text: 
  -- 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_join-b.vhd,v 1.3 2001-10-26 16:29:36 paw Exp $
  -- $Revision: 1.3 $
  --
  -- ---------------------------------------------------------------------
  
  library qsim;
  
  architecture behavior of join is
  
  begin
  
    joiner : process
  
      use qsim.token_fifo_adt.all;
  
      variable source : positive range in_arc'range;
      variable token_fifo : fifo_type := new_fifo;
      variable current_fifo_size : natural := 0;
      variable head_token : token_type;
      variable number_of_tokens_joined : natural := 0;
      type counter_array is array (positive range in_arc'range) of natural;
      variable number_joined_from_source : counter_array := (others => 0);
  
      use std.textio.all;
      file info_file : text;
      variable L : line;
  
  --  Modeltech bug mt043 workaround
      variable in_arc_last_value : arc_vector(in_arc'range) := in_arc;
  --
  
      procedure write_summary is
      begin
        write(L, string'("Summary information for join "));
        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 joined = "));
        write(L, natural(number_of_tokens_joined));
        writeline(info_file, L);
        for source in in_arc'range loop
          write(L, string'("    Number from input("));
          write(L, source);
          write(L, string'(") = "));
          write(L, natural(number_joined_from_source(source)));
          write(L, string'(" ("));
          write(L, real(number_joined_from_source(source))
                / real(number_of_tokens_joined),
                digits => 4);
          write(L, ')');
          writeline(info_file, L);
        end loop;
        writeline(info_file, L);
      end write_summary;
  
      procedure write_trace is
      begin
        write(L, string'("Join "));
        write(L, name);
        write(L, string'(": at "));
        write(L, now, unit => time_unit);
        write(L, string'(" joined from input "));
        write(L, source);
        write(L, ' ');
        write(L, in_arc(source).token, time_unit);
        writeline(info_file, L);
      end write_trace;
  
      procedure accept_new_tokens is
      begin
        for index in 1 to in_arc'length loop
  --  Modeltech bug mt043 workaround
  --      if in_arc(index).transaction /= in_arc'last_value(index).transaction then
          if in_arc(index).transaction /= in_arc_last_value(index).transaction then
  --
            source := index;
            insert(token_fifo, in_arc(source).token);
            current_fifo_size := current_fifo_size + 1;
            number_of_tokens_joined := number_of_tokens_joined + 1;
            number_joined_from_source(source) := number_joined_from_source(source) + 1;
            if info_detail = trace then
              write_trace;
            end if;
          end if;
        end loop;
  --  Modeltech bug mt043 workaround
        in_arc_last_value := in_arc;
  --
      end procedure accept_new_tokens;
  
    begin
      file_open(info_file, info_file_name, write_mode);
      loop
        wait on info_detail'transaction, in_arc;
        if info_detail'active and info_detail = summary then
          write_summary;
        end if;
        if in_arc'event then
  	accept_new_tokens;
          while current_fifo_size > 0 loop
            remove(token_fifo, head_token);
            current_fifo_size := current_fifo_size - 1;
  	  out_arc <= arc_type'( transaction => not out_arc.transaction'driving_value,
  			        token => head_token );
            wait for 0 fs;  -- delta delay before next output token
            if info_detail'active and info_detail = summary then
              write_summary;
            end if;
            if in_arc'event then
  	    accept_new_tokens;
  	  end if;
          end loop;
        end if;
      end loop;
    end process joiner;
  
  end behavior;
  