Rename batcher to instrumentaccumulator, remove active batcher (not used) (#2245)

* Rename batcher to instrumentaccumulator, remove active batcher (not used)

Signed-off-by: Bogdan Drutu <bogdandrutu@gmail.com>

* Fix tests, add back check for has records

Signed-off-by: Bogdan Drutu <bogdandrutu@gmail.com>

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/AbstractAsynchronousInstrument.java

@@ -23,9 +23,9 @@ abstract class AbstractAsynchronousInstrument<T extends AsynchronousInstrument.R
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
-      ActiveBatcher activeBatcher,
+      InstrumentAccumulator instrumentAccumulator,
       @Nullable Callback<T> metricUpdater) {
-    super(descriptor, meterProviderSharedState, meterSharedState, activeBatcher);
+    super(descriptor, meterProviderSharedState, meterSharedState, instrumentAccumulator);
     this.metricUpdater = metricUpdater;
   }
 
@@ -36,15 +36,15 @@ abstract class AbstractAsynchronousInstrument<T extends AsynchronousInstrument.R
     }
     collectLock.lock();
     try {
-      final ActiveBatcher activeBatcher = getActiveBatcher();
+      final InstrumentAccumulator instrumentAccumulator = getInstrumentAccumulator();
-      metricUpdater.update(newResult(activeBatcher));
+      metricUpdater.update(newResult(instrumentAccumulator));
-      return activeBatcher.completeCollectionCycle();
+      return instrumentAccumulator.completeCollectionCycle();
     } finally {
       collectLock.unlock();
     }
   }
 
-  abstract T newResult(ActiveBatcher activeBatcher);
+  abstract T newResult(InstrumentAccumulator instrumentAccumulator);
 
   abstract static class Builder<B extends AbstractInstrument.Builder<?>>
       extends AbstractInstrument.Builder<B> {
@@ -63,29 +63,34 @@ abstract class AbstractAsynchronousInstrument<T extends AsynchronousInstrument.R
         InstrumentDescriptor descriptor,
         MeterProviderSharedState meterProviderSharedState,
         MeterSharedState meterSharedState,
-        ActiveBatcher activeBatcher,
+        InstrumentAccumulator instrumentAccumulator,
         @Nullable Callback<LongResult> metricUpdater) {
-      super(descriptor, meterProviderSharedState, meterSharedState, activeBatcher, metricUpdater);
+      super(
+          descriptor,
+          meterProviderSharedState,
+          meterSharedState,
+          instrumentAccumulator,
+          metricUpdater);
     }
 
     @Override
-    LongResultSdk newResult(ActiveBatcher activeBatcher) {
+    LongResultSdk newResult(InstrumentAccumulator instrumentAccumulator) {
-      return new LongResultSdk(activeBatcher);
+      return new LongResultSdk(instrumentAccumulator);
     }
 
     private static final class LongResultSdk implements LongResult {
 
-      private final ActiveBatcher activeBatcher;
+      private final InstrumentAccumulator instrumentAccumulator;
 
-      private LongResultSdk(ActiveBatcher activeBatcher) {
+      private LongResultSdk(InstrumentAccumulator instrumentAccumulator) {
-        this.activeBatcher = activeBatcher;
+        this.instrumentAccumulator = instrumentAccumulator;
       }
 
       @Override
       public void observe(long sum, Labels labels) {
-        Aggregator aggregator = activeBatcher.getAggregator();
+        Aggregator aggregator = instrumentAccumulator.getAggregator();
         aggregator.recordLong(sum);
-        activeBatcher.batch(labels, aggregator, /* mappedAggregator= */ false);
+        instrumentAccumulator.batch(labels, aggregator, /* mappedAggregator= */ false);
       }
     }
   }
@@ -96,29 +101,34 @@ abstract class AbstractAsynchronousInstrument<T extends AsynchronousInstrument.R
         InstrumentDescriptor descriptor,
         MeterProviderSharedState meterProviderSharedState,
         MeterSharedState meterSharedState,
-        ActiveBatcher activeBatcher,
+        InstrumentAccumulator instrumentAccumulator,
         @Nullable Callback<DoubleResult> metricUpdater) {
-      super(descriptor, meterProviderSharedState, meterSharedState, activeBatcher, metricUpdater);
+      super(
+          descriptor,
+          meterProviderSharedState,
+          meterSharedState,
+          instrumentAccumulator,
+          metricUpdater);
     }
 
     @Override
-    DoubleResultSdk newResult(ActiveBatcher activeBatcher) {
+    DoubleResultSdk newResult(InstrumentAccumulator instrumentAccumulator) {
-      return new DoubleResultSdk(activeBatcher);
+      return new DoubleResultSdk(instrumentAccumulator);
     }
 
     private static final class DoubleResultSdk implements DoubleResult {
 
-      private final ActiveBatcher activeBatcher;
+      private final InstrumentAccumulator instrumentAccumulator;
 
