From 2e6d32844e033399e63e42c88e0ea8b587879af3 Mon Sep 17 00:00:00 2001
From: Ben Manes <ben.manes@gmail.com>
Date: Wed, 30 May 2018 22:07:27 -0700
Subject: [PATCH] JSR-305 migrations (fixes #242)

Migrate removed usages of @Nonnegative (prior commit) to @NonNegative.

Add generic type @NonNull where not excessively verbose.
---
 .../caffeine/cache/AsyncCacheLoader.java      |  4 +--
 .../caffeine/cache/AsyncLoadingCache.java     |  2 +-
 .../github/benmanes/caffeine/cache/Cache.java |  8 +++---
 .../benmanes/caffeine/cache/CacheLoader.java  |  5 ++--
 .../benmanes/caffeine/cache/Caffeine.java     | 13 +++++-----
 .../benmanes/caffeine/cache/CaffeineSpec.java |  3 ++-
 .../benmanes/caffeine/cache/Expiry.java       |  7 +++--
 .../caffeine/cache/FrequencySketch.java       |  4 ++-
 .../benmanes/caffeine/cache/LoadingCache.java |  2 +-
 .../github/benmanes/caffeine/cache/Node.java  |  7 +++--
 .../benmanes/caffeine/cache/Policy.java       | 26 +++++++++++--------
 .../benmanes/caffeine/cache/TimerWheel.java   |  9 ++++---
 .../benmanes/caffeine/cache/Weigher.java      |  2 ++
 .../caffeine/cache/stats/CacheStats.java      | 25 +++++++++++++++---
 .../caffeine/cache/stats/StatsCounter.java    | 11 ++++----
 .../management/JCacheStatisticsMXBean.java    | 12 +++++----
 .../membership/bloom/BloomFilter.java         |  7 +++--
 17 files changed, 95 insertions(+), 52 deletions(-)

diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncCacheLoader.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncCacheLoader.java
index 4f494f44d8..3e32c95f80 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncCacheLoader.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncCacheLoader.java
@@ -69,8 +69,8 @@ public interface AsyncCacheLoader<K, V> {
    *         that key; <b>may not contain null values</b>
    */
   @NonNull
-  default CompletableFuture<Map<K, V>> asyncLoadAll(
-      @NonNull Iterable<? extends K> keys, @NonNull Executor executor) {
+  default CompletableFuture<Map<@NonNull K, @NonNull V>> asyncLoadAll(
+      @NonNull Iterable<? extends @NonNull K> keys, @NonNull Executor executor) {
     throw new UnsupportedOperationException();
   }
 
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncLoadingCache.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncLoadingCache.java
index eb92a70b9a..18fadfb4d3 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncLoadingCache.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncLoadingCache.java
@@ -79,7 +79,7 @@ public interface AsyncLoadingCache<K, V> extends AsyncCache<K, V> {
    *         future, in which case the mapping is left unestablished
    */
   @NonNull
-  CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends K> keys);
+  CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends @NonNull K> keys);
 
   /**
    * Returns a view of the entries stored in this cache as a synchronous {@link LoadingCache}. A
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Cache.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Cache.java
index ffd07922c2..5492831eab 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Cache.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Cache.java
@@ -19,6 +19,7 @@
 import java.util.concurrent.ConcurrentMap;
 import java.util.function.Function;
 
+import org.checkerframework.checker.index.qual.NonNegative;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
@@ -90,7 +91,7 @@ public interface Cache<K, V> {
    * @throws NullPointerException if the specified collection is null or contains a null element
    */
   @NonNull
-  Map<K, V> getAllPresent(@NonNull Iterable<?> keys);
+  Map<@NonNull K, @NonNull V> getAllPresent(@NonNull Iterable<@NonNull ?> keys);
 
   /**
    * Associates the {@code value} with the {@code key} in this cache. If the cache previously
@@ -116,7 +117,7 @@ public interface Cache<K, V> {
    * @throws NullPointerException if the specified map is null or the specified map contains null
    *         keys or values
    */
-  void putAll(@NonNull Map<? extends K,? extends V> map);
+  void putAll(@NonNull Map<? extends @NonNull K,? extends @NonNull V> map);
 
