view contrib/showstack.py @ 51572:13c004b54cbe stable

wireprotoserver: ensure that output stream gets flushed on exception

Previously flush was happening due to Python finalizer being run on
`BufferedWriter`. With upgrade to Python 3.11 this started randomly
failing.

My guess is that the finalizer on the raw `FileIO` object may
be running before the finalizer of `BufferedWriter` has a chance to run.

At any rate, since we're not relying on finalizers in the happy case
we should also not rely on them in case of exception.

# 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