-      private DoubleResultSdk(ActiveBatcher activeBatcher) {
+      private DoubleResultSdk(InstrumentAccumulator instrumentAccumulator) {
-        this.activeBatcher = activeBatcher;
+        this.instrumentAccumulator = instrumentAccumulator;
       }
 
       @Override
       public void observe(double sum, Labels labels) {
-        Aggregator aggregator = activeBatcher.getAggregator();
+        Aggregator aggregator = instrumentAccumulator.getAggregator();
         aggregator.recordDouble(sum);
-        activeBatcher.batch(labels, aggregator, /* mappedAggregator= */ false);
+        instrumentAccumulator.batch(labels, aggregator, /* mappedAggregator= */ false);
       }
     }
   }

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/AbstractInstrument.java

@@ -19,18 +19,18 @@ abstract class AbstractInstrument implements Instrument {
   private final InstrumentDescriptor descriptor;
   private final MeterProviderSharedState meterProviderSharedState;
   private final MeterSharedState meterSharedState;
-  private final ActiveBatcher activeBatcher;
+  private final InstrumentAccumulator instrumentAccumulator;
 
   // All arguments cannot be null because they are checked in the abstract builder classes.
   AbstractInstrument(
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
-      ActiveBatcher activeBatcher) {
+      InstrumentAccumulator instrumentAccumulator) {
     this.descriptor = descriptor;
     this.meterProviderSharedState = meterProviderSharedState;
     this.meterSharedState = meterSharedState;
-    this.activeBatcher = activeBatcher;
+    this.instrumentAccumulator = instrumentAccumulator;
   }
 
   final InstrumentDescriptor getDescriptor() {
@@ -45,8 +45,8 @@ abstract class AbstractInstrument implements Instrument {
     return meterSharedState;
   }
 
-  final ActiveBatcher getActiveBatcher() {
+  final InstrumentAccumulator getInstrumentAccumulator() {
-    return activeBatcher;
+    return instrumentAccumulator;
   }
 
   /**
@@ -131,7 +131,7 @@ abstract class AbstractInstrument implements Instrument {
       return getMeterSharedState().getInstrumentRegistry().register(instrument);
     }
 
-    protected Batcher getBatcher(InstrumentDescriptor descriptor) {
+    protected InstrumentAccumulator getBatcher(InstrumentDescriptor descriptor) {
       return meterSdk.createBatcher(descriptor, meterProviderSharedState, meterSharedState);
     }
   }

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/AbstractSynchronousInstrument.java

@@ -22,8 +22,8 @@ abstract class AbstractSynchronousInstrument<B extends AbstractBoundInstrument>
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
-      ActiveBatcher activeBatcher) {
+      InstrumentAccumulator instrumentAccumulator) {
-    super(descriptor, meterProviderSharedState, meterSharedState, activeBatcher);
+    super(descriptor, meterProviderSharedState, meterSharedState, instrumentAccumulator);
     boundLabels = new ConcurrentHashMap<>();
     collectLock = new ReentrantLock();
   }
@@ -37,7 +37,7 @@ abstract class AbstractSynchronousInstrument<B extends AbstractBoundInstrument>
     }
 
     // Missing entry or no longer mapped, try to add a new entry.
-    binding = newBinding(getActiveBatcher());
+    binding = newBinding(getInstrumentAccumulator());
     while (true) {
       B oldBound = boundLabels.putIfAbsent(labels, binding);
       if (oldBound != null) {
@@ -62,7 +62,7 @@ abstract class AbstractSynchronousInstrument<B extends AbstractBoundInstrument>
   final List<MetricData> collectAll() {
     collectLock.lock();
     try {
-      Batcher batcher = getActiveBatcher();
+      InstrumentAccumulator instrumentAccumulator = getInstrumentAccumulator();
       for (Map.Entry<Labels, B> entry : boundLabels.entrySet()) {
         boolean unmappedEntry = entry.getValue().tryUnmap();
         if (unmappedEntry) {
@@ -70,13 +70,14 @@ abstract class AbstractSynchronousInstrument<B extends AbstractBoundInstrument>
           // acquire but because we requested a specific value only one will succeed.
           boundLabels.remove(entry.getKey(), entry.getValue());
         }
-        batcher.batch(entry.getKey(), entry.getValue().getAggregator(), unmappedEntry);
+        instrumentAccumulator.batch(
+            entry.getKey(), entry.getValue().getAggregator(), unmappedEntry);
       }
-      return batcher.completeCollectionCycle();
+      return instrumentAccumulator.completeCollectionCycle();
     } finally {
       collectLock.unlock();
     }
   }
 
-  abstract B newBinding(Batcher batcher);
+  abstract B newBinding(InstrumentAccumulator instrumentAccumulator);
 }

