Python signal.setitimer() Examples

def sig_vtalrm(self, *args):
        self.hndl_called = True

        if self.hndl_count > 3:
            # it shouldn't be here, because it should have been disabled.
            raise signal.ItimerError("setitimer didn't disable ITIMER_VIRTUAL "
                "timer.")
        elif self.hndl_count == 3:
            # disable ITIMER_VIRTUAL, this function shouldn't be called anymore
            signal.setitimer(signal.ITIMER_VIRTUAL, 0)
            if test_support.verbose:
                print("last SIGVTALRM handler call")

        self.hndl_count += 1

        if test_support.verbose:
            print("SIGVTALRM handler invoked", args) 

def sig_vtalrm(self, *args):
        self.hndl_called = True

        if self.hndl_count > 3:
            # it shouldn't be here, because it should have been disabled.
            raise signal.ItimerError("setitimer didn't disable ITIMER_VIRTUAL "
                "timer.")
        elif self.hndl_count == 3:
            # disable ITIMER_VIRTUAL, this function shouldn't be called anymore
            signal.setitimer(signal.ITIMER_VIRTUAL, 0)
            if test_support.verbose:
                print("last SIGVTALRM handler call")

        self.hndl_count += 1

        if test_support.verbose:
            print("SIGVTALRM handler invoked", args) 

def test_itimer_prof(self):
        self.itimer = signal.ITIMER_PROF
        signal.signal(signal.SIGPROF, self.sig_prof)
        signal.setitimer(self.itimer, 0.2, 0.2)

        start_time = time.monotonic()
        while time.monotonic() - start_time < 60.0:
            # do some work
            _ = pow(12345, 67890, 10000019)
            if signal.getitimer(self.itimer) == (0.0, 0.0):
                break # sig_prof handler stopped this itimer
        else: # Issue 8424
            self.skipTest("timeout: likely cause: machine too slow or load too "
                          "high")

        # profiling itimer should be (0.0, 0.0) now
        self.assertEqual(signal.getitimer(self.itimer), (0.0, 0.0))
        # and the handler should have been called
        self.assertEqual(self.hndl_called, True) 

def test_itimer_virtual(self):
        self.itimer = signal.ITIMER_VIRTUAL
        signal.signal(signal.SIGVTALRM, self.sig_vtalrm)
        signal.setitimer(self.itimer, 0.3, 0.2)

        start_time = time.monotonic()
        while time.monotonic() - start_time < 60.0:
            # use up some virtual time by doing real work
            _ = pow(12345, 67890, 10000019)
            if signal.getitimer(self.itimer) == (0.0, 0.0):
                break # sig_vtalrm handler stopped this itimer
        else: # Issue 8424
            self.skipTest("timeout: likely cause: machine too slow or load too "
                          "high")

        # virtual itimer should be (0.0, 0.0) now
        self.assertEqual(signal.getitimer(self.itimer), (0.0, 0.0))
        # and the handler should have been called
        self.assertEqual(self.hndl_called, True)

    # Issue 3864, unknown if this affects earlier versions of freebsd also 

def test_itimer_prof(self):
        self.itimer = signal.ITIMER_PROF
        signal.signal(signal.SIGPROF, self.sig_prof)
        signal.setitimer(self.itimer, 0.2, 0.2)

        start_time = time.time()
        while time.time() - start_time < 60.0:
            # do some work
            _ = pow(12345, 67890, 10000019)
            if signal.getitimer(self.itimer) == (0.0, 0.0):
                break # sig_prof handler stopped this itimer
        else: # Issue 8424
            self.skipTest("timeout: likely cause: machine too slow or load too "
                          "high")

        # profiling itimer should be (0.0, 0.0) now
        self.assertEqual(signal.getitimer(self.itimer), (0.0, 0.0))
        # and the handler should have been called
        self.assertEqual(self.hndl_called, True) 

def test_itimer_prof(self):
        self.itimer = signal.ITIMER_PROF
        signal.signal(signal.SIGPROF, self.sig_prof)
        signal.setitimer(self.itimer, 0.2, 0.2)

        start_time = time.time()
        while time.time() - start_time < 60.0:
            # do some work
            _ = pow(12345, 67890, 10000019)
            if signal.getitimer(self.itimer) == (0.0, 0.0):
                break # sig_prof handler stopped this itimer
        else: # Issue 8424
            self.skipTest("timeout: likely cause: machine too slow or load too "
                          "high")

