From e8eca4be37a2fe1af25b203ace5e99b31fcc3972 Mon Sep 17 00:00:00 2001
From: Emil Fresk <emil.fresk@gmail.com>
Date: Thu, 22 Oct 2020 21:36:32 +0200
Subject: Now all locks are symmetric

Test fixes

Fix test

Fix comment
---
 examples/big-struct-opt.rs | 48 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 examples/big-struct-opt.rs

(limited to 'examples/big-struct-opt.rs')

diff --git a/examples/big-struct-opt.rs b/examples/big-struct-opt.rs
new file mode 100644
index 00000000..85ec5e61
--- /dev/null
+++ b/examples/big-struct-opt.rs
@@ -0,0 +1,48 @@
+//! examples/big-struct-opt.rs
+//!
+//! Example on how to initialize a large struct without needing to copy it via `LateResources`,
+//! effectively saving stack space needed for the copies.
+
+#![no_main]
+#![no_std]
+
+use panic_halt as _;
+
+/// Some big struct
+pub struct BigStruct {
+    /// Big content
+    pub data: [u8; 2048],
+}
+
+impl BigStruct {
+    fn new() -> Self {
+        BigStruct { data: [22; 2048] }
+    }
+}
+
+#[rtic::app(device = lm3s6965)]
+mod app {
+    use super::BigStruct;
+    use core::mem::MaybeUninit;
+
+    #[resources]
+    struct Resources {
+        big_struct: &'static mut BigStruct,
+    }
+
+    #[init]
+    fn init(_: init::Context) -> init::LateResources {
+        let big_struct = unsafe {
+            static mut BIG_STRUCT: MaybeUninit<BigStruct> = MaybeUninit::uninit();
+
+            // write directly into the static storage
+            BIG_STRUCT.as_mut_ptr().write(BigStruct::new());
+            &mut *BIG_STRUCT.as_mut_ptr()
+        };
+
+        init::LateResources {
+            // assign the reference so we can use the resource
+            big_struct,
+        }
+    }
+}
-- 
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