Add heap implementation for AsyncTimeout (#1658)

* Add heap implementation for AsyncTimeout

* Add AsyncTimeout benchmark tests

* Some test fixes

* linting

* Don't sample the clock too much

* Spotless

* working heap

* benchmark test improvements, async timeout code cleanup

* Visual test

* more tests, clean up heap code

* Spotless

* apiDump

* Fix a bunch of nitpicks

* No new public API

---------

Co-authored-by: Jesse Wilson <[email protected]>

Author: ktabouguia-sq

okio/jvm/jmh/src/jmh/java/com/squareup/okio/benchmarks/AsyncTimeoutBenchmark.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2025 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.squareup.okio.benchmarks;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.TimeUnit;
+import okio.AsyncTimeout;
+import okio.PriorityQueue;
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Fork;
+import org.openjdk.jmh.annotations.Measurement;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Param;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.Warmup;
+
+@Fork(1)
+@Warmup(iterations = 2, time = 2)
+@Measurement(iterations = 3, time = 2)
+@State(Scope.Benchmark)
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+public class AsyncTimeoutBenchmark {
+
+  @Param({ "1", "10", "100", "1000" })
+  int queueSize;
+
+  private List<AsyncTimeout> asyncTimeouts;
+  private PriorityQueue heap = new PriorityQueue();
+  private int next = 0;
+
+  @Setup
+  public void setup() {
+    heap = new PriorityQueue();
+    asyncTimeouts = new ArrayList<>(queueSize);
+    for (int i = 0; i < queueSize; i++) {
+      AsyncTimeout timeout = new AsyncTimeout() {
+        @Override protected void timedOut() {
+          // No-op
+        }
+      };
+      timeout.timeout(i, TimeUnit.SECONDS);
+      asyncTimeouts.add(timeout);
+    }
+    Collections.shuffle(asyncTimeouts, new Random(0));
+    for (int i = 0; i < queueSize; i++) {
+      heap.add(asyncTimeouts.get(i));
+    }
+  }
+
+  @Benchmark
+  public void enterExit() {
+    AsyncTimeout timeout = asyncTimeouts.get(next++);
+    heap.remove(timeout);
+    heap.add(timeout);
+    next = next % queueSize;
+  }
+}