From: cuiweixie <cuiweixie@gmail.com>
Date: Fri, 26 Aug 2022 03:16:52 +0000 (+0800)
Subject: runtime: convert sig.{state,delivering} to atomic type
X-Git-Tag: go1.20rc1~1328
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=d01200e772902ef8178af767a62a059bf340df31;p=gostls13.git

runtime: convert sig.{state,delivering} to atomic type

For #53821

Change-Id: I1c8df255ce9e2345d4fa45bd4d1761b73b9fa064
Reviewed-on: https://go-review.googlesource.com/c/go/+/425780
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
---

diff --git a/src/runtime/sigqueue.go b/src/runtime/sigqueue.go
index 49502cbed3..51e424d55b 100644
--- a/src/runtime/sigqueue.go
+++ b/src/runtime/sigqueue.go
@@ -54,8 +54,8 @@ var sig struct {
 	wanted     [(_NSIG + 31) / 32]uint32
 	ignored    [(_NSIG + 31) / 32]uint32
 	recv       [(_NSIG + 31) / 32]uint32
-	state      uint32
-	delivering uint32
+	state      atomic.Uint32
+	delivering atomic.Uint32
 	inuse      bool
 }
 
@@ -74,11 +74,11 @@ func sigsend(s uint32) bool {
 		return false
 	}
 
-	atomic.Xadd(&sig.delivering, 1)
+	sig.delivering.Add(1)
 	// We are running in the signal handler; defer is not available.
 
 	if w := atomic.Load(&sig.wanted[s/32]); w&bit == 0 {
-		atomic.Xadd(&sig.delivering, -1)
+		sig.delivering.Add(-1)
 		return false
 	}
 
@@ -86,7 +86,7 @@ func sigsend(s uint32) bool {
 	for {
 		mask := sig.mask[s/32]
 		if mask&bit != 0 {
-			atomic.Xadd(&sig.delivering, -1)
+			sig.delivering.Add(-1)
 			return true // signal already in queue
 		}
 		if atomic.Cas(&sig.mask[s/32], mask, mask|bit) {
@@ -97,18 +97,18 @@ func sigsend(s uint32) bool {
 	// Notify receiver that queue has new bit.
 Send:
 	for {
-		switch atomic.Load(&sig.state) {
+		switch sig.state.Load() {
 		default:
 			throw("sigsend: inconsistent state")
 		case sigIdle:
-			if atomic.Cas(&sig.state, sigIdle, sigSending) {
+			if sig.state.CompareAndSwap(sigIdle, sigSending) {
 				break Send
 			}
 		case sigSending:
 			// notification already pending
 			break Send
 		case sigReceiving:
-			if atomic.Cas(&sig.state, sigReceiving, sigIdle) {
+			if sig.state.CompareAndSwap(sigReceiving, sigIdle) {
 				if GOOS == "darwin" || GOOS == "ios" {
 					sigNoteWakeup(&sig.note)
 					break Send
@@ -119,7 +119,7 @@ Send:
 		}
 	}
 
-	atomic.Xadd(&sig.delivering, -1)
+	sig.delivering.Add(-1)
 	return true
 }
 
@@ -140,11 +140,11 @@ func signal_recv() uint32 {
 		// Wait for updates to be available from signal sender.
 	Receive:
 		for {
-			switch atomic.Load(&sig.state) {
+			switch sig.state.Load() {
 			default:
 				throw("signal_recv: inconsistent state")
 			case sigIdle:
-				if atomic.Cas(&sig.state, sigIdle, sigReceiving) {
+				if sig.state.CompareAndSwap(sigIdle, sigReceiving) {
 					if GOOS == "darwin" || GOOS == "ios" {
 						sigNoteSleep(&sig.note)
 						break Receive
@@ -154,7 +154,7 @@ func signal_recv() uint32 {
 					break Receive
 				}
 			case sigSending:
-				if atomic.Cas(&sig.state, sigSending, sigIdle) {
+				if sig.state.CompareAndSwap(sigSending, sigIdle) {
 					break Receive
 				}
 			}
@@ -182,14 +182,14 @@ func signalWaitUntilIdle() {
 	// a signal, has read from sig.wanted, is now updating sig.mask,
 	// and has not yet woken up the processor thread. We need to wait
 	// until all current signal deliveries have completed.
-	for atomic.Load(&sig.delivering) != 0 {
+	for sig.delivering.Load() != 0 {
 		Gosched()
 	}
 
 	// Although WaitUntilIdle seems like the right name for this
 	// function, the state we are looking for is sigReceiving, not
 	// sigIdle.  The sigIdle state is really more like sigProcessing.
-	for atomic.Load(&sig.state) != sigReceiving {
+	for sig.state.Load() != sigReceiving {
 		Gosched()
 	}
 }