UVM Internals - uvm_pool · Techiedeepdive

This post is about one of UVM utility uvm_pool which is wrapper around Systemverilog associative array. UVM defines singletons from uvm_pool as well.

Starting with some internal inside uvm_pool, poolassoc array is delatred as protected as there couple of setters and getter defines anyway.

  typedef uvm_pool #(KEY,T) this_type;

  static protected this_type m_global_pool;
  protected T pool[KEY];

get and setare defined as follows. Easy enough!


  virtual function T get (KEY key);
    if (!pool.exists(key)) begin
      T default_value;
      pool[key] = default_value;
    end
    return pool[key];
  endfunction
  
  virtual function void add (KEY key, T item);
    pool[key] = item;
  endfunction

For the singleton, these methods can be used. Again easy enough! Not that global pool is created once the first time get_global_pool is called.

  static function this_type get_global_pool ();
    if (m_global_pool==null)
      m_global_pool = new("pool");
    return m_global_pool;
  endfunction

  static function T get_global (KEY key);
    this_type gpool;
    gpool = get_global_pool(); 
    return gpool.get(key);
  endfunction

UVM also declares specialization with string type which is again singleton.

class uvm_object_string_pool #(type T=uvm_object) extends uvm_pool #(string,T);