def test_pause2(self, exopy_qtbot):
"""Test pausing and stopping the execution.
"""
def pause_and_stop(task, value):
"""Post a method stopping execution on event loop and pause.
"""
deferred_call(lambda t: t.root.should_stop.set(), task)
task.root.should_pause.set()
root = self.root
par = CheckTask(name='test', custom=pause_and_stop)
comp = ComplexTask(name='comp', stoppable=False,
parallel={'activated': True, 'pool': 'test'})
par2 = CheckTask(name='test2')
comp.add_child_task(0, par2)
par3 = CheckTask(name='test3')
for i, c in enumerate([par, comp, par3]):
root.add_child_task(i, c)
t = threading.Thread(target=root.perform)
t.start()
sleep(0.1)
exopy_qtbot.wait(10)
t.join()
assert root.should_pause.is_set()
assert root.should_stop.is_set()
assert par.perform_called
assert not par2.perform_called
assert not par3.perform_called
def test_pause2(self, exopy_qtbot):
"""Test pausing and stopping the execution.
"""
def pause_and_stop(task, value):
"""Post a method stopping execution on event loop and pause.
"""
deferred_call(lambda t: t.root.should_stop.set(), task)
task.root.should_pause.set()
root = self.root
par = CheckTask(name='test', custom=pause_and_stop)
comp = ComplexTask(name='comp', stoppable=False,
parallel={'activated': True, 'pool': 'test'})
par2 = CheckTask(name='test2')
comp.add_child_task(0, par2)
par3 = CheckTask(name='test3')
for i, c in enumerate([par, comp, par3]):
root.add_child_task(i, c)
t = threading.Thread(target=root.perform)
t.start()
sleep(0.1)
exopy_qtbot.wait(10)
t.join()
assert root.should_pause.is_set()
assert root.should_stop.is_set()
assert par.perform_called
assert not par2.perform_called
assert not par3.perform_called
def test_moving_through_remove_add_child():
"""Test moving a child between different tasks through remove/add.
"""
root = RootTask()
task1 = ComplexTask(name='task1', database_entries={'val1': 2.0})
task2 = ComplexTask(name='task2', database_entries={'val2': 2.0})
task3 = SimpleTask(name='task3',
database_entries={'val3': 1},
access_exs={'val3': 2})
task2.add_child_task(0, task3)
task1.add_child_task(1, task2)
root.add_child_task(0, task1)
task1.remove_child_task(0)
assert task2.parent is None
assert task2.root is None
assert task2.database is None
assert task3.parent is not None
assert task3.root is None
assert task3.database is None
root.add_child_task(0, task2)
assert len(root.children) == 2
def test_task_renaming():
"""Test renaming simple and complex task.
"""
root = RootTask()
task1 = ComplexTask(name='task1', database_entries={'val1': 2.0})
task2 = ComplexTask(name='task2')
task3 = SimpleTask(name='task3',
database_entries={'val2': 1},
access_exs={'val2': 2})
task2.add_child_task(0, task3)
task1.add_child_task(0, task2)
root.add_child_task(0, task1)
task3.name = 'worker3'
with pytest.raises(KeyError):
root.get_from_database('task3_val2')
assert root.get_from_database('worker3_val2') == 1
task1.name = 'worker1'
with pytest.raises(KeyError):
root.get_from_database('task1_val1')
assert root.get_from_database('worker1_val1') == 2.0
assert root.get_from_database('worker3_val2') == 1
def test_database_update_with_exception():
"""Test that replacing the database_entries members refreshes the database.
"""
root = RootTask()
task1 = ComplexTask(name='task1',
database_entries={'val1': 2.0})
task2 = SimpleTask(name='task2',
database_entries={'val2': 1},
access_exs={'val2': 1})
task3 = ComplexTask(name='task3')
task1.add_child_task(0, task2)
root.add_child_task(0, task1)
root.add_child_task(1, task3)
assert task3.get_from_database('task2_val2')
entries = task2.database_entries.copy()
del entries['val2']
task2.database_entries = entries
with pytest.raises(KeyError):
task1.get_from_database('task2_val2')
with pytest.raises(KeyError):
task3.get_from_database('task2_val2')
def test_moving_child():
"""Test moving a child.
