Python threading.settrace() Examples

def test_finalize_with_trace(self):
        # Issue1733757
        # Avoid a deadlock when sys.settrace steps into threading._shutdown
        assert_python_ok("-c", """if 1:
            import sys, threading

            # A deadlock-killer, to prevent the
            # testsuite to hang forever
            def killer():
                import os, time
                time.sleep(2)
                print('program blocked; aborting')
                os._exit(2)
            t = threading.Thread(target=killer)
            t.daemon = True
            t.start()

            # This is the trace function
            def func(frame, event, arg):
                threading.current_thread()
                return func

            sys.settrace(func)
            """) 

def test_finalize_with_trace(self):
        # Issue1733757
        # Avoid a deadlock when sys.settrace steps into threading._shutdown
        assert_python_ok("-c", """if 1:
            import sys, threading

            # A deadlock-killer, to prevent the
            # testsuite to hang forever
            def killer():
                import os, time
                time.sleep(2)
                print('program blocked; aborting')
                os._exit(2)
            t = threading.Thread(target=killer)
            t.daemon = True
            t.start()

            # This is the trace function
            def func(frame, event, arg):
                threading.current_thread()
                return func

            sys.settrace(func)
            """) 

def __call__(self, frame, kind, arg):
        """
        The settrace function.

        .. note::

            This always returns self (drills down) - as opposed to only drilling down when ``predicate(event)`` is True
            because it might match further inside.
        """
        if self._handler is not None:
            if kind == 'return' and self.depth > 0:
                self.depth -= 1
            try:
                self._handler(Event(frame, kind, arg, self))
            except Exception as exc:
                traceback.print_exc(file=hunter._default_stream)
                hunter._default_stream.write('Disabling tracer because handler {} failed ({!r}).\n\n'.format(
                    self._handler, exc))
                self.stop()
                return
            if kind == 'call':
                self.depth += 1
                self.calls += 1

            return self 

def trace(self, predicate):
        """
        Starts tracing with the given callable.

        Args:
            predicate (callable that accepts a single :obj:`~hunter.event.Event` argument):
        Return:
            self
        """
        self._handler = predicate
        if self.threading_support is None or self.threading_support:
            self._threading_previous = getattr(threading, '_trace_hook', None)
            threading.settrace(self)
        self._previous = sys.gettrace()
        sys.settrace(self)
        return self 

def stoptrace():
    global connected
    if connected:
        pydevd_tracing.restore_sys_set_trace_func()
        sys.settrace(None)
        try:
            #not available in jython!
            threading.settrace(None) # for all future threads
        except:
            pass

        from _pydev_bundle.pydev_monkey import undo_patch_thread_modules
        undo_patch_thread_modules()

        debugger = get_global_debugger()

        if debugger:

            debugger.set_trace_for_frame_and_parents(
                    get_frame(), also_add_to_passed_frame=True, overwrite_prev_trace=True, dispatch_func=lambda *args:None)
            debugger.exiting()

            kill_all_pydev_threads()

        connected = False 

def test_finalize_with_trace(self):
        # Issue1733757
        # Avoid a deadlock when sys.settrace steps into threading._shutdown
        assert_python_ok("-c", """if 1:
            import sys, threading

            # A deadlock-killer, to prevent the
            # testsuite to hang forever
            def killer():
                import os, time
                time.sleep(2)
                print('program blocked; aborting')
                os._exit(2)
            t = threading.Thread(target=killer)
            t.daemon = True
            t.start()

            # This is the trace function
            def func(frame, event, arg):
                threading.current_thread()
                return func

            sys.settrace(func)
            """) 

def runfunc(*args, **kw):
        if len(args) >= 2:
            self, func, *args = args
        elif not args:
            raise TypeError("descriptor 'runfunc' of 'Trace' object "
                            "needs an argument")
        elif 'func' in kw:
            func = kw.pop('func')
            self, *args = args
        else:
            raise TypeError('runfunc expected at least 1 positional argument, '
                            'got %d' % (len(args)-1))

        result = None
        if not self.donothing:
            sys.settrace(self.globaltrace)
        try:
            result = func(*args, **kw)
        finally:
            if not self.donothing:
                sys.settrace(None)
        return result 

def _unsettrace():
        sys.settrace(None) 

def _unsettrace():
        sys.settrace(None)
        threading.settrace(None) 

def runfunc(self, func, *args, **kw):
        result = None
        if not self.donothing:
            sys.settrace(self.globaltrace)
        try:
            result = func(*args, **kw)
        finally:
            if not self.donothing:
                sys.settrace(None)
        return result 

def opt_spew(self):
        """Print an insanely verbose log of everything that happens.
        Useful when debugging freezes or locks in complex code."""
        sys.settrace(util.spewer)
        try:
            import threading
        except ImportError:
            return
        threading.settrace(util.spewer) 

