[ENH] Neural network widget that works in a separate thread

Orange/base.py

@@ -383,8 +383,11 @@ def __call__(self, data):
         m.params = self.params
         return m
 
+    def _initialize_wrapped(self):
+        return self.__wraps__(**self.params)
+
     def fit(self, X, Y, W=None):
-        clf = self.__wraps__(**self.params)
+        clf = self._initialize_wrapped()
         Y = Y.reshape(-1)
         if W is None or not self.supports_weights:
             return self.__returns__(clf.fit(X, Y))

Orange/classification/neural_network.py

@@ -5,5 +5,28 @@
 __all__ = ["NNClassificationLearner"]
 
 
+class NIterCallbackMixin:
+    orange_callback = None
+
+    @property
+    def n_iter_(self):
+        return self.__orange_n_iter
+
+    @n_iter_.setter
+    def n_iter_(self, v):
+        self.__orange_n_iter = v
+        if self.orange_callback:
+            self.orange_callback(v)
+
+
+class MLPClassifierWCallback(skl_nn.MLPClassifier, NIterCallbackMixin):
+    pass
+
+
 class NNClassificationLearner(NNBase, SklLearner):
-    __wraps__ = skl_nn.MLPClassifier
+    __wraps__ = MLPClassifierWCallback
+
+    def _initialize_wrapped(self):
+        clf = SklLearner._initialize_wrapped(self)
+        clf.orange_callback = getattr(self, "callback", None)
+        return clf

Orange/modelling/neural_network.py

@@ -8,3 +8,10 @@
 class NNLearner(SklFitter):
     __fits__ = {'classification': NNClassificationLearner,
                 'regression': NNRegressionLearner}
+
+    callback = None
+
+    def get_learner(self, problem_type):
+        learner = super().get_learner(problem_type)
+        learner.callback = self.callback
+        return learner

Orange/regression/neural_network.py

@@ -1,9 +1,19 @@
 import sklearn.neural_network as skl_nn
 from Orange.base import NNBase
 from Orange.regression import SklLearner
+from Orange.classification.neural_network import NIterCallbackMixin
 
 __all__ = ["NNRegressionLearner"]
 
 
+class MLPRegressorWCallback(skl_nn.MLPRegressor, NIterCallbackMixin):
+    pass
+
+
 class NNRegressionLearner(NNBase, SklLearner):
-    __wraps__ = skl_nn.MLPRegressor
+    __wraps__ = MLPRegressorWCallback
+
+    def _initialize_wrapped(self):
+        clf = SklLearner._initialize_wrapped(self)
+        clf.orange_callback = getattr(self, "callback", None)
+        return clf

Orange/widgets/model/owneuralnetwork.py

@@ -1,15 +1,48 @@
+from functools import partial
+import copy
+import logging
 import re
 import sys
+import concurrent.futures
 
-from AnyQt.QtWidgets import QApplication
-from AnyQt.QtCore import Qt
+from AnyQt.QtWidgets import QApplication, qApp
+from AnyQt.QtCore import Qt, QThread
+from AnyQt.QtCore import pyqtSlot as Slot
 
 from Orange.data import Table
 from Orange.modelling import NNLearner
 from Orange.widgets import gui
 from Orange.widgets.settings import Setting
 from Orange.widgets.utils.owlearnerwidget import OWBaseLearner
 
+from Orange.widgets.utils.concurrent import (
+    ThreadExecutor, FutureWatcher, methodinvoke
+)
+
+
+class Task:
+    """
+    A class that will hold the state for an learner evaluation.
+    """
+    future = ...       # type: concurrent.futures.Future
+    watcher = ...      # type: FutureWatcher
+    cancelled = False  # type: bool
+
+    def cancel(self):
+        """
+        Cancel the task.
+
+        Set the `cancelled` field to True and block until the future is done.
+        """
+        # set cancelled state
+        self.cancelled = True
+        self.future.cancel()
+        concurrent.futures.wait([self.future])
+
+
+class CancelThreadException(BaseException):
+    pass
+
 
 class OWNNLearner(OWBaseLearner):
     name = "Neural Network"
@@ -53,11 +86,20 @@ def add_main_layout(self):
             label="Alpha:", decimals=5, alignment=Qt.AlignRight,
             callback=self.settings_changed, controlWidth=80)
         self.max_iter_spin = gui.spin(
-            box, self, "max_iterations", 10, 300, step=10,
+            box, self, "max_iterations", 10, 10000, step=10,
             label="Max iterations:", orientation=Qt.Horizontal,
             alignment=Qt.AlignRight, callback=self.settings_changed,
             controlWidth=80)
 
