view contrib/showstack.py @ 43394:d359dfc15aca stable

fsmonitor: handle unicode keys in tuples

In Python 3, keys in the bset tuple are typically str, not
bytes. PyBytes_AsString() would return NULL. But we weren't
checking the return value and this would lead to a segfault.

This commit makes the code type and Python version aware. The
Python version specific code is to allow us to utilize a
modern API for converting str -> char* without having to
allocate an extra PyObject.

FWIW I wanted to assume that keys were always str. However,
there appear to be some bytes keys in some cases. I haven't
debugged this further.

Differential Revision: https://phab.mercurial-scm.org/D7210

# 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