view contrib/showstack.py @ 47024:8fcc0a829f3d

chg: pass --no-profile to disable profiling when starting hg serve

If profiling is enabled via global/user config (as far as I can tell, this
doesn't affect use of the --profile flag, but it probably does affect --config
profiling.enabled=1), then the profiling data can be *cumulative* for the
lifetime of the chg process.

This leads to some "interesting" results where hg claims the walltime is
something like 200s on a command that took only a second or two to run. Worse,
however, is that with at least some profilers (such as the default "stat"
profiler), this can cause a large slowdown while generating the profiler output.

Differential Revision: https://phab.mercurial-scm.org/D10470

# 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