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/ActiveBatcher.java

@@ -1,49 +0,0 @@
-/*
- * Copyright The OpenTelemetry Authors
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package io.opentelemetry.sdk.metrics;
-
-import io.opentelemetry.api.common.Labels;
-import io.opentelemetry.sdk.metrics.aggregator.Aggregator;
-import io.opentelemetry.sdk.metrics.data.MetricData;
-import java.util.List;
-
-/**
- * Tracks a list of active Batchers used to aggregate measurements recorded by one {@code
- * Instrument}.
- *
- * <p>TODO: Add support for multiple "Batchers" in the same time.
- *
- * <p>TODO: Consider if support for changing batchers at runtime is needed.
- */
-final class ActiveBatcher implements Batcher {
-  private final Batcher batcher;
-
-  ActiveBatcher(Batcher batcher) {
-    this.batcher = batcher;
-  }
-
-  @Override
-  public Aggregator getAggregator() {
-    return batcher.getAggregator();
-  }
-
-  @Override
-  public void batch(Labels labelSet, Aggregator aggregator, boolean mappedAggregator) {
-    if (aggregator.hasRecordings()) {
-      batcher.batch(labelSet, aggregator, mappedAggregator);
-    }
-  }
-
-  @Override
-  public List<MetricData> completeCollectionCycle() {
-    return batcher.completeCollectionCycle();
-  }
-
-  @Override
-  public boolean generatesDeltas() {
-    return batcher.generatesDeltas();
-  }
-}

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/DoubleCounterSdk.java

@@ -18,8 +18,8 @@ final class DoubleCounterSdk extends AbstractSynchronousInstrument<BoundInstrume
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
-      Batcher batcher) {
+      InstrumentAccumulator instrumentAccumulator) {
-    super(descriptor, meterProviderSharedState, meterSharedState, new ActiveBatcher(batcher));
+    super(descriptor, meterProviderSharedState, meterSharedState, instrumentAccumulator);
   }
 
   @Override
@@ -38,15 +38,15 @@ final class DoubleCounterSdk extends AbstractSynchronousInstrument<BoundInstrume
   }
 
   @Override
-  BoundInstrument newBinding(Batcher batcher) {
+  BoundInstrument newBinding(InstrumentAccumulator instrumentAccumulator) {
-    return new BoundInstrument(batcher);
+    return new BoundInstrument(instrumentAccumulator);
   }
 
   static final class BoundInstrument extends AbstractBoundInstrument
       implements DoubleCounter.BoundDoubleCounter {
 
-    BoundInstrument(Batcher batcher) {
+    BoundInstrument(InstrumentAccumulator instrumentAccumulator) {
-      super(batcher.getAggregator());
+      super(instrumentAccumulator.getAggregator());
     }
 
     @Override

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/DoubleSumObserverSdk.java

@@ -18,13 +18,13 @@ final class DoubleSumObserverSdk extends AbstractDoubleAsynchronousInstrument
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
-      Batcher batcher,
+      InstrumentAccumulator instrumentAccumulator,
       @Nullable Callback<DoubleResult> metricUpdater) {
     super(
         descriptor,
         meterProviderSharedState,
         meterSharedState,
-        new ActiveBatcher(batcher),
+        instrumentAccumulator,
         metricUpdater);
   }
 

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/DoubleUpDownCounterSdk.java

@@ -18,8 +18,8 @@ final class DoubleUpDownCounterSdk extends AbstractSynchronousInstrument<BoundIn
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
-      Batcher batcher) {
+      InstrumentAccumulator instrumentAccumulator) {
-    super(descriptor, meterProviderSharedState, meterSharedState, new ActiveBatcher(batcher));
+    super(descriptor, meterProviderSharedState, meterSharedState, instrumentAccumulator);
   }
 
   @Override
@@ -35,15 +35,15 @@ final class DoubleUpDownCounterSdk extends AbstractSynchronousInstrument<BoundIn
   }
 
   @Override
-  BoundInstrument newBinding(Batcher batcher) {
+  BoundInstrument newBinding(InstrumentAccumulator instrumentAccumulator) {
-    return new BoundInstrument(batcher);
+    return new BoundInstrument(instrumentAccumulator);
   }
 
   static final class BoundInstrument extends AbstractBoundInstrument
       implements BoundDoubleUpDownCounter {
 
-    BoundInstrument(Batcher batcher) {
+    BoundInstrument(InstrumentAccumulator instrumentAccumulator) {
-      super(batcher.getAggregator());
+      super(instrumentAccumulator.getAggregator());
     }
 
     @Override

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/DoubleUpDownSumObserverSdk.java

@@ -18,13 +18,13 @@ final class DoubleUpDownSumObserverSdk extends AbstractDoubleAsynchronousInstrum
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
-      Batcher batcher,
+      InstrumentAccumulator instrumentAccumulator,
       @Nullable Callback<DoubleResult> metricUpdater) {
     super(
         descriptor,
         meterProviderSharedState,
         meterSharedState,
-        new ActiveBatcher(batcher),
+        instrumentAccumulator,
         metricUpdater);
   }
 

