From 6da967969445f331f199ac5c32677f6bb917bd1a Mon Sep 17 00:00:00 2001
From: Marco Realacci <marco@marcorealacci.me>
Date: Tue, 18 Mar 2025 08:54:12 +0100
Subject: [PATCH] vault backup: 2025-03-18 08:54:12

---
 .obsidian/workspace.json                  | 40 ++++++++---------------
 Concurrent Systems/notes/6 - Atomicity.md |  5 +++
 2 files changed, 18 insertions(+), 27 deletions(-)
 create mode 100644 Concurrent Systems/notes/6 - Atomicity.md

diff --git a/.obsidian/workspace.json b/.obsidian/workspace.json
index 251b9bb..2723d4f 100644
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+++ b/.obsidian/workspace.json
@@ -6,19 +6,20 @@
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@@ -26,34 +27,19 @@
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@@ -232,11 +218,12 @@
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+    "Concurrent Systems/slides/class 5.pdf",
+    "Concurrent Systems/notes/5 - Software Transactional Memory.md",
     "Concurrent Systems/notes/4c - Dining Philosophers.md",
     "Concurrent Systems/notes/4 - Semaphores.md",
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@@ -278,7 +265,6 @@
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\ No newline at end of file
diff --git a/Concurrent Systems/notes/6 - Atomicity.md b/Concurrent Systems/notes/6 - Atomicity.md
new file mode 100644
index 0000000..e34d29c
--- /dev/null
+++ b/Concurrent Systems/notes/6 - Atomicity.md	
@@ -0,0 +1,5 @@
+We have a set of n sequential processes $p_{1},...,p_n$ , that access $m$ concurrent objects $X_1,...,X_m$ by invoking operations on the form `Xi.op(args)(ret)`.
+
+When invoked by $p_j$, the invocation `Xi.op(args)(ret)` is modeled by two events: `inv[Xi.op(args) by pj]` and `res[Xi.op(ret) to pj]`.
+
+A **history** (or **trace**) is a pair $\hat{H}=(H, <_{H})$ where H is a set of events and $<_{H}$ is a total order on them.
\ No newline at end of file