   /**
    * Discards any cached value for the {@code key}. The behavior of this operation is undefined for
@@ -150,6 +151,7 @@ public interface Cache<K, V> {
    *
    * @return the estimated number of mappings
    */
+  @NonNegative
   long estimatedSize();
 
   /**
@@ -175,7 +177,7 @@ public interface Cache<K, V> {
    * @return a thread-safe view of this cache supporting all of the optional {@link Map} operations
    */
   @NonNull
-  ConcurrentMap<K, V> asMap();
+  ConcurrentMap<@NonNull K, @NonNull V> asMap();
 
   /**
    * Performs any pending maintenance operations needed by the cache. Exactly which activities are
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CacheLoader.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CacheLoader.java
index 4194b12214..1bfae198b2 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CacheLoader.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CacheLoader.java
@@ -83,7 +83,8 @@ public interface CacheLoader<K, V> extends AsyncCacheLoader<K, V> {
    *         caught, the thread's interrupt status is set
    */
   @NonNull
-  default Map<K, V> loadAll(@NonNull Iterable<? extends K> keys) throws Exception {
+  default Map<@NonNull K, @NonNull V> loadAll(
+      @NonNull Iterable<? extends @NonNull K> keys) throws Exception {
     throw new UnsupportedOperationException();
   }
 
@@ -128,7 +129,7 @@ default CompletableFuture<V> asyncLoad(@NonNull K key, @NonNull Executor executo
    *         that key; <b>may not contain null values</b>
    */
   @Override @NonNull
-  default CompletableFuture<Map<K, V>> asyncLoadAll(
+  default CompletableFuture<Map<@NonNull K, @NonNull V>> asyncLoadAll(
       @NonNull Iterable<? extends K> keys, @NonNull Executor executor) {
     requireNonNull(keys);
     requireNonNull(executor);
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Caffeine.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Caffeine.java
index 6e474d75c9..e83daa6a15 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Caffeine.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Caffeine.java
@@ -34,6 +34,7 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
+import org.checkerframework.checker.index.qual.NonNegative;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
@@ -243,7 +244,7 @@ public static Caffeine<Object, Object> from(String spec) {
    * @throws IllegalStateException if an initial capacity was already set
    */
   @NonNull
-  public Caffeine<K, V> initialCapacity(int initialCapacity) {
+  public Caffeine<K, V> initialCapacity(@NonNegative int initialCapacity) {
     requireState(this.initialCapacity == UNSET_INT,
         "initial capacity was already set to %s", this.initialCapacity);
     requireArgument(initialCapacity >= 0);
@@ -306,7 +307,7 @@ Executor getExecutor() {
    * @throws IllegalStateException if a maximum size or weight was already set
    */
   @NonNull
-  public Caffeine<K, V> maximumSize(long maximumSize) {
+  public Caffeine<K, V> maximumSize(@NonNegative long maximumSize) {
     requireState(this.maximumSize == UNSET_INT,
         "maximum size was already set to %s", this.maximumSize);
     requireState(this.maximumWeight == UNSET_INT,
@@ -342,7 +343,7 @@ public Caffeine<K, V> maximumSize(long maximumSize) {
    * @throws IllegalStateException if a maximum weight or size was already set
    */
   @NonNull
-  public Caffeine<K, V> maximumWeight(long maximumWeight) {
+  public Caffeine<K, V> maximumWeight(@NonNegative long maximumWeight) {
     requireState(this.maximumWeight == UNSET_INT,
         "maximum weight was already set to %s", this.maximumWeight);
     requireState(this.maximumSize == UNSET_INT,
@@ -546,7 +547,7 @@ public Caffeine<K, V> expireAfterWrite(@NonNull Duration duration) {
    * @throws IllegalStateException if the time to live or variable expiration was already set
    */
   @NonNull
-  public Caffeine<K, V> expireAfterWrite(long duration, @NonNull TimeUnit unit) {
+  public Caffeine<K, V> expireAfterWrite(@NonNegative long duration, @NonNull TimeUnit unit) {
     requireState(expireAfterWriteNanos == UNSET_INT,
         "expireAfterWrite was already set to %s ns", expireAfterWriteNanos);
     requireState(expiry == null, "expireAfterAccess may not be used with variable expiration");
@@ -605,7 +606,7 @@ public Caffeine<K, V> expireAfterAccess(@NonNull Duration duration) {
    * @throws IllegalStateException if the time to idle or variable expiration was already set
    */
   @NonNull
-  public Caffeine<K, V> expireAfterAccess(long duration, @NonNull TimeUnit unit) {
+  public Caffeine<K, V> expireAfterAccess(@NonNegative long duration, @NonNull TimeUnit unit) {
     requireState(expireAfterAccessNanos == UNSET_INT,
         "expireAfterAccess was already set to %s ns", expireAfterAccessNanos);
     requireState(expiry == null, "expireAfterAccess may not be used with variable expiration");
@@ -710,7 +711,7 @@ public Caffeine<K, V> refreshAfterWrite(@NonNull Duration duration) {
    * @throws IllegalStateException if the refresh interval was already set
    */
   @NonNull
-  public Caffeine<K, V> refreshAfterWrite(long duration, @NonNull TimeUnit unit) {
+  public Caffeine<K, V> refreshAfterWrite(@NonNegative long duration, @NonNull TimeUnit unit) {
     requireNonNull(unit);
     requireState(refreshNanos == UNSET_INT, "refresh was already set to %s ns", refreshNanos);
     requireArgument(duration > 0, "duration must be positive: %s %s", duration, unit);
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CaffeineSpec.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CaffeineSpec.java
index 9086a541ec..4d6c345849 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CaffeineSpec.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/CaffeineSpec.java
@@ -23,6 +23,7 @@
 import java.util.Objects;
 import java.util.concurrent.TimeUnit;
 
