Must hold guard when accessing _lidInfo size and return 0 as memory gain when lid space cannot be shrunk.

3 files changed, 15 insertions, 2 deletions

diff --git a/searchlib/src/tests/docstore/logdatastore/logdatastore_test.cpp b/searchlib/src/tests/docstore/logdatastore/logdatastore_test.cpp
index 99259b109b2..1952cf2b9ea 100644
--- a/searchlib/src/tests/docstore/logdatastore/logdatastore_test.cpp
+++ b/searchlib/src/tests/docstore/logdatastore/logdatastore_test.cpp
@@ -913,6 +913,7 @@ TEST_F("require that lid space can be compacted and shrunk", Fixture)
 {
     f.write(1).write(2);
     EXPECT_FALSE(f.store.canShrinkLidSpace());
+    EXPECT_EQUAL(0u, f.store.getEstimatedShrinkLidSpaceGain());
 
     f.compactLidSpace(2);
     MemoryUsage before = f.store.getMemoryUsage();
diff --git a/searchlib/src/vespa/searchlib/docstore/logdatastore.cpp b/searchlib/src/vespa/searchlib/docstore/logdatastore.cpp
index e7b80fbe1cb..69a11b31ec1 100644
--- a/searchlib/src/vespa/searchlib/docstore/logdatastore.cpp
+++ b/searchlib/src/vespa/searchlib/docstore/logdatastore.cpp
@@ -1138,6 +1138,13 @@ LogDataStore::compactLidSpace(uint32_t wantedDocLidLimit)
 bool
 LogDataStore::canShrinkLidSpace() const
 {
+    LockGuard guard(_updateLock);
+    return canShrinkLidSpace(guard);
+}
+
+bool
+LogDataStore::canShrinkLidSpace(const vespalib::LockGuard &) const
+{
     return getDocIdLimit() < _lidInfo.size() &&
            _compactLidSpaceGeneration < _genHandler.getFirstUsedGeneration();
 }
@@ -1145,16 +1152,20 @@ LogDataStore::canShrinkLidSpace() const
 size_t
 LogDataStore::getEstimatedShrinkLidSpaceGain() const
 {
+    LockGuard guard(_updateLock);
+    if (!canShrinkLidSpace(guard)) {
+        return 0;
+    }
     return (_lidInfo.size() - getDocIdLimit()) * sizeof(uint64_t);
 }
 
 void
 LogDataStore::shrinkLidSpace()
 {
-    if (!canShrinkLidSpace()) {
+    LockGuard guard(_updateLock);
+    if (!canShrinkLidSpace(guard)) {
         return;
     }
-    LockGuard guard(_updateLock);
     _lidInfo.shrink(getDocIdLimit());
     incGeneration();
 }
diff --git a/searchlib/src/vespa/searchlib/docstore/logdatastore.h b/searchlib/src/vespa/searchlib/docstore/logdatastore.h
index 45b0d6e5f50..9325baf14aa 100644
--- a/searchlib/src/vespa/searchlib/docstore/logdatastore.h
+++ b/searchlib/src/vespa/searchlib/docstore/logdatastore.h
@@ -306,6 +306,7 @@ private:
     bool shouldCompactToActiveFile(size_t compactedSize) const;
     std::pair<bool, FileId> findNextToCompact();
     void incGeneration();
+    bool canShrinkLidSpace(const vespalib::LockGuard &guard) const;
 
     typedef std::vector<FileId> FileIdxVector;
     Config                                   _config;