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/DoubleValueObserverSdk.java

@@ -18,13 +18,13 @@ final class DoubleValueObserverSdk extends AbstractDoubleAsynchronousInstrument
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
-      Batcher batcher,
+      InstrumentAccumulator instrumentAccumulator,
       @Nullable Callback<DoubleResult> metricUpdater) {
     super(
         descriptor,
         meterProviderSharedState,
         meterSharedState,
-        new ActiveBatcher(batcher),
+        instrumentAccumulator,
         metricUpdater);
   }
 

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/DoubleValueRecorderSdk.java

@@ -18,8 +18,8 @@ final class DoubleValueRecorderSdk extends AbstractSynchronousInstrument<BoundIn
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
-      Batcher batcher) {
+      InstrumentAccumulator instrumentAccumulator) {
-    super(descriptor, meterProviderSharedState, meterSharedState, new ActiveBatcher(batcher));
+    super(descriptor, meterProviderSharedState, meterSharedState, instrumentAccumulator);
   }
 
   @Override
@@ -35,15 +35,15 @@ final class DoubleValueRecorderSdk extends AbstractSynchronousInstrument<BoundIn
   }
 
   @Override
-  BoundInstrument newBinding(Batcher batcher) {
+  BoundInstrument newBinding(InstrumentAccumulator instrumentAccumulator) {
-    return new BoundInstrument(batcher);
+    return new BoundInstrument(instrumentAccumulator);
   }
 
   static final class BoundInstrument extends AbstractBoundInstrument
       implements BoundDoubleValueRecorder {
 
-    BoundInstrument(Batcher batcher) {
+    BoundInstrument(InstrumentAccumulator instrumentAccumulator) {
-      super(batcher.getAggregator());
+      super(instrumentAccumulator.getAggregator());
     }
 
     @Override

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/InstrumentAccumulator.java

@@ -11,15 +11,15 @@ import io.opentelemetry.sdk.metrics.data.MetricData;
 import java.util.List;
 
 /**
- * A {@code Batcher} represents an internal representation of an {code Instrument} aggregation
+ * An {@code InstrumentAccumulator} represents an internal instance of an {@code Accumulator} for a
- * process. It records individual measurements (via the {@code Aggregator}). It batches together
+ * specific {code Instrument}. It records individual measurements (via the {@code Aggregator}). It
- * {@code Aggregator}s for the similar sets of labels.
+ * batches together {@code Aggregator}s for the similar sets of labels.
  *
  * <p>The only thread safe method in this class is {@link #getAggregator()}. An entire collection
  * cycle must be protected by a lock. A collection cycle is defined by multiple calls to {@link
  * #batch(Labels, Aggregator, boolean)} followed by one {@link #completeCollectionCycle()};
  */
-interface Batcher {
+interface InstrumentAccumulator {
 
   /**
    * Returns the {@link Aggregator} that should be used by the bindings, or observers.

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/InstrumentAccumulators.java

@@ -20,11 +20,12 @@ import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 
-/** A collection of available Batchers. */
+/** A collection of available InstrumentAccumulators. */
-final class Batchers {
+final class InstrumentAccumulators {
 
-  static Batcher getNoop() {
+  static InstrumentAccumulator getNoop() {
     return Noop.INSTANCE;
   }
 
@@ -33,7 +34,7 @@ final class Batchers {
    * "Cumulative" means that all metrics that are generated will be considered for the lifetime of
    * the Instrument being aggregated.
    */
-  static Batcher getCumulativeAllLabels(
+  static InstrumentAccumulator getCumulativeAllLabels(
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
@@ -51,7 +52,7 @@ final class Batchers {
    * Create a Batcher that uses the "delta" Temporality and uses all labels for aggregation. "Delta"
    * means that all metrics that are generated are only for the most recent collection interval.
    */
-  static Batcher getDeltaAllLabels(
+  static InstrumentAccumulator getDeltaAllLabels(
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
@@ -65,7 +66,7 @@ final class Batchers {
         /* delta= */ true);
   }
 
-  private static final class Noop implements Batcher {
+  private static final class Noop implements InstrumentAccumulator {
     private static final Noop INSTANCE = new Noop();
 
     @Override
@@ -87,7 +88,7 @@ final class Batchers {
     }
   }
 
-  private static final class AllLabels implements Batcher {
+  private static final class AllLabels implements InstrumentAccumulator {
     private final InstrumentDescriptor descriptor;
     private final Aggregation aggregation;
     private final Resource resource;
@@ -123,6 +124,9 @@ final class Batchers {
 
