Merge pull request #13700 from vespa-engine/arnej/keep-read-guard-until-write-finished

Arnej/keep read guard until write finished

2 files changed, 13 insertions, 8 deletions

diff --git a/searchlib/src/vespa/searchlib/tensor/hnsw_index.cpp b/searchlib/src/vespa/searchlib/tensor/hnsw_index.cpp
index 5c36f7bcb37..2a17378f58a 100644
--- a/searchlib/src/vespa/searchlib/tensor/hnsw_index.cpp
+++ b/searchlib/src/vespa/searchlib/tensor/hnsw_index.cpp
@@ -289,16 +289,17 @@ HnswIndex::~HnswIndex() = default;
 void
 HnswIndex::add_document(uint32_t docid)
 {
-    PreparedAddDoc op = internal_prepare_add(docid, get_vector(docid));
+    vespalib::GenerationHandler::Guard no_guard_needed;
+    PreparedAddDoc op = internal_prepare_add(docid, get_vector(docid), no_guard_needed);
     internal_complete_add(docid, op);
 }
 
 HnswIndex::PreparedAddDoc
-HnswIndex::internal_prepare_add(uint32_t docid, TypedCells input_vector) const
+HnswIndex::internal_prepare_add(uint32_t docid, TypedCells input_vector, vespalib::GenerationHandler::Guard read_guard) const
 {
     // TODO: Add capping on num_levels
     int level = _level_generator->max_level();
-    PreparedAddDoc op(docid, level);
+    PreparedAddDoc op(docid, level, std::move(read_guard));
     auto entry = _graph.get_entry_node();
     if (entry.docid == 0) {
         // graph has no entry point
@@ -379,8 +380,7 @@ HnswIndex::prepare_add_document(uint32_t docid,
         // to ensure they are linked together:
         return std::unique_ptr<PrepareResult>();
     }
-    PreparedAddDoc op = internal_prepare_add(docid, vector);
-    (void) read_guard; // must keep guard until this point
+    PreparedAddDoc op = internal_prepare_add(docid, vector, std::move(read_guard));
     return std::make_unique<PreparedAddDoc>(std::move(op));
 }
 
diff --git a/searchlib/src/vespa/searchlib/tensor/hnsw_index.h b/searchlib/src/vespa/searchlib/tensor/hnsw_index.h
index c237e3b8fcf..f9adef0b86c 100644
--- a/searchlib/src/vespa/searchlib/tensor/hnsw_index.h
+++ b/searchlib/src/vespa/searchlib/tensor/hnsw_index.h
@@ -126,17 +126,22 @@ protected:
                                          const BitVector *filter, uint32_t explore_k) const;
 
     struct PreparedAddDoc : public PrepareResult {
+        using ReadGuard = vespalib::GenerationHandler::Guard;
         uint32_t docid;
         int32_t max_level;
+        ReadGuard read_guard;
         using Links = std::vector<std::pair<uint32_t, HnswGraph::NodeRef>>;
         std::vector<Links> connections;
-        PreparedAddDoc(uint32_t docid_in, int32_t max_level_in)
-          : docid(docid_in), max_level(max_level_in), connections(max_level+1)
+        PreparedAddDoc(uint32_t docid_in, int32_t max_level_in, ReadGuard read_guard_in)
+          : docid(docid_in), max_level(max_level_in),
+            read_guard(std::move(read_guard_in)),
+            connections(max_level+1)
         {}
         ~PreparedAddDoc() = default;
         PreparedAddDoc(PreparedAddDoc&& other) = default;
     };
-    PreparedAddDoc internal_prepare_add(uint32_t docid, TypedCells input_vector) const;
+    PreparedAddDoc internal_prepare_add(uint32_t docid, TypedCells input_vector,
+                                        vespalib::GenerationHandler::Guard read_guard) const;
     LinkArray filter_valid_docids(uint32_t level, const PreparedAddDoc::Links &neighbors, uint32_t me);
     void internal_complete_add(uint32_t docid, PreparedAddDoc &op);
 public: