vault backup: 2025-03-03 09:12:47

Concurrent Systems/notes/Lezione1.md

@@ -64,3 +64,14 @@ While `read()` and `write()` may be considered as atomic, their sequential compo
 #### Mutual Exclusion (MUTEX)
 Ensure that some parts of the code are executed as *atomic*.
 This is needed in competition but also in cooperation.
+
+Of course, MUTEX is required only when accessing shared data.
+
+###### Critical section
+A set of code parts that must be run without interferences, i.e. when a process is in a certain shared object (C.S.) than no other process is on that C.S..
+
+###### MUTEX problem
+Design an entry protocol (lock) and an exit protocol (unlock) such that, when used to encapsulate a C.S. (for a given shared object), ensure that at most one process at a time is in a C.S. (for that shared object).
+
+We assume that all C.S.s terminate and that the code is well-formed (*lock ; critical section ; unlock*).
+