        # profiling itimer should be (0.0, 0.0) now
        self.assertEqual(signal.getitimer(self.itimer), (0.0, 0.0))
        # and the handler should have been called
        self.assertEqual(self.hndl_called, True) 

def start(self):
        self.last_profile_time = timer()

        if self.use_signal:
            try:
                signal.signal(signal.SIGALRM, self._signal)
                # the following tells the system to restart interrupted system calls if they are
                # interrupted before any data has been transferred. This avoids many of the problems
                # related to signals interrupting system calls, see issue #16
                signal.siginterrupt(signal.SIGALRM, False)
            except ValueError:
                raise NotMainThreadError()

            signal.setitimer(signal.ITIMER_REAL, self.interval, 0.0)
        else:
            sys.setprofile(self._profile) 

def run(self, profiler):
        weak_profiler = weakref.proxy(profiler)
        handle = functools.partial(self.handle_signal, weak_profiler)
        t = self.interval
        with deferral() as defer:
            prev_handle = signal.signal(signal.SIGPROF, handle)
            if prev_handle == signal.SIG_DFL:
                # sometimes the process receives SIGPROF although the sampler
                # unsets the itimer.  If the previous handler was SIG_DFL, the
                # process will crash when received SIGPROF.  To prevent this
                # risk, it makes the process to ignore SIGPROF when it isn't
                # running if the previous handler was SIG_DFL.
                prev_handle = signal.SIG_IGN
            defer(signal.signal, signal.SIGPROF, prev_handle)
            prev_itimer = signal.setitimer(signal.ITIMER_PROF, t, t)
            defer(signal.setitimer, signal.ITIMER_PROF, *prev_itimer)
            yield 

def set_blocking_signal_threshold(self, seconds, action):
        """Sends a signal if the ioloop is blocked for more than s seconds.

        Pass seconds=None to disable.  Requires python 2.6 on a unixy
        platform.

        The action parameter is a python signal handler.  Read the
        documentation for the python 'signal' module for more information.
        If action is None, the process will be killed if it is blocked for
        too long.
        """
        if not hasattr(signal, "setitimer"):
            #logging.error("set_blocking_signal_threshold requires a signal module "
            #           "with the setitimer method")
            ht.logger.error("set_blocking_signal_threshold requires a signal module "
                       "with the setitimer method")
            return
        self._blocking_signal_threshold = seconds
        if seconds is not None:
            signal.signal(signal.SIGALRM,
                          action if action is not None else signal.SIG_DFL) 

def sample(self, signum, frame):  #pylint: disable=unused-argument
        """Samples current stack and writes result in self._stats.

        Args:
            signum: Signal that activates handler.
            frame: Frame on top of the stack when signal is handled.
        """
        stack = []
        while frame and frame != self.base_frame:
            stack.append((
                frame.f_code.co_name,
                frame.f_code.co_filename,
                frame.f_code.co_firstlineno))
            frame = frame.f_back
        self._stats[tuple(stack)] += 1
        signal.setitimer(signal.ITIMER_PROF, _SAMPLE_INTERVAL) 

def sig_vtalrm(self, *args):
        self.hndl_called = True

        if self.hndl_count > 3:
            # it shouldn't be here, because it should have been disabled.
            raise signal.ItimerError("setitimer didn't disable ITIMER_VIRTUAL "
                "timer.")
        elif self.hndl_count == 3:
            # disable ITIMER_VIRTUAL, this function shouldn't be called anymore
            signal.setitimer(signal.ITIMER_VIRTUAL, 0)
            if test_support.verbose:
                print("last SIGVTALRM handler call")

        self.hndl_count += 1

        if test_support.verbose:
            print("SIGVTALRM handler invoked", args) 

def test_itimer_prof(self):
        self.itimer = signal.ITIMER_PROF
        signal.signal(signal.SIGPROF, self.sig_prof)
        signal.setitimer(self.itimer, 0.2, 0.2)

        start_time = time.time()
        while time.time() - start_time < 60.0:
            # do some work
            _ = pow(12345, 67890, 10000019)
            if signal.getitimer(self.itimer) == (0.0, 0.0):
                break # sig_prof handler stopped this itimer
        else: # Issue 8424
            self.skipTest("timeout: likely cause: machine too slow or load too "
                          "high")

        # profiling itimer should be (0.0, 0.0) now
        self.assertEqual(signal.getitimer(self.itimer), (0.0, 0.0))
        # and the handler should have been called
        self.assertEqual(self.hndl_called, True) 

def set_blocking_log_threshold(self, s):
        """Logs a stack trace if the ioloop is blocked for more than s seconds.
        Pass None to disable.  Requires python 2.6 on a unixy platform.
        """
        if not hasattr(signal, "setitimer"):
            logging.error("set_blocking_log_threshold requires a signal module "
                       "with the setitimer method")
            return
        self._blocking_log_threshold = s
        if s is not None:
            signal.signal(signal.SIGALRM, self._handle_alarm) 

def stop(self):
        if self.use_signal:
            signal.setitimer(signal.ITIMER_REAL, 0.0, 0.0)

            try:
                signal.signal(signal.SIGALRM, signal.SIG_IGN)
            except ValueError:
                raise NotMainThreadError()
        else:
            sys.setprofile(None) 

def timeout_setup(item):
    """Setup up a timeout trigger and handler."""
    params = get_params(item)
    if params.timeout is None or params.timeout <= 0:
        return
    if params.method == "signal":

        def handler(signum, frame):
            __tracebackhide__ = True
            timeout_sigalrm(item, params.timeout)

