SERVER-50678 Implement lock-free version of AutoGetCollection

1 files changed, 13 insertions, 0 deletions

diff --git a/src/mongo/db/catalog/database_holder.h b/src/mongo/db/catalog/database_holder.h
index 890ad037de1..32e422b2e0c 100644
--- a/src/mongo/db/catalog/database_holder.h
+++ b/src/mongo/db/catalog/database_holder.h
@@ -42,6 +42,7 @@ class CollectionCatalogEntry;
 class Database;
 class OperationContext;
 class RecordStore;
+class ViewCatalog;
 
 /**
  * Registry of opened databases.
@@ -65,6 +66,18 @@ public:
     virtual Database* getDb(OperationContext* const opCtx, const StringData ns) const = 0;
 
     /**
+     * Fetches the ViewCatalog decorating the Database matching 'dbName', or returns nullptr if the
+     * database does not exist. The returned ViewCatalog is safe to access without a lock because it
+     * is held as a shared_ptr.
+     *
+     * The ViewCatalog must be fetched through this interface if the caller holds no database lock
+     * to ensure the Database object is safe to access. This class' internal mutex provides
+     * concurrency protection around looking up and accessing the Database object matching 'dbName.
+     */
+    virtual std::shared_ptr<ViewCatalog> getSharedViewCatalog(OperationContext* const opCtx,
+                                                              StringData dbName) const = 0;
+
+    /**
      * Retrieves a database reference if it is already opened, or opens it if it hasn't been
      * opened/created yet. Must be called with the database locked in X-mode.
      *