+import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import com.github.benmanes.caffeine.cache.Caffeine.Strength;
@@ -145,7 +146,7 @@ Caffeine<Object, Object> toBuilder() {
    * @return the parsed specification
    */
   @SuppressWarnings("StringSplitter")
-  public static CaffeineSpec parse(String specification) {
+  public static @NonNull CaffeineSpec parse(@NonNull String specification) {
     CaffeineSpec spec = new CaffeineSpec(specification);
     for (String option : specification.split(SPLIT_OPTIONS)) {
       spec.parseOption(option.trim());
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Expiry.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Expiry.java
index c6017e6b73..824dee11f4 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Expiry.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Expiry.java
@@ -15,6 +15,7 @@
  */
 package com.github.benmanes.caffeine.cache;
 
+import org.checkerframework.checker.index.qual.NonNegative;
 import org.checkerframework.checker.nullness.qual.NonNull;
 
 /**
@@ -57,7 +58,8 @@ public interface Expiry<K, V> {
    * @param currentDuration the current duration, in nanoseconds
    * @return the length of time before the entry expires, in nanoseconds
    */
-  long expireAfterUpdate(@NonNull K key, @NonNull V value, long currentTime, long currentDuration);
+  long expireAfterUpdate(@NonNull K key, @NonNull V value,
+      long currentTime, @NonNegative long currentDuration);
 
   /**
    * Specifies that the entry should be automatically removed from the cache once the duration has
@@ -75,5 +77,6 @@ public interface Expiry<K, V> {
    * @param currentDuration the current duration, in nanoseconds
    * @return the length of time before the entry expires, in nanoseconds
    */
-  long expireAfterRead(@NonNull K key, @NonNull V value, long currentTime, long currentDuration);
+  long expireAfterRead(@NonNull K key, @NonNull V value,
+      long currentTime, @NonNegative long currentDuration);
 }
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/FrequencySketch.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/FrequencySketch.java
index 8d2e005d48..8b0230f0a9 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/FrequencySketch.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/FrequencySketch.java
@@ -19,6 +19,7 @@
 
 import java.util.concurrent.ThreadLocalRandom;
 
+import org.checkerframework.checker.index.qual.NonNegative;
 import org.checkerframework.checker.nullness.qual.NonNull;
 
 /**
@@ -87,7 +88,7 @@ public FrequencySketch() {
    *
    * @param maximumSize the maximum size of the cache
    */
-  public void ensureCapacity(long maximumSize) {
+  public void ensureCapacity(@NonNegative long maximumSize) {
     requireArgument(maximumSize >= 0);
     int maximum = (int) Math.min(maximumSize, Integer.MAX_VALUE >>> 1);
     if ((table != null) && (table.length >= maximum)) {
@@ -117,6 +118,7 @@ public boolean isNotInitialized() {
    * @param e the element to count occurrences of
    * @return the estimated number of occurrences of the element; possibly zero but never negative
    */
+  @NonNegative
   public int frequency(@NonNull E e) {
     if (isNotInitialized()) {
       return 0;
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LoadingCache.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LoadingCache.java
index c003265301..63dd489346 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LoadingCache.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/LoadingCache.java
@@ -89,7 +89,7 @@ public interface LoadingCache<K, V> extends Cache<K, V> {
    *         is left unestablished
    */
   @NonNull
-  Map<K, V> getAll(@NonNull Iterable<? extends K> keys);
+  Map<@NonNull K, @NonNull V> getAll(@NonNull Iterable<? extends @NonNull K> keys);
 
