From 7a2a5279164ee7fae1711635802207569ae0a74f Mon Sep 17 00:00:00 2001
From: Simon Renblad <srenblad@m-labs.hk>
Date: Fri, 18 Oct 2024 18:07:07 +0800
Subject: [PATCH] cleaning up RTIO_DEVICE_MAP

---
 src/libksupport/src/lib.rs | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/src/libksupport/src/lib.rs b/src/libksupport/src/lib.rs
index 7f978d4..a3e972f 100644
--- a/src/libksupport/src/lib.rs
+++ b/src/libksupport/src/lib.rs
@@ -35,6 +35,7 @@ pub mod rtio;
 #[rustfmt::skip]
 #[path = "../../../build/pl.rs"]
 pub mod pl;
+use core::ptr::addr_of;
 
 
 #[derive(Debug, Clone)]
@@ -115,6 +116,7 @@ pub async fn report_async_rtio_errors() {
     }
 }
 
+// use interior mutability -> no need for this to be a static mut (no volatile r/ws or FFI)
 static mut RTIO_DEVICE_MAP: BTreeMap<u32, String> = BTreeMap::new();
 
 fn read_device_map(cfg: &Config) -> BTreeMap<u32, String> {
@@ -146,15 +148,14 @@ fn read_device_map(cfg: &Config) -> BTreeMap<u32, String> {
     device_map
 }
 
-fn _resolve_channel_name(channel: u32, device_map: &BTreeMap<u32, String>) -> String {
-    match device_map.get(&channel) {
-        Some(val) => val.clone(),
-        None => String::from("unknown"),
-    }
-}
-
 pub fn resolve_channel_name(channel: u32) -> String {
-    _resolve_channel_name(channel, unsafe { &RTIO_DEVICE_MAP })
+    unsafe {
+        let ptr: *const BTreeMap<u32, String> = addr_of!(RTIO_DEVICE_MAP);
+        match ptr.as_ref().unwrap().get(&channel) {
+            Some(val) => val.clone(),
+            None => String::from("unknown"),
+        }
+    }
 }
 
 pub fn setup_device_map(cfg: &Config) {