SqliteCatalogue::getNextArchiveFileId() now serializes it access to the database

catalogue/SqliteCatalogue.cpp

@@ -98,6 +98,10 @@ common::dataStructures::ArchiveFile SqliteCatalogue::deleteArchiveFile(const std
 //------------------------------------------------------------------------------
 uint64_t SqliteCatalogue::getNextArchiveFileId(rdbms::PooledConn &conn) {
   try {
+    // The SQLite implemenation of getNextArchiveFileId() serializes access to
+    // the SQLite database in order to avoid busy errors
+    std::lock_guard<std::mutex> m_lock(m_mutex);
+
     rdbms::AutoRollback autoRollback(conn);
 
     conn.executeNonQuery("UPDATE ARCHIVE_FILE_ID SET ID = ID + 1", rdbms::Stmt::AutocommitMode::OFF);

catalogue/SqliteCatalogue.hpp

@@ -72,6 +72,10 @@ protected:
    * because different database technologies propose different solution to the
    * problem of generating ever increasing numeric identifiers.
    *
+   * PLEASE NOTE the SQLite implemenation of getNextArchiveFileId() takes a lock
+   * on m_mutex in order to serialize access to the SQLite database.  This has
+   * been done in an attempt to avoid SQLite busy errors.
+   *
    * @param conn The database connection.
    * @return A unique archive ID that can be used by a new archive file within
    * the catalogue.