"""
root = RootTask()
task1 = ComplexTask(name='task1',
database_entries={'val1': 2.0})
task2 = SimpleTask(name='task2',
database_entries={'val2': 1},
access_exs={'val2': 2})
task3 = ComplexTask(name='task3')
task4 = ComplexTask(name='task4')
task1.add_child_task(0, task2)
task1.add_child_task(1, task4)
root.add_child_task(0, task1)
root.add_child_task(1, task3)
listener = SignalListener()
task1.observe('children_changed', listener.listen)
assert task1.preferences['children_0']['name'] == 'task2'
assert task1.preferences['children_1']['name'] == 'task4'
task1.move_child_task(0, 1)
assert listener.counter == 1
assert listener.signals[0].moved
assert task1.preferences['children_0']['name'] == 'task4'
assert task1.preferences['children_1']['name'] == 'task2'
assert task3.get_from_database('task2_val2') == 1
def test_root_perform_complex(self):
"""Test running a simple task.
"""
root = self.root
task = ComplexTask(name='comp')
aux = CheckTask(name='test')
root.add_child_task(0, task)
task.add_child_task(0, aux)
root.perform()
assert not root.should_pause.is_set()
assert not root.should_stop.is_set()
assert aux.perform_called == 1
def test_root_perform_complex(self):
"""Test running a simple task.
"""
root = self.root
task = ComplexTask(name='comp')
aux = CheckTask(name='test')
root.add_child_task(0, task)
task.add_child_task(0, aux)
root.perform()
assert not root.should_pause.is_set()
assert not root.should_stop.is_set()
assert aux.perform_called == 1
def test_moving_through_remove_add_child():
"""Test moving a child between different tasks through remove/add.
"""
root = RootTask()
task1 = ComplexTask(name='task1',
database_entries={'val1': 2.0})
task2 = ComplexTask(name='task2',
database_entries={'val2': 2.0})
task3 = SimpleTask(name='task3',
database_entries={'val3': 1},
access_exs={'val3': 2})
task2.add_child_task(0, task3)
task1.add_child_task(1, task2)
root.add_child_task(0, task1)
task1.remove_child_task(0)
assert task2.parent is None
assert task2.root is None
assert task2.database is None
assert task3.parent is not None
assert task3.root is None
assert task3.database is None
root.add_child_task(0, task2)
assert len(root.children) == 2
def test_task_renaming():
"""Test renaming simple and complex task.
"""
root = RootTask()
task1 = ComplexTask(name='task1',
database_entries={'val1': 2.0})
task2 = ComplexTask(name='task2')
task3 = SimpleTask(name='task3',
database_entries={'val2': 1},
access_exs={'val2': 2})
task2.add_child_task(0, task3)
task1.add_child_task(0, task2)
root.add_child_task(0, task1)
task3.name = 'worker3'
with pytest.raises(KeyError):
root.get_from_database('task3_val2')
assert root.get_from_database('worker3_val2') == 1
task1.name = 'worker1'
with pytest.raises(KeyError):
root.get_from_database('task1_val1')
assert root.get_from_database('worker1_val1') == 2.0
assert root.get_from_database('worker3_val2') == 1
def test_traverse():
"""Test traversing a task hierarchy to collect infos.
"""
root = RootTask()
task1 = ComplexTask(name='task1', database_entries={'val1': 2.0})
task2 = SimpleTask(name='task2',
database_entries={'val2': 1},
access_exs={'val2': 2})
task3 = ComplexTask(name='task3')
task1.add_child_task(0, task2)
root.add_child_task(0, task1)
root.add_child_task(1, task3)
flat = list(root.traverse())
assert flat == [root, task1, task2, task3]
flat = list(root.traverse(0))
assert flat == [root, task1, task3]
def test_traverse():
"""Test traversing a task hierarchy to collect infos.
"""
root = RootTask()
task1 = ComplexTask(name='task1',
database_entries={'val1': 2.0})
task2 = SimpleTask(name='task2',
database_entries={'val2': 1},
access_exs={'val2': 2})
task3 = ComplexTask(name='task3')
task1.add_child_task(0, task2)
root.add_child_task(0, task1)
root.add_child_task(1, task3)
flat = list(root.traverse())
assert flat == [root, task1, task2, task3]
flat = list(root.traverse(0))
assert flat == [root, task1, task3]
def test_build_complex_from_config():
"""Test building a complex task from config.
"""
config = {'name': 'test',
'children_0': {'name': 'test_child',
'task_id': 'SimpleTask'}}
task = ComplexTask.build_from_config(config,
{'exopy.task':
{'SimpleTask': SimpleTask}})
assert task.name == 'test'
assert len(task.children) == 1
assert task.children[0].name == 'test_child'
assert isinstance(task.children[0], SimpleTask)
def test_deleting_child():
"""Test deleting a child.