     @Override
     public final void batch(Labels labelSet, Aggregator aggregator, boolean unmappedAggregator) {
+      if (!aggregator.hasRecordings()) {
+        return;
+      }
       Aggregator currentAggregator = aggregatorMap.get(labelSet);
       if (currentAggregator == null) {
         // This aggregator is not mapped, we can use this instance.
@@ -183,35 +187,25 @@ final class Batchers {
       if (delta != allLabels.delta) {
         return false;
       }
-      if (descriptor != null
+      if (!Objects.equals(descriptor, allLabels.descriptor)) {
-          ? !descriptor.equals(allLabels.descriptor)
-          : allLabels.descriptor != null) {
         return false;
       }
-      if (aggregation != null
+      if (!Objects.equals(aggregation, allLabels.aggregation)) {
-          ? !aggregation.equals(allLabels.aggregation)
-          : allLabels.aggregation != null) {
         return false;
       }
-      if (resource != null ? !resource.equals(allLabels.resource) : allLabels.resource != null) {
+      if (!Objects.equals(resource, allLabels.resource)) {
         return false;
       }
-      if (instrumentationLibraryInfo != null
+      if (!Objects.equals(instrumentationLibraryInfo, allLabels.instrumentationLibraryInfo)) {
-          ? !instrumentationLibraryInfo.equals(allLabels.instrumentationLibraryInfo)
-          : allLabels.instrumentationLibraryInfo != null) {
         return false;
       }
-      if (clock != null ? !clock.equals(allLabels.clock) : allLabels.clock != null) {
+      if (!Objects.equals(clock, allLabels.clock)) {
         return false;
       }
-      if (aggregatorFactory != null
+      if (!Objects.equals(aggregatorFactory, allLabels.aggregatorFactory)) {
-          ? !aggregatorFactory.equals(allLabels.aggregatorFactory)
-          : allLabels.aggregatorFactory != null) {
         return false;
       }
-      return aggregatorMap != null
+      return Objects.equals(aggregatorMap, allLabels.aggregatorMap);
-          ? aggregatorMap.equals(allLabels.aggregatorMap)
-          : allLabels.aggregatorMap == null;
     }
 
     @Override
@@ -231,5 +225,5 @@ final class Batchers {
     }
   }
 
-  private Batchers() {}
+  private InstrumentAccumulators() {}
 }

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/LongCounterSdk.java

@@ -18,8 +18,8 @@ final class LongCounterSdk extends AbstractSynchronousInstrument<BoundInstrument
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
-      Batcher batcher) {
+      InstrumentAccumulator instrumentAccumulator) {
-    super(descriptor, meterProviderSharedState, meterSharedState, new ActiveBatcher(batcher));
+    super(descriptor, meterProviderSharedState, meterSharedState, instrumentAccumulator);
   }
 
   @Override
@@ -38,15 +38,15 @@ final class LongCounterSdk extends AbstractSynchronousInstrument<BoundInstrument
   }
 
   @Override
-  BoundInstrument newBinding(Batcher batcher) {
+  BoundInstrument newBinding(InstrumentAccumulator instrumentAccumulator) {
-    return new BoundInstrument(batcher);
+    return new BoundInstrument(instrumentAccumulator);
   }
 
   static final class BoundInstrument extends AbstractBoundInstrument
       implements LongCounter.BoundLongCounter {
 
-    BoundInstrument(Batcher batcher) {
+    BoundInstrument(InstrumentAccumulator instrumentAccumulator) {
-      super(batcher.getAggregator());
+      super(instrumentAccumulator.getAggregator());
     }
 
     @Override

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/LongSumObserverSdk.java

@@ -17,13 +17,13 @@ final class LongSumObserverSdk extends AbstractLongAsynchronousInstrument
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
-      Batcher batcher,
+      InstrumentAccumulator instrumentAccumulator,
       @Nullable Callback<LongResult> metricUpdater) {
     super(
         descriptor,
         meterProviderSharedState,
         meterSharedState,
-        new ActiveBatcher(batcher),
+        instrumentAccumulator,
         metricUpdater);
   }
 

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/LongUpDownCounterSdk.java

@@ -18,8 +18,8 @@ final class LongUpDownCounterSdk extends AbstractSynchronousInstrument<BoundInst
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
-      Batcher batcher) {
+      InstrumentAccumulator instrumentAccumulator) {
-    super(descriptor, meterProviderSharedState, meterSharedState, new ActiveBatcher(batcher));
+    super(descriptor, meterProviderSharedState, meterSharedState, instrumentAccumulator);
   }
 
   @Override
@@ -35,15 +35,15 @@ final class LongUpDownCounterSdk extends AbstractSynchronousInstrument<BoundInst
   }
 
   @Override
-  BoundInstrument newBinding(Batcher batcher) {
+  BoundInstrument newBinding(InstrumentAccumulator instrumentAccumulator) {
-    return new BoundInstrument(batcher);
+    return new BoundInstrument(instrumentAccumulator);
   }
 
   static final class BoundInstrument extends AbstractBoundInstrument
       implements BoundLongUpDownCounter {
 
