From 0cdab01c7e2869be559537fabbbebd2f727ce5f3 Mon Sep 17 00:00:00 2001
From: Jesse Glick <jglick@cloudbees.com>
Date: Tue, 6 Jan 2015 09:54:16 -0500
Subject: [PATCH] Jenkins was failing to log exceptions from raw
 Runnable/Callable sent to Timer (without using SafeTimerTask, PeriodicWork,
 etc.).

---
 ...rorLoggingScheduledThreadPoolExecutor.java | 85 +++++++++++++++++++
 core/src/main/java/jenkins/util/Timer.java    |  5 +-
 2 files changed, 86 insertions(+), 4 deletions(-)
 create mode 100644 core/src/main/java/jenkins/util/ErrorLoggingScheduledThreadPoolExecutor.java

diff --git a/core/src/main/java/jenkins/util/ErrorLoggingScheduledThreadPoolExecutor.java b/core/src/main/java/jenkins/util/ErrorLoggingScheduledThreadPoolExecutor.java
new file mode 100644
index 0000000000..8765af84bf
--- /dev/null
+++ b/core/src/main/java/jenkins/util/ErrorLoggingScheduledThreadPoolExecutor.java
@@ -0,0 +1,85 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2015 Jesse Glick.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package jenkins.util;
+
+import java.util.concurrent.CancellationException;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+import java.util.concurrent.RejectedExecutionHandler;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * Executor service that logs otherwise uncaught errors.
+ * TODO is there anything in Guava for this?
+ */
+class ErrorLoggingScheduledThreadPoolExecutor extends ScheduledThreadPoolExecutor {
+
+    private static final Logger LOGGER = Logger.getLogger(ErrorLoggingScheduledThreadPoolExecutor.class.getName());
+
+    ErrorLoggingScheduledThreadPoolExecutor(int corePoolSize) {
+        super(corePoolSize);
+    }
+
+    ErrorLoggingScheduledThreadPoolExecutor(int corePoolSize, ThreadFactory threadFactory) {
+        super(corePoolSize, threadFactory);
+    }
+
+    ErrorLoggingScheduledThreadPoolExecutor(int corePoolSize, RejectedExecutionHandler handler) {
+        super(corePoolSize, handler);
+    }
+    
+    ErrorLoggingScheduledThreadPoolExecutor(int corePoolSize, ThreadFactory threadFactory, RejectedExecutionHandler handler) {
+        super(corePoolSize, threadFactory, handler);
+    }
+    
+    @Override protected void afterExecute(Runnable r, Throwable t) {
+        super.afterExecute(r, t);
+        if (t == null && r instanceof Future<?>) {
+            Future<?> f = (Future<?>) r;
+            if (f.isDone()) { // TODO super Javadoc does not suggest this, but without it, we hang in FutureTask.awaitDone!
+                try {
+                    f.get(/* just to be on the safe side, do not wait */0, TimeUnit.NANOSECONDS);
+                } catch (TimeoutException x) {
+                    // should not happen, right?
+                } catch (CancellationException x) {
+                    // probably best to ignore this
+                } catch (ExecutionException x) {
+                    t = x.getCause();
+                } catch (InterruptedException x) {
+                    Thread.currentThread().interrupt();
+                }
+            }
+        }
+        if (t != null) {
+            LOGGER.log(Level.WARNING, "failure in task not wrapped in SafeTimerTask", t);
+        }
+    }
+
+}
diff --git a/core/src/main/java/jenkins/util/Timer.java b/core/src/main/java/jenkins/util/Timer.java
index a84162364b..27870fd26b 100644
--- a/core/src/main/java/jenkins/util/Timer.java
+++ b/core/src/main/java/jenkins/util/Timer.java
@@ -1,13 +1,10 @@
 package jenkins.util;
 
-
 import hudson.util.DaemonThreadFactory;
 import hudson.util.NamingThreadFactory;
 import javax.annotation.Nonnull;
-import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 
-
 /**
  * Holds the {@link ScheduledExecutorService} for running all background tasks in Jenkins.
  * This ExecutorService will create additional threads to execute due (enabled) tasks.
@@ -42,7 +39,7 @@ public class Timer {
         if (executorService == null) {
             // corePoolSize is set to 10, but will only be created if needed.
             // ScheduledThreadPoolExecutor "acts as a fixed-sized pool using corePoolSize threads"
-            executorService = Executors.newScheduledThreadPool(10, new NamingThreadFactory(new DaemonThreadFactory(), "jenkins.util.Timer"));
+            executorService =  new ErrorLoggingScheduledThreadPoolExecutor(10, new NamingThreadFactory(new DaemonThreadFactory(), "jenkins.util.Timer"));
         }
         return executorService;
     }