Janitor threadpool must be available across JettyHttpServer instances

1 files changed, 46 insertions, 0 deletions

diff --git a/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/Janitor.java b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/Janitor.java
new file mode 100644
index 00000000000..cd2b9ca23c0
--- /dev/null
+++ b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/Janitor.java
@@ -0,0 +1,46 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.jdisc.http.server.jetty;
+
+import com.google.inject.Inject;
+import com.yahoo.component.AbstractComponent;
+import com.yahoo.concurrent.DaemonThreadFactory;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Logger;
+
+/**
+ * Separate janitor threadpool for tasks that cannot be executed on the jdisc default threadpool due to risk of deadlock.
+ * Modelled as a separate component as the underlying executor must be available across {@link JettyHttpServer} instances.
+ *
+ * @author bjorncs
+ */
+public class Janitor extends AbstractComponent {
+
+    private static final Logger log = Logger.getLogger(Janitor.class.getName());
+
+    private final ExecutorService executor;
+
+    @Inject
+    public Janitor() {
+        int threadPoolSize = Math.max(2, Runtime.getRuntime().availableProcessors()/4);
+        log.info("Creating janitor executor with " + threadPoolSize + " threads");
+        this.executor = Executors.newFixedThreadPool(threadPoolSize, new DaemonThreadFactory("jdisc-janitor-"));
+    }
+
+    public void scheduleTask(Runnable task) { executor.execute(task); }
+
+    @Override
+    public void deconstruct() {
+        try {
+            executor.shutdown();
+            if (!executor.awaitTermination(10, TimeUnit.SECONDS)) {
+                log.warning("Failed to shutdown janitor in time");
+            }
+        } catch (InterruptedException e) {
+            log.warning("Interrupted while shutting down janitor");
+            Thread.currentThread().interrupt();
+        }
+    }
+}