Handle rejections in `IncrementalBulkIT` (#113940)

Submitting a bare runnable to a threadpool risks an exception being
thrown if the queue is full. This commit moves to submitting
`AbstractRunnable` instances that won't be rejected.

Closes #113365
Backport of #113599 to `8.x`

server/src/internalClusterTest/java/org/elasticsearch/action/bulk/IncrementalBulkIT.java

@@ -15,6 +15,7 @@ import org.elasticsearch.action.support.PlainActionFuture;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.util.concurrent.AbstractRunnable;
 import org.elasticsearch.common.util.concurrent.EsRejectedExecutionException;
 import org.elasticsearch.core.AbstractRefCounted;
 import org.elasticsearch.core.Releasable;
@@ -38,6 +39,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.CyclicBarrier;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -215,14 +217,8 @@ public class IncrementalBulkIT extends ESIntegTestCase {
             IncrementalBulkService incrementalBulkService = internalCluster().getInstance(IncrementalBulkService.class, randomNodeName);
             ThreadPool threadPool = internalCluster().getInstance(ThreadPool.class, randomNodeName);
 
-            int threadCount = threadPool.info(ThreadPool.Names.WRITE).getMax();
-            long queueSize = threadPool.info(ThreadPool.Names.WRITE).getQueueSize().singles();
-            blockWritePool(threadCount, threadPool, blockingLatch);
-
-            Runnable runnable = () -> {};
-            for (int i = 0; i < queueSize; i++) {
-                threadPool.executor(ThreadPool.Names.WRITE).execute(runnable);
-            }
+            blockWritePool(threadPool, blockingLatch);
+            fillWriteQueue(threadPool);
 
             IncrementalBulkService.Handler handler = incrementalBulkService.newBulkRequest();
             if (randomBoolean()) {
@@ -254,35 +250,32 @@ public class IncrementalBulkIT extends ESIntegTestCase {
             AbstractRefCounted refCounted = AbstractRefCounted.of(() -> {});
             PlainActionFuture<BulkResponse> future = new PlainActionFuture<>();
 
-            int threadCount = threadPool.info(ThreadPool.Names.WRITE).getMax();
-            long queueSize = threadPool.info(ThreadPool.Names.WRITE).getQueueSize().singles();
-
             CountDownLatch blockingLatch1 = new CountDownLatch(1);
 
             AtomicBoolean nextRequested = new AtomicBoolean(true);
             AtomicLong hits = new AtomicLong(0);
-            try (Releasable ignored2 = blockingLatch1::countDown;) {
-                blockWritePool(threadCount, threadPool, blockingLatch1);
+            try {
+                blockWritePool(threadPool, blockingLatch1);
                 while (nextRequested.get()) {
                     nextRequested.set(false);
                     refCounted.incRef();
                     handler.addItems(List.of(indexRequest(index)), refCounted::decRef, () -> nextRequested.set(true));
                     hits.incrementAndGet();
                 }
+            } finally {
+                blockingLatch1.countDown();
             }
             assertBusy(() -> assertTrue(nextRequested.get()));
 
             CountDownLatch blockingLatch2 = new CountDownLatch(1);
 
-            try (Releasable ignored3 = blockingLatch2::countDown;) {
-                blockWritePool(threadCount, threadPool, blockingLatch2);
-                Runnable runnable = () -> {};
-                // Fill Queue
-                for (int i = 0; i < queueSize; i++) {
-                    threadPool.executor(ThreadPool.Names.WRITE).execute(runnable);
-                }
+            try {
+                blockWritePool(threadPool, blockingLatch2);
+                fillWriteQueue(threadPool);
 
                 handler.lastItems(List.of(indexRequest(index)), refCounted::decRef, future);
+            } finally {
+                blockingLatch2.countDown();
             }
 
             // Should not throw because some succeeded
@@ -460,19 +453,55 @@ public class IncrementalBulkIT extends ESIntegTestCase {
         }
     }
 
-    private static void blockWritePool(int threadCount, ThreadPool threadPool, CountDownLatch blockingLatch) throws InterruptedException {
-        CountDownLatch startedLatch = new CountDownLatch(threadCount);
+    private static void blockWritePool(ThreadPool threadPool, CountDownLatch finishLatch) {
+        final var threadCount = threadPool.info(ThreadPool.Names.WRITE).getMax();
+        final var startBarrier = new CyclicBarrier(threadCount + 1);
+        final var blockingTask = new AbstractRunnable() {
+            @Override
+            public void onFailure(Exception e) {
+                fail(e);
+            }
+
+            @Override
+            protected void doRun() {
+                safeAwait(startBarrier);
+                safeAwait(finishLatch);
+            }
+
+            @Override
+            public boolean isForceExecution() {
+                return true;
+            }
+        };
         for (int i = 0; i < threadCount; i++) {
-            threadPool.executor(ThreadPool.Names.WRITE).execute(() -> {
-                startedLatch.countDown();
-                try {
-                    blockingLatch.await();
-                } catch (InterruptedException e) {
-                    throw new RuntimeException(e);
-                }
-            });
+            threadPool.executor(ThreadPool.Names.WRITE).execute(blockingTask);
+        }
+        safeAwait(startBarrier);
+    }
+
+    private static void fillWriteQueue(ThreadPool threadPool) {
+        final var queueSize = Math.toIntExact(threadPool.info(ThreadPool.Names.WRITE).getQueueSize().singles());
+        final var queueFilled = new AtomicBoolean(false);
+        final var queueFillingTask = new AbstractRunnable() {
+            @Override
+            public void onFailure(Exception e) {
+                fail(e);
+            }
+
+            @Override
+            protected void doRun() {
+                assertTrue("thread pool not blocked", queueFilled.get());
+            }
+
+            @Override
+            public boolean isForceExecution() {
+                return true;
+            }
+        };
+        for (int i = 0; i < queueSize; i++) {
+            threadPool.executor(ThreadPool.Names.WRITE).execute(queueFillingTask);
         }
-        startedLatch.await();
+        queueFilled.set(true);
     }
 
     private BulkResponse executeBulk(long docs, String index, IncrementalBulkService.Handler handler, ExecutorService executorService) {