   /**
    * Loads a new value for the {@code key}, asynchronously. While the new value is loading the
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Node.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Node.java
index 1695b73363..f6d1c9939d 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Node.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Node.java
@@ -17,6 +17,7 @@
 
 import java.lang.ref.ReferenceQueue;
 
+import org.checkerframework.checker.index.qual.NonNegative;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
@@ -69,6 +70,7 @@ abstract class Node<K, V> implements AccessOrder<Node<K, V>>, WriteOrder<Node<K,
   public abstract boolean containsValue(@NonNull Object value);
 
   /** Returns the weight of this entry from the entry's perspective. */
+  @NonNegative
   @GuardedBy("this")
   public int getWeight() {
     return 1;
@@ -76,9 +78,10 @@ public int getWeight() {
 
   /** Sets the weight from the entry's perspective. */
   @GuardedBy("this")
-  public void setWeight(int weight) {}
+  public void setWeight(@NonNegative int weight) {}
 
   /** Returns the weight of this entry from the policy's perspective. */
+  @NonNegative
   @GuardedBy("evictionLock")
   public int getPolicyWeight() {
     return 1;
@@ -86,7 +89,7 @@ public int getPolicyWeight() {
 
   /** Sets the weight from the policy's perspective. */
   @GuardedBy("evictionLock")
-  public void setPolicyWeight(int weight) {}
+  public void setPolicyWeight(@NonNegative int weight) {}
 
   /* ---------------- Health -------------- */
 
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Policy.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Policy.java
index b3820ecde8..b3e46be34b 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Policy.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Policy.java
@@ -22,6 +22,7 @@
 import java.util.OptionalLong;
 import java.util.concurrent.TimeUnit;
 
+import org.checkerframework.checker.index.qual.NonNegative;
 import org.checkerframework.checker.nullness.qual.NonNull;
 
 /**
@@ -148,6 +149,7 @@ default OptionalInt weightOf(@NonNull K key) {
      *
      * @return the maximum size bounding, which may be either weighted or unweighted
      */
+    @NonNegative
     long getMaximum();
 
     /**
@@ -163,7 +165,7 @@ default OptionalInt weightOf(@NonNull K key) {
      *        cache was constructed
      * @throws IllegalArgumentException if the maximum size specified is negative
      */
-    void setMaximum(long maximum);
+    void setMaximum(@NonNegative long maximum);
 
     /**
      * Returns an unmodifiable snapshot {@link Map} view of the cache with ordered traversal. The
@@ -180,7 +182,7 @@ default OptionalInt weightOf(@NonNull K key) {
      * @return a snapshot view of the cache from coldest entry to the hottest
      */
     @NonNull
-    Map<K, V> coldest(int limit);
+    Map<@NonNull K, @NonNull V> coldest(@NonNegative int limit);
 
     /**
      * Returns an unmodifiable snapshot {@link Map} view of the cache with ordered traversal. The
@@ -197,7 +199,7 @@ default OptionalInt weightOf(@NonNull K key) {
      * @return a snapshot view of the cache from hottest entry to the coldest
      */
     @NonNull
-    Map<K, V> hottest(int limit);
+    Map<@NonNull K, @NonNull V> hottest(@NonNegative int limit);
   }
 
   /** The low-level operations for a cache with a fixed expiration policy. */
@@ -251,6 +253,7 @@ default Optional<Duration> ageOf(@NonNull K key) {
      * @param unit the unit that duration is expressed in
      * @return the length of time after which an entry should be automatically removed
      */
+    @NonNegative
     long getExpiresAfter(@NonNull TimeUnit unit);
 
