view contrib/showstack.py @ 49192:2ab79873786e

auto-upgrade: introduce a way to auto-upgrade to/from share-safe

This is the first "automatic-upgrade" capability. In the following commits,
similar features are coming for other "fast to upgrade" formats.

This is different from the `safe-mismatch.source-not-safe` and
`safe-mismatch.source-safe` configuration that deal with mismatch between a
share and its share-source. Here we are dealing with mismatch between a
repository configuration and its actual format.

We will need further work for cases were the repository cannot be locked. A
basic protection is in place to avoid  a infinite loop for now, but it will get
proper attention in a later changeset.

Differential Revision: https://phab.mercurial-scm.org/D12611

# 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)
"""

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