"""
root = RootTask()
task1 = ComplexTask(name='task1',
database_entries={'val1': 2.0})
task2 = SimpleTask(name='task2',
database_entries={'val2': 1},
access_exs={'val2': 2})
task3 = ComplexTask(name='task3')
task4 = ComplexTask(name='task4')
task1.add_child_task(0, task2)
task1.add_child_task(1, task4)
root.add_child_task(0, task1)
root.add_child_task(1, task3)
listener = SignalListener()
task1.observe('children_changed', listener.listen)
task1.remove_child_task(0)
assert task2.parent is None
assert task2.root is None
assert task2.database is None
assert listener.counter == 1
assert listener.signals[0].removed
assert task1.preferences['children_0']['name'] == 'task4'
assert 'task2_val2' not in task3.list_accessible_database_entries()
root.remove_child_task(0)
assert task1.parent is None
assert task1.root is None
assert task1.database is None
assert task4.root is None
assert task4.database is None
assert len(root.children) == 1
with pytest.raises(KeyError):
root.get_from_database('task1_val1')
def test_root_perform_parallel_in_finalization(self):
"""Ensure that the ThreadResources release does not prevent to start
new threads.
"""
root = self.root
event1 = threading.Event()
event2 = threading.Event()
event3 = threading.Event()
comp = ComplexTask(name='comp')
comp.parallel = {'activated': True, 'pool': 'test'}
aux = CheckTask(name='signal', custom=lambda t, x: event1.set())
wait = CheckTask(name='test', custom=lambda t, x: event2.wait())
par = CheckTask(name='signal', custom=lambda t, x: event3.set())
# Test creating a new thread as by priority active_threads is released
# later.
par.parallel = {'activated': True, 'pool': 'test2'}
comp.add_child_task(0, aux)
comp.add_child_task(1, wait)
comp.add_child_task(2, par)
root.add_child_task(0, comp)
root.check()
t = threading.Thread(target=root.perform)
t.start()
event1.wait()
assert root.resources['active_threads']['test']
assert not root.resources['active_threads']['test2']
event2.set()
event3.wait()
t.join()
assert not root.should_pause.is_set()
assert not root.should_stop.is_set()
assert par.perform_called == 1
assert aux.perform_called == 1
assert wait.perform_called == 1
assert not root.resources['active_threads']['test']
def test_swapping(exopy_qtbot, task_workbench, dialog_sleep):
"""Test moving a view between containers.
"""
task = RootTask()
view = RootTaskView(task=task,
core=task_workbench.get_plugin('enaml.workbench.core'))
subtask = ComplexTask(name='Test')
subview = view.view_for(subtask)
task.add_child_task(0, subtask)
cont = Container()
show_widget(exopy_qtbot, cont)
view.set_parent(cont)
view.refresh()
def assert_children():
assert cont.children == [view]
exopy_qtbot.wait_until(assert_children)
exopy_qtbot.wait(dialog_sleep)
view.set_parent(None)
subview.set_parent(cont)
subview.refresh()
def assert_children():
assert cont.children == [subview]
exopy_qtbot.wait_until(assert_children)
exopy_qtbot.wait(dialog_sleep)
subview.set_parent(None)
view.set_parent(cont)
view.refresh()
def assert_children():
assert cont.children == [view]
exopy_qtbot.wait_until(assert_children)
assert subview.visible
exopy_qtbot.wait(dialog_sleep)
def test_build_complex_from_config():
"""Test building a complex task from config.
"""
config = {
'name': 'test',
'children_0': {
'name': 'test_child',
'task_id': 'SimpleTask'
}
}
task = ComplexTask.build_from_config(
config, {'exopy.task': {
'SimpleTask': SimpleTask
}})
assert task.name == 'test'
assert len(task.children) == 1
assert task.children[0].name == 'test_child'
assert isinstance(task.children[0], SimpleTask)
def test_root_perform_parallel_in_finalization(self):
"""Ensure that the ThreadResources release does not prevent to start
new threads.
