Python threading._MainThread() Examples

def _set_SIGCHLD_handler():
    # Windows doesn't support SIGCHLD handler
    if sys.platform == 'win32':
        return
    # can't set signal in child threads
    if not isinstance(threading.current_thread(), threading._MainThread):
        return
    global _SIGCHLD_handler_set
    if _SIGCHLD_handler_set:
        return
    previous_handler = signal.getsignal(signal.SIGCHLD)
    if not callable(previous_handler):
        previous_handler = None

    def handler(signum, frame):
        # This following call uses `waitid` with WNOHANG from C side. Therefore,
        # Python can still get and update the process status successfully.
        _error_if_any_worker_fails()
        if previous_handler is not None:
            previous_handler(signum, frame)

    signal.signal(signal.SIGCHLD, handler)
    _SIGCHLD_handler_set = True 

def _set_SIGCHLD_handler():
    # Windows doesn't support SIGCHLD handler
    if sys.platform == 'win32':
        return
    # can't set signal in child threads
    if not isinstance(threading.current_thread(), threading._MainThread):
        return
    global _SIGCHLD_handler_set
    if _SIGCHLD_handler_set:
        return
    previous_handler = signal.getsignal(signal.SIGCHLD)
    if not callable(previous_handler):
        previous_handler = None

    def handler(signum, frame):
        # This following call uses `waitid` with WNOHANG from C side. Therefore,
        # Python can still get and update the process status successfully.
        _error_if_any_worker_fails()
        if previous_handler is not None:
            previous_handler(signum, frame)

    signal.signal(signal.SIGCHLD, handler)
    _SIGCHLD_handler_set = True 

def call_on_qt_thread(func):
    @functools.wraps(func)
    def _call_on_qt_thread_wrapper(*args, **kwargs):
        # If the current thread is the main thread, which is the Qt thread, directly call the function.
        current_thread = threading.current_thread()
        if isinstance(current_thread, threading._MainThread):
            return func(*args, **kwargs)

        def _handle_call(ico, *args, **kwargs):
            ico.result = func(*args, **kwargs)
            ico.finish_event.set()
        inter_call_object = InterCallObject()
        new_args = tuple([inter_call_object] + list(args)[:])
        CuraApplication.getInstance().callLater(_handle_call, *new_args, **kwargs)
        inter_call_object.finish_event.wait()
        return inter_call_object.result
    return _call_on_qt_thread_wrapper 

def _set_SIGCHLD_handler():
    # Windows doesn't support SIGCHLD handler
    if sys.platform == "win32":
        return
    # can't set signal in child threads
    if not isinstance(threading.current_thread(), threading._MainThread):
        return
    global _SIGCHLD_handler_set
    if _SIGCHLD_handler_set:
        return
    previous_handler = signal.getsignal(signal.SIGCHLD)
    if not callable(previous_handler):
        previous_handler = None

    def handler(signum, frame):
        # This following call uses `waitid` with WNOHANG from C side. Therefore,
        # Python can still get and update the process status successfully.
        #  C._error_if_any_worker_fails()
        if previous_handler is not None:
            previous_handler(signum, frame)

    signal.signal(signal.SIGCHLD, handler)
    _SIGCHLD_handler_set = True 

def _set_SIGCHLD_handler():
    # Windows doesn't support SIGCHLD handler
    if sys.platform == 'win32':
        return
    # can't set signal in child threads
    if not isinstance(threading.current_thread(), threading._MainThread):
        return
    global _SIGCHLD_handler_set
    if _SIGCHLD_handler_set:
        return
    previous_handler = signal.getsignal(signal.SIGCHLD)
    if not callable(previous_handler):
        previous_handler = None

    def handler(signum, frame):
        # This following call uses `waitid` with WNOHANG from C side. Therefore,
        # Python can still get and update the process status successfully.
        #  C._error_if_any_worker_fails()
        if previous_handler is not None:
            previous_handler(signum, frame)

    signal.signal(signal.SIGCHLD, handler)
    _SIGCHLD_handler_set = True 

def _set_SIGCHLD_handler():
    # Windows doesn't support SIGCHLD handler
    if sys.platform == 'win32':
        return
    # can't set signal in child threads
    if not isinstance(threading.current_thread(), threading._MainThread):
        return
    global _SIGCHLD_handler_set
    if _SIGCHLD_handler_set:
        return
    previous_handler = signal.getsignal(signal.SIGCHLD)
    if not callable(previous_handler):
        previous_handler = None

