hash table comment fix.

[urcu.git] / formal-model / ooomem-two-writes / mem.spin

diff --git a/formal-model/ooomem-two-writes/mem.spin b/formal-model/ooomem-two-writes/mem.spin
index 9202043692079304e5c88460df81cad6a9c15309..304c3f80f534aeba276c7ef7dc1efa3706a04fc9 100644 (file)
--- a/formal-model/ooomem-two-writes/mem.spin
+++ b/formal-model/ooomem-two-writes/mem.spin
@@ -1,5 +1,21 @@
 /*
- * mem.spin: Promela code to validate memory barriers with OOO memory.
+ * mem.spin: Promela code to validate memory barriers with out-of-order memory
+ * and out-of-order instruction scheduling.
+ *
+ * Algorithm verified :
+ *
+ * alpha = 0;
+ * beta = 0;
+ * x = 1;
+ * y = 1;
+ *
+ * Process A                  Process B
+ * alpha = 1;                 beta = 1;
+ * mb();                      mb();
+ * x = beta;                  y = alpha;
+ *
+ * if x = 0, then y != 0
+ * if y = 0, then x != 0
  *
  * 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
@@ -142,9 +158,8 @@ inline smp_mb()
 DECLARE_CACHED_VAR(byte, alpha, 0);
 DECLARE_CACHED_VAR(byte, beta, 0);
 
-/* value 2 is uninitialized */
-byte read_one = 2;
-byte read_two = 2;
+byte read_one = 1;
+byte read_two = 1;
 
 /*
  * Bit encoding, proc_one_produced :