-    BoundInstrument(Batcher batcher) {
+    BoundInstrument(InstrumentAccumulator instrumentAccumulator) {
-      super(batcher.getAggregator());
+      super(instrumentAccumulator.getAggregator());
     }
 
     @Override

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/LongUpDownSumObserverSdk.java

@@ -17,13 +17,13 @@ final class LongUpDownSumObserverSdk extends AbstractLongAsynchronousInstrument
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
-      Batcher batcher,
+      InstrumentAccumulator instrumentAccumulator,
       @Nullable Callback<LongResult> metricUpdater) {
     super(
         descriptor,
         meterProviderSharedState,
         meterSharedState,
-        new ActiveBatcher(batcher),
+        instrumentAccumulator,
         metricUpdater);
   }
 

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/LongValueObserverSdk.java

@@ -18,13 +18,13 @@ final class LongValueObserverSdk extends AbstractLongAsynchronousInstrument
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
-      Batcher batcher,
+      InstrumentAccumulator instrumentAccumulator,
       @Nullable Callback<LongResult> metricUpdater) {
     super(
         descriptor,
         meterProviderSharedState,
         meterSharedState,
-        new ActiveBatcher(batcher),
+        instrumentAccumulator,
         metricUpdater);
   }
 

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/LongValueRecorderSdk.java

@@ -18,8 +18,8 @@ final class LongValueRecorderSdk extends AbstractSynchronousInstrument<BoundInst
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
-      Batcher batcher) {
+      InstrumentAccumulator instrumentAccumulator) {
-    super(descriptor, meterProviderSharedState, meterSharedState, new ActiveBatcher(batcher));
+    super(descriptor, meterProviderSharedState, meterSharedState, instrumentAccumulator);
   }
 
   @Override
@@ -35,15 +35,15 @@ final class LongValueRecorderSdk extends AbstractSynchronousInstrument<BoundInst
   }
 
   @Override
-  BoundInstrument newBinding(Batcher batcher) {
+  BoundInstrument newBinding(InstrumentAccumulator instrumentAccumulator) {
-    return new BoundInstrument(batcher);
+    return new BoundInstrument(instrumentAccumulator);
   }
 
   static final class BoundInstrument extends AbstractBoundInstrument
       implements BoundLongValueRecorder {
 
-    BoundInstrument(Batcher batcher) {
+    BoundInstrument(InstrumentAccumulator instrumentAccumulator) {
-      super(batcher.getAggregator());
+      super(instrumentAccumulator.getAggregator());
     }
 
     @Override

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/MeterSdk.java

@@ -112,8 +112,11 @@ final class MeterSdk implements Meter {
     return result;
   }
 
-  /** Creates a {@link Batcher}, by using the {@link ViewRegistry} to do the actual work. */
+  /**
-  Batcher createBatcher(
+   * Creates a {@link InstrumentAccumulator}, by using the {@link ViewRegistry} to do the actual
+   * work.
+   */
+  InstrumentAccumulator createBatcher(
       InstrumentDescriptor descriptor,
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState) {

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/ViewRegistry.java

@@ -44,11 +44,8 @@ class ViewRegistry {
     aggregationChooser.addView(selector, specification);
   }
 
-  /**
+  /** Create a new {@link InstrumentAccumulator} for use in metric recording aggregation. */
-   * Create a new {@link io.opentelemetry.sdk.metrics.Batcher} for use in metric recording
+  InstrumentAccumulator createBatcher(
-   * aggregation.
-   */
-  Batcher createBatcher(
       MeterProviderSharedState meterProviderSharedState,
       MeterSharedState meterSharedState,
       InstrumentDescriptor descriptor) {
@@ -58,10 +55,10 @@ class ViewRegistry {
     Aggregation aggregation = specification.aggregation();
 
     if (Temporality.CUMULATIVE == specification.temporality()) {
-      return Batchers.getCumulativeAllLabels(
+      return InstrumentAccumulators.getCumulativeAllLabels(
           descriptor, meterProviderSharedState, meterSharedState, aggregation);
     } else if (Temporality.DELTA == specification.temporality()) {
-      return Batchers.getDeltaAllLabels(
+      return InstrumentAccumulators.getDeltaAllLabels(
           descriptor, meterProviderSharedState, meterSharedState, aggregation);
     }
     throw new IllegalStateException("unsupported Temporality: " + specification.temporality());

sdk/metrics/src/test/java/io/opentelemetry/sdk/metrics/AbstractInstrumentTest.java

@@ -28,17 +28,20 @@ class AbstractInstrumentTest {
       InstrumentationLibraryInfo.create("test_abstract_instrument", "");
   private static final MeterSharedState METER_SHARED_STATE =
       MeterSharedState.create(INSTRUMENTATION_LIBRARY_INFO);
-  private static final ActiveBatcher ACTIVE_BATCHER = new ActiveBatcher(Batchers.getNoop());
 