    def handler(signum, frame):
        # This following call uses `waitid` with WNOHANG from C side. Therefore,
        # Python can still get and update the process status successfully.
        _error_if_any_worker_fails()
        if previous_handler is not None:
            previous_handler(signum, frame)

    signal.signal(signal.SIGCHLD, handler)
    _SIGCHLD_handler_set = True 

def _set_SIGCHLD_handler():
    # Windows doesn't support SIGCHLD handler
    if sys.platform == 'win32':
        return
    # can't set signal in child threads
    if not isinstance(threading.current_thread(), threading._MainThread):
        return
    global _SIGCHLD_handler_set
    if _SIGCHLD_handler_set:
        return
    previous_handler = signal.getsignal(signal.SIGCHLD)
    if not callable(previous_handler):
        previous_handler = None

    def handler(signum, frame):
        # This following call uses `waitid` with WNOHANG from C side. Therefore,
        # Python can still get and update the process status successfully.
        _error_if_any_worker_fails()
        if previous_handler is not None:
            previous_handler(signum, frame)

    signal.signal(signal.SIGCHLD, handler)
    _SIGCHLD_handler_set = True 

def is_main_thread():
    if six.PY2:
        return isinstance(threading.current_thread(), threading._MainThread)
    else:
        # a nicer solution with py3
        return threading.current_thread() == threading.main_thread() 

def __enter__(self):
            if not isinstance(threading.current_thread(), threading._MainThread):
                logging.warning("timeout only works on main thread, are you running pyspider in threads?")
                self.seconds = 0
            if self.seconds:
                signal.signal(signal.SIGALRM, self.handle_timeout)
                signal.alarm(int(math.ceil(self.seconds))) 

def is_main_thread():
    """returns true if we are within the main thread"""
    cur_thread = threading.current_thread()
    if sys.version_info >= (3, 4):
        return cur_thread is threading.main_thread()
    else:
        # noinspection PyUnresolvedReferences
        return isinstance(cur_thread, threading._MainThread)


# noinspection PyPep8Naming 

def inside_main_thread():
        in_main_thread = isinstance(threading.current_thread(), threading._MainThread)
        return in_main_thread 

def check():
        """
            The actual checker.
        """

        try:  # for Python > 3.4
            res = threading.current_thread() is threading.main_thread()
        except AttributeError:
            res = isinstance(threading.current_thread(), threading._MainThread)

        return res 

def effective_n_jobs(self, n_jobs):
        """Determine the number of jobs which are going to run in parallel.

        This also checks if we are attempting to create a nested parallel
        loop.
        """
        if mp is None:
            return 1

        if mp.current_process().daemon:
            # Daemonic processes cannot have children
            if n_jobs != 1:
                warnings.warn(
                    'Multiprocessing-backed parallel loops cannot be nested,'
                    ' setting n_jobs=1',
                    stacklevel=3)
            return 1

        if not isinstance(threading.current_thread(), threading._MainThread):
            # Prevent posix fork inside in non-main posix threads
            warnings.warn(
                'Multiprocessing-backed parallel loops cannot be nested'
                ' below threads, setting n_jobs=1',
                stacklevel=3)
            return 1

        return super(MultiprocessingBackend, self).effective_n_jobs(n_jobs) 

def test_is_main_thread():
    from _pydevd_bundle.pydevd_utils import is_current_thread_main_thread
    from _pydevd_bundle.pydevd_utils import dump_threads
    if not is_current_thread_main_thread():
        error_msg = 'Current thread does not seem to be a main thread. Details:\n'
        current_thread = threading.current_thread()
        error_msg += 'Current thread: %s\n' % (current_thread,)

        if hasattr(threading, 'main_thread'):
            error_msg += 'Main thread found: %s\n' % (threading.main_thread(),)
        else:
            error_msg += 'Current main thread not instance of: %s (%s)' % (
                threading._MainThread, current_thread.__class__.__mro__,)

        try:
            from StringIO import StringIO
        except:
            from io import StringIO

        stream = StringIO()
        dump_threads(stream=stream)
        error_msg += '\n\n' + stream.getvalue()
        raise AssertionError(error_msg)

    class NonMainThread(threading.Thread):

        def run(self):
            self.is_main_thread = is_current_thread_main_thread()

    non_main_thread = NonMainThread()
    non_main_thread.start()
    non_main_thread.join()
    assert not non_main_thread.is_main_thread 

def _in_main_thread():
        # noinspection PyUnresolvedReferences
        return isinstance(threading.current_thread(), threading._MainThread)


