Add methods to SampleListener to handle primitives

concurrency-limits-core/src/main/java/com/netflix/concurrency/limits/MetricRegistry.java

@@ -27,6 +27,14 @@ public interface MetricRegistry {
      */
     interface SampleListener {
         void addSample(Number value);
+
+        default void addLongSample(long value) {
+            addSample(value);
+        }
+
+        default void addDoubleSample(double value) {
+            addSample(value);
+        }
     }
 
     interface Counter {

concurrency-limits-core/src/main/java/com/netflix/concurrency/limits/limit/Gradient2Limit.java

@@ -268,9 +268,9 @@ public int _update(final long startTime, final long rtt, final int inflight, fin
         final double shortRtt = (double)rtt;
         final double longRtt = this.longRtt.add(rtt).doubleValue();
 
-        shortRttSampleListener.addSample(shortRtt);
-        longRttSampleListener.addSample(longRtt);
-        queueSizeSampleListener.addSample(queueSize);
+        shortRttSampleListener.addDoubleSample(shortRtt);
+        longRttSampleListener.addDoubleSample(longRtt);
+        queueSizeSampleListener.addDoubleSample(queueSize);
 
         // If the long RTT is substantially larger than the short RTT then reduce the long RTT measurement.
         // This can happen when latency returns to normal after a prolonged prior of excessive load.  Reducing the

concurrency-limits-core/src/main/java/com/netflix/concurrency/limits/limit/GradientLimit.java

@@ -264,10 +264,10 @@ private int nextProbeCountdown() {
     @Override
     public int _update(final long startTime, final long rtt, final int inflight, final boolean didDrop) {
         lastRtt = rtt;
-        minWindowRttSampleListener.addSample(rtt);
+        minWindowRttSampleListener.addLongSample(rtt);
 
         final double queueSize = this.queueSize.apply((int)this.estimatedLimit);
-        queueSizeSampleListener.addSample(queueSize);
+        queueSizeSampleListener.addDoubleSample(queueSize);
 
         // Reset or probe for a new noload RTT and a new estimatedLimit.  It's necessary to cut the limit
         // in half to avoid having the limit drift upwards when the RTT is probed during heavy load.
@@ -283,7 +283,7 @@ public int _update(final long startTime, final long rtt, final int inflight, fin
         }
 
         final long rttNoLoad = rttNoLoadMeasurement.add(rtt).longValue();
-        minRttSampleListener.addSample(rttNoLoad);
+        minRttSampleListener.addLongSample(rttNoLoad);
 
         // Rtt could be higher than rtt_noload because of smoothing rtt noload updates
         // so set to 1.0 to indicate no queuing.  Otherwise calculate the slope and don't

concurrency-limits-core/src/main/java/com/netflix/concurrency/limits/limit/VegasLimit.java

@@ -218,7 +218,7 @@ protected int _update(long startTime, long rtt, int inflight, boolean didDrop) {
             return (int)estimatedLimit;
         }
 
-        rttSampleListener.addSample(rtt_noload);
+        rttSampleListener.addLongSample(rtt_noload);
 
         return updateEstimatedLimit(rtt, inflight, didDrop);
     }

concurrency-limits-core/src/main/java/com/netflix/concurrency/limits/limiter/AbstractPartitionedLimiter.java

@@ -138,7 +138,7 @@ boolean isLimitExceeded() {
 
         void acquire() {
             int nowBusy = busy.incrementAndGet();
-            inflightDistribution.addSample(nowBusy);
+            inflightDistribution.addLongSample(nowBusy);
         }
 
         /**
@@ -149,7 +149,7 @@ boolean tryAcquire() {
             int current = busy.get();
             while (current < limit) {
                 if (busy.compareAndSet(current, current + 1)) {
-                    inflightDistribution.addSample(current + 1);
+                    inflightDistribution.addLongSample(current + 1);
                     return true;
                 }
                 current = busy.get();

concurrency-limits-core/src/main/java/com/netflix/concurrency/limits/limiter/SimpleLimiter.java

@@ -59,7 +59,7 @@ else if (!semaphore.tryAcquire()) {
         else {
             listener = Optional.of(new Listener(createListener()));
         }
-        inflightDistribution.addSample(getInflight());
+        inflightDistribution.addLongSample(getInflight());
         return listener;
     }
 

concurrency-limits-spectator/src/main/java/com/netflix/concurrency/limits/spectator/SpectatorMetricRegistry.java

@@ -31,11 +31,24 @@ public SpectatorMetricRegistry(Registry registry, Id baseId) {
         this.registry = registry;
         this.baseId = baseId;
     }
-    
+
     @Override
     public SampleListener distribution(String id, String... tagNameValuePairs) {
         DistributionSummary summary = registry.distributionSummary(suffixBaseId(id).withTags(tagNameValuePairs));
-        return value -> summary.record(value.longValue());
+        return new SampleListener() {
+            @Override
+            public void addSample(Number value) {
+                summary.record(value.longValue());
+            }
+            @Override
+            public void addLongSample(long value) {
+                summary.record(value);
+            }
+            @Override
+            public void addDoubleSample(double value) {
+                summary.record((long) value);
+            }
+        };
     }
 
     @Override
@@ -52,7 +65,7 @@ public void gauge(String id, Supplier<Number> supplier, String... tagNameValuePa
     public Counter counter(String id, String... tagNameValuePairs) {
         Id metricId = suffixBaseId(id).withTags(tagNameValuePairs);
         com.netflix.spectator.api.Counter spectatorCounter = registry.counter(metricId);
-        return () -> spectatorCounter.increment();
+        return spectatorCounter::increment;
     }
 
     private Id suffixBaseId(String suffix) {