   @Test
   void getValues() {
     TestInstrument testInstrument =
         new TestInstrument(
-            INSTRUMENT_DESCRIPTOR, METER_PROVIDER_SHARED_STATE, METER_SHARED_STATE, ACTIVE_BATCHER);
+            INSTRUMENT_DESCRIPTOR,
+            METER_PROVIDER_SHARED_STATE,
+            METER_SHARED_STATE,
+            InstrumentAccumulators.getNoop());
     assertThat(testInstrument.getDescriptor()).isSameAs(INSTRUMENT_DESCRIPTOR);
     assertThat(testInstrument.getMeterProviderSharedState()).isSameAs(METER_PROVIDER_SHARED_STATE);
     assertThat(testInstrument.getMeterSharedState()).isSameAs(METER_SHARED_STATE);
-    assertThat(testInstrument.getActiveBatcher()).isSameAs(ACTIVE_BATCHER);
+    assertThat(testInstrument.getInstrumentAccumulator())
+        .isSameAs(InstrumentAccumulators.getNoop());
   }
 
   private static final class TestInstrument extends AbstractInstrument {
@@ -46,8 +49,8 @@ class AbstractInstrumentTest {
         InstrumentDescriptor descriptor,
         MeterProviderSharedState meterProviderSharedState,
         MeterSharedState meterSharedState,
-        ActiveBatcher activeBatcher) {
+        InstrumentAccumulator instrumentAccumulator) {
-      super(descriptor, meterProviderSharedState, meterSharedState, activeBatcher);
+      super(descriptor, meterProviderSharedState, meterSharedState, instrumentAccumulator);
     }
 
     @Override

sdk/metrics/src/test/java/io/opentelemetry/sdk/metrics/InstrumentRegistryTest.java

@@ -29,7 +29,6 @@ class InstrumentRegistryTest {
           "name", "other_description", "1", InstrumentType.COUNTER, InstrumentValueType.LONG);
   private static final MeterProviderSharedState METER_PROVIDER_SHARED_STATE =
       MeterProviderSharedState.create(TestClock.create(), Resource.getEmpty());
-  private static final ActiveBatcher ACTIVE_BATCHER = new ActiveBatcher(Batchers.getNoop());
 
   @Test
   void register() {
@@ -37,7 +36,10 @@ class InstrumentRegistryTest {
         MeterSharedState.create(InstrumentationLibraryInfo.getEmpty());
     TestInstrument testInstrument =
         new TestInstrument(
-            INSTRUMENT_DESCRIPTOR, METER_PROVIDER_SHARED_STATE, meterSharedState, ACTIVE_BATCHER);
+            INSTRUMENT_DESCRIPTOR,
+            METER_PROVIDER_SHARED_STATE,
+            meterSharedState,
+            InstrumentAccumulators.getNoop());
     assertThat(meterSharedState.getInstrumentRegistry().register(testInstrument))
         .isSameAs(testInstrument);
     assertThat(meterSharedState.getInstrumentRegistry().register(testInstrument))
@@ -50,7 +52,7 @@ class InstrumentRegistryTest {
                         INSTRUMENT_DESCRIPTOR,
                         METER_PROVIDER_SHARED_STATE,
                         meterSharedState,
-                        ACTIVE_BATCHER)))
+                        InstrumentAccumulators.getNoop())))
         .isSameAs(testInstrument);
   }
 
@@ -59,7 +61,10 @@ class InstrumentRegistryTest {
     MeterSharedState meterSharedState = MeterSharedState.create(getEmpty());
     TestInstrument testInstrument =
         new TestInstrument(
-            INSTRUMENT_DESCRIPTOR, METER_PROVIDER_SHARED_STATE, meterSharedState, ACTIVE_BATCHER);
+            INSTRUMENT_DESCRIPTOR,
+            METER_PROVIDER_SHARED_STATE,
+            meterSharedState,
+            InstrumentAccumulators.getNoop());
     assertThat(meterSharedState.getInstrumentRegistry().register(testInstrument))
         .isSameAs(testInstrument);
 
@@ -73,7 +78,7 @@ class InstrumentRegistryTest {
                         OTHER_INSTRUMENT_DESCRIPTOR,
                         METER_PROVIDER_SHARED_STATE,
                         meterSharedState,
-                        ACTIVE_BATCHER)),
+                        InstrumentAccumulators.getNoop())),
         "Instrument with same name and different descriptor already created.");
   }
 
@@ -82,7 +87,10 @@ class InstrumentRegistryTest {
     MeterSharedState meterSharedState = MeterSharedState.create(getEmpty());
     TestInstrument testInstrument =
         new TestInstrument(
-            INSTRUMENT_DESCRIPTOR, METER_PROVIDER_SHARED_STATE, meterSharedState, ACTIVE_BATCHER);
+            INSTRUMENT_DESCRIPTOR,
+            METER_PROVIDER_SHARED_STATE,
+            meterSharedState,
+            InstrumentAccumulators.getNoop());
     assertThat(meterSharedState.getInstrumentRegistry().register(testInstrument))
         .isSameAs(testInstrument);
 
