The <uvm_config_db> class provides a convenience interface on top of the <uvm_resource_db> to simplify the basic interface that is used for configuring <uvm_component> instances.
以下代码来自uvm-1.1d/src/base/uvm_config_db.svh
class uvm_config_db#(type T=int) extends uvm_resource_db#(T);
static uvm_pool#(string, uvm_resource#(T) m_rsc[uvm_component];
static local uvm_queue#(m_uvm_waiter) m_waiters[string];