Introduce NamedForkJoinPool, a ForkJoinPool with named worker threads.

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MOS_MIGRATED_REVID=133624676

1 files changed, 65 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/concurrent/NamedForkJoinPool.java b/src/main/java/com/google/devtools/build/lib/concurrent/NamedForkJoinPool.java
new file mode 100644
index 0000000000..33a5e86f5b
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/concurrent/NamedForkJoinPool.java
@@ -0,0 +1,65 @@
+// Copyright 2016 The Bazel Authors. All rights reserved.
+//
+// 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.google.devtools.build.lib.concurrent;
+
+import java.util.concurrent.ForkJoinPool;
+import java.util.concurrent.ForkJoinWorkerThread;
+import java.util.concurrent.atomic.AtomicLong;
+
+/** A {@link ForkJoinPool} with support for thread naming. */
+public class NamedForkJoinPool extends ForkJoinPool {
+
+  protected NamedForkJoinPool(String name, int poolSize) {
+    super(
+        poolSize,
+        new NamedForkJoinWorkerThreadFactory(name + "-%s"),
+        /*getUncaughtExceptionHandler=*/ null,
+        /*asyncMode=*/ false);
+  }
+
+  public static NamedForkJoinPool newNamedPool(String name, int numThreads) {
+    return new NamedForkJoinPool(name, numThreads);
+  }
+
+  /** A {@link ForkJoinWorkerThread} named on construction. */
+  private static class NamedForkJoinWorkerThread extends ForkJoinWorkerThread {
+
+    public NamedForkJoinWorkerThread(ForkJoinPool forkJoinPool, String name) {
+      super(forkJoinPool);
+      this.setName(name);
+    }
+  }
+
+  /**
+   * A factory for {@link NamedForkJoinWorkerThread}s that names those threads using a
+   * client-provided name format that consumes a thread index.
+   */
+  private static class NamedForkJoinWorkerThreadFactory implements ForkJoinWorkerThreadFactory {
+
+    private final String nameFormat;
+    private final AtomicLong nextUnusedThreadIndex = new AtomicLong(0L);
+
+    public NamedForkJoinWorkerThreadFactory(String nameFormat) {
+      // Fail fast if nameFormat is bad.
+      String ignored = String.format(nameFormat, 0L);
+      this.nameFormat = nameFormat;
+    }
+
+    @Override
+    public ForkJoinWorkerThread newThread(ForkJoinPool forkJoinPool) {
+      return new NamedForkJoinWorkerThread(
+          forkJoinPool, String.format(nameFormat, nextUnusedThreadIndex.getAndIncrement()));
+    }
+  }
+}