        def cancel():
            signal.setitimer(signal.ITIMER_REAL, 0)
            signal.signal(signal.SIGALRM, signal.SIG_DFL)

        item.cancel_timeout = cancel
        signal.signal(signal.SIGALRM, handler)
        signal.setitimer(signal.ITIMER_REAL, params.timeout)
    elif params.method == "thread":
        timer = threading.Timer(params.timeout, timeout_timer, (item, params.timeout))
        timer.name = "%s %s" % (__name__, item.nodeid)

        def cancel():
            timer.cancel()
            timer.join()

        item.cancel_timeout = cancel
        timer.start() 

def _signal(self, signum, frame):
        now = timer()
        time_since_last_signal = now - self.last_profile_time

        self._record(frame, time_since_last_signal)

        signal.setitimer(signal.ITIMER_REAL, self.interval, 0.0)
        self.last_profile_time = now 

def sig_vtalrm(self, *args):
        self.hndl_called = True

        if self.hndl_count > 3:
            # it shouldn't be here, because it should have been disabled.
            raise signal.ItimerError("setitimer didn't disable ITIMER_VIRTUAL "
                "timer.")
        elif self.hndl_count == 3:
            # disable ITIMER_VIRTUAL, this function shouldn't be called anymore
            signal.setitimer(signal.ITIMER_VIRTUAL, 0)

        self.hndl_count += 1 

def setAlarm(self, seconds):
            signal.setitimer(signal.ITIMER_REAL, seconds) 

def sig_prof(self, *args):
        self.hndl_called = True
        signal.setitimer(signal.ITIMER_PROF, 0) 

def stop_alarm(cls):
        signal.setitimer(signal.ITIMER_REAL, 0, 0) 

def test_itimer_real(self):
        self.itimer = signal.ITIMER_REAL
        signal.setitimer(self.itimer, 1.0)
        signal.pause()
        self.assertEqual(self.hndl_called, True)

    # Issue 3864, unknown if this affects earlier versions of freebsd also 

def sig_prof(self, *args):
        self.hndl_called = True
        signal.setitimer(signal.ITIMER_PROF, 0) 

def sig_vtalrm(self, *args):
        self.hndl_called = True

        if self.hndl_count > 3:
            # it shouldn't be here, because it should have been disabled.
            raise signal.ItimerError("setitimer didn't disable ITIMER_VIRTUAL "
                "timer.")
        elif self.hndl_count == 3:
            # disable ITIMER_VIRTUAL, this function shouldn't be called anymore
            signal.setitimer(signal.ITIMER_VIRTUAL, 0)

        self.hndl_count += 1 

def tearDown(self):
        signal.signal(signal.SIGALRM, self.old_alarm)
        if self.itimer is not None: # test_itimer_exc doesn't change this attr
            # just ensure that itimer is stopped
            signal.setitimer(self.itimer, 0) 

def setAlarm(self, seconds):
            signal.setitimer(signal.ITIMER_REAL, seconds) 

def _proc_worker_wrapper_helper(caplog, worker_class, args=None, expect_shutdown_evt=True, alarm_secs=1.0):
    startup_evt = mp.Event()
    shutdown_evt = mp.Event()
    event_q = MPQueue()
    if args is None:
        args = ()

    def alarm_handler(signal_num, current_stack_frame):
        shutdown_evt.set()

    if alarm_secs:
        signal.signal(signal.SIGALRM, alarm_handler)
        signal.setitimer(signal.ITIMER_REAL, alarm_secs)
    caplog.set_level(logging.DEBUG)
    exitcode = proc_worker_wrapper(worker_class, "TEST", startup_evt, shutdown_evt, event_q, *args)
    assert startup_evt.is_set()
    assert shutdown_evt.is_set() == expect_shutdown_evt
    items = list(event_q.drain())
    assert items
    last_item = items[-1]
    assert last_item.msg_src == "TEST"
    assert last_item.msg_type == "SHUTDOWN"
    assert last_item.msg == "Normal"
    assert exitcode == 0

    return items[:-1] 

def setup_death_penalty(self):
        """Sets up an alarm signal and a signal handler that raises
        a JobTimeoutException after the timeout amount (expressed in
        seconds).
        """
        signal.signal(signal.SIGALRM, self.handle_death_penalty)
        signal.setitimer(signal.ITIMER_REAL, self._timeout) 

def cancel(self):
        signal.setitimer(signal.ITIMER_REAL, 0) 

def __enter__(self):
        signal.signal(signal.SIGALRM, self.stop)
        if self.seconds > 0:
            signal.setitimer(signal.ITIMER_REAL, self.seconds)
        return self 

def set_blocking_signal_threshold(self, seconds, action):
        if not hasattr(signal, "setitimer"):
            gen_log.error("set_blocking_signal_threshold requires a signal module "
                          "with the setitimer method")
            return
        self._blocking_signal_threshold = seconds
        if seconds is not None:
            signal.signal(signal.SIGALRM,
                          action if action is not None else signal.SIG_DFL)