     /**
@@ -277,7 +280,7 @@ default Duration getExpiresAfter() {
      * @param unit the unit that {@code duration} is expressed in
      * @throws IllegalArgumentException if {@code duration} is negative
      */
-    void setExpiresAfter(long duration, @NonNull TimeUnit unit);
+    void setExpiresAfter(@NonNegative long duration, @NonNull TimeUnit unit);
 
     /**
      * Specifies that each entry should be automatically removed from the cache once a fixed
@@ -306,7 +309,7 @@ default void setExpiresAfter(@NonNull Duration duration) {
      * @return a snapshot view of the cache from oldest entry to the youngest
      */
     @NonNull
-    Map<K, V> oldest(int limit);
+    Map<@NonNull K, @NonNull V> oldest(@NonNegative int limit);
 
     /**
      * Returns an unmodifiable snapshot {@link Map} view of the cache with ordered traversal. The
@@ -323,7 +326,7 @@ default void setExpiresAfter(@NonNull Duration duration) {
      * @return a snapshot view of the cache from youngest entry to the oldest
      */
     @NonNull
-    Map<K, V> youngest(int limit);
+    Map<@NonNull K, @NonNull V> youngest(@NonNegative int limit);
   }
 
   /** The low-level operations for a cache with a variable expiration policy. */
@@ -368,7 +371,7 @@ default Optional<Duration> getExpiresAfter(@NonNull K key) {
      * @throws IllegalArgumentException if {@code duration} is negative
      * @throws NullPointerException if the unit is null
      */
-    void setExpiresAfter(@NonNull K key, long duration, @NonNull TimeUnit unit);
+    void setExpiresAfter(@NonNull K key, @NonNegative long duration, @NonNull TimeUnit unit);
 
     /**
      * Specifies that the entry should be automatically removed from the cache once the duration has
@@ -399,7 +402,7 @@ default void setExpiresAfter(@NonNull K key, @NonNull Duration duration) {
      * @throws IllegalArgumentException if {@code duration} is negative
      */
     default boolean putIfAbsent(@NonNull K key, @NonNull V value,
-        long duration, @NonNull TimeUnit unit) {
+        @NonNegative long duration, @NonNull TimeUnit unit) {
       // This method was added & implemented in version 2.6.0
       throw new UnsupportedOperationException();
     }
@@ -436,7 +439,8 @@ default boolean putIfAbsent(@NonNull K key, @NonNull V value, @NonNull Duration
      * @throws IllegalArgumentException if {@code duration} is negative
      * @throws NullPointerException if the specified key or value is null
      */
-    default void put(@NonNull K key, @NonNull V value, long duration, @NonNull TimeUnit unit) {
+    default void put(@NonNull K key, @NonNull V value,
+        @NonNegative long duration, @NonNull TimeUnit unit) {
       // This method was added & implemented in version 2.6.0
       throw new UnsupportedOperationException();
     }
@@ -472,7 +476,7 @@ default void put(@NonNull K key, @NonNull V value, @NonNull Duration duration) {
      * @return a snapshot view of the cache from oldest entry to the youngest
      */
     @NonNull
-    Map<K, V> oldest(int limit);
+    Map<@NonNull K, @NonNull V> oldest(@NonNegative int limit);
 
     /**
      * Returns an unmodifiable snapshot {@link Map} view of the cache with ordered traversal. The
@@ -489,6 +493,6 @@ default void put(@NonNull K key, @NonNull V value, @NonNull Duration duration) {
      * @return a snapshot view of the cache from youngest entry to the oldest
      */
     @NonNull
-    Map<K, V> youngest(int limit);
+    Map<@NonNull K, @NonNull V> youngest(@NonNegative int limit);
   }
 }
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/TimerWheel.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/TimerWheel.java
index d7268eb46c..7b78d23868 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/TimerWheel.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/TimerWheel.java
@@ -28,6 +28,7 @@
 import java.util.concurrent.TimeUnit;
 import java.util.function.Function;
 
