SERVER-40004 Modified compareAndSwap to return boolean

1 files changed, 2 insertions, 9 deletions

diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_session_cache.cpp b/src/mongo/db/storage/wiredtiger/wiredtiger_session_cache.cpp
index fb33870e114..fb41f7c2b3b 100644
--- a/src/mongo/db/storage/wiredtiger/wiredtiger_session_cache.cpp
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_session_cache.cpp
@@ -215,16 +215,9 @@ WiredTigerSessionCache::~WiredTigerSessionCache() {
 }
 
 void WiredTigerSessionCache::shuttingDown() {
-    uint32_t actual = _shuttingDown.load();
-    uint32_t expected;
-
     // Try to atomically set _shuttingDown flag, but just return if another thread was first.
-    do {
-        expected = actual;
-        actual = _shuttingDown.compareAndSwap(expected, expected | kShuttingDownMask);
-        if (actual & kShuttingDownMask)
-            return;
-    } while (actual != expected);
+    if (_shuttingDown.fetchAndBitOr(kShuttingDownMask) & kShuttingDownMask)
+        return;
 
     // Spin as long as there are threads in releaseSession
     while (_shuttingDown.load() != kShuttingDownMask) {