UVM:: drop all objection forcelly

在VIP中一般有如下代碼

phase.raise_objection(this);  

get_next_item(req);

drive_command(req);

seq_item_port.item_done();

phase.drop_objection(this);

但是有時候環境中有interrupt，使得vip完成不了一次握手就要推出，這樣就需要在外部強制drop objection

方法如下：

virtual task run_phase(uvm_phase phase);
  uvm_objection objection;
  uvm_object    object_list[$];
  TIMEOUT_TIMER_EXPIRED = 0;
  #(this.SYS_GLOBAL_TIMEOUT);
 
  // Fetching the objection from current phase
  objection = phase.get_objection();
 
  // Collecting all the objects which doesn't drop the objection 
  objection.get_objectors(object_list);
 
  // Dropping the objection forcefully
  foreach(object_list[i]) begin
    while(objection.get_objection_count(object_list[i]) != 0) begin
      objection.drop_objection(object_list[i]);
    end
  end
  TIMEOUT_TIMER_EXPIRED = 1;
endtask: run_phase