annotate contrib/showstack.py @ 42423:0ae593e791fb

profiling: show actual time spent in hotpath display

To get, for instance:

...
 \  6.6%  4.08s  lock.py:        __exit__          line 1566: ...
   |  6.5%  4.01s  exchange.py:    close           line 1191: ...
   |  6.5%  4.01s  transaction.py: _active         line 1443: ...
   |  6.5%  4.01s  transaction.py: close           line 47:   ...
   |  6.2%  3.84s  scmutil.py:     wrapped         line 529:  ...
   |  6.2%  3.81s  localrepo.py:   wrapper         line 2114: ...
   |  6.2%  3.81s  localrepo.py:   updatecaches    line 177:  ...
   ...

instead of:

...
 \  6.6%  lock.py:        __exit__          line 1566: ...
   |  6.5%  exchange.py:    close           line 1191: ...
   |  6.5%  transaction.py: _active         line 1443: ...
   |  6.5%  transaction.py: close           line 47:   ...
   |  6.2%  scmutil.py:     wrapped         line 529:  ...
   |  6.2%  localrepo.py:   wrapper         line 2114: ...
   |  6.2%  localrepo.py:   updatecaches    line 177:  ...
   ...

I find that if it's not displayed, I frequently end up estimating the
numbers by hand.

Differential Revision: https://phab.mercurial-scm.org/D6477

# showstack.py - extension to dump a Python stack trace on signal
#
# binds to both SIGQUIT (Ctrl-\) and SIGINFO (Ctrl-T on BSDs)
r"""dump stack trace when receiving SIGQUIT (Ctrl-\) or SIGINFO (Ctrl-T on BSDs)
"""

from __future__ import absolute_import, print_function
import signal
import sys
import traceback

def sigshow(*args):
    sys.stderr.write("\n")
    traceback.print_stack(args[1], limit=10, file=sys.stderr)
    sys.stderr.write("----\n")

def sigexit(*args):
    sigshow(*args)
    print('alarm!')
    sys.exit(1)

def extsetup(ui):
    signal.signal(signal.SIGQUIT, sigshow)
    signal.signal(signal.SIGALRM, sigexit)
    try:
        signal.signal(signal.SIGINFO, sigshow)
    except AttributeError:
        pass