Use atomic variables for search::transactionlog::DomainPart range.

2 files changed, 21 insertions, 12 deletions

diff --git a/searchlib/src/vespa/searchlib/transactionlog/domainpart.cpp b/searchlib/src/vespa/searchlib/transactionlog/domainpart.cpp
index 38b463d6bc2..00bbd5e81d2 100644
--- a/searchlib/src/vespa/searchlib/transactionlog/domainpart.cpp
+++ b/searchlib/src/vespa/searchlib/transactionlog/domainpart.cpp
@@ -235,9 +235,9 @@ DomainPart::buildPacketMapping(bool allowTruncate)
             set_size(size() + packet.size());
             const SerialNum firstSerial = packet.range().from();
             if (currPos == _headerLen) {
-                _range.from(firstSerial);
+                set_range_from(firstSerial);
             }
-            _range.to(packet.range().to());
+            set_range_to(packet.range().to());
             // Called only from constructor so no need to hold lock
             _skipList.emplace_back(firstSerial, firstPos);
         } else {
@@ -252,7 +252,8 @@ DomainPart::DomainPart(const string & name, const string & baseDir, SerialNum s,
                        const FileHeaderContext &fileHeaderContext, bool allowTruncate)
     : _lock(),
       _fileLock(),
-      _range(s),
+      _range_from(s),
+      _range_to(s ? s - 1 : s),
       _sz(0),
       _byteSize(0),
       _fileName(fmt("%s/%s-%016" PRIu64, baseDir.c_str(), name.c_str(), s)),
@@ -295,7 +296,7 @@ DomainPart::DomainPart(const string & name, const string & baseDir, SerialNum s,
                                 _transLog->GetFileName(), _transLog->GetSize()));
     }
     handleSync(*_transLog);
-    _writtenSerial = _range.to();
+    _writtenSerial = get_range_to();
     _syncedSerial = _writtenSerial;
     assert(int64_t(byteSize()) == _transLog->GetSize());
     assert(int64_t(byteSize()) == _transLog->GetPosition());
@@ -368,11 +369,14 @@ bool
 DomainPart::erase(SerialNum to)
 {
     bool retval(true);
-    if (to > _range.to()) {
+    if (to > get_range_to()) {
         close();
         _transLog->Delete();
     } else {
-        _range.from(std::max(to, _range.from()));
+        auto range_from = get_range_from();
+        if (to > range_from) {
+            set_range_from(to);
+        }
     }
     return retval;
 }
@@ -383,11 +387,11 @@ DomainPart::commit(const SerializedChunk & serialized)
     SerialNumRange range = serialized.range();
 
     int64_t firstPos(byteSize());
-    assert(_range.to() < range.to());
+    assert(get_range_to() < range.to());
     set_size(size() + serialized.getNumEntries());
-    _range.to(range.to());
-    if (_range.from() == 0) {
-        _range.from(range.from());
+    set_range_to(range.to());
+    if (get_range_from() == 0) {
+        set_range_from(range.from());
     }
 
     write(*_transLog, range, serialized.getData());
diff --git a/searchlib/src/vespa/searchlib/transactionlog/domainpart.h b/searchlib/src/vespa/searchlib/transactionlog/domainpart.h
index fd84040228d..4b8d52644a9 100644
--- a/searchlib/src/vespa/searchlib/transactionlog/domainpart.h
+++ b/searchlib/src/vespa/searchlib/transactionlog/domainpart.h
@@ -30,7 +30,7 @@ public:
     bool visit(FastOS_FileInterface &file, SerialNumRange &r, Packet &packet);
     bool close();
     void sync();
-    SerialNumRange range() const { return _range; }
+    SerialNumRange range() const { return SerialNumRange(get_range_from(), get_range_to()); }
 
     SerialNum getSynced() const {
         std::lock_guard guard(_writeLock);
@@ -52,6 +52,10 @@ private:
     void write(FastOS_FileInterface &file, SerialNumRange range, vespalib::ConstBufferRef buf);
     void writeHeader(const common::FileHeaderContext &fileHeaderContext);
     void set_size(size_t sz) noexcept { _sz.store(sz, std::memory_order_relaxed); }
+    SerialNum get_range_from() const noexcept { return _range_from.load(std::memory_order_relaxed); }
+    SerialNum get_range_to() const noexcept { return _range_to.load(std::memory_order_relaxed); }
+    void set_range_from(SerialNum range_from) noexcept { _range_from.store(range_from, std::memory_order_relaxed); }
+    void set_range_to(SerialNum range_to) noexcept { _range_to.store(range_to, std::memory_order_relaxed); }
 
     class SkipInfo
     {
@@ -72,7 +76,8 @@ private:
     };
     std::mutex            _lock;
     std::mutex            _fileLock;
-    SerialNumRange        _range;
+    std::atomic<SerialNum> _range_from;
+    std::atomic<SerialNum> _range_to;
     std::atomic<size_t>   _sz;
     std::atomic<uint64_t> _byteSize;
     vespalib::string      _fileName;