+import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -165,7 +166,7 @@ void expire(int index, long previousTicks, long currentTicks) {
    *
    * @param node the entry in the cache
    */
-  public void schedule(Node<K, V> node) {
+  public void schedule(@NonNull Node<K, V> node) {
     Node<K, V> sentinel = findBucket(node.getVariableTime());
     link(sentinel, node);
   }
@@ -175,7 +176,7 @@ public void schedule(Node<K, V> node) {
    *
    * @param node the entry in the cache
    */
-  public void reschedule(Node<K, V> node) {
+  public void reschedule(@NonNull Node<K, V> node) {
     if (node.getNextInVariableOrder() != null) {
       unlink(node);
       schedule(node);
@@ -187,7 +188,7 @@ public void reschedule(Node<K, V> node) {
    *
    * @param node the entry in the cache
    */
-  public void deschedule(Node<K, V> node) {
+  public void deschedule(@NonNull Node<K, V> node) {
     unlink(node);
     node.setNextInVariableOrder(null);
     node.setPreviousInVariableOrder(null);
@@ -241,7 +242,7 @@ void unlink(Node<K, V> node) {
    * @param transformer a function that unwraps the value
    * @return an unmodifiable snapshot in the desired order
    */
-  public Map<K, V> snapshot(boolean ascending, int limit, Function<V, V> transformer) {
+  public Map<K, V> snapshot(boolean ascending, int limit, @NonNull Function<V, V> transformer) {
     requireArgument(limit >= 0);
 
     Map<K, V> map = new LinkedHashMap<>(Math.min(limit, cache.size()));
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Weigher.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Weigher.java
index 4064ecdd22..030ed96982 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Weigher.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/Weigher.java
@@ -19,6 +19,7 @@
 
 import java.io.Serializable;
 
+import org.checkerframework.checker.index.qual.NonNegative;
 import org.checkerframework.checker.nullness.qual.NonNull;
 
 /**
@@ -40,6 +41,7 @@ public interface Weigher<K, V> {
    * @param value the value to weigh
    * @return the weight of the entry; must be non-negative
    */
+  @NonNegative
   int weigh(@NonNull K key, @NonNull V value);
 
   /**
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/CacheStats.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/CacheStats.java
index f99a85feba..e11e7a5f46 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/CacheStats.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/CacheStats.java
@@ -17,6 +17,7 @@
 
 import java.util.Objects;
 
+import org.checkerframework.checker.index.qual.NonNegative;
 import org.checkerframework.checker.nullness.qual.NonNull;
 
 import com.github.benmanes.caffeine.cache.Cache;
@@ -79,8 +80,9 @@ public final class CacheStats {
    * @deprecated This constructor is scheduled for removal in version <tt>3.0.0</tt>.
    */
   @Deprecated
-  public CacheStats(long hitCount, long missCount, long loadSuccessCount,
-      long loadFailureCount, long totalLoadTime, long evictionCount) {
+  public CacheStats(@NonNegative long hitCount, @NonNegative long missCount,
+      @NonNegative long loadSuccessCount, @NonNegative long loadFailureCount,
+      @NonNegative long totalLoadTime, @NonNegative long evictionCount) {
     this(hitCount, missCount, loadSuccessCount, loadFailureCount, totalLoadTime, evictionCount, 0L);
   }
 
