+/*
+ * mem.spin: Promela code to validate memory barriers with OOO memory.
+ *
+ * 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
+ */
+
+/* Promela validation variables. */
+
+#define NR_READERS 1
+#define NR_WRITERS 1
+
+#define NR_PROCS 2
+
+#define get_pid() (_pid)
+
+/*
+ * Each process have its own data in cache. Caches are randomly updated.
+ * smp_wmb and smp_rmb forces cache updates (write and read), wmb_mb forces
+ * both.
+ */
+
+#define DECLARE_CACHED_VAR(type, x, v) \
+ type mem_##x = v; \
+ type cached_##x[NR_PROCS] = v; \
+ bit cache_dirty_##x[NR_PROCS] = 0
+
+#define IS_CACHE_DIRTY(x, id) (cache_dirty_##x[id])
+
+#define READ_CACHED_VAR(x) (cached_##x[get_pid()])
+
+#define WRITE_CACHED_VAR(x, v) \
+ atomic { \
+ cached_##x[get_pid()] = v; \
+ cache_dirty_##x[get_pid()] = 1; \
+ }
+
+#define CACHE_WRITE_TO_MEM(x, id) \
+ if \
+ :: IS_CACHE_DIRTY(x, id) -> \
+ mem_##x = cached_##x[id]; \
+ cache_dirty_##x[id] = 0; \
+ :: else -> \
+ skip \
+ fi;
+
+#define CACHE_READ_FROM_MEM(x, id) \
+ if \
+ :: !IS_CACHE_DIRTY(x, id) -> \
+ cached_##x[id] = mem_##x;\
+ :: else -> \
+ skip \
+ fi;
+
+/*
+ * May update other caches if cache is dirty, or not.
+ */
+#define RANDOM_CACHE_WRITE_TO_MEM(x, id)\
+ if \
+ :: 1 -> CACHE_WRITE_TO_MEM(x, id); \
+ :: 1 -> skip \
+ fi;
+
+#define RANDOM_CACHE_READ_FROM_MEM(x, id)\
+ if \
+ :: 1 -> CACHE_READ_FROM_MEM(x, id); \
+ :: 1 -> skip \
+ fi;
+
+inline smp_rmb()
+{
+ atomic {
+ CACHE_READ_FROM_MEM(alpha, get_pid());
+ CACHE_READ_FROM_MEM(beta, get_pid());
+ }
+}
+
+inline smp_wmb()
+{
+ atomic {
+ CACHE_WRITE_TO_MEM(alpha, get_pid());
+ CACHE_WRITE_TO_MEM(beta, get_pid());
+ }
+}
+
+inline smp_mb()
+{
+ atomic {
+ smp_wmb();
+ smp_rmb();
+ }
+}
+
+/* Keep in sync manually with smp_rmb, wmp_wmb and ooo_mem */
+DECLARE_CACHED_VAR(byte, alpha, 0);
+DECLARE_CACHED_VAR(byte, beta, 0);
+
+inline ooo_mem()
+{
+ atomic {
+ RANDOM_CACHE_WRITE_TO_MEM(alpha, get_pid());
+ RANDOM_CACHE_WRITE_TO_MEM(beta, get_pid());
+ RANDOM_CACHE_READ_FROM_MEM(alpha, get_pid());
+ RANDOM_CACHE_READ_FROM_MEM(beta, get_pid());
+ }
+}
+
+/* value 2 is uninitialized */
+byte read_one = 2;
+byte read_two = 2;
+
+active proctype test_proc_one()
+{
+ assert(get_pid() < NR_PROCS);
+
+ ooo_mem();
+ WRITE_CACHED_VAR(alpha, 1);
+ ooo_mem();
+#ifndef NO_WMB
+ smp_wmb();
+ ooo_mem();
+#endif
+#ifndef NO_RMB
+ smp_rmb();
+ ooo_mem();
+#endif
+ read_one = READ_CACHED_VAR(beta);
+ ooo_mem();
+ // test : [] (read_one == 0 -> read_two != 0)
+ // test : [] (read_two == 0 -> read_one != 0)
+ assert(!(read_one == 0 && read_two == 0));
+}
+
+active proctype test_proc_two()
+{
+ assert(get_pid() < NR_PROCS);
+
+ ooo_mem();
+ WRITE_CACHED_VAR(beta, 1);
+ ooo_mem();
+#ifndef NO_WMB
+ smp_wmb();
+ ooo_mem();
+#endif
+#ifndef NO_RMB
+ smp_rmb();
+ ooo_mem();
+#endif
+ read_two = READ_CACHED_VAR(alpha);
+ ooo_mem();
+ // test : [] (read_one == 0 -> read_two != 0)
+ // test : [] (read_two == 0 -> read_one != 0)
+ assert(!(read_one == 0 && read_two == 0));
+}