def _unsettrace():
        sys.settrace(None)
        threading.settrace(None) 

def has_data_to_redirect():
    if getattr(sys, 'stdoutBuf', None):
        if not sys.stdoutBuf.empty():
            return True
    if getattr(sys, 'stderrBuf', None):
        if not sys.stderrBuf.empty():
            return True

    return False

#=======================================================================================================================
# settrace
#======================================================================================================================= 

def settrace_forked():
    '''
    When creating a fork from a process in the debugger, we need to reset the whole debugger environment!
    '''
    host, port = dispatch()

    from _pydevd_bundle import pydevd_tracing
    pydevd_tracing.restore_sys_set_trace_func()

    if port is not None:
        global connected
        connected = False

        custom_frames_container_init()

        settrace(
                host,
                port=port,
                suspend=False,
                trace_only_current_thread=False,
                overwrite_prev_trace=True,
                patch_multiprocessing=True,
        )

#=======================================================================================================================
# SetupHolder
#======================================================================================================================= 

def runfunc(self, func, *args, **kw):
        result = None
        if not self.donothing:
            sys.settrace(self.globaltrace)
        try:
            result = func(*args, **kw)
        finally:
            if not self.donothing:
                sys.settrace(None)
        return result 

def _settrace(func):
        threading.settrace(func)
        sys.settrace(func) 

def _unsettrace():
        sys.settrace(None) 

def _unsettrace():
        sys.settrace(None)
        threading.settrace(None) 

def patch_threads(self):
        try:
            # not available in jython!
            import threading
            threading.settrace(self.trace_dispatch)  # for all future threads
        except:
            pass

        from _pydev_bundle.pydev_monkey import patch_thread_modules
        patch_thread_modules() 

def _settrace(func):
        threading.settrace(func)
        sys.settrace(func) 

def _unsettrace():
        sys.settrace(None) 

def _settrace(func):
        threading.settrace(func)
        sys.settrace(func) 

def _unsettrace():
        sys.settrace(None)
        threading.settrace(None) 

def _settrace(func):
        threading.settrace(func)
        sys.settrace(func) 

def _unsettrace():
        sys.settrace(None) 

def test_frame_tstate_tracing(self):
        # Issue #14432: Crash when a generator is created in a C thread that is
        # destroyed while the generator is still used. The issue was that a
        # generator contains a frame, and the frame kept a reference to the
        # Python state of the destroyed C thread. The crash occurs when a trace
        # function is setup.

        def noop_trace(frame, event, arg):
            # no operation
            return noop_trace

        def generator():
            while 1:
                yield "genereator"

        def callback():
            if callback.gen is None:
                callback.gen = generator()
            return next(callback.gen)
        callback.gen = None

        old_trace = sys.gettrace()
        sys.settrace(noop_trace)
        try:
            # Install a trace function
            threading.settrace(noop_trace)

            # Create a generator in a C thread which exits after the call
            _testcapi.call_in_temporary_c_thread(callback)

            # Call the generator in a different Python thread, check that the
            # generator didn't keep a reference to the destroyed thread state
            for test in range(3):
                # The trace function is still called here
                callback()
        finally:
            sys.settrace(old_trace) 

def test_finalize_with_trace(self):
        # Issue1733757
        # Avoid a deadlock when sys.settrace steps into threading._shutdown
        p = subprocess.Popen([sys.executable, "-c", """if 1:
            import sys, threading

            # A deadlock-killer, to prevent the
            # testsuite to hang forever
            def killer():
                import os, time
                time.sleep(2)
                print 'program blocked; aborting'
                os._exit(2)
            t = threading.Thread(target=killer)
            t.daemon = True
            t.start()

            # This is the trace function
            def func(frame, event, arg):
                threading.current_thread()
                return func

            sys.settrace(func)
            """],
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE)
        self.addCleanup(p.stdout.close)
        self.addCleanup(p.stderr.close)
        stdout, stderr = p.communicate()
        rc = p.returncode
        self.assertFalse(rc == 2, "interpreted was blocked")
        self.assertTrue(rc == 0,
                        "Unexpected error: " + repr(stderr)) 

def stop(self):
        """
        Stop tracing. Reinstalls the :attr:`~hunter.tracer.Tracer.previous` tracer.
        """
        if self._handler is not None:
            sys.settrace(self._previous)
            self._handler = self._previous = None
            if self.threading_support is None or self.threading_support:
                threading.settrace(self._threading_previous)
                self._threading_previous = None 

def runfunc(self, func, *args, **kw):
        result = None
        if not self.donothing:
            sys.settrace(self.globaltrace)
        try:
            result = func(*args, **kw)
        finally:
            if not self.donothing:
                sys.settrace(None)
        return result 

def _unsettrace():
        sys.settrace(None)
        threading.settrace(None)