"""
root = self.root
event1 = threading.Event()
event2 = threading.Event()
event3 = threading.Event()
comp = ComplexTask(name='comp')
comp.parallel = {'activated': True, 'pool': 'test'}
aux = CheckTask(name='signal', custom=lambda t, x: event1.set())
wait = CheckTask(name='test', custom=lambda t, x: event2.wait())
par = CheckTask(name='signal', custom=lambda t, x: event3.set())
# Test creating a new thread as by priority active_threads is released
# later.
par.parallel = {'activated': True, 'pool': 'test2'}
comp.add_child_task(0, aux)
comp.add_child_task(1, wait)
comp.add_child_task(2, par)
root.add_child_task(0, comp)
t = threading.Thread(target=root.perform)
t.start()
event1.wait()
assert root.resources['active_threads']['test']
assert not root.resources['active_threads']['test2']
event2.set()
event3.wait()
t.join()
assert not root.should_pause.is_set()
assert not root.should_stop.is_set()
assert par.perform_called == 1
assert aux.perform_called == 1
assert wait.perform_called == 1
assert not root.resources['active_threads']['test']
def test_adding_child():
"""Test adding children.
This test adding a child with and without access_exs to a task which is not
root and then to the root. This makes sure that giving the root afterwards
does trigger the right updates.
"""
root = RootTask()
listener = SignalListener()
root.observe('children_changed', listener.listen)
task1 = ComplexTask(name='task1', database_entries={'val1': 2.0})
task2 = SimpleTask(name='task2',
database_entries={'val2': 1},
access_exs={'val2': 2})
task3 = ComplexTask(name='task3')
task1.add_child_task(0, task2)
root.add_child_task(0, task1)
root.add_child_task(1, task3)
assert task1.depth == 1
assert task1.path == 'root'
assert task1.database is root.database
assert task1.root is root
assert task1.parent is root
assert task2.depth == 2
assert task2.path == 'root/task1'
assert task2.database is root.database
assert task2.root is root
assert task2.parent is task1
assert task1.get_from_database('task1_val1') == 2.0
assert root.get_from_database('task1_val1') == 2.0
assert task3.get_from_database('task2_val2') == 1
assert listener.counter == 2
assert all([bool(c.added) for c in listener.signals])
def test_adding_child():
"""Test adding children.
This test adding a child with and without access_exs to a task which is not
root and then to the root. This makes sure that giving the root afterwards
does trigger the right updates.
"""
root = RootTask()
listener = SignalListener()
root.observe('children_changed', listener.listen)
task1 = ComplexTask(name='task1',
database_entries={'val1': 2.0})
task2 = SimpleTask(name='task2',
database_entries={'val2': 1},
access_exs={'val2': 2})
task3 = ComplexTask(name='task3')
task1.add_child_task(0, task2)
root.add_child_task(0, task1)
root.add_child_task(1, task3)
assert task1.depth == 1
assert task1.path == 'root'
assert task1.database is root.database
assert task1.root is root
assert task1.parent is root
assert task2.depth == 2
assert task2.path == 'root/task1'
assert task2.database is root.database
assert task2.root is root
assert task2.parent is task1
assert task1.get_from_database('task1_val1') == 2.0
assert root.get_from_database('task1_val1') == 2.0
assert task3.get_from_database('task2_val2') == 1
assert listener.counter == 2
assert all([bool(c.added) for c in listener.signals])
def test_root_view(exopy_qtbot, task_workbench, dialog_sleep):
"""Test the behavior of the root task view.
"""
task = RootTask()
view = RootTaskView(task=task,
core=task_workbench.get_plugin('enaml.workbench.core'))
editor = view.children[-1]
win = show_widget(exopy_qtbot, view)
exopy_qtbot.wait(dialog_sleep)
assert editor.task is task
assert editor.root is view
TASK_NAME = 'Foo'
def answer_dialog(bot, dial):
selector = dial.selector
selector.selected_task = 'exopy.ComplexTask'
dial.config.task_name = TASK_NAME
with handle_dialog(exopy_qtbot, 'accept', answer_dialog, cls=BuilderView):
editor._empty_button.clicked = True
def assert_task_children():
assert task.children
exopy_qtbot.wait_until(assert_task_children)
assert type(task.children[0]) is ComplexTask
assert len(editor._children_buttons) == 1
exopy_qtbot.wait(dialog_sleep)
TASK_NAME = 'Bar'
with handle_dialog(exopy_qtbot, 'accept', answer_dialog, cls=BuilderView):
editor.operations['add'](0, 'after')
exopy_qtbot.wait(10)
exopy_qtbot.wait(dialog_sleep)
task.children[0].add_child_task(0, ComplexTask(name='Test'))
get_window(exopy_qtbot).maximize()
exopy_qtbot.wait(10)
exopy_qtbot.wait(dialog_sleep)
editor.operations['move'](0, 1)
exopy_qtbot.wait(10)
exopy_qtbot.wait(dialog_sleep)
task.remove_child_task(1)
exopy_qtbot.wait(10)
exopy_qtbot.wait(dialog_sleep)
assert len(view._cache) == 2
# Test removing the last child and removing a view for an already removed
# task
child_task = task.children[0]
editor.operations['remove'](0)
exopy_qtbot.wait(10)
exopy_qtbot.wait(dialog_sleep)
assert len(view._cache) == 1
view.discard_view(child_task)
win.close()
def test_pause1(self, exopy_qtbot):
"""Test pausing and resuming the execution. (add instrs)
Tricky as only the main thread is allowed to resume.
