aws/credentials: Remove unnecessary modification of Expiry CurrentTime (

#2094)

Removes the unnecessary setting Expiry's CurrentTime member when
IsExpired method is called. This prevents the possibility of a data race
with the Expiry's IsExpired method.

aws/credentials/credentials.go

@@ -158,13 +158,14 @@ func (e *Expiry) SetExpiration(expiration time.Time, window time.Duration) {
 
 // IsExpired returns if the credentials are expired.
 func (e *Expiry) IsExpired() bool {
- if e.CurrentTime == nil {
- e.CurrentTime = time.Now
+ curTime := e.CurrentTime
+ if curTime == nil {
+ curTime = time.Now
  }
- return e.expiration.Before(e.CurrentTime())
+ return e.expiration.Before(curTime())
 }
 
-// A Credentials provides synchronous safe retrieval of AWS credentials Value.
+// A Credentials provides concurrency safe retrieval of AWS credentials Value.
 // Credentials will cache the credentials value until they expire. Once the value
 // expires the next Get will attempt to retrieve valid credentials.
 //

aws/credentials/credentials_test.go

@@ -2,6 +2,7 @@ package credentials
 
 import (
  "testing"
+ "time"
 
  "github.com/aws/aws-sdk-go/aws/awserr"
  "github.com/stretchr/testify/assert"
@@ -62,6 +63,14 @@ func TestCredentialsExpire(t *testing.T) {
  assert.True(t, c.IsExpired(), "Expected to be expired")
 }
 
+type MockProvider struct {
+ Expiry
+}
+
+func (*MockProvider) Retrieve() (Value, error) {
+ return Value{}, nil
+}
+
 func TestCredentialsGetWithProviderName(t *testing.T) {
  stub := &stubProvider{}
 
@@ -71,3 +80,20 @@ func TestCredentialsGetWithProviderName(t *testing.T) {
  assert.Nil(t, err, "Expected no error")
  assert.Equal(t, creds.ProviderName, "stubProvider", "Expected provider name to match")
 }
+
+func TestCredentialsIsExpired_Race(t *testing.T) {
+ creds := NewChainCredentials([]Provider{&MockProvider{}})
+
+ starter := make(chan struct{})
+ for i := 0; i < 10; i++ {
+ go func() {
+ <-starter
+ for {
+ creds.IsExpired()
+ }
+ }()
+ }
+ close(starter)
+
+ time.Sleep(10 * time.Second)
+}