@@ -98,8 +100,10 @@ public CacheStats(long hitCount, long missCount, long loadSuccessCount,
    * @param evictionCount the number of entries evicted from the cache
    * @param evictionWeight the sum of weights of entries evicted from the cache
    */
-  public CacheStats(long hitCount, long missCount, long loadSuccessCount, long loadFailureCount,
-      long totalLoadTime, long evictionCount, long evictionWeight) {
+  public CacheStats(@NonNegative long hitCount, @NonNegative long missCount,
+      @NonNegative long loadSuccessCount, @NonNegative long loadFailureCount,
+      @NonNegative long totalLoadTime, @NonNegative long evictionCount,
+      @NonNegative long evictionWeight) {
     if ((hitCount < 0) || (missCount < 0) || (loadSuccessCount < 0) || (loadFailureCount < 0)
         || (totalLoadTime < 0) || (evictionCount < 0) || (evictionWeight < 0)) {
       throw new IllegalArgumentException();
@@ -129,6 +133,7 @@ public static CacheStats empty() {
    *
    * @return the {@code hitCount + missCount}
    */
+  @NonNegative
   public long requestCount() {
     return hitCount + missCount;
   }
@@ -138,6 +143,7 @@ public long requestCount() {
    *
    * @return the number of times {@link Cache} lookup methods have returned a cached value
    */
+  @NonNegative
   public long hitCount() {
     return hitCount;
   }
@@ -149,6 +155,7 @@ public long hitCount() {
    *
    * @return the ratio of cache requests which were hits
    */
+  @NonNegative
   public double hitRate() {
     long requestCount = requestCount();
     return (requestCount == 0) ? 1.0 : (double) hitCount / requestCount;
@@ -163,6 +170,7 @@ public double hitRate() {
    * @return the number of times {@link Cache} lookup methods have returned an uncached (newly
    *         loaded) value, or null
    */
+  @NonNegative
   public long missCount() {
     return missCount;
   }
@@ -178,6 +186,7 @@ public long missCount() {
    *
    * @return the ratio of cache requests which were misses
    */
+  @NonNegative
   public double missRate() {
     long requestCount = requestCount();
     return (requestCount == 0) ? 0.0 : (double) missCount / requestCount;
@@ -190,6 +199,7 @@ public double missRate() {
    *
    * @return the {@code loadSuccessCount + loadFailureCount}
    */
+  @NonNegative
   public long loadCount() {
     return loadSuccessCount + loadFailureCount;
   }
@@ -203,6 +213,7 @@ public long loadCount() {
    *
    * @return the number of times {@link Cache} lookup methods have successfully loaded a new value
    */
+  @NonNegative
   public long loadSuccessCount() {
     return loadSuccessCount;
   }
@@ -216,6 +227,7 @@ public long loadSuccessCount() {
    *
    * @return the number of times {@link Cache} lookup methods failed to load a new value
    */
+  @NonNegative
   public long loadFailureCount() {
     return loadFailureCount;
   }
@@ -227,6 +239,7 @@ public long loadFailureCount() {
    *
    * @return the ratio of cache loading attempts which threw exceptions
    */
+  @NonNegative
   public double loadFailureRate() {
     long totalLoadCount = loadSuccessCount + loadFailureCount;
     return (totalLoadCount == 0)
@@ -241,6 +254,7 @@ public double loadFailureRate() {
    *
    * @return the total number of nanoseconds the cache has spent loading new values
    */
+  @NonNegative
   public long totalLoadTime() {
     return totalLoadTime;
   }
@@ -251,6 +265,7 @@ public long totalLoadTime() {
    *
    * @return the average time spent loading new values
    */
+  @NonNegative
   public double averageLoadPenalty() {
     long totalLoadCount = loadSuccessCount + loadFailureCount;
     return (totalLoadCount == 0)
@@ -264,6 +279,7 @@ public double averageLoadPenalty() {
    *
    * @return the number of times an entry has been evicted
    */
+  @NonNegative
   public long evictionCount() {
     return evictionCount;
   }
@@ -274,6 +290,7 @@ public long evictionCount() {
    *
    * @return the sum of weights of evicted entities
    */
+  @NonNegative
   public long evictionWeight() {
     return evictionWeight;
   }
diff --git a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/StatsCounter.java b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/StatsCounter.java
index 3141b812ac..44438f36f3 100644
--- a/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/StatsCounter.java
+++ b/caffeine/src/main/java/com/github/benmanes/caffeine/cache/stats/StatsCounter.java
@@ -17,6 +17,7 @@
 
 import java.util.Map;
 
+import org.checkerframework.checker.index.qual.NonNegative;
 import org.checkerframework.checker.nullness.qual.NonNull;
 
 import com.github.benmanes.caffeine.cache.Cache;
@@ -34,7 +35,7 @@ public interface StatsCounter {
    *
    * @param count the number of hits to record
    */
-  void recordHits(int count);
+  void recordHits(@NonNegative int count);
 
   /**
    * Records cache misses. This should be called when a cache request returns a value that was not
@@ -46,7 +47,7 @@ public interface StatsCounter {
    *
    * @param count the number of misses to record
    */
-  void recordMisses(int count);
+  void recordMisses(@NonNegative int count);
 
   /**
    * Records the successful load of a new entry. This method should be called when a cache request
@@ -56,7 +57,7 @@ public interface StatsCounter {
    *
    * @param loadTime the number of nanoseconds the cache spent computing or retrieving the new value
    */
-  void recordLoadSuccess(long loadTime);
+  void recordLoadSuccess(@NonNegative long loadTime);
 
   /**
    * Records the failed load of a new entry. This method should be called when a cache request
@@ -67,7 +68,7 @@ public interface StatsCounter {
    * @param loadTime the number of nanoseconds the cache spent computing or retrieving the new value
    *        prior to discovering the value doesn't exist or an exception being thrown
    */
-  void recordLoadFailure(long loadTime);
+  void recordLoadFailure(@NonNegative long loadTime);
 
