view mercurial/lsprofcalltree.py @ 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

"""
lsprofcalltree.py - lsprof output which is readable by kcachegrind

Authors:
    * David Allouche <david <at> allouche.net>
    * Jp Calderone & Itamar Shtull-Trauring
    * Johan Dahlin

This software may be used and distributed according to the terms
of the GNU General Public License, incorporated herein by reference.
"""

from __future__ import absolute_import, print_function

def label(code):
    if isinstance(code, str):
        return '~' + code    # built-in functions ('~' sorts at the end)
    else:
        return '%s %s:%d' % (code.co_name,
                             code.co_filename,
                             code.co_firstlineno)

class KCacheGrind(object):
    def __init__(self, profiler):
        self.data = profiler.getstats()
        self.out_file = None

    def output(self, out_file):
        self.out_file = out_file
        print('events: Ticks', file=out_file)
        self._print_summary()
        for entry in self.data:
            self._entry(entry)

    def _print_summary(self):
        max_cost = 0
        for entry in self.data:
            totaltime = int(entry.totaltime * 1000)
            max_cost = max(max_cost, totaltime)
        print('summary: %d' % max_cost, file=self.out_file)

    def _entry(self, entry):
        out_file = self.out_file

        code = entry.code
        if isinstance(code, str):
            print('fi=~', file=out_file)
        else:
            print('fi=%s' % code.co_filename, file=out_file)
        print('fn=%s' % label(code), file=out_file)

        inlinetime = int(entry.inlinetime * 1000)
        if isinstance(code, str):
            print('0 ', inlinetime, file=out_file)
        else:
            print('%d %d' % (code.co_firstlineno, inlinetime), file=out_file)

        # recursive calls are counted in entry.calls
        if entry.calls:
            calls = entry.calls
        else:
            calls = []

        if isinstance(code, str):
            lineno = 0
        else:
            lineno = code.co_firstlineno

        for subentry in calls:
            self._subentry(lineno, subentry)
        print(file=out_file)

    def _subentry(self, lineno, subentry):
        out_file = self.out_file
        code = subentry.code
        print('cfn=%s' % label(code), file=out_file)
        if isinstance(code, str):
            print('cfi=~', file=out_file)
            print('calls=%d 0' % subentry.callcount, file=out_file)
        else:
            print('cfi=%s' % code.co_filename, file=out_file)
            print('calls=%d %d' % (
                subentry.callcount, code.co_firstlineno), file=out_file)

        totaltime = int(subentry.totaltime * 1000)
        print('%d %d' % (lineno, totaltime), file=out_file)