vault backup: 2025-03-03 10:06:24

Concurrent Systems/notes/Lezione1.md

@@ -154,4 +154,14 @@ lock(i) :=
 unlock(i) :=
 	FLAG[i] <- down
 	return
-```
+```
+
+**Features:**
+- it satisfies MUTEX
+- it satisfies bounded bypass, with bound = 1
+- it requires 2 one-bit SRSW registers (the flags and 1 one-bit MRMW registers (AFTER_YOU)
+- Each lock-unlock requires 5 accesses to the registers (4 for lock and 1 for unlock)
+
+##### MUTEX proof
+Assume p0 and p1 are simultaneously in the CS.
+How has p0 entered its CS?