Update examples to use 'shutdown' (#385)

docs/source/guide/contexts.rst

@@ -45,7 +45,7 @@ a multiprocessing context::
             view = SquaringHelper(traits_executor=traits_executor)
             view.configure_traits()
         finally:
-            traits_executor.stop()
+            traits_executor.shutdown()
             context.close()
 
 Here's a :download:`complete TraitsUI example

docs/source/guide/examples/background_processes.py

@@ -23,7 +23,16 @@
 import random
 import time
 
-from traits.api import Button, Dict, Instance, List, Property, Range, Str
+from traits.api import (
+    Button,
+    Dict,
+    HasStrictTraits,
+    Instance,
+    List,
+    Property,
+    Range,
+    Str,
+)
 from traits_futures.api import (
     CallFuture,
     CANCELLED,
@@ -37,7 +46,6 @@
     WAITING,
 )
 from traitsui.api import (
-    Handler,
     HGroup,
     Item,
     TabularAdapter,
@@ -100,7 +108,7 @@ def _get_state_text(self):
         return state_text
 
 
-class SquaringHelper(Handler):
+class SquaringHelper(HasStrictTraits):
     #: The Traits executor for the background jobs.
     traits_executor = Instance(TraitsExecutor)
 
@@ -168,7 +176,7 @@ def main():
         view = SquaringHelper(traits_executor=traits_executor)
         view.configure_traits()
     finally:
-        traits_executor.stop()
+        traits_executor.shutdown()
         context.close()
 
 

docs/source/guide/examples/fizz_buzz_ui.py

@@ -29,7 +29,7 @@
 
 class FizzBuzzUI(HasStrictTraits):
     #: The executor to submit tasks to.
-    executor = Instance(TraitsExecutor, ())
+    traits_executor = Instance(TraitsExecutor)
 
     #: The future object returned on task submission.
     future = Instance(FizzBuzzFuture)
@@ -48,7 +48,7 @@ class FizzBuzzUI(HasStrictTraits):
     @observe("calculate")
     def _submit_calculation(self, event):
         self.message = "Running"
-        self.future = submit_fizz_buzz(self.executor)
+        self.future = submit_fizz_buzz(self.traits_executor)
 
     @observe("cancel")
     def _cancel_running_task(self, event):
@@ -89,4 +89,8 @@ def _get_can_cancel(self):
 
 
 if __name__ == "__main__":
-    FizzBuzzUI().configure_traits()
+    traits_executor = TraitsExecutor()
+    try:
+        FizzBuzzUI(traits_executor=traits_executor).configure_traits()
+    finally:
+        traits_executor.shutdown()

docs/source/guide/examples/interruptible_task.py

@@ -56,7 +56,7 @@ def approximate_pi(sample_count=10 ** 8):
 
 class InterruptibleTaskExample(HasStrictTraits):
     #: The executor to submit tasks to.
-    executor = Instance(TraitsExecutor, ())
+    traits_executor = Instance(TraitsExecutor)
 
     #: The future object returned on task submission.
     future = Instance(IFuture)
@@ -79,7 +79,7 @@ class InterruptibleTaskExample(HasStrictTraits):
     def _submit_calculation(self, event):
         self.message = "Calculating π"
         self.future = submit_iteration(
-            self.executor, approximate_pi, self.sample_count
+            self.traits_executor, approximate_pi, self.sample_count
         )
 
     @observe("cancel")
@@ -123,4 +123,10 @@ def _get_can_cancel(self):
 
 
 if __name__ == "__main__":
-    InterruptibleTaskExample().configure_traits()
+    traits_executor = TraitsExecutor()
+    try:
+        InterruptibleTaskExample(
+            traits_executor=traits_executor
+        ).configure_traits()
+    finally:
+        traits_executor.shutdown()

docs/source/guide/examples/non_interruptible_task.py

@@ -54,7 +54,7 @@ def approximate_pi(sample_count=10 ** 8):
 
 class NonInterruptibleTaskExample(HasStrictTraits):
     #: The executor to submit tasks to.
-    executor = Instance(TraitsExecutor, ())
+    traits_executor = Instance(TraitsExecutor)
 
