Take the message out of the send Q in order to ensure progress if handleReply is called in sender context.

1 files changed, 6 insertions, 6 deletions

diff --git a/messagebus/src/main/java/com/yahoo/messagebus/SourceSession.java b/messagebus/src/main/java/com/yahoo/messagebus/SourceSession.java
index f4aed92e8ce..4017252715e 100644
--- a/messagebus/src/main/java/com/yahoo/messagebus/SourceSession.java
+++ b/messagebus/src/main/java/com/yahoo/messagebus/SourceSession.java
@@ -4,6 +4,7 @@ package com.yahoo.messagebus;
 import com.yahoo.messagebus.routing.Route;
 import com.yahoo.messagebus.routing.RoutingTable;
 
+import java.util.Deque;
 import java.util.LinkedList;
 import java.util.Queue;
 import java.util.concurrent.CountDownLatch;
@@ -26,7 +27,7 @@ public final class SourceSession implements ReplyHandler, MessageBus.SendBlocked
     private volatile double timeout;
     private volatile int pendingCount = 0;
     private volatile boolean closed = false;
-    private final Queue<BlockedMessage> blockedQ = new LinkedList<>();
+    private final Deque<BlockedMessage> blockedQ = new LinkedList<>();
 
     /**
      * The default constructor requires values for all final member variables
@@ -174,8 +175,6 @@ public final class SourceSession implements ReplyHandler, MessageBus.SendBlocked
             }
         }
 
-        Message getMessage() { return msg; }
-
         boolean notifyIfExpired() {
             if (msg.isExpired()) {
                 Error error = new Error(ErrorCode.TIMEOUT, "Timed out in sendQ");
@@ -252,9 +251,10 @@ public final class SourceSession implements ReplyHandler, MessageBus.SendBlocked
     private void sendBlockedMessages() {
         synchronized (lock) {
             for (boolean success = true; success && !blockedQ.isEmpty(); ) {
-                success = blockedQ.element().sendOrExpire();
-                if (success) {
-                    blockedQ.remove();
+                BlockedMessage msg = blockedQ.remove();
+                success = msg.sendOrExpire();
+                if ( ! success) {
+                    blockedQ.addFirst(msg);
                 }
             }
         }