std panicking: ALWAYS_ABORT: use Relaxed memory ordering

ijackson · ijackson · commit 45803ca143e2 · 2021-05-07T11:17:44.000+01:00
As per rust-lang#81858 (comment) Suggested-by: Mara Bos <m-ou.se@m-ou.se> Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
diff --git a/std/src/panicking.rs b/std/src/panicking.rs
@@ -259,7 +259,7 @@ pub mod panic_count {
 
     pub fn increase() -> (bool, usize) {
         (
-            GLOBAL_PANIC_COUNT.fetch_add(1, Ordering::Acquire) & ALWAYS_ABORT_FLAG != 0,
+            GLOBAL_PANIC_COUNT.fetch_add(1, Ordering::Relaxed) & ALWAYS_ABORT_FLAG != 0,
             LOCAL_PANIC_COUNT.with(|c| {
                 let next = c.get() + 1;
                 c.set(next);
@@ -278,7 +278,7 @@ pub mod panic_count {
     }
 
     pub fn set_always_abort() {
-        GLOBAL_PANIC_COUNT.fetch_or(ALWAYS_ABORT_FLAG, Ordering::Release);
+        GLOBAL_PANIC_COUNT.fetch_or(ALWAYS_ABORT_FLAG, Ordering::Relaxed);
     }
 
     // Disregards ALWAYS_ABORT_FLAG

Original file line number	Diff line number	Diff line change
`@@ -259,7 +259,7 @@ pub mod panic_count {`
`259`	`259`
`260`	`260`	`pub fn increase() -> (bool, usize) {`
`261`	`261`	`(`
`262`		`- GLOBAL_PANIC_COUNT.fetch_add(1, Ordering::Acquire) & ALWAYS_ABORT_FLAG != 0,`
	`262`	`+ GLOBAL_PANIC_COUNT.fetch_add(1, Ordering::Relaxed) & ALWAYS_ABORT_FLAG != 0,`
`263`	`263`	`LOCAL_PANIC_COUNT.with(\|c\| {`
`264`	`264`	`let next = c.get() + 1;`
`265`	`265`	`c.set(next);`
`@@ -278,7 +278,7 @@ pub mod panic_count {`
`278`	`278`	`}`
`279`	`279`
`280`	`280`	`pub fn set_always_abort() {`
`281`		`- GLOBAL_PANIC_COUNT.fetch_or(ALWAYS_ABORT_FLAG, Ordering::Release);`
	`281`	`+ GLOBAL_PANIC_COUNT.fetch_or(ALWAYS_ABORT_FLAG, Ordering::Relaxed);`
`282`	`282`	`}`
`283`	`283`
`284`	`284`	`// Disregards ALWAYS_ABORT_FLAG`