"""
class Dummy(object):
"""False instrument checking that restarting does its job.
"""
owner = 'test'
called = 0
def finalize(self):
pass
def clear_cache(self):
self.called += 1
class Starter(object):
"""False instrument starter.
"""
def reset(self, driver):
driver.clear_cache()
driver.owner = ''
def stop(self, driver):
driver.stop()
def pause(task, value):
"""Post a method restarting execution on event loop and pause.
"""
deferred_call(lambda t: t.root.should_pause.clear(), task)
task.root.should_pause.set()
root = self.root
dummy = Dummy()
root.resources['instrs']['test'] = dummy, Starter()
par = CheckTask(name='test', custom=pause)
comp = ComplexTask(name='comp',
stoppable=False,
parallel={
'activated': True,
'pool': 'test'
})
par2 = CheckTask(name='test2')
comp.add_child_task(0, par2)
par3 = CheckTask(name='test3')
for i, c in enumerate([par, comp, par3]):
root.add_child_task(i, c)
t = threading.Thread(target=root.perform)
t.start()
sleep(0.1)
exopy_qtbot.wait(10)
t.join()
assert not root.should_pause.is_set()
assert not root.should_stop.is_set()
assert par.perform_called == 1
assert par2.perform_called == 1
assert par3.perform_called == 1
assert root.resumed.is_set()
assert dummy.called == 1
assert dummy.owner == ''
def test_access_exceptions():
"""Test adding, modifying and removing an access exception after creation.
"""
root = RootTask()
listener = SignalListener()
root.observe('children_changed', listener.listen)
task1 = ComplexTask(name='task1',
database_entries={'val1': 2.0})
task2 = ComplexTask(name='task2')
task3 = SimpleTask(name='task3',
database_entries={'val2': 1, 'val3': 2},
)
task2.add_child_task(0, task3)
task1.add_child_task(0, task2)
root.add_child_task(0, task1)
with pytest.raises(KeyError):
task2.get_from_database('task3_val2')
task3.add_access_exception('val2', 1)
task3.add_access_exception('val3', 1)
assert task2.get_from_database('task3_val2') == 1
assert task2.get_from_database('task3_val2') == 1
with pytest.raises(KeyError):
task1.get_from_database('task3_val2')
task3.modify_access_exception('val2', 2)
task3.modify_access_exception('val3', -1)
assert task1.get_from_database('task3_val2') == 1
with pytest.raises(KeyError):
task2.get_from_database('task3_val3')
task3.remove_access_exception('val2')
with pytest.raises(KeyError):
task2.get_from_database('task3_val2')
def test_database_update_with_exception():
"""Test that replacing the database_entries members refreshes the database.
"""
root = RootTask()
task1 = ComplexTask(name='task1', database_entries={'val1': 2.0})
task2 = SimpleTask(name='task2',
database_entries={'val2': 1},
access_exs={'val2': 1})
task3 = ComplexTask(name='task3')
task1.add_child_task(0, task2)
root.add_child_task(0, task1)
root.add_child_task(1, task3)
assert task3.get_from_database('task2_val2')
entries = task2.database_entries.copy()
del entries['val2']
task2.database_entries = entries
with pytest.raises(KeyError):
task1.get_from_database('task2_val2')
with pytest.raises(KeyError):
task3.get_from_database('task2_val2')
def test_access_exceptions():
"""Test adding, modifying and removing an access exception after creation.
