Mailbox: Systemverilog

SystemVerilog
1

I am trying an example in SV language on edaplayground. I am putting some transactions into the mailbox using the put() method while taking the same transactions using get() method I am not receiving anything. Can someone please help me where I am getting wrong?

class transactions;
  randc bit[3:0] i1;
  randc bit[1:0] sel;
  bit out;
endclass

class generator;
  integer i;
  transactions trans;
  mailbox mbx;
  event done;
  
  function new(mailbox mbx);
    this.mbx = mbx;
    //this.done = done;
  endfunction
  
  task gen_task();
      trans = new();
      for(i=0;i<15;i++) begin//{
        assert(trans.randomize()) begin //{
          $display("Randomization successful");
          
        end//}
            mbx.put(trans);
        	$display("Stimuli generation completes");
        $display("[GEN]The value of inputs are as follows = %b and select line = %b",trans.i1, trans.sel);
      end//}
      ->done;
    #1;
  endtask
endclass

class driver;
    transactions trans;
    mailbox mbx;
  
    function new(mailbox mbx);
      this.mbx = mbx;
    endfunction
   
 
    task drv_task();
      forever begin
      trans = new();
       mbx.get(trans);
        $display("[DRV] The value of outputs are as follows = %b and select line = %b",trans.i1, trans.sel);
      end
      #1;
    endtask
endclass

module tb;
  	generator gen;
  	driver    drv;
  	mailbox 	mbx;
  
  	initial begin
    	gen = new(mbx);
    	drv = new(mbx);
    	mbx = new();
    
    	fork
      		gen.gen_task();
          	#1
      		drv.drv_task();
    	join
  	end
endmodule
2

In reply to Lalita_Meena:

2 issues one is mailbox construction happened later, second you were just creating one packet and pushing only the last pkt.



// Code your testbench here
// or browse Examples
class transactions;
randc bit[3:0] i1;
randc bit[1:0] sel;
bit out;
endclass

class generator;
integer i;
transactions trans;
mailbox mbx;
event done;

function new(mailbox mbx);
this.mbx = mbx;
//this.done = done;
endfunction

task gen_task();

for(i=0;i<15;i++) begin//{
  trans = new();
assert(trans.randomize()) begin //{
$display("Randomization successful");

end//}
mbx.put(trans);
$display("Stimuli generation completes");
$display("[GEN]The value of inputs are as follows = %b and select line = %b",trans.i1, trans.sel);
end//}
->done;
#1;
endtask
endclass

class driver;
transactions trans;
mailbox mbx;

function new(mailbox mbx);
this.mbx = mbx;
endfunction


task drv_task();
forever begin
trans = new();
mbx.get(trans);
$display("[DRV] The value of outputs are as follows = %b and select line = %b",trans.i1, trans.sel);
end
#1;
endtask
endclass

module tb;
generator gen;
driver drv;
mailbox mbx;

initial begin
mbx = new();
  gen = new(mbx);
drv = new(mbx);


fork
gen.gen_task();
#1
drv.drv_task();
join
end
endmodule