view mercurial/help/hgignore.5.txt @ 35460:8652ab4046e4

osutil: add a function to unblock signals

Signals could be blocked by something like:

  #include <unistd.h>
  #include <signal.h>
  int main(int argc, char * const argv[]) {
    sigset_t set;
    sigfillset(&set);
    sigprocmask(SIG_BLOCK, &set, NULL);
    execv("/bin/hg", argv);
    return 0;
  }

One of the problems is if SIGCHLD is blocked, chgserver would not reap
zombie workers since it depends on SIGCHLD handler entirely.

While it's the parent process to blame but it seems a good idea to just
unblock the signal from hg. FWIW git does that for SIGPIPE already [1].

Unfortunately Python 2 does not reset or provide APIs to change signal
masks. Therefore let's add one in osutil. Note: Python 3.3 introduced
`signal.pthread_sigmask` which solves the problem.

`sigprocmask` is part of POSIX [2] so there is no feature testing in
`setup.py`.

[1]: https://github.com/git/git/commit/7559a1be8a0afb10df41d25e4cf4c5285a5faef1
[2]: http://pubs.opengroup.org/onlinepubs/7908799/xsh/sigprocmask.html

Differential Revision: https://phab.mercurial-scm.org/D1736

==========
 hgignore
==========

---------------------------------
syntax for Mercurial ignore files
---------------------------------

:Author:         Vadim Gelfer <[e-mail]>
:Organization:   Mercurial
:Manual section: 5
:Manual group:   Mercurial Manual

.. include:: hgignore.5.gendoc.txt

Author
======
Vadim Gelfer <[e-mail]>

Mercurial was written by Matt Mackall <[e-mail]>.

See Also
========
|hg(1)|_, |hgrc(5)|_

Copying
=======
This manual page is copyright 2006 Vadim Gelfer.
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