added AtomicUInt64::fetchAndAdd

1 files changed, 8 insertions, 0 deletions

diff --git a/src/mongo/platform/atomic_uint64.h b/src/mongo/platform/atomic_uint64.h
index a9ec18757bf..ac910f9690c 100644
--- a/src/mongo/platform/atomic_uint64.h
+++ b/src/mongo/platform/atomic_uint64.h
@@ -37,6 +37,7 @@ namespace mongo {
 
         inline void set(unsigned long long newValue);
         inline void add(unsigned long long by );
+        inline unsigned long long fetchAndAdd( unsigned long long by = 1 );
         AtomicUInt64& operator+=( unsigned long long by ){ add( by ); return *this; }
         
         inline void zero() { set(0); }
@@ -62,6 +63,13 @@ namespace mongo {
         boost::mutex::scoped_lock lk( _mutex );
         _counter += by;
     }
+
+    inline unsigned long long AtomicUInt64::fetchAndAdd(unsigned long long by) {
+        boost::mutex::scoped_lock lk( _mutex );
+        unsigned long long old = _counter;
+        _counter += by;
+        return old;
+    }
     
 }