Merge pull request #745 from zsxwing/issue-737

Fixed issue #737

Author: benjchristensen

rxjava-core/src/main/java/rx/operators/OperationSwitch.java

@@ -20,7 +20,7 @@
 import rx.Observer;
 import rx.Subscription;
 import rx.subscriptions.CompositeSubscription;
-import rx.subscriptions.MultipleAssignmentSubscription;
+import rx.subscriptions.SerialSubscription;
 import rx.util.functions.Func1;
 
 /**
@@ -62,8 +62,7 @@ public Subscription onSubscribe(Observer<? super T> observer) {
             SafeObservableSubscription parent;
             parent = new SafeObservableSubscription();
 
-            MultipleAssignmentSubscription child;
-            child = new MultipleAssignmentSubscription();
+            SerialSubscription child = new SerialSubscription();
 
             parent.wrap(sequences.subscribe(new SwitchObserver<T>(observer, parent, child)));
 
@@ -76,13 +75,13 @@ private static class SwitchObserver<T> implements Observer<Observable<? extends
         private final Object gate;
         private final Observer<? super T> observer;
         private final SafeObservableSubscription parent;
-        private final MultipleAssignmentSubscription child;
+        private final SerialSubscription child;
         private long latest;
         private boolean stopped;
         private boolean hasLatest;
 
         public SwitchObserver(Observer<? super T> observer, SafeObservableSubscription parent,
-                MultipleAssignmentSubscription child) {
+                SerialSubscription child) {
             this.observer = observer;
             this.parent = parent;
             this.child = child;
@@ -97,8 +96,7 @@ public void onNext(Observable<? extends T> args) {
                 this.hasLatest = true;
             }
 
-            final SafeObservableSubscription sub;
-            sub = new SafeObservableSubscription();
+            final SafeObservableSubscription sub = new SafeObservableSubscription();
             sub.wrap(args.subscribe(new Observer<T>() {
                 @Override
                 public void onNext(T args) {
@@ -111,28 +109,35 @@ public void onNext(T args) {
 
                 @Override
                 public void onError(Throwable e) {
+                    sub.unsubscribe();
+                    SafeObservableSubscription s = null;
                     synchronized (gate) {
-                        sub.unsubscribe();
                         if (latest == id) {
                             SwitchObserver.this.observer.onError(e);
-                            SwitchObserver.this.parent.unsubscribe();
+                            s = SwitchObserver.this.parent;
                         }
                     }
+                    if(s != null) {
+                        s.unsubscribe();
+                    }
                 }
 
                 @Override
                 public void onCompleted() {
+                    sub.unsubscribe();
+                    SafeObservableSubscription s = null;
                     synchronized (gate) {
-                        sub.unsubscribe();
                         if (latest == id) {
                             SwitchObserver.this.hasLatest = false;
-                        }
 
-                        if (stopped) {
-                            SwitchObserver.this.observer.onCompleted();
-                            SwitchObserver.this.parent.unsubscribe();
+                            if (stopped) {
+                                SwitchObserver.this.observer.onCompleted();
+                                s = SwitchObserver.this.parent;
+                            }
                         }
-
+                    }
+                    if(s != null) {
+                        s.unsubscribe();
                     }
                 }
 
@@ -152,13 +157,17 @@ public void onError(Throwable e) {
 
         @Override
         public void onCompleted() {
+            SafeObservableSubscription s = null;
             synchronized (gate) {
                 this.stopped = true;
                 if (!this.hasLatest) {
                     this.observer.onCompleted();
-                    this.parent.unsubscribe();
+                    s = this.parent;
                 }
             }
+            if(s != null) {
+                s.unsubscribe();
+            }
         }
 
     }

rxjava-core/src/test/java/rx/operators/OperationSwitchTest.java

@@ -380,4 +380,51 @@ public void call() {
     @SuppressWarnings("serial")
     private class TestException extends Throwable {
     }
+
+    @Test
+    public void testSwitchIssue737() {
+        // https://github.com/Netflix/RxJava/issues/737
+        Observable<Observable<String>> source = Observable.create(new Observable.OnSubscribeFunc<Observable<String>>() {
+            @Override
+            public Subscription onSubscribe(Observer<? super Observable<String>> observer) {
+                publishNext(observer, 0, Observable.create(new Observable.OnSubscribeFunc<String>() {
+                    @Override
+                    public Subscription onSubscribe(Observer<? super String> observer) {
+                        publishNext(observer, 10, "1-one");
+                        publishNext(observer, 20, "1-two");
+                        // The following events will be ignored
+                        publishNext(observer, 30, "1-three");
+                        publishCompleted(observer, 40);
+                        return Subscriptions.empty();
+                    }
+                }));
+                publishNext(observer, 25, Observable.create(new Observable.OnSubscribeFunc<String>() {
+                    @Override
+                    public Subscription onSubscribe(Observer<? super String> observer) {
+                        publishNext(observer, 10, "2-one");
+                        publishNext(observer, 20, "2-two");
+                        publishNext(observer, 30, "2-three");
+                        publishCompleted(observer, 40);
+                        return Subscriptions.empty();
+                    }
+                }));
+                publishCompleted(observer, 30);
+                return Subscriptions.empty();
+            }
+        });
+
+        Observable<String> sampled = Observable.create(OperationSwitch.switchDo(source));
+        sampled.subscribe(observer);
+
+        scheduler.advanceTimeTo(1000, TimeUnit.MILLISECONDS);
+
+        InOrder inOrder = inOrder(observer);
+        inOrder.verify(observer, times(1)).onNext("1-one");
+        inOrder.verify(observer, times(1)).onNext("1-two");
+        inOrder.verify(observer, times(1)).onNext("2-one");
+        inOrder.verify(observer, times(1)).onNext("2-two");
+        inOrder.verify(observer, times(1)).onNext("2-three");
+        inOrder.verify(observer, times(1)).onCompleted();
+        inOrder.verifyNoMoreInteractions();
+    }
 }