Github user aledsage commented on a diff in the pull request:
https://github.com/apache/brooklyn-server/pull/816#discussion_r141917156
--- Diff:
core/src/main/java/org/apache/brooklyn/util/core/task/BasicExecutionContext.java
---
@@ -100,6 +123,121 @@ public ExecutionManager getExecutionManager() {
@Override
public Set<Task<?>> getTasks() { return
executionManager.getTasksWithAllTags(tags); }
+ @Override
+ public <T> T get(TaskAdaptable<T> task) {
+ final TaskInternal<T> t = (TaskInternal<T>) task.asTask();
+
+ if (t.isQueuedOrSubmitted()) {
+ if (t.isDone()) {
+ return t.getUnchecked();
+ } else {
+ throw new ImmediateUnsupportedException("Task is in
progress and incomplete: "+t);
+ }
+ }
+
+ ContextSwitchingInfo<T> switchContextWrapper =
getContextSwitchingTask(t, Collections.emptyList(), false);
+ if (switchContextWrapper!=null) {
+ return
switchContextWrapper.context.get(switchContextWrapper.wrapperTask);
+ }
+
+ try {
+ return runInSameThread(t, new Callable<Maybe<T>>() {
--- End diff --
Good point, you're right.
I think it's therefore the usage pattern that's scary - blocking on some
alien code (i.e. a task) to finish executing while potentially holding a bunch
of synchronization locks yourself. But anything we do in that area would need
careful review of the callers rather than changes here.
---
