vault backup: 2025-03-03 09:02:47

.obsidian/workspace.json

@@ -36,9 +36,9 @@
               "type": "pdf",
               "state": {
                 "file": "Concurrent Systems/slides/class 1.pdf",
-                "page": 2,
+                "page": 4,
                 "left": -22,
-                "top": 596,
+                "top": 42,
                 "zoom": 0.7036817102137768
               },
               "icon": "lucide-file-text",
@@ -220,6 +220,7 @@
   },
   "active": "bfdcb298848e6147",
   "lastOpenFiles": [
+    "Pasted image 20250303090135.png",
     "Concurrent Systems/slides/class 1.pdf",
     "Concurrent Systems/notes/Lezione1.md",
     "Concurrent Systems/notes",

Concurrent Systems/notes/Lezione1.md

@@ -42,3 +42,22 @@ Different processes work to let all of them succeed in their task.
 	- only produced data can be consumed
 	- every datum can be consumed at most once
 
+#### Competition
+Different processes aim at executing some action, but only one of them succeeds.
+Usually, this is related to the access of the same shared resource.
+
+Example: two processes want to withdraw from a bank account.
+
+```js
+function withdraw() {
+	x := account.read();
+	if x ≥ 1M€ {
+		account.write(x – 1M€);
+	}
+}
+```
+
+While `read()` and `write()` may be considered as atomic, their sequential composition **is not**.
+
+![[Pasted image 20250303090135.png]]
+