Add a monitor for virtual thread pin events

service/src/test/java/org/whispersystems/textsecuregcm/util/VirtualThreadPinEventMonitorTest.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright 2024 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+package org.whispersystems.textsecuregcm.util;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.time.Duration;
+import java.util.Set;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.TimeUnit;
+import jdk.jfr.consumer.RecordedEvent;
+import org.apache.commons.lang3.tuple.Pair;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+
+public class VirtualThreadPinEventMonitorTest {
+  private void synchronizedSleep1() {
+    synchronized (this) {
+      try {
+        Thread.sleep(2);
+      } catch (InterruptedException e) {
+        throw new RuntimeException(e);
+      }
+    }
+  }
+
+  private void synchronizedSleep2() {
+    synchronized (this) {
+      try {
+        Thread.sleep(2);
+      } catch (InterruptedException e) {
+        throw new RuntimeException(e);
+      }
+    }
+  }
+
+  @Test
+  public void testPinEventProduced() throws InterruptedException, ExecutionException {
+    final BlockingQueue<Pair<RecordedEvent, Boolean>> bq = new LinkedBlockingQueue<>();
+    final ExecutorService exec = Executors.newVirtualThreadPerTaskExecutor();
+    VirtualThreadPinEventMonitor eventMonitor = queueingLogger(exec, Set.of(), bq);
+    eventMonitor.start();
+    // give start a moment to begin the event stream thread
+    Thread.sleep(100);
+    exec.submit(() -> synchronizedSleep1()).get();
+    eventMonitor.stop();
+
+    final Pair<RecordedEvent, Boolean> nxt = bq.take();
+    assertThat(nxt.getRight()).isFalse();
+    assertThat(bq.isEmpty());
+    exec.shutdown();
+    exec.awaitTermination(1, TimeUnit.MILLISECONDS);
+  }
+
+  @ParameterizedTest
+  @ValueSource(strings = {"VirtualThreadPinEventMonitorTest.synchronizedSleep1", "synchronizedSleep1"})
+  public void testPinEventFiltered(final String allowString) throws InterruptedException, ExecutionException {
+    final BlockingQueue<Pair<RecordedEvent, Boolean>> bq = new LinkedBlockingQueue<>();
+    final ExecutorService exec = Executors.newVirtualThreadPerTaskExecutor();
+    final VirtualThreadPinEventMonitor eventMonitor = queueingLogger(exec, Set.of(allowString), bq);
+    eventMonitor.start();
+    // give start a moment to begin the event stream thread
+    Thread.sleep(100);
+    exec.submit(() -> synchronizedSleep1()).get();
+    exec.submit(() -> synchronizedSleep2()).get();
+    eventMonitor.stop();
+
+    final boolean sleep1Allowed = bq.take().getRight();
+    final boolean sleep2Allowed = bq.take().getRight();
+    assertThat(sleep1Allowed).isTrue();
+    assertThat(sleep2Allowed).isFalse();
+    assertThat(bq.isEmpty());
+    exec.shutdown();
+    exec.awaitTermination(1, TimeUnit.MILLISECONDS);
+  }
+
+  private static VirtualThreadPinEventMonitor queueingLogger(
+      final ExecutorService exec,
+      final Set<String> allowedMethods,
+      final BlockingQueue<Pair<RecordedEvent, Boolean>> bq) {
+    return new VirtualThreadPinEventMonitor(exec,
+        () -> allowedMethods,
+        Duration.ofMillis(1),
+        (event, allowed) -> {
+          try {
+            bq.put(Pair.of(event, allowed));
+          } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+          }
+        });
+
+  }
+}