     #: The future object returned on task submission.
     future = Instance(IFuture)
@@ -77,7 +77,7 @@ class NonInterruptibleTaskExample(HasStrictTraits):
     def _submit_calculation(self, event):
         self.message = "Calculating π"
         self.future = submit_call(
-            self.executor, approximate_pi, self.sample_count
+            self.traits_executor, approximate_pi, self.sample_count
         )
 
     @observe("cancel")
@@ -117,4 +117,10 @@ def _get_can_cancel(self):
 
 
 if __name__ == "__main__":
-    NonInterruptibleTaskExample().configure_traits()
+    traits_executor = TraitsExecutor()
+    try:
+        NonInterruptibleTaskExample(
+            traits_executor=traits_executor
+        ).configure_traits()
+    finally:
+        traits_executor.shutdown()

docs/source/guide/examples/pi_iterations.py

@@ -24,6 +24,7 @@
     Bool,
     Button,
     Float,
+    HasStrictTraits,
     Instance,
     Int,
     List,
@@ -36,7 +37,7 @@
     submit_iteration,
     TraitsExecutor,
 )
-from traitsui.api import Handler, HGroup, Item, UItem, VGroup, View
+from traitsui.api import HGroup, Item, UItem, VGroup, View
 
 
 def pi_iterations(chunk_size):
@@ -79,13 +80,13 @@ def pi_iterations(chunk_size):
         yield nsamples, approximation, error
 
 
-class PiIterator(Handler):
+class PiIterator(HasStrictTraits):
     """
     View and plot of pi approximation running in the background.
     """
 
     #: The Traits executor for the background jobs.
-    traits_executor = Instance(TraitsExecutor, ())
+    traits_executor = Instance(TraitsExecutor)
 
     #: Chunk size to use for the approximations.
     chunk_size = Int(1000000)
@@ -117,11 +118,6 @@ class PiIterator(Handler):
     #: The plot.
     plot = Instance(Plot)
 
-    def closed(self, info, is_ok):
-        # Stopping the executor cancels any running future.
-        self.traits_executor.stop()
-        super().closed(info, is_ok)
-
     def _approximate_fired(self):
         self.future = submit_iteration(
             self.traits_executor, pi_iterations, chunk_size=self.chunk_size
@@ -197,5 +193,9 @@ def default_traits_view(self):
 
 
 if __name__ == "__main__":
-    view = PiIterator()
-    view.configure_traits()
+    traits_executor = TraitsExecutor()
+    try:
+        view = PiIterator(traits_executor=traits_executor)
+        view.configure_traits()
+    finally:
+        traits_executor.shutdown()

docs/source/guide/examples/prime_counting.py

@@ -32,7 +32,7 @@
     submit_progress,
     TraitsExecutor,
 )
-from traitsui.api import Handler, HGroup, Item, UItem, VGroup, View
+from traitsui.api import HGroup, Item, UItem, VGroup, View
 
 
 class ProgressDialog(Dialog, HasStrictTraits):
@@ -175,13 +175,13 @@ def count_primes_less_than(n, chunk_size, progress=None):
     return prime_count
 
 
-class PrimeCounter(Handler):
+class PrimeCounter(HasStrictTraits):
     """
     UI to compute primes less than a given number.
     """
 
     #: The Traits executor for the background jobs.
-    traits_executor = Instance(TraitsExecutor, ())
+    traits_executor = Instance(TraitsExecutor)
 
     #: Calculation future.
     future = Instance(ProgressFuture)
@@ -204,11 +204,6 @@ class PrimeCounter(Handler):
     #: Limit used for most recent run.
     _last_limit = Int()
 
-    def closed(self, info, is_ok):
-        # Stopping the executor cancels any running future.
-        self.traits_executor.stop()
-        super().closed(info, is_ok)
-
     def _count_fired(self):
         self._last_limit = self.limit
         self.future = submit_progress(
@@ -256,5 +251,9 @@ def default_traits_view(self):
 
 
 if __name__ == "__main__":
-    view = PrimeCounter()
-    view.configure_traits()
+    traits_executor = TraitsExecutor()
+    try:
+        view = PrimeCounter(traits_executor=traits_executor)
+        view.configure_traits()
+    finally:
+        traits_executor.shutdown()

docs/source/guide/examples/quick_start.py

@@ -32,7 +32,7 @@ def slow_square(n):
 
 class QuickStartExample(HasStrictTraits):
     #: The executor to submit tasks to.
-    executor = Instance(TraitsExecutor, ())
+    traits_executor = Instance(TraitsExecutor)
 
