Github user aledsage commented on a diff in the pull request:
https://github.com/apache/brooklyn-server/pull/480#discussion_r101868262
--- Diff:
core/src/test/java/org/apache/brooklyn/core/entity/EntityConfigTest.java ---
@@ -244,59 +252,152 @@ public void
testGetConfigMapWithSubValueAsStringNotCoerced() throws Exception {
// of the previous "test.confMapThing.obj".
//
// Presumably an earlier call to task.get() timed out, causing it to
cancel the task?
+ // Alex: yes, a task.cancel is performed for maps in
+ //
AbstractEntity$BasicConfigurationSupport(AbstractConfigurationSupportInternal).getNonBlockingResolvingStructuredKey(ConfigKey<T>)
+
+ //
// I (Aled) question whether we want to support passing a task (rather
than a
// DeferredSupplier or TaskFactory, for example). Our
EntitySpec.configure is overloaded
// to take a Task, but that feels wrong!?
- @Test(groups="Broken")
- public void testGetTaskNonBlocking() throws Exception {
- final CountDownLatch latch = new CountDownLatch(1);
- Task<String> task = Tasks.<String>builder().body(
+ //
+ // If starting clean I (Alex) would agree, we should use TaskFactory.
However the
+ // DependentConfiguration methods -- including the ubiquitous
AttributeWhenReady --
+ // return Task instances so they should survive a getNonBlocking or
get with a short timeout
+ // access, and if a value is subsequently available it should be
returned
+ // (which this test asserts, but is currently failing). If TaskFactory
is used the
+ // intended semantics are clear -- you create a new task on each
access, and can interrupt it
+ // and discard it if needed. For a Task it's less clear: probably the
semantics are that the
+ // first returned value is what the value is forevermore. Probably it
should not be interrupted
+ // on a non-blocking / short-wait access, or possibly it should simply
be re-run if a previous
+ // execution was interrupted (but take care if we have a simultaneous
non-blocking and blocking
+ // access, if the first one interrupts the second one should still get
a value).
+ // I tend to think ideally we should switch to using TaskFactory in
DependentConfiguration.
+ class ConfigNonBlockingFixture {
+ final Semaphore latch = new Semaphore(0);
+ final String expectedVal = "myval";
+ Object blockingVal;
+
+ protected ConfigNonBlockingFixture usingTask() {
+ blockingVal = taskFactory().newTask();
+ return this;
+ }
+
+ protected ConfigNonBlockingFixture usingTaskFactory() {
+ blockingVal = taskFactory();
+ return this;
+ }
+
+ protected ConfigNonBlockingFixture usingDeferredSupplier() {
+ blockingVal = deferredSupplier();
+ return this;
+ }
+
+ protected ConfigNonBlockingFixture usingImmediateSupplier() {
+ blockingVal = new
InterruptingImmediateSupplier<String>(deferredSupplier());
+ return this;
+ }
+
+ private TaskFactory<Task<String>> taskFactory() {
+ return Tasks.<String>builder().body(
new Callable<String>() {
@Override
public String call() throws Exception {
- latch.await();
+ if (!latch.tryAcquire()) latch.acquire();
+ latch.release();
return "myval";
}})
- .build();
- runGetConfigNonBlocking(latch, task, "myval");
- }
-
- @Test
- public void testGetDeferredSupplierNonBlocking() throws Exception {
- final CountDownLatch latch = new CountDownLatch(1);
- DeferredSupplier<String> task = new DeferredSupplier<String>() {
- @Override public String get() {
- try {
- latch.await();
- } catch (InterruptedException e) {
- throw Exceptions.propagate(e);
- }
- return "myval";
- }
- };
- runGetConfigNonBlocking(latch, task, "myval");
- }
-
- @SuppressWarnings({"unchecked", "rawtypes"})
- protected void runGetConfigNonBlocking(CountDownLatch latch, Object
blockingVal, String expectedVal) throws Exception {
- TestEntity entity = (TestEntity)
mgmt.getEntityManager().createEntity(EntitySpec.create(TestEntity.class)
- .configure(TestEntity.CONF_MAP_OBJ_THING,
ImmutableMap.<String, Object>of("mysub", blockingVal))
- .configure((ConfigKey)TestEntity.CONF_NAME, blockingVal));
-
- // Will initially return absent, because task is not done
-
assertTrue(entity.config().getNonBlocking(TestEntity.CONF_MAP_OBJ_THING).isAbsent());
-
assertTrue(entity.config().getNonBlocking(TestEntity.CONF_MAP_OBJ_THING.subKey("mysub")).isAbsent());
