diff --git a/micrometer-core/src/main/java/io/micrometer/core/instrument/histogram/TimeWindowHistogram.java b/micrometer-core/src/main/java/io/micrometer/core/instrument/histogram/TimeWindowHistogram.java
index f4b1349e29..951919f9ea 100644
--- a/micrometer-core/src/main/java/io/micrometer/core/instrument/histogram/TimeWindowHistogram.java
+++ b/micrometer-core/src/main/java/io/micrometer/core/instrument/histogram/TimeWindowHistogram.java
@@ -32,6 +32,7 @@ public class TimeWindowHistogram extends TimeWindowHistogramBase<DoubleRecorder,
     public TimeWindowHistogram(Clock clock, HistogramConfig histogramConfig) {
         super(clock, histogramConfig, DoubleRecorder.class);
         intervalHistogram = new DoubleHistogram(NUM_SIGNIFICANT_VALUE_DIGITS);
+        initRingBuffer();
     }
 
     @Override
diff --git a/micrometer-core/src/main/java/io/micrometer/core/instrument/histogram/TimeWindowHistogramBase.java b/micrometer-core/src/main/java/io/micrometer/core/instrument/histogram/TimeWindowHistogramBase.java
index fe47f64e57..4e80876372 100644
--- a/micrometer-core/src/main/java/io/micrometer/core/instrument/histogram/TimeWindowHistogramBase.java
+++ b/micrometer-core/src/main/java/io/micrometer/core/instrument/histogram/TimeWindowHistogramBase.java
@@ -46,7 +46,7 @@ abstract class TimeWindowHistogramBase<T, U> {
     private final HistogramConfig histogramConfig;
 
     private final T[] ringBuffer;
-    private final U accumulatedHistogram;
+    private U accumulatedHistogram;
     private volatile boolean accumulatedHistogramStale;
 
     private final long durationBetweenRotatesMillis;
@@ -64,8 +64,8 @@ abstract class TimeWindowHistogramBase<T, U> {
             rejectHistogramConfig("histogramBufferLength (" + ageBuckets + ") must be greater than 0.");
         }
 
-        ringBuffer = newRingBuffer(bucketType, ageBuckets, histogramConfig);
-        accumulatedHistogram = newAccumulatedHistogram(ringBuffer);
+        //noinspection unchecked
+        ringBuffer = (T[]) Array.newInstance(bucketType, ageBuckets);
 
         durationBetweenRotatesMillis = histogramConfig.getHistogramExpiry().toMillis() / ageBuckets;
         if (durationBetweenRotatesMillis <= 0) {
@@ -75,7 +75,6 @@ abstract class TimeWindowHistogramBase<T, U> {
 
         currentBucket = 0;
         lastRotateTimestampMillis = clock.wallTime();
-
     }
 
     private static HistogramConfig validateHistogramConfig(HistogramConfig histogramConfig) {
@@ -107,13 +106,11 @@ private static HistogramConfig validateHistogramConfig(HistogramConfig histogram
         return histogramConfig;
     }
 
-    private T[] newRingBuffer(Class<T> bucketType, int ageBuckets, HistogramConfig histogramConfig) {
-        @SuppressWarnings("unchecked")
-        final T[] ringBuffer = (T[]) Array.newInstance(bucketType, ageBuckets);
-        for (int i = 0; i < ageBuckets; i++) {
+    void initRingBuffer() {
+        for (int i = 0; i < ringBuffer.length; i++) {
             ringBuffer[i] = newBucket(histogramConfig);
         }
-        return ringBuffer;
+        accumulatedHistogram = newAccumulatedHistogram(ringBuffer);
     }
 
     private static void rejectHistogramConfig(String msg) {
diff --git a/micrometer-core/src/main/java/io/micrometer/core/instrument/histogram/TimeWindowLatencyHistogram.java b/micrometer-core/src/main/java/io/micrometer/core/instrument/histogram/TimeWindowLatencyHistogram.java
index 4a619cbb7d..bbd9f6ee6f 100644
--- a/micrometer-core/src/main/java/io/micrometer/core/instrument/histogram/TimeWindowLatencyHistogram.java
+++ b/micrometer-core/src/main/java/io/micrometer/core/instrument/histogram/TimeWindowLatencyHistogram.java
@@ -28,6 +28,8 @@
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
+import static java.util.Objects.requireNonNull;
+
 /**
  * @author Jon Schneider
  * @author Trustin Heuiseung Lee
@@ -54,7 +56,7 @@ public TimeWindowLatencyHistogram(Clock clock, HistogramConfig histogramConfig,
                                       io.micrometer.core.instrument.histogram.pause.PauseDetector pauseDetector) {
         super(clock, histogramConfig, LatencyStats.class);
 
-        this.pauseDetector = pauseDetectorCache.computeIfAbsent(pauseDetector, detector -> {
+        this.pauseDetector = requireNonNull(pauseDetectorCache.computeIfAbsent(pauseDetector, detector -> {
             if (detector instanceof ClockDriftPauseDetector) {
                 ClockDriftPauseDetector clockDriftPauseDetector = (ClockDriftPauseDetector) detector;
                 return new SimplePauseDetector(clockDriftPauseDetector.getSleepInterval().toNanos(),
@@ -63,11 +65,15 @@ public TimeWindowLatencyHistogram(Clock clock, HistogramConfig histogramConfig,
                 return new NoopPauseDetector();
             }
             return new NoopPauseDetector();
-        });
+        }));
+
+        initRingBuffer();
     }
 
     @Override
     LatencyStats newBucket(HistogramConfig histogramConfig) {
+        requireNonNull(pauseDetector);
+
         return new LatencyStats.Builder()
             .pauseDetector(pauseDetector)
             .lowestTrackableLatency(histogramConfig.getMinimumExpectedValue())
diff --git a/scripts/cpu.sh b/scripts/cpu.sh
new file mode 100755
index 0000000000..ad624e0452
--- /dev/null
+++ b/scripts/cpu.sh
@@ -0,0 +1,2 @@
+#!/usr/bin/env bash
+htop -p $(ps ax | grep '[m]icrometer-core' | awk '{print $1}')
\ No newline at end of file