Log immediately when AbstractQueueVisitor encounters a critical error.

If there's a holdup propagating the exception, at least we will see it in the logs.

--
MOS_MIGRATED_REVID=105075242

1 files changed, 9 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/concurrent/AbstractQueueVisitor.java b/src/main/java/com/google/devtools/build/lib/concurrent/AbstractQueueVisitor.java
index fe010c860a..e1a980ff97 100644
--- a/src/main/java/com/google/devtools/build/lib/concurrent/AbstractQueueVisitor.java
+++ b/src/main/java/com/google/devtools/build/lib/concurrent/AbstractQueueVisitor.java
@@ -29,6 +29,8 @@ import java.util.concurrent.RejectedExecutionHandler;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 /**
  * AbstractQueueVisitor is a wrapper around {@link ThreadPoolExecutor} which
@@ -146,6 +148,8 @@ public class AbstractQueueVisitor {
    */
   private boolean jobsMustBeStopped = false;
 
+  private static final Logger LOG = Logger.getLogger(AbstractQueueVisitor.class.getName());
+
   /**
    * Create the AbstractQueueVisitor.
    *
@@ -600,7 +604,11 @@ public class AbstractQueueVisitor {
   }
 
   private boolean isCriticalErrorInternal(Throwable e) {
-    return isCriticalError(e) || (e instanceof Error);
+    boolean isCritical = isCriticalError(e) || (e instanceof Error);
+    if (isCritical) {
+      LOG.log(Level.WARNING, "Found critical error in queue visitor", e);
+    }
+    return isCritical;
   }
 
   private void setRejectedExecutionHandler() {