expvar: add locking to String, and use RWMutex properly throughout.
R=bradfitz
CC=golang-dev
https://golang.org/cl/5754043
diff --git a/src/pkg/expvar/expvar.go b/src/pkg/expvar/expvar.go
index af5ce61..b065995 100644
--- a/src/pkg/expvar/expvar.go
+++ b/src/pkg/expvar/expvar.go
@@ -41,12 +41,12 @@
// Int is a 64-bit integer variable that satisfies the Var interface.
type Int struct {
i int64
- mu sync.Mutex
+ mu sync.RWMutex
}
func (v *Int) String() string {
- v.mu.Lock()
- defer v.mu.Unlock()
+ v.mu.RLock()
+ defer v.mu.RUnlock()
return strconv.FormatInt(v.i, 10)
}
@@ -65,12 +65,12 @@
// Float is a 64-bit float variable that satisfies the Var interface.
type Float struct {
f float64
- mu sync.Mutex
+ mu sync.RWMutex
}
func (v *Float) String() string {
- v.mu.Lock()
- defer v.mu.Unlock()
+ v.mu.RLock()
+ defer v.mu.RUnlock()
return strconv.FormatFloat(v.f, 'g', -1, 64)
}
@@ -188,12 +188,21 @@
// String is a string variable, and satisfies the Var interface.
type String struct {
- s string
+ s string
+ mu sync.RWMutex
}
-func (v *String) String() string { return strconv.Quote(v.s) }
+func (v *String) String() string {
+ v.mu.RLock()
+ defer v.mu.RUnlock()
+ return strconv.Quote(v.s)
+}
-func (v *String) Set(value string) { v.s = value }
+func (v *String) Set(value string) {
+ v.mu.Lock()
+ defer v.mu.Unlock()
+ v.s = value
+}
// Func implements Var by calling the function
// and formatting the returned value using JSON.
