remove rule 1:12 (produce same elements to all Subscribers)

This rule is in conflict with 1:11 which allows a Publisher to treat
multiple Subscribers as either as unicast or multicast recipients. The
verification of proper multicast behavior (which 1:12 specified) has
been retained, the test methods renamed accordingly.

README.md

@@ -93,7 +93,6 @@ public interface Publisher<T> {
 | <a name="1.9">9</a>       | `Publisher.subscribe` MUST call `onSubscribe` on the provided `Subscriber` prior to any other signals to that `Subscriber` and MUST return normally, except when the provided `Subscriber` is `null` in which case it MUST throw a `java.lang.NullPointerException` to the caller, for all other situations the only legal way to signal failure (or reject the `Subscriber`) is by calling `onError` (after calling `onSubscribe`). |
 | <a name="1.10">10</a>     | `Publisher.subscribe` MAY be called as many times as wanted but MUST be with a different `Subscriber` each time [see [2.12](#2.12)]. |
 | <a name="1.11">11</a>     | A `Publisher` MAY support multiple `Subscriber`s and decides whether each `Subscription` is unicast or multicast. |
-| <a name="1.12">12</a>     | A `Publisher` MUST produce the same elements, starting with the oldest element still available, in the same sequence for all its subscribers and MAY produce the stream elements at (temporarily) differing rates to different subscribers. |
 
 [<a name="footnote-1-1">1</a>] :  A stateful Publisher can be overwhelmed, bounded by a finite number of underlying resources, exhausted, shut-down or in a failed state.
 

tck/src/main/java/org/reactivestreams/tck/IdentityProcessorVerification.java

@@ -297,18 +297,18 @@ public void optional_spec111_maySupportMultiSubscribe() throws Throwable {
   }
 
   @Override @Test
-  public void required_spec112_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingOneByOne() throws Throwable {
-    publisherVerification.required_spec112_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingOneByOne();
+  public void optional_spec111_multicast_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingOneByOne() throws Throwable {
+    publisherVerification.optional_spec111_multicast_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingOneByOne();
   }
 
   @Override @Test
-  public void required_spec112_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfront() throws Throwable {
-    publisherVerification.required_spec112_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfront();
+  public void optional_spec111_multicast_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfront() throws Throwable {
+    publisherVerification.optional_spec111_multicast_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfront();
   }
 
   @Override @Test
-  public void required_spec112_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfrontAndCompleteAsExpected() throws Throwable {
-    publisherVerification.required_spec112_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfrontAndCompleteAsExpected();
+  public void optional_spec111_multicast_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfrontAndCompleteAsExpected() throws Throwable {
+    publisherVerification.optional_spec111_multicast_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfrontAndCompleteAsExpected();
   }
 
   @Override @Test
@@ -755,4 +755,4 @@ public void expectError(Throwable cause, long timeoutMillis) throws InterruptedE
       }
     }
   }
-}
+}

tck/src/main/java/org/reactivestreams/tck/PublisherVerification.java

@@ -551,7 +551,7 @@ public void run(Publisher<T> pub) throws Throwable {
 
   // Verifies rule: https://github.com/reactive-streams/reactive-streams#1.12
   @Override @Test
-  public void required_spec112_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingOneByOne() throws Throwable {
+  public void optional_spec111_multicast_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingOneByOne() throws Throwable {
     optionalActivePublisherTest(5, true, new PublisherTestRun<T>() { // This test is skipped if the publisher is unbounded (never sends onComplete)
       @Override
       public void run(Publisher<T> pub) throws InterruptedException {
@@ -602,7 +602,7 @@ public void run(Publisher<T> pub) throws InterruptedException {
 
   // Verifies rule: https://github.com/reactive-streams/reactive-streams#1.12
   @Override @Test
-  public void required_spec112_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfront() throws Throwable {
+  public void optional_spec111_multicast_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfront() throws Throwable {
     optionalActivePublisherTest(3, false, new PublisherTestRun<T>() { // This test is skipped if the publisher cannot produce enough elements
       @Override
       public void run(Publisher<T> pub) throws Throwable {
@@ -635,7 +635,7 @@ public void run(Publisher<T> pub) throws Throwable {
 
   // Verifies rule: https://github.com/reactive-streams/reactive-streams#1.12
   @Override @Test
-  public void required_spec112_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfrontAndCompleteAsExpected() throws Throwable {
+  public void optional_spec111_multicast_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfrontAndCompleteAsExpected() throws Throwable {
     optionalActivePublisherTest(3, true, new PublisherTestRun<T>() { // This test is skipped if the publisher is unbounded (never sends onComplete)
       @Override
       public void run(Publisher<T> pub) throws Throwable {

tck/src/main/java/org/reactivestreams/tck/support/PublisherVerificationRules.java

@@ -26,9 +26,9 @@ public interface PublisherVerificationRules {
   void required_spec109_mayRejectCallsToSubscribeIfPublisherIsUnableOrUnwillingToServeThemRejectionMustTriggerOnErrorAfterOnSubscribe() throws Throwable;
   void untested_spec110_rejectASubscriptionRequestIfTheSameSubscriberSubscribesTwice() throws Throwable;
   void optional_spec111_maySupportMultiSubscribe() throws Throwable;
-  void required_spec112_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingOneByOne() throws Throwable;
-  void required_spec112_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfront() throws Throwable;
-  void required_spec112_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfrontAndCompleteAsExpected() throws Throwable;
+  void optional_spec111_multicast_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingOneByOne() throws Throwable;
+  void optional_spec111_multicast_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfront() throws Throwable;
+  void optional_spec111_multicast_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfrontAndCompleteAsExpected() throws Throwable;
   void required_spec302_mustAllowSynchronousRequestCallsFromOnNextAndOnSubscribe() throws Throwable;
   void required_spec303_mustNotAllowUnboundedRecursion() throws Throwable;
   void untested_spec304_requestShouldNotPerformHeavyComputations() throws Exception;
@@ -42,4 +42,4 @@ public interface PublisherVerificationRules {
   void required_spec317_mustSupportAPendingElementCountUpToLongMaxValue() throws Throwable;
   void required_spec317_mustSupportACumulativePendingElementCountUpToLongMaxValue() throws Throwable;
   void required_spec317_mustNotSignalOnErrorWhenPendingAboveLongMaxValue() throws Throwable;
-}
+}

tck/src/test/java/org/reactivestreams/tck/PublisherVerificationTest.java

@@ -352,7 +352,7 @@ public void optional_spec111_maySupportMultiSubscribe_shouldFailBy_actuallyPass(
   }
 
   @Test
-  public void required_spec112_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfront_shouldFailBy_expectingOnError() throws Throwable {
+  public void optional_spec111_multicast_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfront_shouldFailBy_expectingOnError() throws Throwable {
     requireTestFailure(new ThrowingRunnable() {
       @Override public void run() throws Throwable {
         customPublisherVerification(new Publisher<Integer>() {
@@ -370,7 +370,7 @@ public void required_spec112_mustProduceTheSameElementsInTheSameSequenceToAllOfI
               }
             });
           }
-        }).required_spec112_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfront();
+        }).optional_spec111_multicast_mustProduceTheSameElementsInTheSameSequenceToAllOfItsSubscribersWhenRequestingManyUpfront();
       }
     }, "Expected elements to be signaled in the same sequence to 1st and 2nd subscribers: Lists differ at element ");
   }