"""
root = RootTask()
listener = SignalListener()
root.observe('children_changed', listener.listen)
task1 = ComplexTask(name='task1', database_entries={'val1': 2.0})
task2 = ComplexTask(name='task2')
task3 = SimpleTask(
name='task3',
database_entries={
'val2': 1,
'val3': 2
},
)
task2.add_child_task(0, task3)
task1.add_child_task(0, task2)
root.add_child_task(0, task1)
with pytest.raises(KeyError):
task2.get_from_database('task3_val2')
task3.add_access_exception('val2', 1)
task3.add_access_exception('val3', 1)
assert task2.get_from_database('task3_val2') == 1
assert task2.get_from_database('task3_val2') == 1
with pytest.raises(KeyError):
task1.get_from_database('task3_val2')
task3.modify_access_exception('val2', 2)
task3.modify_access_exception('val3', -1)
assert task1.get_from_database('task3_val2') == 1
with pytest.raises(KeyError):
task2.get_from_database('task3_val3')
task3.remove_access_exception('val2')
with pytest.raises(KeyError):
task2.get_from_database('task3_val2')
def test_pause1(self, exopy_qtbot):
"""Test pausing and resuming the execution. (add instrs)
Tricky as only the main thread is allowed to resume.
"""
class Dummy(object):
"""False instrument checking that restarting does its job.
"""
owner = 'test'
called = 0
def finalize(self):
pass
def clear_cache(self):
self.called += 1
class Starter(object):
"""False instrument starter.
"""
def reset(self, driver):
driver.clear_cache()
driver.owner = ''
def stop(self, driver):
driver.stop()
def pause(task, value):
"""Post a method restarting execution on event loop and pause.
"""
deferred_call(lambda t: t.root.should_pause.clear(), task)
task.root.should_pause.set()
root = self.root
dummy = Dummy()
root.resources['instrs']['test'] = dummy, Starter()
par = CheckTask(name='test', custom=pause)
comp = ComplexTask(name='comp', stoppable=False,
parallel={'activated': True, 'pool': 'test'})
par2 = CheckTask(name='test2')
comp.add_child_task(0, par2)
par3 = CheckTask(name='test3')
for i, c in enumerate([par, comp, par3]):
root.add_child_task(i, c)
t = threading.Thread(target=root.perform)
t.start()
sleep(0.1)
exopy_qtbot.wait(10)
t.join()
assert not root.should_pause.is_set()
assert not root.should_stop.is_set()
assert par.perform_called == 1
assert par2.perform_called == 1
assert par3.perform_called == 1
assert root.resumed.is_set()
assert dummy.called == 1
assert dummy.owner == ''
def test_deleting_child():
"""Test deleting a child.
"""
root = RootTask()
task1 = ComplexTask(name='task1', database_entries={'val1': 2.0})
task2 = SimpleTask(name='task2',
database_entries={'val2': 1},
access_exs={'val2': 2})
task3 = ComplexTask(name='task3')
task4 = ComplexTask(name='task4')
task1.add_child_task(0, task2)
task1.add_child_task(1, task4)
root.add_child_task(0, task1)
root.add_child_task(1, task3)
listener = SignalListener()
task1.observe('children_changed', listener.listen)
task1.remove_child_task(0)
assert listener.counter == 1
assert listener.signals[0].removed
assert task1.preferences['children_0']['name'] == 'task4'
assert 'task2_val2' not in task3.list_accessible_database_entries()
root.remove_child_task(0)
assert len(root.children) == 1
with pytest.raises(KeyError):
root.get_from_database('task1_val1')
def test_moving_child():
"""Test moving a child.
"""
root = RootTask()
task1 = ComplexTask(name='task1', database_entries={'val1': 2.0})
task2 = SimpleTask(name='task2',
database_entries={'val2': 1},
access_exs={'val2': 2})
task3 = ComplexTask(name='task3')
task4 = ComplexTask(name='task4')
task1.add_child_task(0, task2)
task1.add_child_task(1, task4)
root.add_child_task(0, task1)
root.add_child_task(1, task3)
listener = SignalListener()
task1.observe('children_changed', listener.listen)
assert task1.preferences['children_0']['name'] == 'task2'
assert task1.preferences['children_1']['name'] == 'task4'
task1.move_child_task(0, 1)
assert listener.counter == 1
assert listener.signals[0].moved
assert task1.preferences['children_0']['name'] == 'task4'
assert task1.preferences['children_1']['name'] == 'task2'
assert task3.get_from_database('task2_val2') == 1