[
https://issues.apache.org/jira/browse/BROOKLYN-544?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16201663#comment-16201663
]
ASF GitHub Bot commented on BROOKLYN-544:
-----------------------------------------
Github user aledsage commented on a diff in the pull request:
https://github.com/apache/brooklyn-server/pull/860#discussion_r144225899
--- Diff:
core/src/main/java/org/apache/brooklyn/core/sensor/AttributeMap.java ---
@@ -138,62 +165,91 @@ private void checkPath(Collection<String> path) {
Preconditions.checkArgument(!path.isEmpty(), "path can't be
empty");
}
+ /**
+ * Sets a value and published it.
+ * <p>
+ * Constraints of {@link #getLockInternal()} apply, with lock-holder
being the supplied {@link Function}.
+ */
public <T> T update(AttributeSensor<T> attribute, T newValue) {
// 2017-10 this was unsynched which meant if two threads updated
// the last publication would not correspond to the last value.
- // could introduce deadlock but emit internal and publish should
- // not seek any locks. _subscribe_ and _delivery_ might, but they
- // won't be in this block. an issue with
_subscribe-and-get-initial_
- // should be resolved by initial subscription queueing the
publication
- // to a context where locks are not held.
- synchronized (values) {
- T oldValue = updateWithoutPublishing(attribute, newValue);
+ // a crude `synchronized (values)` could cause deadlock as
+ // this does publish (doing `synch(LSM)`) whereas _subscribe_
+ // would have the LSM lock and try to `synch(values)`
+ // as described at
https://issues.apache.org/jira/browse/BROOKLYN-544.
+ // the addition of getLockInternal should make this much cleaner,
+ // as no one holding `synch(LSM)` should be updating here,
+ // ands gets here won't call any other code at all
+ return withLock(() -> {
+ T oldValue = updateInternalWithoutLockOrPublish(attribute,
newValue);
entity.emitInternal(attribute, newValue);
return oldValue;
- }
+ });
}
+ /** @deprecated since 0.13.0 this is becoming an internal method,
{@link #updateInternalWithoutLockOrPublish(AttributeSensor, Object)} */
--- End diff --
Should be `since 1.0.0`
> Deadlock in enricher's subscription
> -----------------------------------
>
> Key: BROOKLYN-544
> URL: https://issues.apache.org/jira/browse/BROOKLYN-544
> Project: Brooklyn
> Issue Type: Bug
> Reporter: Aled Sage
> Priority: Blocker
>
> With brooklyn 1.0.0-SNAPSHOT, running the test
> {{YamlRollingTimeWindowMeanEnricherTest}} many times, it hung with the
> deadlock shown below:
> {noformat}
> Found one Java-level deadlock:
> =============================
> "brooklyn-execmanager-CkWF5Jg7-1":
> waiting to lock monitor 0x00007f8e9c025de8 (object 0x00000007b5fee528, a
> org.apache.brooklyn.core.mgmt.internal.LocalSubscriptionManager),
> which is held by "main"
> "main":
> waiting to lock monitor 0x00007f8e9b95ebe8 (object 0x00000007b6042cf8, a
> java.util.Collections$SynchronizedMap),
> which is held by "brooklyn-execmanager-CkWF5Jg7-1"
> Java stack information for the threads listed above:
> ===================================================
> "brooklyn-execmanager-CkWF5Jg7-1":
> at
> org.apache.brooklyn.core.mgmt.internal.LocalSubscriptionManager.getSubscriptionsForEntitySensor(LocalSubscriptionManager.java:207)
> - waiting to lock <0x00000007b5fee528> (a
> org.apache.brooklyn.core.mgmt.internal.LocalSubscriptionManager)
> at
> org.apache.brooklyn.core.mgmt.internal.LocalSubscriptionManager.publish(LocalSubscriptionManager.java:255)
> at
> org.apache.brooklyn.core.mgmt.internal.BasicSubscriptionContext.publish(BasicSubscriptionContext.java:176)
> at
> org.apache.brooklyn.core.entity.AbstractEntity$BasicSensorSupport.emitInternal(AbstractEntity.java:1059)
> at
> org.apache.brooklyn.core.sensor.AttributeMap.update(AttributeMap.java:151)
> - locked <0x00000007b6042cf8> (a
> java.util.Collections$SynchronizedMap)
> at
> org.apache.brooklyn.core.entity.AbstractEntity$BasicSensorSupport.set(AbstractEntity.java:957)
> at
> org.apache.brooklyn.core.enricher.AbstractEnricher.emit(AbstractEnricher.java:144)
> at
> org.apache.brooklyn.enricher.stock.AbstractTransformer.onEvent(AbstractTransformer.java:157)
> at
