make tsan happy by using atomic operations on bits

... related to document existence

2 files changed, 17 insertions, 7 deletions

diff --git a/searchlib/src/vespa/searchlib/common/bitvector.cpp b/searchlib/src/vespa/searchlib/common/bitvector.cpp
index d2e6d9027ea..7eef1e7f8f2 100644
--- a/searchlib/src/vespa/searchlib/common/bitvector.cpp
+++ b/searchlib/src/vespa/searchlib/common/bitvector.cpp
@@ -106,11 +106,13 @@ BitVector::clearIntervalNoInvalidation(Range range_in)
     Index endw = wordNum(last);
 
     if (endw > startw) {
-        _words[startw++] &= startBits(range.start());
-        memset(_words+startw, 0, sizeof(*_words)*(endw-startw));
-        _words[endw] &= endBits(last);
+        vespalib::atomic::store_ref_relaxed(_words[startw], _words[startw] & startBits(range.start()));
+        for (Index i = startw + 1; i < endw; ++i) {
+            vespalib::atomic::store_ref_relaxed(_words[i], 0);
+        }
+        vespalib::atomic::store_ref_relaxed(_words[endw], _words[endw] & endBits(last));
     } else {
-        _words[startw] &= (startBits(range.start()) | endBits(last));
+        vespalib::atomic::store_ref_relaxed(_words[startw], _words[startw] & (startBits(range.start()) | endBits(last)));
     }
 }
 
diff --git a/searchlib/src/vespa/searchlib/common/bitvector.h b/searchlib/src/vespa/searchlib/common/bitvector.h
index 02f51fe8758..779e9887daf 100644
--- a/searchlib/src/vespa/searchlib/common/bitvector.h
+++ b/searchlib/src/vespa/searchlib/common/bitvector.h
@@ -5,6 +5,7 @@
 #include "bitword.h"
 #include <memory>
 #include <vespa/vespalib/util/alloc.h>
+#include <vespa/vespalib/util/atomic.h>
 #include <vespa/vespalib/util/generationholder.h>
 #include <vespa/fastos/types.h>
 
@@ -46,6 +47,11 @@ public:
     bool testBit(Index idx) const {
         return ((_words[wordNum(idx)] & mask(idx)) != 0);
     }
+    bool testBitSafe(Index idx) const {
+        auto my_words = vespalib::atomic::load_ref_acquire(_words);
+        auto my_word = vespalib::atomic::load_ref_acquire(my_words[wordNum(idx)]);
+        return (my_word & mask(idx)) != 0;
+    }
     bool hasTrueBits() const {
         return isValidCount()
             ? (countTrueBits() != 0)
@@ -136,10 +142,10 @@ public:
         _sz = sz;
     }
     void setBit(Index idx) {
-        _words[wordNum(idx)] |= mask(idx);
+        vespalib::atomic::store_ref_relaxed(_words[wordNum(idx)], _words[wordNum(idx)] | mask(idx));
     }
     void clearBit(Index idx) {
-        _words[wordNum(idx)] &= ~ mask(idx);
+        vespalib::atomic::store_ref_relaxed(_words[wordNum(idx)], _words[wordNum(idx)] & ~ mask(idx));
     }
     void flipBit(Index idx) {
         _words[wordNum(idx)] ^= mask(idx);
@@ -200,7 +206,9 @@ public:
     }
 
     void swap(BitVector & rhs) {
-        std::swap(_words, rhs._words);
+        auto my_words = _words;
+        vespalib::atomic::store_ref_release(_words, rhs._words);
+        vespalib::atomic::store_ref_release(rhs._words, my_words);
         std::swap(_startOffset, rhs._startOffset);
         std::swap(_sz, rhs._sz);
         Index tmp = rhs._numTrueBits;