+ .buildFactory();
+ }
- latch.countDown();
+ private DeferredSupplier<String> deferredSupplier() {
+ return new DeferredSupplier<String>() {
+ @Override public String get() {
+ try {
+ log.trace("acquiring");
+ if (!latch.tryAcquire()) latch.acquire();
+ latch.release();
+ log.trace("acquired and released");
+ } catch (InterruptedException e) {
+ log.trace("interrupted");
+ throw Exceptions.propagate(e);
+ }
+ return "myval";
+ }
+ };
+ }
- // Can now finish task, so will return expectedVal
- assertEquals(entity.config().get(TestEntity.CONF_MAP_OBJ_THING),
ImmutableMap.of("mysub", expectedVal));
-
assertEquals(entity.config().get(TestEntity.CONF_MAP_OBJ_THING.subKey("mysub")),
expectedVal);
+ protected void runGetConfigNonBlockingInKey() throws Exception {
+ Preconditions.checkNotNull(blockingVal, "Fixture must set
blocking val before running this");
+
+ @SuppressWarnings("unchecked")
+ TestEntity entity = (TestEntity)
mgmt.getEntityManager().createEntity(EntitySpec.create(TestEntity.class)
+
.configure((ConfigKey<Object>)(ConfigKey<?>)TestEntity.CONF_NAME, blockingVal));
+
+ log.trace("get non-blocking");
+ // Will initially return absent, because task is not done
+
assertTrue(entity.config().getNonBlocking(TestEntity.CONF_NAME).isAbsent());
+ log.trace("got absent");
+
+ latch.release();
+
+ // Can now finish task, so will return expectedVal
+ log.trace("get blocking");
+ assertEquals(entity.config().get(TestEntity.CONF_NAME),
expectedVal);
+ log.trace("got blocking");
+
assertEquals(entity.config().getNonBlocking(TestEntity.CONF_NAME).get(),
expectedVal);
+
+ latch.acquire();
+ log.trace("finished");
+ }
-
assertEquals(entity.config().getNonBlocking(TestEntity.CONF_MAP_OBJ_THING).get(),
ImmutableMap.of("mysub", expectedVal));
-
assertEquals(entity.config().getNonBlocking(TestEntity.CONF_MAP_OBJ_THING.subKey("mysub")).get(),
expectedVal);
+ protected void runGetConfigNonBlockingInMap() throws Exception {
+ Preconditions.checkNotNull(blockingVal, "Fixture must set
blocking val before running this");
+ TestEntity entity = (TestEntity)
mgmt.getEntityManager().createEntity(EntitySpec.create(TestEntity.class)
+ .configure(TestEntity.CONF_MAP_OBJ_THING,
ImmutableMap.<String, Object>of("mysub", blockingVal)));
+
+ // Will initially return absent, because task is not done
+
assertTrue(entity.config().getNonBlocking(TestEntity.CONF_MAP_OBJ_THING).isAbsent());
+
assertTrue(entity.config().getNonBlocking(TestEntity.CONF_MAP_OBJ_THING.subKey("mysub")).isAbsent());
+
+ latch.release();
+
+ // Can now finish task, so will return expectedVal
+
assertEquals(entity.config().get(TestEntity.CONF_MAP_OBJ_THING),
ImmutableMap.of("mysub", expectedVal));
+
assertEquals(entity.config().get(TestEntity.CONF_MAP_OBJ_THING.subKey("mysub")),
expectedVal);
+
+
assertEquals(entity.config().getNonBlocking(TestEntity.CONF_MAP_OBJ_THING).get(),
ImmutableMap.of("mysub", expectedVal));
+
assertEquals(entity.config().getNonBlocking(TestEntity.CONF_MAP_OBJ_THING.subKey("mysub")).get(),
expectedVal);
+ }
}
+ @Test(groups="Integration") // because takes 1s+
+ public void testGetTaskNonBlockingKey() throws Exception {
+ new
ConfigNonBlockingFixture().usingTask().runGetConfigNonBlockingInKey(); }
+ @Test(groups="Integration") // because takes 1s+
+ public void testGetTaskNonBlockingMap() throws Exception {
+ new
ConfigNonBlockingFixture().usingTask().runGetConfigNonBlockingInMap(); }
+
+ @Test(groups="Integration") // because takes 1s+
+ public void testGetTaskFactoryNonBlockingKey() throws Exception {
+ new
ConfigNonBlockingFixture().usingTaskFactory().runGetConfigNonBlockingInKey(); }
+ @Test(groups="Integration") // because takes 1s+
+ public void testGetTaskFactoryNonBlockingMap() throws Exception {
--- End diff --
Why does this now work? We still have the call to `task.cancel(true)` in
`AbstractConfigurationSupportInternal.getNonBlockingResolvingStructuredKey()`,
so during the first call to `getNonBlocking` we'll cancel the task. Is it
because that is a different task that does not pass the `cancel()` call down to
the actual config-key-value task that we are trying to evaluate?
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