Use std::atomic_ref for updating and reading single value non-enumerated

attribute vectors with small numeric types.

2 files changed, 9 insertions, 6 deletions

diff --git a/searchlib/src/vespa/searchlib/attribute/singlesmallnumericattribute.cpp b/searchlib/src/vespa/searchlib/attribute/singlesmallnumericattribute.cpp
index ce232749514..368a081e020 100644
--- a/searchlib/src/vespa/searchlib/attribute/singlesmallnumericattribute.cpp
+++ b/searchlib/src/vespa/searchlib/attribute/singlesmallnumericattribute.cpp
@@ -214,7 +214,7 @@ bool SingleValueSmallNumericAttribute::SingleSearchContext::valid() const { retu
 SingleValueSmallNumericAttribute::SingleSearchContext::SingleSearchContext(std::unique_ptr<QueryTermSimple> qTerm,
                                                                            const SingleValueSmallNumericAttribute & toBeSearched)
     : NumericAttribute::Range<T>(*qTerm),
-      SearchContext(toBeSearched), _wordData(&toBeSearched._wordData[0]),
+      SearchContext(toBeSearched), _wordData(&toBeSearched._wordData.acquire_elem_ref(0)),
       _valueMask(toBeSearched._valueMask),
       _valueShiftShift(toBeSearched._valueShiftShift),
       _valueShiftMask(toBeSearched._valueShiftMask),
diff --git a/searchlib/src/vespa/searchlib/attribute/singlesmallnumericattribute.h b/searchlib/src/vespa/searchlib/attribute/singlesmallnumericattribute.h
index 42d51b2a2c7..6c78708593a 100644
--- a/searchlib/src/vespa/searchlib/attribute/singlesmallnumericattribute.h
+++ b/searchlib/src/vespa/searchlib/attribute/singlesmallnumericattribute.h
@@ -4,6 +4,7 @@
 
 #include "integerbase.h"
 #include "floatbase.h"
+#include <vespa/vespalib/util/atomic.h>
 #include <vespa/vespalib/util/rcuvector.h>
 #include <limits>
 
@@ -45,10 +46,12 @@ protected:
     }
 
     void set(DocId doc, T v) {
-        Word &word = _wordData[doc >> _wordShift];
+        Word &word_ref = _wordData[doc >> _wordShift];
         uint32_t valueShift = (doc & _valueShiftMask) << _valueShiftShift;
+        Word word = vespalib::atomic::load_ref_relaxed(word_ref);
         word = (word & ~(_valueMask << valueShift)) |
                ((v & _valueMask) << valueShift);
+        vespalib::atomic::store_ref_relaxed(word_ref, word);
     }
 
 
@@ -82,7 +85,7 @@ public:
             if ( elemId != 0) return -1;
             const Word &word = _wordData[docId >> _wordShift];
             uint32_t valueShift = (docId & _valueShiftMask) << _valueShiftShift;
-            T v = (word >> valueShift) & _valueMask;
+            T v = (vespalib::atomic::load_ref_relaxed(word) >> valueShift) & _valueMask;
             weight = 1;
             return match(v) ? 0 : -1;
         }
@@ -91,7 +94,7 @@ public:
             if ( elemId != 0) return -1;
             const Word &word = _wordData[docId >> _wordShift];
             uint32_t valueShift = (docId & _valueShiftMask) << _valueShiftShift;
-            T v = (word >> valueShift) & _valueMask;
+            T v = (vespalib::atomic::load_ref_relaxed(word) >> valueShift) & _valueMask;
             return match(v) ? 0 : -1;
         }
 
@@ -125,9 +128,9 @@ public:
     getSearch(std::unique_ptr<QueryTermSimple> term, const attribute::SearchContextParams & params) const override;
 
     T getFast(DocId doc) const {
-        const Word &word = _wordData[doc >> _wordShift];
+        const Word &word = _wordData.acquire_elem_ref(doc >> _wordShift);
         uint32_t valueShift = (doc & _valueShiftMask) << _valueShiftShift;
-        return (word >> valueShift) & _valueMask;
+        return (vespalib::atomic::load_ref_relaxed(word) >> valueShift) & _valueMask;
     }
 
     //-------------------------------------------------------------------------