From: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Date: Wed, 17 Aug 2022 07:34:46 +0000 (+0700)
Subject: runtime: convert mSpanStateBox.s to atomic type
X-Git-Tag: go1.20rc1~1595
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=014f0e8205aa5d88a0dc1be75ec09a18132b216c;p=gostls13.git

runtime: convert mSpanStateBox.s to atomic type

Updates #53821

Change-Id: I02f31a7a8295deb3e840565412abf10ff776c2c3
Reviewed-on: https://go-review.googlesource.com/c/go/+/424395
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Keith Randall <khr@google.com>
---

diff --git a/src/runtime/mheap.go b/src/runtime/mheap.go
index 12307594f0..00d445c1fa 100644
--- a/src/runtime/mheap.go
+++ b/src/runtime/mheap.go
@@ -363,19 +363,19 @@ var mSpanStateNames = []string{
 	"mSpanFree",
 }
 
-// mSpanStateBox holds an mSpanState and provides atomic operations on
-// it. This is a separate type to disallow accidental comparison or
-// assignment with mSpanState.
+// mSpanStateBox holds an atomic.Uint8 to provide atomic operations on
+// an mSpanState. This is a separate type to disallow accidental comparison
+// or assignment with mSpanState.
 type mSpanStateBox struct {
-	s mSpanState
+	s atomic.Uint8
 }
 
 func (b *mSpanStateBox) set(s mSpanState) {
-	atomic.Store8((*uint8)(&b.s), uint8(s))
+	b.s.Store(uint8(s))
 }
 
 func (b *mSpanStateBox) get() mSpanState {
-	return mSpanState(atomic.Load8((*uint8)(&b.s)))
+	return mSpanState(b.s.Load())
 }
 
 // mSpanList heads a linked list of spans.