From: qydysky <qydysky@foxmail.com>
Date: Thu, 27 Jul 2023 01:54:08 +0000 (+0800)
Subject: add
X-Git-Tag: v0.28.0+202307272ddbeb9
X-Git-Url: http://127.0.0.1:8081/?a=commitdiff_plain;h=2ddbeb9fb36a3be537e0df8952bf53d624446ff2;p=part%2F.git

add
---

diff --git a/sync/RWMutex.go b/sync/RWMutex.go
index f3f8b45..e2f2a93 100644
--- a/sync/RWMutex.go
+++ b/sync/RWMutex.go
@@ -93,11 +93,17 @@ func tof(to time.Duration) (inTimeCall func() (called bool)) {
 //
 // 不要在Rlock内设置变量，有DATA RACE风险
 func (m *RWMutex) RLock(to ...time.Duration) (unlockf func()) {
-	_, rlcLoop := lcas(&m.rlc, ulock, rlock)
-	if e := rlcLoop(to...); e != nil {
-		panic(e)
+	if m.read.Add(1) == 1 {
+		_, rlcLoop := cas(&m.rlc, ulock, rlock)
+		if e := rlcLoop(to...); e != nil {
+			panic(e)
+		}
+	} else {
+		_, rlcLoop := lcas(&m.rlc, ulock, rlock)
+		if e := rlcLoop(to...); e != nil {
+			panic(e)
+		}
 	}
-	m.read.Add(1)
 	var callC atomic.Bool
 	var done func() (called bool)
 	if len(to) > 1 {
diff --git a/sync/RWMutex_test.go b/sync/RWMutex_test.go
index 7f45ccd..07644f9 100644
--- a/sync/RWMutex_test.go
+++ b/sync/RWMutex_test.go
@@ -14,6 +14,18 @@ func check(l *RWMutex, r, read int32) {
 	}
 }
 
+func Test0(t *testing.T) {
+	var l RWMutex
+	ul := l.RLock()
+	go func() {
+		l.Lock()()
+	}()
+	go func() {
+		l.RLock()()
+	}()
+	ul()
+}
+
 // ulock rlock rlock
 func Test1(t *testing.T) {
 	var l RWMutex
@@ -53,7 +65,7 @@ func Test3(t *testing.T) {
 	ul := l.Lock()
 	check(&l, lock, 0)
 	time.AfterFunc(time.Second, func() {
-		check(&l, lock, 0)
+		check(&l, lock, 1)
 		ul()
 	})
 	c := time.Now()
@@ -101,25 +113,6 @@ func Panic_Test5(t *testing.T) {
 	check(&l, ulock, 0)
 }
 
-// ulock lock rlock
-func Test6(t *testing.T) {
-	var l RWMutex
-	ul := l.Lock()
-	check(&l, lock, 0)
-	time.AfterFunc(time.Second, func() {
-		check(&l, lock, 0)
-		ul()
-	})
-	c := time.Now()
-	ul1 := l.RLock()
-	check(&l, rlock, 1)
-	if time.Since(c) < time.Second {
-		t.Fail()
-	}
-	ul1()
-	check(&l, ulock, 0)
-}
-
 func BenchmarkRlock(b *testing.B) {
 	var lock1 RWMutex
 	var a bool