// called when creating wrapper for private (internal) environment of DB;
// call must be synchronized on rscLock; db.Evp must be != null, not checked;
internal void SetOwnerDatabase(Db db) {
evp = db.GetEvp();
databases.Insert(db);
isOwnedByDb = true;
// so that callbacks can refer back to the DbEnv instance
instanceHandle = GCHandle.Alloc(this, GCHandleType.WeakTrackResurrection);
evp->api_internal = (IntPtr)instanceHandle;
}