From 9772a79c937d1e85c361b52b5baa17ac38d086ae Mon Sep 17 00:00:00 2001
From: Marco Realacci <marco@marcorealacci.me>
Date: Mon, 17 Mar 2025 10:24:23 +0100
Subject: [PATCH] vault backup: 2025-03-17 10:24:23

---
 .obsidian/workspace.json                      | 24 +++++++++----------
 .../notes/4c - Dining Philosophers.md         |  3 ++-
 .../5 - Software Transactional Memory.md      |  6 +++++
 3 files changed, 20 insertions(+), 13 deletions(-)
 create mode 100644 Concurrent Systems/notes/5 - Software Transactional Memory.md

diff --git a/.obsidian/workspace.json b/.obsidian/workspace.json
index 352734c..40dca75 100644
--- a/.obsidian/workspace.json
+++ b/.obsidian/workspace.json
@@ -13,12 +13,12 @@
             "state": {
               "type": "markdown",
               "state": {
-                "file": "Concurrent Systems/notes/4c - Dining Philosophers.md",
+                "file": "Concurrent Systems/notes/5 - Software Transactional Memory.md",
                 "mode": "source",
                 "source": false
               },
               "icon": "lucide-file",
-              "title": "4c - Dining Philosophers"
+              "title": "5 - Software Transactional Memory"
             }
           }
         ]
@@ -28,19 +28,19 @@
         "type": "tabs",
         "children": [
           {
-            "id": "071b6cd23e4b1e9d",
+            "id": "3d13408a0af8bc82",
             "type": "leaf",
             "state": {
               "type": "pdf",
               "state": {
-                "file": "Concurrent Systems/slides/class 4.pdf",
-                "page": 24,
-                "left": -26,
-                "top": 340,
-                "zoom": 0.57541567695962
+                "file": "Concurrent Systems/slides/class 5.pdf",
+                "page": 1,
+                "left": -27,
+                "top": 10,
+                "zoom": 0.5754156769596199
               },
               "icon": "lucide-file-text",
-              "title": "class 4"
+              "title": "class 5"
             }
           }
         ]
@@ -218,11 +218,12 @@
   },
   "active": "6edd4157a160e462",
   "lastOpenFiles": [
-    "Concurrent Systems/slides/class 4.pdf",
+    "Concurrent Systems/slides/class 5.pdf",
+    "Concurrent Systems/notes/5 - Software Transactional Memory.md",
     "Concurrent Systems/notes/4c - Dining Philosophers.md",
+    "Concurrent Systems/slides/class 4.pdf",
     "Concurrent Systems/notes/images/Pasted image 20250317100456.png",
     "Concurrent Systems/notes/4b - Monitors.md",
-    "Concurrent Systems/slides/class 5.pdf",
     "HCIW/slides/4 HUI2016-6-forcefeedback.pdf",
     "HCIW/slides/3b Haptic slides.pdf",
     "HCIW/slides/3Haptic interaction.pdf",
@@ -262,7 +263,6 @@
     "Foundation of data science/notes/4 L1 and L2 normalization - Lasso and Ridge.md",
     "Foundation of data science/notes/3.2 LLM generated from notes.md",
     "Foundation of data science/notes/2 Linear Regression.md",
-    "Biometric Systems/notes/6. Face recognition 2D.md",
     "Senza nome.canvas"
   ]
 }
\ No newline at end of file
diff --git a/Concurrent Systems/notes/4c - Dining Philosophers.md b/Concurrent Systems/notes/4c - Dining Philosophers.md
index 52dcacb..9e11dae 100644
--- a/Concurrent Systems/notes/4c - Dining Philosophers.md	
+++ b/Concurrent Systems/notes/4c - Dining Philosophers.md	
@@ -95,4 +95,5 @@ test(i) :=
 		&& state[i] == hungry) then
 			state[i] = eating;
 			self[i].signal();
-```
\ No newline at end of file
+```
+N.B.: pickup picks both forks simultaneously
\ No newline at end of file
diff --git a/Concurrent Systems/notes/5 - Software Transactional Memory.md b/Concurrent Systems/notes/5 - Software Transactional Memory.md
new file mode 100644
index 0000000..42d8ad1
--- /dev/null
+++ b/Concurrent Systems/notes/5 - Software Transactional Memory.md	
@@ -0,0 +1,6 @@
+- Group together parts of the code that must look like atomic, in a way that is transparent, scalable and easy-to-use for the programmer
+- Differently from monitors, the part of the code to group is not part of the definition of the objects, but is application dependent
+- Differently from transactions in databases, the code can be any code, not just queries on the DB
+
+**Transaction:** an atomic unit of computation (look like instantaneous and without overlap with any other transaction), that can access atomic objects.
+	when executed alone, every transaction success
\ No newline at end of file