> org.apache.brooklyn.core.mgmt.internal.LocalSubscriptionManager$1.run(LocalSubscriptionManager.java:336)
> at
> org.apache.brooklyn.core.mgmt.internal.LocalSubscriptionManager.submitPublishEvent(LocalSubscriptionManager.java:352)
> at
> org.apache.brooklyn.core.mgmt.internal.LocalSubscriptionManager.lambda$0(LocalSubscriptionManager.java:192)
> at
> org.apache.brooklyn.core.mgmt.internal.LocalSubscriptionManager$$Lambda$3/871160466.run(Unknown
> Source)
> at
> java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> at
> org.apache.brooklyn.util.core.task.BasicExecutionManager$SubmissionCallable.call(BasicExecutionManager.java:565)
> at
> org.apache.brooklyn.util.core.task.SingleThreadedScheduler$1.call(SingleThreadedScheduler.java:116)
> at java.util.concurrent.FutureTask.run(FutureTask.java:266)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> at java.lang.Thread.run(Thread.java:745)
> "main":
> at java.util.Collections$SynchronizedMap.get(Collections.java:2584)
> - waiting to lock <0x00000007b6042cf8> (a
> java.util.Collections$SynchronizedMap)
> at
> org.apache.brooklyn.core.sensor.AttributeMap.getValue(AttributeMap.java:219)
> at
> org.apache.brooklyn.core.sensor.AttributeMap.getValue(AttributeMap.java:225)
> at
> org.apache.brooklyn.core.entity.AbstractEntity$BasicSensorSupport.get(AbstractEntity.java:932)
> at
> org.apache.brooklyn.core.mgmt.internal.LocalSubscriptionManager.subscribe(LocalSubscriptionManager.java:147)
> - locked <0x00000007b5fee528> (a
> org.apache.brooklyn.core.mgmt.internal.LocalSubscriptionManager)
> at
> org.apache.brooklyn.core.mgmt.internal.AbstractSubscriptionManager.subscribe(AbstractSubscriptionManager.java:106)
> at
> org.apache.brooklyn.core.mgmt.internal.BasicSubscriptionContext.subscribe(BasicSubscriptionContext.java:98)
> at
> org.apache.brooklyn.core.mgmt.internal.SubscriptionTracker.subscribe(SubscriptionTracker.java:67)
> at
> org.apache.brooklyn.core.objs.AbstractEntityAdjunct$BasicSubscriptionSupport.subscribe(AbstractEntityAdjunct.java:238)
> at
> org.apache.brooklyn.enricher.stock.AbstractTransformer.setEntity(AbstractTransformer.java:120)
> at
> org.apache.brooklyn.enricher.stock.YamlRollingTimeWindowMeanEnricher.setEntity(YamlRollingTimeWindowMeanEnricher.java:93)
> at
> org.apache.brooklyn.core.entity.AbstractEntity$BasicEnricherSupport.add(AbstractEntity.java:1443)
> at
> org.apache.brooklyn.core.entity.AbstractEntity$BasicEnricherSupport.add(AbstractEntity.java:1429)
> at
> org.apache.brooklyn.enricher.stock.YamlRollingTimeWindowMeanEnricherTest.setUp(YamlRollingTimeWindowMeanEnricherTest.java:68)
> at sun.reflect.GeneratedMethodAccessor16.invoke(Unknown Source)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at java.lang.reflect.Method.invoke(Method.java:498)
> at
> org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:104)
> at
> org.testng.internal.Invoker.invokeConfigurationMethod(Invoker.java:515)
> at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:217)
> at org.testng.internal.Invoker.invokeMethod(Invoker.java:590)
> at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:851)
> at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1177)
> at
> org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:129)
> at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:112)
> at org.testng.TestRunner.privateRun(TestRunner.java:756)
> at org.testng.TestRunner.run(TestRunner.java:610)
> at org.testng.SuiteRunner.runTest(SuiteRunner.java:387)
> at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:382)
> at org.testng.SuiteRunner.privateRun(SuiteRunner.java:340)
> at org.testng.SuiteRunner.run(SuiteRunner.java:289)
> at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
> at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
> at org.testng.TestNG.runSuitesSequentially(TestNG.java:1293)
> at org.testng.TestNG.runSuitesLocally(TestNG.java:1218)
> at org.testng.TestNG.runSuites(TestNG.java:1133)
> at org.testng.TestNG.run(TestNG.java:1104)
> at
> org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:132)
> at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:230)
> at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:76)
> Found 1 deadlock.
> {noformat}
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