~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2006, 2007 Canonical Ltd

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""Blackbox tests for debugger breakin"""

import errno

import os

import signal

import subprocess

import sys

import time

from bzrlib import (

    errors,

    tests,

    )

class TestBreakin(tests.TestCase):

    # FIXME: If something is broken, these tests may just hang indefinitely in

    # wait() waiting for the child to exit when it's not going to.

    def setUp(self):

        if sys.platform == 'win32':

            raise tests.TestSkipped('breakin signal not tested on win32')

        super(TestBreakin, self).setUp()

    def _dont_SIGQUIT_on_darwin(self):

        if sys.platform == 'darwin':

            # At least on Leopard and with python 2.6, this test will raise a

            # popup window asking if the python failure should be reported to

            # Apple... That's not the point of the test :) Marking the test as

            # not applicable Until we find a way to disable that intrusive

            # behavior... --vila20080611

            raise tests.TestNotApplicable(

                '%s raises a popup on OSX' % self.id())

    def _wait_for_process(self, pid, sig=None):

        # We don't know quite how long waiting for the process 'pid' will take,

        # but if it's more than 10s then it's probably not going to work.

        for i in range(100):

            time.sleep(0.1)

            if sig is not None:

                os.kill(pid, sig)

            # Use WNOHANG to ensure we don't get blocked, doing so, we may

            # leave the process continue after *we* die...

            try:

                # note: waitpid is different on win32, but this test only runs

                # on unix

                pid_killed, returncode = os.waitpid(pid, os.WNOHANG)

                if (pid_killed, returncode) != (0, 0):

                    if sig is not None:

                        # high bit in low byte says if core was dumped; we

                        # don't care

                        status, sig = (returncode >> 8, returncode & 0x7f)

                        return True, sig

            except OSError, e:

                if e.errno in (errno.ECHILD, errno.ESRCH):

                    # The process doesn't exist anymore

                    return True, None

                else:

                    raise

        return False, None

    # port 0 means to allocate any port

    _test_process_args = ['serve', '--port', 'localhost:0']

    def test_breakin(self):

        # Break in to a debugger while bzr is running

        # we need to test against a command that will wait for

        # a while -- bzr serve should do

        proc = self.start_bzr_subprocess(self._test_process_args,

                env_changes=dict(BZR_SIGQUIT_PDB=None))

        # wait for it to get started, and print the 'listening' line

        proc.stderr.readline()

        # first sigquit pops into debugger

        os.kill(proc.pid, signal.SIGQUIT)

        # Wait for the debugger to acknowledge the signal reception

        err = proc.stderr.readline()

        self.assertContainsRe(err, r'entering debugger')

        # Now that the debugger is entered, we can ask him to quit

        proc.stdin.write("q\n")

        # We wait a bit to let the child process handles our query and avoid

        # triggering deadlocks leading to hangs on multi-core hosts...

        dead, sig = self._wait_for_process(proc.pid)

        if not dead:

            # The process didn't finish, let's kill it before reporting failure

            dead, sig = self._wait_for_process(proc.pid, signal.SIGKILL)

            if dead:

                raise tests.KnownFailure(

                    "subprocess wasn't terminated, it had to be killed")

            else:

                self.fail("subprocess %d wasn't terminated by repeated SIGKILL",

                          proc.pid)

    def test_breakin_harder(self):

        """SIGQUITting twice ends the process."""

        self._dont_SIGQUIT_on_darwin()

        proc = self.start_bzr_subprocess(self._test_process_args,

                env_changes=dict(BZR_SIGQUIT_PDB=None))

        # wait for it to get started, and print the 'listening' line

        proc.stderr.readline()

        # break into the debugger

        os.kill(proc.pid, signal.SIGQUIT)

        # Wait for the debugger to acknowledge the signal reception (since we

        # want to send a second signal, we ensure it doesn't get lost by

        # validating the first get received and produce its effect).

        err = proc.stderr.readline()

        self.assertContainsRe(err, r'entering debugger')

        dead, sig = self._wait_for_process(proc.pid, signal.SIGQUIT)

        self.assertTrue((dead and sig == signal.SIGQUIT),

                        msg="subprocess wasn't terminated by repeated SIGQUIT")

    def test_breakin_disabled(self):

        self._dont_SIGQUIT_on_darwin()

        proc = self.start_bzr_subprocess(self._test_process_args,

                env_changes=dict(BZR_SIGQUIT_PDB='0'))

        # wait for it to get started, and print the 'listening' line

        proc.stderr.readline()

        # first hit should just kill it

        os.kill(proc.pid, signal.SIGQUIT)

        proc.wait()