. This lets us decide exactly when the
handlers run (after each request has completed), and control what
the process state is when that occurs (and afterwards).
| author | Bryan O'Sullivan <bryano@fb.com> |
|---|---|
| date | Tue, 11 Apr 2017 14:54:12 -0700 |
| parents | 75149f84eac7 |
| children | 854a7315603e |
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====== hgrc ====== --------------------------------- configuration files for Mercurial --------------------------------- :Author: Bryan O'Sullivan <bos@serpentine.com> :Organization: Mercurial :Manual section: 5 :Manual group: Mercurial Manual .. contents:: :backlinks: top :class: htmlonly Description =========== .. include:: hgrc.5.gendoc.txt Author ====== Bryan O'Sullivan <bos@serpentine.com>. Mercurial was written by Matt Mackall <mpm@selenic.com>. See Also ======== |hg(1)|_, |hgignore(5)|_ Copying ======= This manual page is copyright 2005 Bryan O'Sullivan. Mercurial is copyright 2005-2017 Matt Mackall. Free use of this software is granted under the terms of the GNU General Public License version 2 or any later version. .. include:: common.txt