Hi everyone,
In the following code, my_mbx is an unbounded mailbox that can be populated from multiple sources at the same simulation time:
virtual task mbx_monitor();
mbx_data_object mbx_data;
forever begin
my_mbx.get(mbx_data);
if (mbx_data.decrement_counter) begin
fork wait_and_decrement_counter(mbx_data.id); join_none
end // if (mbx_data.decrement_counter)
end // forever
endtask : mbx_monitor
virtual task wait_and_decrement_counter(int id);
`uvm_info(get_name(), $sformatf("Decrementing counter due to item #%0d", id), verbosity)
#50;
counter--;
endtask : wait_and_decrement_counterAt time X, mailbox include two objects:
- object #0: decrement_counter == 1, id == 0
- object #1: decrement_counter == 0, id == 1
My expectation is that object #0 should call the wait_and_decrement_counter task while object 1 should not, i.e. I should see the following print:
UVM_INFO |@ X ps | uvm_test_top | Decrementing counter due to item #0
Actually I am seeing this one:
UVM_INFO |@ X ps | uvm_test_top | Decrementing counter due to item #1
After some GUI debug, it seems that I have an issue with passing the object.id as an argument to the wait_and_decrement_counter task.
Here the thread:
- Getting item 0 from mailbox
- Since item0.decrement_counter == 1, I'm getting into the if condition, calling the forked task
- Getting item 1 from mailbox
- Since item1.decrement_counter == 0, I'm not getting into the if condition
- Getting into the wait_and_decrement_counter task, seeing item1.id as passed argument
The trivial solution will be to add a #1 delay after the task call (i.e. into the if condition), but I would prefer to not add any delay there, can someone advise ?
Thanks in advance,
Ruben
