diff options
Diffstat (limited to 'testsuite/vests/vhdl-93/ashenden/compliant/ch_19_wtfifo-b.vhd')
-rw-r--r-- | testsuite/vests/vhdl-93/ashenden/compliant/ch_19_wtfifo-b.vhd | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/testsuite/vests/vhdl-93/ashenden/compliant/ch_19_wtfifo-b.vhd b/testsuite/vests/vhdl-93/ashenden/compliant/ch_19_wtfifo-b.vhd new file mode 100644 index 000000000..93618fbb6 --- /dev/null +++ b/testsuite/vests/vhdl-93/ashenden/compliant/ch_19_wtfifo-b.vhd @@ -0,0 +1,77 @@ + +-- 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_wtfifo-b.vhd,v 1.3 2001-10-26 16:29:36 paw Exp $ +-- $Revision: 1.3 $ +-- +-- --------------------------------------------------------------------- + +package body waiting_token_fifo_adt is + + function new_fifo return fifo_type is + begin + return new fifo_record'( null, null ); + end function new_fifo; + + + procedure test_empty ( variable fifo : in fifo_type; + variable is_empty : out boolean ) is + begin + is_empty := fifo.head_entry = null; + end procedure test_empty; + + + procedure insert ( fifo : inout fifo_type; + element : in element_type ) is + + variable new_entry : fifo_entry + := new fifo_entry_record'( next_entry => null, + element => element ); + begin + if fifo.tail_entry /= null then + fifo.tail_entry.next_entry := new_entry; + else + fifo.head_entry := new_entry; + end if; + fifo.tail_entry := new_entry; + end procedure insert; + + + procedure remove ( fifo : inout fifo_type; + element : out element_type ) is + variable empty_fifo : boolean; + variable removed_entry : fifo_entry; + begin + test_empty(fifo, empty_fifo); + if empty_fifo then + report "remove from empty fifo" severity failure; + else + removed_entry := fifo.head_entry; + element := removed_entry.element; + fifo.head_entry := removed_entry.next_entry; + if fifo.head_entry = null then -- fifo now empty + fifo.tail_entry := null; + end if; + deallocate(removed_entry); + end if; + end procedure remove; + +end package body waiting_token_fifo_adt; |