From f8f4cd0944689bfc4d8cc39f6066e9c3c4660105 Mon Sep 17 00:00:00 2001
From: Dave Moten <davidmoten@gmail.com>
Date: Sun, 19 Apr 2015 22:01:43 +1000
Subject: [PATCH] fix race condition for range where two threads concurrently
 request Long.MAX_VALUE and both start the fast path thus possibly some items
 more than once

---
 src/main/java/rx/internal/operators/OnSubscribeRange.java | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/main/java/rx/internal/operators/OnSubscribeRange.java b/src/main/java/rx/internal/operators/OnSubscribeRange.java
index f648e6f414..bcfbe0736b 100644
--- a/src/main/java/rx/internal/operators/OnSubscribeRange.java
+++ b/src/main/java/rx/internal/operators/OnSubscribeRange.java
@@ -55,12 +55,11 @@ private RangeProducer(Subscriber<? super Integer> o, int start, int end) {
 
         @Override
         public void request(long n) {
-            if (REQUESTED_UPDATER.get(this) == Long.MAX_VALUE) {
+            if (requested == Long.MAX_VALUE) {
                 // already started with fast-path
                 return;
             }
-            if (n == Long.MAX_VALUE) {
-                REQUESTED_UPDATER.set(this, n);
+            if (n == Long.MAX_VALUE && REQUESTED_UPDATER.compareAndSet(this, 0, Long.MAX_VALUE)) {
                 // fast-path without backpressure
                 for (long i = index; i <= end; i++) {
                     if (o.isUnsubscribed()) {