     #: The future object returned on task submission.
     future = Instance(CallFuture)
@@ -58,7 +58,7 @@ def _submit_background_call(self, event):
         input = self.input
         self.input_for_calculation = self.input
         self.message = "Calculating square of {} ...".format(input)
-        self.future = submit_call(self.executor, slow_square, input)
+        self.future = submit_call(self.traits_executor, slow_square, input)
         # Keep a record so that we can present messages accurately.
         self.input_for_calculation = input
 
@@ -80,4 +80,9 @@ def _get_no_running_future(self):
     )
 
 
-QuickStartExample().configure_traits()
+if __name__ == "__main__":
+    traits_executor = TraitsExecutor()
+    try:
+        QuickStartExample(traits_executor=traits_executor).configure_traits()
+    finally:
+        traits_executor.shutdown()

docs/source/guide/examples/slow_squares.py

@@ -12,7 +12,16 @@
 import random
 import time
 
-from traits.api import Button, Dict, Instance, List, Property, Range, Str
+from traits.api import (
+    Button,
+    Dict,
+    HasStrictTraits,
+    Instance,
+    List,
+    Property,
+    Range,
+    Str,
+)
 from traits_futures.api import (
     CallFuture,
     CANCELLED,
@@ -25,7 +34,6 @@
     WAITING,
 )
 from traitsui.api import (
-    Handler,
     HGroup,
     Item,
     TabularAdapter,
@@ -88,9 +96,9 @@ def _get_state_text(self):
         return state_text
 
 
-class SquaringHelper(Handler):
+class SquaringHelper(HasStrictTraits):
     #: The Traits executor for the background jobs.
-    traits_executor = Instance(TraitsExecutor, ())
+    traits_executor = Instance(TraitsExecutor)
 
     #: List of the submitted jobs, for display purposes.
     current_futures = List(Instance(CallFuture))
@@ -107,11 +115,6 @@ class SquaringHelper(Handler):
     #: Value that we'll square.
     input = Range(low=0, high=100)
 
-    def closed(self, info, is_ok):
-        # Cancel all jobs at shutdown.
-        self.traits_executor.stop()
-        super().closed(info, is_ok)
-
     def _square_fired(self):
         future = submit_call(self.traits_executor, slow_square, self.input)
         self.current_futures.append(future)
@@ -158,5 +161,9 @@ def default_traits_view(self):
             "%(asctime)s %(levelname)-8.8s [%(name)s:%(lineno)s] %(message)s"
         ),
     )
-    view = SquaringHelper()
-    view.configure_traits()
+    traits_executor = TraitsExecutor()
+    try:
+        view = SquaringHelper(traits_executor=traits_executor)
+        view.configure_traits()
+    finally:
+        traits_executor.shutdown()

docs/source/guide/examples/test_future.py

@@ -31,25 +31,23 @@
 class TestMyFuture(GuiTestAssistant, unittest.TestCase):
     def setUp(self):
         GuiTestAssistant.setUp(self)
-        self.executor = TraitsExecutor()
+        self.traits_executor = TraitsExecutor()
 
     def tearDown(self):
         # Request the executor to stop, and wait for that stop to complete.
-        self.executor.stop()
-        self.assertEventuallyTrueInGui(
-            lambda: self.executor.stopped, timeout=SAFETY_TIMEOUT
-        )
-
+        self.traits_executor.shutdown(timeout=SAFETY_TIMEOUT)
         GuiTestAssistant.tearDown(self)
 
     def test_my_future(self):
-        executor = self.executor
-
-        future = submit_call(executor, pow, 3, 5)
+        future = submit_call(self.traits_executor, pow, 3, 5)
 
         # Wait for the future to complete.
         self.assertEventuallyTrueInGui(
             lambda: future.done, timeout=SAFETY_TIMEOUT
         )
 
         self.assertEqual(future.result, 243)
+
+
+if __name__ == "__main__":
+    unittest.main()