   /**
    * Records the eviction of an entry from the cache. This should only been called when an entry is
@@ -87,7 +88,7 @@ public interface StatsCounter {
    *
    * @param weight the weight of the evicted entry
    */
-  default void recordEviction(int weight) {
+  default void recordEviction(@NonNegative int weight) {
     // This method will be abstract in version 3.0.0
     recordEviction();
   }
diff --git a/jcache/src/main/java/com/github/benmanes/caffeine/jcache/management/JCacheStatisticsMXBean.java b/jcache/src/main/java/com/github/benmanes/caffeine/jcache/management/JCacheStatisticsMXBean.java
index bcdbd9627a..f45772c018 100644
--- a/jcache/src/main/java/com/github/benmanes/caffeine/jcache/management/JCacheStatisticsMXBean.java
+++ b/jcache/src/main/java/com/github/benmanes/caffeine/jcache/management/JCacheStatisticsMXBean.java
@@ -20,6 +20,8 @@
 
 import javax.cache.management.CacheStatisticsMXBean;
 
+import org.checkerframework.checker.index.qual.NonNegative;
+
 /**
  * Caffeine JCache statistics.
  *
@@ -79,7 +81,7 @@ public float getCacheHitPercentage() {
    *
    * @param count the number of hits to record
    */
-  public void recordHits(long count) {
+  public void recordHits(@NonNegative long count) {
     if (enabled) {
       hits.add(count);
     }
@@ -102,7 +104,7 @@ public float getCacheMissPercentage() {
    *
    * @param count the number of misses to record
    */
-  public void recordMisses(long count) {
+  public void recordMisses(@NonNegative long count) {
     if (enabled) {
       misses.add(count);
     }
@@ -123,7 +125,7 @@ public long getCachePuts() {
    *
    * @param count the number of writes to record
    */
-  public void recordPuts(long count) {
+  public void recordPuts(@NonNegative long count) {
     if (enabled && (count != 0)) {
       puts.add(count);
     }
@@ -139,7 +141,7 @@ public long getCacheRemovals() {
    *
    * @param count the number of removals to record
    */
-  public void recordRemovals(long count) {
+  public void recordRemovals(@NonNegative long count) {
     if (enabled) {
       removals.add(count);
     }
@@ -155,7 +157,7 @@ public long getCacheEvictions() {
    *
    * @param count the number of evictions to record
    */
-  public void recordEvictions(long count) {
+  public void recordEvictions(@NonNegative long count) {
     if (enabled) {
       evictions.add(count);
     }
diff --git a/simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/membership/bloom/BloomFilter.java b/simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/membership/bloom/BloomFilter.java
index 4f3d645064..037ec1152e 100644
--- a/simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/membership/bloom/BloomFilter.java
+++ b/simulator/src/main/java/com/github/benmanes/caffeine/cache/simulator/membership/bloom/BloomFilter.java
@@ -19,6 +19,8 @@
 
 import java.util.Arrays;
 
+import org.checkerframework.checker.index.qual.NonNegative;
+
 import com.github.benmanes.caffeine.cache.simulator.membership.Membership;
 
 /**
@@ -49,7 +51,8 @@ public final class BloomFilter implements Membership {
    * @param fpp the false positive probability, where 0.0 > fpp < 1.0
    * @param randomSeed the smear to protect against hash flooding, adjusted to an odd value
    */
-  public BloomFilter(long expectedInsertions, double fpp, int randomSeed) {
+  public BloomFilter(@NonNegative long expectedInsertions,
+      @NonNegative double fpp, int randomSeed) {
     this.randomSeed = ((randomSeed & 1) == 0) ? randomSeed + 1 : randomSeed;
     ensureCapacity(expectedInsertions, fpp);
   }
@@ -62,7 +65,7 @@ public BloomFilter(long expectedInsertions, double fpp, int randomSeed) {
    * @param expectedInsertions the number of expected insertions
    * @param fpp the false positive probability, where 0.0 > fpp < 1.0
    */
-  void ensureCapacity(long expectedInsertions, double fpp) {
+  void ensureCapacity(@NonNegative long expectedInsertions, @NonNegative double fpp) {
     checkArgument(expectedInsertions >= 0);
     checkArgument(fpp > 0 && fpp < 1);