Mercurial > hg
diff mercurial/chgserver.py @ 45035:3862de62d5cf
chg: suppress OSError in _restoreio() and add some logging (issue6330)
According to issue6330, running chg on heavy loaded systems can lead to
following error:
```
Traceback (most recent call last):
File "path-to-hg/mercurial/commandserver.py", line 650, in _acceptnewconnection
self._runworker(conn)
File "path-to-hg/mercurial/commandserver.py", line 701, in _runworker
prereposetups=[self._reposetup],
File "path-to-hg/mercurial/commandserver.py", line 470, in _serverequest
sv.cleanup()
File "path-to-hg/mercurial/chgserver.py", line 381, in cleanup
self._restoreio()
File "path-to-hg/mercurial/chgserver.py", line 444, in _restoreio
os.dup2(fd, fp.fileno())
OSError: [Errno 16] Device or resource busy
```
[man dup2] indicates that, on Linux, EBUSY comes from a race condition
between open() and dup2().
However it's not clear why open() race occurred for newfd=stdin/out/err.
We suppress the OSError in _restoreio() since the forked worker process will
finish anyway and add some logging.
Thanks to Mitchell Plamann for a detailed bug description and Yuya Nishihara for
suggesting the fix.
author | Pulkit Goyal <7895pulkit@gmail.com> |
---|---|
date | Fri, 03 Jul 2020 13:45:59 +0530 |
parents | 8e8fd938ca07 |
children | a17454a189d1 |
line wrap: on
line diff
--- a/mercurial/chgserver.py Thu Jul 02 19:54:44 2020 +0200 +++ b/mercurial/chgserver.py Fri Jul 03 13:45:59 2020 +0530 @@ -442,7 +442,20 @@ if newfp is not fp: newfp.close() # restore original fd: fp is open again - os.dup2(fd, fp.fileno()) + try: + os.dup2(fd, fp.fileno()) + except OSError as err: + # According to issue6330, running chg on heavy loaded systems + # can lead to EBUSY. [man dup2] indicates that, on Linux, + # EBUSY comes from a race condition between open() and dup2(). + # However it's not clear why open() race occurred for + # newfd=stdin/out/err. + self.ui.log( + b'chgserver', + b'got %s while duplicating %s\n', + stringutil.forcebytestr(err), + fn, + ) os.close(fd) setattr(self, cn, ch) setattr(ui, fn, fp)