    #
    # Class preparation with external monkey patching 

def is_main_thread():
    return isinstance(threading.current_thread(), threading._MainThread) 

def start_gtk():
    # check if twisted is imported
    if reactor_required():
        from twisted.internet import reactor
        import threading
        is_main_thread = isinstance(threading.current_thread(), threading._MainThread)
        reactor.run(installSignalHandlers=is_main_thread)
    else:
        Gtk.main() 

def _init_watcher(self):
        with events._lock:
            if self._watcher is None:  # pragma: no branch
                self._watcher = SafeChildWatcher()
                if isinstance(threading.current_thread(),
                              threading._MainThread):
                    self._watcher.attach_loop(self._local._loop) 

def set_event_loop(self, loop):
        """Set the event loop.

        As a side effect, if a child watcher was set before, then calling
        .set_event_loop() from the main thread will call .attach_loop(loop) on
        the child watcher.
        """

        super().set_event_loop(loop)

        if self._watcher is not None and \
            isinstance(threading.current_thread(), threading._MainThread):
            self._watcher.attach_loop(loop) 

def get_event_loop(self):
        """Get the event loop.

        This may be None or an instance of EventLoop.
        """
        if (self._local._loop is None and
            not self._local._set_called and
            isinstance(threading.current_thread(), threading._MainThread)):
            self.set_event_loop(self.new_event_loop())
        if self._local._loop is None:
            raise RuntimeError('There is no current event loop in thread %r.'
                               % threading.current_thread().name)
        return self._local._loop 

def _init_watcher(self):
        with events._lock:
            if self._watcher is None:  # pragma: no branch
                self._watcher = SafeChildWatcher()
                if isinstance(threading.current_thread(),
                              threading._MainThread):
                    self._watcher.attach_loop(self._local._loop) 

def set_event_loop(self, loop):
        """Set the event loop.

        As a side effect, if a child watcher was set before, then calling
        .set_event_loop() from the main thread will call .attach_loop(loop) on
        the child watcher.
        """

        super().set_event_loop(loop)

        if (self._watcher is not None and
                isinstance(threading.current_thread(), threading._MainThread)):
            self._watcher.attach_loop(loop) 

def get_event_loop(self):
        """Get the event loop.

        This may be None or an instance of EventLoop.
        """
        if (self._local._loop is None and
                not self._local._set_called and
                isinstance(threading.current_thread(), threading._MainThread)):
            self.set_event_loop(self.new_event_loop())

        if self._local._loop is None:
            raise RuntimeError('There is no current event loop in thread %r.'
                               % threading.current_thread().name)

        return self._local._loop 

def new_event_loop(self):
        """Create a new event loop and return it."""
        if not self._default_loop and isinstance(threading.current_thread(), threading._MainThread):
            l = self.get_default_loop()
        else:
            l = GLibEventLoop()
        l._policy = self

        return l 

def is_mainthread():
    """
    Return a bool that indicates if this is the main application thread.
    """
    return isinstance(threading.current_thread(), threading._MainThread) 

def _init_watcher(self):
        with events._lock:
            if self._watcher is None:  # pragma: no branch
                self._watcher = SafeChildWatcher()
                if isinstance(threading.current_thread(),
                              threading._MainThread):
                    self._watcher.attach_loop(self._local._loop) 

def set_event_loop(self, loop):
        """Set the event loop.

        As a side effect, if a child watcher was set before, then calling
        .set_event_loop() from the main thread will call .attach_loop(loop) on
        the child watcher.
        """

        super().set_event_loop(loop)

        if self._watcher is not None and \
            isinstance(threading.current_thread(), threading._MainThread):
            self._watcher.attach_loop(loop) 

def get_event_loop(self):
        """Get the event loop.

        This may be None or an instance of EventLoop.
        """
        if (self._local._loop is None and
            not self._local._set_called and
            isinstance(threading.current_thread(), threading._MainThread)):
            self.set_event_loop(self.new_event_loop())
        if self._local._loop is None:
            raise RuntimeError('There is no current event loop in thread %r.'
                               % threading.current_thread().name)
        return self._local._loop 

def is_main_thread():
    if six.PY2:
        return isinstance(threading.current_thread(), threading._MainThread)
    else:
        # a nicer solution with py3
        return threading.current_thread() == threading.main_thread() 

def is_main_thread():
    if six.PY2:
        return isinstance(threading.current_thread(), threading._MainThread)
    else:
        # a nicer solution with py3
        return threading.current_thread() == threading.main_thread()