vault backup: 2025-03-17 10:44:23

Concurrent Systems/notes/5 - Software Transactional Memory.md

@@ -46,4 +46,14 @@ We now present an atomic STM system, called *Transactional Locking 2*:
 	- `lc(XX)`: a local copy of the implementation of reg. X
 	- `read_set(T)`: the set of names of all the registers read by T up to that moment
 	- `write_set(T)`: the set of names of all the registers written by T up to that moment
-	- `birthdate(T)`: the value of CLOCK(+1) at the starting of 
+	- `birthdate(T)`: the value of CLOCK(+1) at the starting of T
+
+**Idea:** commit a transaction if and only if (iff) it could appear as executed at its birthdate time
+**Consistency:**
+- if T reads X, then it must be that `XX.date < birthdate(T)`
+- to commit, all registers accessed by T cannot have been modified after T's birthdate (again, `XX.date < birthdate(T)`)
+
+###### Implementation:
+```
+poi la scrivo giuro
+```