-- Copyright (C) 1996 Morgan Kaufmann Publishers, Inc
-- This file is part of VESTs (Vhdl tESTs).
-- VESTs is free software; you can redistribute it and/or modify it
-- under the terms of the GNU General Public License as published by the
-- Free Software Foundation; either version 2 of the License, or (at
-- your option) any later version.
-- VESTs is distributed in the hope that it will be useful, but WITHOUT
-- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
-- FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
-- for more details.
-- You should have received a copy of the GNU General Public License
-- along with VESTs; if not, write to the Free Software Foundation,
-- Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-- ---------------------------------------------------------------------
--
-- $Id: ch_19_queue-b.vhd,v 1.3 2001-10-26 16:29:36 paw Exp $
-- $Revision: 1.3 $
--
-- ---------------------------------------------------------------------
library math;
architecture behavior of queue is
begin
queue_manager : process is
use qsim.queue_types.all, qsim.waiting_token_fifo_adt.all;
variable waiting_token, head_token : waiting_token_type;
variable waiting_token_fifo : fifo_type := new_fifo;
variable out_token_in_transit : boolean := false;
variable number_of_tokens_released : natural := 0;
variable current_queue_size : natural := 0;
variable maximum_queue_size : natural := 0;
variable waiting_time : natural; -- in time_unit
variable sum_of_waiting_times : real := 0.0; -- in time_unit
variable sum_of_squares_of_waiting_times : real := 0.0; --in time_unit**2
use std.textio.all;
file info_file : text;
variable L : line;
use math.math_real.sqrt;
procedure write_summary is
variable mean_waiting_time : real
:= sum_of_waiting_times / real(number_of_tokens_released);
variable std_dev_of_waiting_times : real
:= sqrt ( ( sum_of_squares_of_waiting_times
- sum_of_waiting_times**2 / real(number_of_tokens_released) )
/ real( number_of_tokens_released - 1 ) );
begin
write(L, string'("Summary information for queue "));
write(L, name);
write(L, string'(" up to time "));
write(L, now, unit => time_unit);
writeline(info_file, L);
write(L, string'(" Number of tokens currently waiting = "));
write(L, natural(current_queue_size));
writeline(info_file, L);
write(L, string'(" Number of tokens released = "));
write(L, natural(number_of_tokens_released));
writeline(info_file, L);
write(L, string'(" Maximum queue size = "));
write(L, natural(maximum_queue_size));
writeline(info_file, L);
write(L, string'(" Mean waiting time = "));
write(L, mean_waiting_time * time_unit, unit => time_unit);
writeline(info_file, L);
write(L, string'(" Standard deviation of waiting times = "));
write(L, std_dev_of_waiting_times * time_unit, unit => time_unit);
writeline(info_file, L);
writeline(info_file, L);
end procedure write_summary;
procedure write_trace_enqueue is
begin
write(L, string'("Queue "));
write(L, name);
write(L, string'(": at "));
write(L, now, unit => time_unit);
write(L, string'(" enqueued "));
write(L, waiting_token.token, time_unit);
writeline(info_file, L);
end procedure write_trace_enqueue;
procedure write_trace_dequeue is
begin
write(L, string'("Queue "));
write(L, name);
write(L, string'(": at "));
write(L, now, unit => time_unit);
write(L, string'(" dequeued "));
write(L, head_token.token, time_unit);
writeline(info_file, L);
end procedure write_trace_dequeue;
begin
file_open(info_file, info_file_name, write_mode);
loop
wait on info_detail'transaction, in_arc, out_ready;
if info_detail'active and info_detail = summary then
write_summary;
end if;
if in_arc'event then
waiting_token := waiting_token_type'( token => in_arc.token,
time_when_enqueued => now );
insert(waiting_token_fifo, waiting_token);
current_queue_size := current_queue_size + 1;
if current_queue_size > maximum_queue_size then
maximum_queue_size := current_queue_size;
end if;
if info_detail = trace then
write_trace_enqueue;
end if;
end if;
if out_ready and current_queue_size > 0 and not out_token_in_transit then
remove(waiting_token_fifo, head_token);
current_queue_size := current_queue_size - 1;
out_arc <= arc_type'( transaction => not out_arc.transaction'driving_value,
token => head_token.token );
out_token_in_transit := true;
number_of_tokens_released := number_of_tokens_released + 1;
waiting_time := (now - head_token.time_when_enqueued) / time_unit;
sum_of_waiting_times := sum_of_waiting_times + real(waiting_time);
sum_of_squares_of_waiting_times := sum_of_squares_of_waiting_times
+ real(waiting_time) ** 2;
if info_detail = trace then
write_trace_dequeue;
end if;
end if;
if out_token_in_transit and not out_ready then
out_token_in_transit := false;
end if;
end loop;
end process queue_manager;
end architecture behavior;