What's the difference between uvm_sqr_if_base::peek() and uvm_sqr_if_base::get_next_item()?

In System Verilog UVM, the interface present in TLM ports for communication between sequences and drivers (uvm_sqr_if_base) offers flexibility. For pulling requests, I'll summarize the four options in this table:

                  blocking   item_done  get_next_item()      yes        no  try_next_item()       no        no            get()      yes       yes           peek()      yes        no  

... where blocking indicates that if you call the method, but no sequence is ready to provide data, then the task will BLOCK and wait until data is ready and can and will be returned.

... where item_done indicates that the method also calls item_done() after successfully pulling an item from the sequence.

What's the difference between peek() and get_next_item() then?

Consider these two code snippets from two imaginary drivers ...

  while(1) begin: loop1                          while(1) begin: loop2      seq_item_port.get_next_item(req);              seq_item_port.peek(req);      process(req);                                  process(req);      seq_item_port.item_done();                     seq_item_port.item_done();    end: loop1                                     end: loop2  

What's the difference? Why are there two methods for accomplishing the same thing? It doesn't seem to be TLM1 vs TLM2 styles.

https://stackoverflow.com/questions/67410914/whats-the-difference-between-uvm-sqr-if-basepeek-and-uvm-sqr-if-baseget-n May 06, 2021 at 10:05AM