From d1756b927e1618fca59a288f4a021c2a040068e7 Mon Sep 17 00:00:00 2001
From: Botond Hejj <botond.hejj@gmail.com>
Date: Fri, 6 Jul 2018 10:43:18 -0400
Subject: [PATCH] ZOOKEEPER-3072: Throttle race condition fix Making the
 throttle check before passing over the request to the next thread will
 prevent the possibility of throttling code running after unthrottle

---
 .../zookeeper/server/ZooKeeperServer.java     | 30 +++++++++----------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/src/java/main/org/apache/zookeeper/server/ZooKeeperServer.java b/src/java/main/org/apache/zookeeper/server/ZooKeeperServer.java
index ff5b3b66a90..d9a93156bbf 100644
--- a/src/java/main/org/apache/zookeeper/server/ZooKeeperServer.java
+++ b/src/java/main/org/apache/zookeeper/server/ZooKeeperServer.java
@@ -1123,24 +1123,22 @@ public void processPacket(ServerCnxn cnxn, ByteBuffer incomingBuffer) throws IOE
                 cnxn.disableRecv();
             }
             return;
+        } else if (h.getType() == OpCode.sasl) {
+            Record rsp = processSasl(incomingBuffer,cnxn);
+            ReplyHeader rh = new ReplyHeader(h.getXid(), 0, KeeperException.Code.OK.intValue());
+            cnxn.sendResponse(rh,rsp, "response"); // not sure about 3rd arg..what is it?
+            return;
         } else {
-            if (h.getType() == OpCode.sasl) {
-                Record rsp = processSasl(incomingBuffer,cnxn);
-                ReplyHeader rh = new ReplyHeader(h.getXid(), 0, KeeperException.Code.OK.intValue());
-                cnxn.sendResponse(rh,rsp, "response"); // not sure about 3rd arg..what is it?
-                return;
-            }
-            else {
-                Request si = new Request(cnxn, cnxn.getSessionId(), h.getXid(),
-                  h.getType(), incomingBuffer, cnxn.getAuthInfo());
-                si.setOwner(ServerCnxn.me);
-                // Always treat packet from the client as a possible
-                // local request.
-                setLocalSessionFlag(si);
-                submitRequest(si);
-            }
+            cnxn.incrOutstandingRequests(h);
+            Request si = new Request(cnxn, cnxn.getSessionId(), h.getXid(),
+              h.getType(), incomingBuffer, cnxn.getAuthInfo());
+            si.setOwner(ServerCnxn.me);
+            // Always treat packet from the client as a possible
+            // local request.
+            setLocalSessionFlag(si);
+            submitRequest(si);
+            return;
         }
-        cnxn.incrOutstandingRequests(h);
     }
 
     private Record processSasl(ByteBuffer incomingBuffer, ServerCnxn cnxn) throws IOException {