From ad80d225d5442c4e880276491f8f495f0ca890e6 Mon Sep 17 00:00:00 2001
From: Per Lindgren <per.lindgren@ltu.se>
Date: Wed, 20 Oct 2021 09:57:10 +0200
Subject: [PATCH] comparison between lock approaches

---
 examples/multilock_vs_lockall.rs | 91 ++++++++++++++++++++++++++++++++
 1 file changed, 91 insertions(+)
 create mode 100644 examples/multilock_vs_lockall.rs

diff --git a/examples/multilock_vs_lockall.rs b/examples/multilock_vs_lockall.rs
new file mode 100644
index 0000000000..bf5d03714a
--- /dev/null
+++ b/examples/multilock_vs_lockall.rs
@@ -0,0 +1,91 @@
+//! examples/mutlilock_vs_lockall.rs
+
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+use panic_semihosting as _;
+
+#[rtic::app(device = lm3s6965, dispatchers = [GPIOA])]
+mod app {
+    use cortex_m_semihosting::{debug, hprintln};
+
+    #[shared]
+    struct Shared {
+        shared1: u32,
+        shared2: u32,
+        shared3: u32,
+    }
+
+    #[local]
+    struct Local {}
+
+    #[init]
+    fn init(_: init::Context) -> (Shared, Local, init::Monotonics) {
+        locks::spawn().unwrap();
+
+        (
+            Shared {
+                shared1: 0,
+                shared2: 0,
+                shared3: 0,
+            },
+            Local {},
+            init::Monotonics(),
+        )
+    }
+
+    // when omitted priority is assumed to be `1`
+    #[task(shared = [shared1, shared2, shared3])]
+    fn locks(mut c: locks::Context) {
+        // lock-all structure
+        c.shared.lock(|s| {
+            *s.shared1 += 1;
+            *s.shared2 += 2;
+            *s.shared3 += 3;
+            hprintln!(
+                "Multiple locks, s1: {}, s2: {}, s3: {}",
+                s.shared1,
+                s.shared2,
+                s.shared3
+            )
+            .ok();
+        });
+
+        // lock-all destructure
+        c.shared.lock(
+            |locks::Shared {
+                 shared1,
+                 shared2,
+                 shared3,
+             }| {
+                **shared1 += 1;
+                **shared2 += 2;
+                **shared3 += 3;
+                hprintln!(
+                    "Multiple locks, s1: {}, s2: {}, s3: {}",
+                    shared1,
+                    shared2,
+                    shared3
+                )
+                .ok();
+            },
+        );
+
+        // nested multi-lock
+        let s1 = c.shared.shared1;
+        let s2 = c.shared.shared2;
+        let s3 = c.shared.shared3;
+
+        (s1, s2, s3).lock(|s1, s2, s3| {
+            *s1 += 1;
+            *s2 += 2;
+            *s3 += 3;
+
+            hprintln!("Multiple locks, s1: {}, s2: {}, s3: {}", s1, s2, s3).ok();
+        });
+
+        debug::exit(debug::EXIT_SUCCESS); // Exit QEMU simulator
+    }
+}