启动适配器序列后测试挂起

Question

当我启动适配器序列以进行寄存器读取和随后的写入时，完成读取操作后，execute_op会挂起。任何人都可以推理出这种情况下可能出现的问题吗？

    class apb_rgm_master_sequencer extends apb_master_sequencer;

    `uvm_component_utils(apb_rgm_master_sequencer) 

    uvm_blocking_put_imp_reg_apb   #(uvm_rgm_reg_op, apb_rgm_master_sequencer) reg_req_export;

    uvm_analysis_port#(uvm_rgm_reg_op) reg_rsp_port;   

    apb_rgm_adapter_seq adapter_seq;

    function new(string name, uvm_component parent); 
    super.new(name, parent); 
    reg_req_export  = new("reg_req_export",this);
    reg_rsp_port    = new("reg_rsp_port",this);  
    adapter_seq     = apb_rgm_adapter_seq::type_id::create("adapter_seq",this);
    endfunction // new

    virtual task run_phase(uvm_phase phase);   
    fork
    adapter_seq.start(this);
    super.run_phase(phase);     
    join_none
    endtask // run 

    task put_reg_apb(uvm_rgm_reg_op op);  
    adapter_seq.execute_op(op);
    endtask

    endclass

以下是适配器序列的实现

class apb_rgm_adapter_seq extends apb_master_base_sequence;
  `uvm_declare_p_sequencer(apb_rgm_master_sequencer) 

  //Note::Instead of using the `uvm_sequence_utils, we use the `uvm_object_utils and the 
  //`uvm_declare_p_sequencer to not register the adapter sequence in the sequencer. This  
  //prevents it from being randomly picked and executed again in the sequencer random traffic.
  `uvm_object_utils(apb_rgm_adapter_seq)  

  // Register Operation Handle used by the adapter sequence 
  uvm_rgm_reg_op   m_reg_cur_op_h;     

  int address=0;

  // ---------------------------------------------------------------------------   
  function new(string name="apb_rgm_adapter_seq"); 
    super.new(name);   
  endfunction // new

  // ---------------------------------------------------------------------------   
  virtual task body();   
     process_response(); 
  endtask // body  

  // ---------------------------------------------------------------------------   
  virtual task execute_op(uvm_rgm_reg_op op);  
    apb_configuration get_cfg; 

    m_reg_cur_op_h  = op; 

    /** Obtain a handle to the port configuration */   
    p_sequencer.get_cfg(get_cfg);   
    if (!$cast(cfg, get_cfg)) begin  
      `uvm_fatal("body", "Unable to $cast the configuration to a apb_apb_port_configuration class");
    end  

    $display("apb_adapter_seq ::  op.get_address() = %h", op.get_address());
    address = op.get_address;

    `uvm_create(req)
    if(op.get_direction() == uvm_rgm_pkg::OP_WR) begin 
      $display("apb_rgm_master_sequencer start of WR req  ::  address() = %h", req.address);
      if (!req.randomize() with {   
         req.address     == address; 
         req.cfg         == cfg;     
         req.xact_type   == apb_transaction::WRITE; 
         req.data        == op.get_reg_value();
         req.pprot1      == apb_transaction::SECURE; 
      } ) begin  
         `uvm_fatal(get_name(), "APB WR Req Randomize failed") 
         end 
      req.address     = address; 
      $display("apb_rgm_master_sequencer before WR req  ::  address() = %h", req.address);
    `uvm_send(req)
      $display("apb_rgm_master_sequencer After WR req  ::  address() = %h", req.address);
    end
    else begin
      $display("apb_rgm_master_sequencer start of RD req  ::  address() = %h", req.address);
      if (!req.randomize() with {
         req.address     == address;
         req.cfg         == cfg; 
         req.xact_type   == apb_transaction::READ;
         req.pprot1      == apb_transaction::SECURE;  
      } ) begin 
         `uvm_fatal(get_name(), "APB RD Req Randomize failed") 
         end
      req.address     = address; 
      $display("apb_rgm_master_sequencer before RD req  ::  address() = %h", req.address);
    `uvm_send(req)
      $display("apb_rgm_master_sequencer After RD req  ::  address() = %h", req.address);
    end   

  endtask // execute_op  

  // ---------------------------------------------------------------------------
  virtual task process_response(); 
    while(1) begin 
      $display("apb_rgm_master_sequencer waiting for the response of address sent");
      get_response(rsp); 
      `uvm_info("process_response ",$sformatf("Response received for address - %h data - %h", rsp.address, rsp.data), UVM_LOW) 
      m_reg_cur_op_h.set_reg_value(rsp.data); 
      p_sequencer.reg_rsp_port.write(m_reg_cur_op_h);  
    end  
  endtask  
endclass // apb_rgm_adapter_seq 

没有随机分组失败或任何错误，但事务未进行到DUT。