+    def setup_layout(self):
+        super().setup_layout()
+
+        self._task = None  # type: Optional[Task]
+        self._executor = ThreadExecutor()
+
+        # just a test cancel button
+        gui.button(self.controlArea, self, "Cancel", callback=self.cancel)
+
     def create_learner(self):
         return self.LEARNER(
             hidden_layer_sizes=self.get_hidden_layers(),
@@ -81,6 +123,106 @@ def get_hidden_layers(self):
             self.hidden_layers_edit.setText("100,")
         return layers
 
+    def update_model(self):
+        self.show_fitting_failed(None)
+        self.model = None
+        if self.check_data():
+            self.__update()
+        else:
+            self.Outputs.model.send(self.model)
+
+    @Slot(float)
+    def setProgressValue(self, value):
+        assert self.thread() is QThread.currentThread()
+        self.progressBarSet(value)
+
+    def __update(self):
+        if self._task is not None:
+            # First make sure any pending tasks are cancelled.
+            self.cancel()
+        assert self._task is None
+
+        self.setBlocking(True)
+
+        self._task = task = Task()
+
+        # A thread safe way to invoke a method
+        set_progress = methodinvoke(self, "setProgressValue", (float,))
+
+        max_iter = self.learner.kwargs["max_iter"]
+
+        def callback(iteration):
+            if task.cancelled:
+                raise CancelThreadException()  # this stop the thread
+            set_progress(iteration/max_iter*100)
+
+        # copy to set the callback so that the learner output is not modified
+        # (currently we can not pass callbacks to learners __call__)
+        learner = copy.copy(self.learner)
+        learner.callback = callback
+
+        def build_model(data, learner):
+            return learner(data)
+
+        build_model_func = partial(build_model, self.data, learner)
+
+        self.progressBarInit()
+
+        task.future = self._executor.submit(build_model_func)
+        task.watcher = FutureWatcher(task.future)
+        task.watcher.done.connect(self._task_finished)
+
+    @Slot(concurrent.futures.Future)
+    def _task_finished(self, f):
+        """
+        Parameters
+        ----------
+        f : Future
+            The future instance holding the built model
+        """
+        assert self.thread() is QThread.currentThread()
+        assert self._task is not None
+        assert self._task.future is f
+        assert f.done()
+
+        self.setBlocking(False)
+
+        self._task = None
+        self.progressBarFinished()
+
+        try:
+            self.model = f.result()
+        except Exception as ex:  # pylint: disable=broad-except
+            # Log the exception with a traceback
+            log = logging.getLogger()
+            log.exception(__name__, exc_info=True)
+            self.model = None
+            self.show_fitting_failed(ex)
+        else:
+            self.model.name = self.learner_name
+            self.model.instances = self.data
+            self.Outputs.model.send(self.model)
+
+    def cancel(self):
+        """
+        Cancel the current task (if any).
+        """
+        if self._task is not None:
+            self._task.cancel()
+            assert self._task.future.done()
+            # disconnect the `_task_finished` slot
+            self._task.watcher.done.disconnect(self._task_finished)
+            self._task = None
+        # threads use signals to run functions in the main thread and some
+        # can still be quoued (perhaps change)
+        qApp.processEvents()
+        self.progressBarFinished()
+        self.setBlocking(False)
+
+    def onDeleteWidget(self):
+        self.cancel()
+        super().onDeleteWidget()
+
 
 if __name__ == "__main__":
     a = QApplication(sys.argv)

Orange/widgets/tests/base.py

@@ -514,13 +514,16 @@ def test_input_data(self):
         self.assertEqual(self.widget.data, None)
         self.send_signal("Data", self.data)
         self.assertEqual(self.widget.data, self.data)
+        self.wait_until_stop_blocking()
 
     def test_input_data_disconnect(self):
         """Check widget's data and model after disconnecting data from input"""
         self.send_signal("Data", self.data)
         self.assertEqual(self.widget.data, self.data)
         self.widget.apply_button.button.click()
+        self.wait_until_stop_blocking()
         self.send_signal("Data", None)
+        self.wait_until_stop_blocking()
         self.assertEqual(self.widget.data, None)
         self.assertIsNone(self.get_output(self.widget.Outputs.model))
 
