Class PromiseCombiner
A promise combiner monitors the outcome of a number of discrete futures, then notifies a final, aggregate promise when all of the combined futures are finished. The aggregate promise will succeed if and only if all of the combined futures succeed. If any of the combined futures fail, the aggregate promise will fail. The cause failure for the aggregate promise will be the failure for one of the failed combined futures; if more than one of the combined futures fails, exactly which cause of failure will be assigned to the aggregate promise is undefined.
Callers may populate a promise combiner with any number of futures to be combined via the
add(Future)
and addAll(Future[])
methods. When all futures to be
combined have been added, callers must provide an aggregate promise to be notified when all combined promises have
finished via the finish(Promise)
method.
This implementation is NOT thread-safe and all methods must be called
from the EventExecutor
thread.
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate Throwable
private int
private final EventExecutor
private int
private final GenericFutureListener
<Future<?>> -
Constructor Summary
ConstructorsConstructorDescriptionDeprecated.PromiseCombiner
(EventExecutor executor) TheEventExecutor
to use for notifications. -
Method Summary
Modifier and TypeMethodDescriptionvoid
Adds a new future to be combined.void
Deprecated.void
Adds new futures to be combined.void
Deprecated.Replaced byaddAll(Future[])
private void
private void
void
Sets the promise to be notified when all combined futures have finished.private boolean
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Field Details
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expectedCount
private int expectedCount -
doneCount
private int doneCount -
aggregatePromise
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cause
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listener
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executor
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Constructor Details
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PromiseCombiner
Deprecated.Deprecated usePromiseCombiner(EventExecutor)
. -
PromiseCombiner
TheEventExecutor
to use for notifications. You must calladd(Future)
,addAll(Future[])
andfinish(Promise)
from within theEventExecutor
thread.- Parameters:
executor
- theEventExecutor
to use for notifications.
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Method Details
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add
Deprecated.Replaced byadd(Future)
.Adds a new promise to be combined. New promises may be added until an aggregate promise is added via thefinish(Promise)
method.- Parameters:
promise
- the promise to add to this promise combiner
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add
Adds a new future to be combined. New futures may be added until an aggregate promise is added via thefinish(Promise)
method.- Parameters:
future
- the future to add to this promise combiner
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addAll
Deprecated.Replaced byaddAll(Future[])
Adds new promises to be combined. New promises may be added until an aggregate promise is added via thefinish(Promise)
method.- Parameters:
promises
- the promises to add to this promise combiner
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addAll
Adds new futures to be combined. New futures may be added until an aggregate promise is added via thefinish(Promise)
method.- Parameters:
futures
- the futures to add to this promise combiner
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finish
Sets the promise to be notified when all combined futures have finished. If all combined futures succeed, then the aggregate promise will succeed. If one or more combined futures fails, then the aggregate promise will fail with the cause of one of the failed futures. If more than one combined future fails, then exactly which failure will be assigned to the aggregate promise is undefined.
After this method is called, no more futures may be added via the
add(Future)
oraddAll(Future[])
methods.- Parameters:
aggregatePromise
- the promise to notify when all combined futures have finished
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checkInEventLoop
private void checkInEventLoop() -
tryPromise
private boolean tryPromise() -
checkAddAllowed
private void checkAddAllowed()
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add(Future)
.