contrib/showstack.py

profiler: flush after writing the profiler output

Otherwise, the profiler output might only partially appears until the next flush
of the buffer. Since profiling often happens for long operation, the next flush
can be a long time away.

# 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