@@ -529,9 +532,11 @@ def test_input_data_learner_adequacy(self):
         for inadequate in self.inadequate_dataset:
             self.send_signal("Data", inadequate)
             self.widget.apply_button.button.click()
+            self.wait_until_stop_blocking()
             self.assertTrue(self.widget.Error.data_error.is_shown())
         for valid in self.valid_datasets:
             self.send_signal("Data", valid)
+            self.wait_until_stop_blocking()
             self.assertFalse(self.widget.Error.data_error.is_shown())
 
     def test_input_preprocessor(self):
@@ -542,6 +547,7 @@ def test_input_preprocessor(self):
             randomize, self.widget.preprocessors,
             'Preprocessor not added to widget preprocessors')
         self.widget.apply_button.button.click()
+        self.wait_until_stop_blocking()
         self.assertEqual(
             (randomize,), self.widget.learner.preprocessors,
             'Preprocessors were not passed to the learner')
@@ -551,6 +557,7 @@ def test_input_preprocessors(self):
         pp_list = PreprocessorList([Randomize(), RemoveNaNColumns()])
         self.send_signal("Preprocessor", pp_list)
         self.widget.apply_button.button.click()
+        self.wait_until_stop_blocking()
         self.assertEqual(
             (pp_list,), self.widget.learner.preprocessors,
             '`PreprocessorList` was not added to preprocessors')
@@ -560,10 +567,12 @@ def test_input_preprocessor_disconnect(self):
         randomize = Randomize()
         self.send_signal("Preprocessor", randomize)
         self.widget.apply_button.button.click()
+        self.wait_until_stop_blocking()
         self.assertEqual(randomize, self.widget.preprocessors)
 
         self.send_signal("Preprocessor", None)
         self.widget.apply_button.button.click()
+        self.wait_until_stop_blocking()
         self.assertIsNone(self.widget.preprocessors,
                           'Preprocessors not removed on disconnect.')
 
@@ -585,6 +594,7 @@ def test_output_model(self):
         self.assertIsNone(self.get_output(self.widget.Outputs.model))
         self.send_signal('Data', self.data)
         self.widget.apply_button.button.click()
+        self.wait_until_stop_blocking()
         model = self.get_output(self.widget.Outputs.model)
         self.assertIsNotNone(model)
         self.assertIsInstance(model, self.widget.LEARNER.__returns__)
@@ -598,6 +608,7 @@ def test_output_learner_name(self):
                          self.widget.name_line_edit.text())
         self.widget.name_line_edit.setText(new_name)
         self.widget.apply_button.button.click()
+        self.wait_until_stop_blocking()
         self.assertEqual(self.get_output("Learner").name, new_name)
 
     def test_output_model_name(self):
@@ -606,6 +617,7 @@ def test_output_model_name(self):
         self.widget.name_line_edit.setText(new_name)
         self.send_signal("Data", self.data)
         self.widget.apply_button.button.click()
+        self.wait_until_stop_blocking()
         self.assertEqual(self.get_output(self.widget.Outputs.model).name, new_name)
 
     def _get_param_value(self, learner, param):
@@ -626,6 +638,7 @@ def test_parameters_default(self):
         for dataset in self.valid_datasets:
             self.send_signal("Data", dataset)
             self.widget.apply_button.button.click()
+            self.wait_until_stop_blocking()
             for parameter in self.parameters:
                 # Skip if the param isn't used for the given data type
                 if self._should_check_parameter(parameter, dataset):
@@ -639,6 +652,7 @@ def test_parameters(self):
         # to only certain problem types
         for dataset in self.valid_datasets:
             self.send_signal("Data", dataset)
+            self.wait_until_stop_blocking()
 
             for parameter in self.parameters:
                 # Skip if the param isn't used for the given data type
@@ -650,6 +664,7 @@ def test_parameters(self):
                 for value in parameter.values:
                     parameter.set_value(value)
                     self.widget.apply_button.button.click()
+                    self.wait_until_stop_blocking()
                     param = self._get_param_value(self.widget.learner, parameter)
                     self.assertEqual(
                         param, parameter.get_value(),
@@ -674,6 +689,7 @@ def test_params_trigger_settings_changed(self):
         """Check that the learner gets updated whenever a param is changed."""
         for dataset in self.valid_datasets:
             self.send_signal("Data", dataset)
+            self.wait_until_stop_blocking()
 
             for parameter in self.parameters:
                 # Skip if the param isn't used for the given data type