@@ -96,7 +104,7 @@ class InstrumentRegistryTest {
                         INSTRUMENT_DESCRIPTOR,
                         METER_PROVIDER_SHARED_STATE,
                         meterSharedState,
-                        ACTIVE_BATCHER)),
+                        InstrumentAccumulators.getNoop())),
         "Instrument with same name and different descriptor already created.");
   }
 
@@ -105,8 +113,8 @@ class InstrumentRegistryTest {
         InstrumentDescriptor descriptor,
         MeterProviderSharedState meterProviderSharedState,
         MeterSharedState meterSharedState,
-        ActiveBatcher activeBatcher) {
+        InstrumentAccumulator instrumentAccumulator) {
-      super(descriptor, meterProviderSharedState, meterSharedState, activeBatcher);
+      super(descriptor, meterProviderSharedState, meterSharedState, instrumentAccumulator);
     }
 
     @Override
@@ -120,8 +128,8 @@ class InstrumentRegistryTest {
         InstrumentDescriptor descriptor,
         MeterProviderSharedState meterProviderSharedState,
         MeterSharedState meterSharedState,
-        ActiveBatcher activeBatcher) {
+        InstrumentAccumulator instrumentAccumulator) {
-      super(descriptor, meterProviderSharedState, meterSharedState, activeBatcher);
+      super(descriptor, meterProviderSharedState, meterSharedState, instrumentAccumulator);
     }
 
     @Override

sdk/metrics/src/test/java/io/opentelemetry/sdk/metrics/LongCounterSdkTest.java

@@ -81,7 +81,7 @@ class LongCounterSdkTest {
             .setDescription("My very own counter")
             .setUnit("ms")
             .build();
-    BoundInstrument ignored = longCounter.bind(Labels.of("foo", "bar"));
+    BoundInstrument bound = longCounter.bind(Labels.of("foo", "bar"));
 
     List<MetricData> metricDataList = longCounter.collectAll();
     assertThat(metricDataList).hasSize(1);
@@ -93,6 +93,8 @@ class LongCounterSdkTest {
     assertThat(metricData.getResource()).isEqualTo(RESOURCE);
     assertThat(metricData.getInstrumentationLibraryInfo()).isEqualTo(INSTRUMENTATION_LIBRARY_INFO);
     assertThat(metricData.getPoints()).isEmpty();
+
+    bound.unbind();
   }
 
   @Test

sdk/metrics/src/test/java/io/opentelemetry/sdk/metrics/ViewRegistryTest.java

@@ -55,16 +55,17 @@ class ViewRegistryTest {
     AggregationConfiguration specification =
         AggregationConfiguration.create(
             Aggregations.count(), AggregationConfiguration.Temporality.CUMULATIVE);
-    Batcher expectedBatcher =
+    InstrumentAccumulator expectedInstrumentAccumulator =
-        Batchers.getCumulativeAllLabels(
+        InstrumentAccumulators.getCumulativeAllLabels(
             descriptor, providerSharedState, meterSharedState, Aggregations.count());
 
     when(chooser.chooseAggregation(descriptor)).thenReturn(specification);
 
-    Batcher result = viewRegistry.createBatcher(providerSharedState, meterSharedState, descriptor);
+    InstrumentAccumulator result =
+        viewRegistry.createBatcher(providerSharedState, meterSharedState, descriptor);
 
     assertThat(result.generatesDeltas()).isFalse();
-    assertThat(result).isEqualTo(expectedBatcher);
+    assertThat(result).isEqualTo(expectedInstrumentAccumulator);
 
     assertThat(result).isNotNull();
   }
@@ -86,16 +87,17 @@ class ViewRegistryTest {
     AggregationConfiguration specification =
         AggregationConfiguration.create(
             Aggregations.count(), AggregationConfiguration.Temporality.DELTA);
-    Batcher expectedBatcher =
+    InstrumentAccumulator expectedInstrumentAccumulator =
-        Batchers.getDeltaAllLabels(
+        InstrumentAccumulators.getDeltaAllLabels(
             descriptor, providerSharedState, meterSharedState, Aggregations.count());
 
     when(chooser.chooseAggregation(descriptor)).thenReturn(specification);
 
-    Batcher result = viewRegistry.createBatcher(providerSharedState, meterSharedState, descriptor);
+    InstrumentAccumulator result =
+        viewRegistry.createBatcher(providerSharedState, meterSharedState, descriptor);
 
     assertThat(result.generatesDeltas()).isTrue();
-    assertThat(result).isEqualTo(expectedBatcher);
+    assertThat(result).isEqualTo(expectedInstrumentAccumulator);
 
     assertThat(result).isNotNull();
   }