+++ /dev/null
-#define refcount_gt_one (refcount > 1)
-/*
- * This program 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.
- *
- * This program 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 this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- *
- * Copyright (c) 2009 Mathieu Desnoyers
- */
-
-/* 16 CPUs max (byte has 8 bits, divided in two) */
-
-#ifndef CONFIG_BITS_PER_BYTE
-#define BITS_PER_BYTE 8
-#else
-#define BITS_PER_BYTE CONFIG_BITS_PER_BYTE
-#endif
-
-#define HBPB (BITS_PER_BYTE / 2) /* 4 */
-#define HMASK ((1 << HBPB) - 1) /* 0x0F */
-
-/* for byte type */
-#define LOW_HALF(val) ((val) & HMASK)
-#define LOW_HALF_INC 1
-
-#define HIGH_HALF(val) ((val) & (HMASK << HBPB))
-#define HIGH_HALF_INC (1 << HBPB)
-
-byte lock = 0;
-byte refcount = 0;
-
-#define need_pause() (_pid == 1)
-
-/*
- * Test weak fairness by either not pausing or cycling for any number of
- * steps, or forever.
- * Models a slow thread. Should be added between each atomic steps.
- * To test for wait-freedom (no starvation of a specific thread), add do_pause
- * in threads other than the one we are checking for progress (and which
- * contains the progress label).
- * To test for lock-freedom (system-wide progress), add to all threads except
- * one. All threads contain progress labels.
- */
-inline do_pause()
-{
- if
- :: need_pause() ->
- do
- :: 1 ->
- if
- :: 1 -> skip;
- :: 1 -> break;
- fi;
- od;
- :: else ->
- skip;
- fi;
-}
-
-inline spin_lock(lock, ticket)
-{
- atomic {
- ticket = HIGH_HALF(lock) >> HBPB;
- lock = lock + HIGH_HALF_INC; /* overflow expected */
- }
-
- do
- :: 1 ->
- if
- :: (LOW_HALF(lock) == ticket) ->
- break;
- :: else ->
- skip;
- fi;
- od;
-}
-
-inline spin_unlock(lock)
-{
- lock = HIGH_HALF(lock) | LOW_HALF(lock + LOW_HALF_INC);
-}
-
-proctype proc_X()
-{
- byte ticket;
-
- do
- :: 1->
- spin_lock(lock, ticket);
-progress:
- refcount = refcount + 1;
- do_pause();
- refcount = refcount - 1;
- spin_unlock(lock);
- od;
-}
-
-init
-{
- run proc_X();
- run proc_X();
- //run proc_X();
- //run proc_X();
- //run proc_X();
-}