Skip to content

1.x: merge/flatMap to keep scalar/inner element relative order #4209

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Jul 20, 2016
Merged

1.x: merge/flatMap to keep scalar/inner element relative order #4209

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
e741bb9
1.x: merge/flatMap to keep scalar/inner element relative order
akarnokd Jul 18, 2016
7ff13ed
Read the queue references once
akarnokd Jul 20, 2016
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 14 additions & 4 deletions src/main/java/rx/internal/operators/OperatorMerge.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -352,9 +352,15 @@ void tryEmit(InnerSubscriber<T> subscriber, T value) {
}
}
if (success) {
emitScalar(subscriber, value, r);
if (subscriber.queue == null || subscriber.queue.isEmpty()) {
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

assign subscriber.queue to local variable to avoid double volatile read?

emitScalar(subscriber, value, r);
} else {
queueScalar(subscriber, value);
emitLoop();
}
} else {
queueScalar(subscriber, value);
emit();
}
}

Expand Down Expand Up @@ -383,7 +389,6 @@ protected void queueScalar(InnerSubscriber<T> subscriber, T value) {
}
return;
}
emit();
}

protected void emitScalar(InnerSubscriber<T> subscriber, T value, long r) {
Expand Down Expand Up @@ -460,9 +465,15 @@ void tryEmit(T value) {
}
}
if (success) {
emitScalar(value, r);
if (queue == null || queue.isEmpty()) {
emitScalar(value, r);
} else {
queueScalar(value);
emitLoop();
}
} else {
queueScalar(value);
emit();
}
}

Expand Down Expand Up @@ -495,7 +506,6 @@ protected void queueScalar(T value) {
onError(OnErrorThrowable.addValueAsLastCause(new MissingBackpressureException(), value));
return;
}
emit();
}

protected void emitScalar(T value, long r) {
Expand Down
41 changes: 41 additions & 0 deletions src/test/java/rx/internal/operators/OperatorMergeTest.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -34,6 +34,7 @@
import rx.Observer;
import rx.Scheduler.Worker;
import rx.functions.*;
import rx.internal.operators.OperatorMerge.*;
import rx.internal.util.*;
import rx.observers.TestSubscriber;
import rx.schedulers.*;
Expand Down Expand Up @@ -1498,4 +1499,44 @@ public void flatMapMaxConcurrentJustRange() {
ts.assertNoErrors();
ts.assertCompleted();
}

@Test
public void noInnerReordering() {
TestSubscriber<Integer> ts = TestSubscriber.create(0);
MergeSubscriber<Integer> ms = new MergeSubscriber<Integer>(ts, false, 128);
ms.producer = new MergeProducer<Integer>(ms);
ts.setProducer(ms.producer);

PublishSubject<Integer> ps = PublishSubject.create();

ms.onNext(ps);

ps.onNext(1);

BackpressureUtils.getAndAddRequest(ms.producer, 2);

ps.onNext(2);

ms.emit();

ts.assertValues(1, 2);
}

@Test
public void noOuterScalarReordering() {
TestSubscriber<Integer> ts = TestSubscriber.create(0);
MergeSubscriber<Integer> ms = new MergeSubscriber<Integer>(ts, false, 128);
ms.producer = new MergeProducer<Integer>(ms);
ts.setProducer(ms.producer);

ms.onNext(Observable.just(1));

BackpressureUtils.getAndAddRequest(ms.producer, 2);

ms.onNext(Observable.just(2));

ms.emit();

ts.assertValues(1, 2);
}
}