Remove mutex from local Clock instances

They will only be used in tests, but it doesn't play
nice with copy operations many tests use. The linter was
not happy. While the global clock needs mutexes for parallelism,
local Clocks only used it for Set/Add and didn't even use the
mutex for actual time functions.

pkg/apis/sessions/session_state.go

@@ -4,13 +4,14 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"io"
+	"io/ioutil"
+	"time"
+
 	"github.com/oauth2-proxy/oauth2-proxy/v7/pkg/clock"
 	"github.com/oauth2-proxy/oauth2-proxy/v7/pkg/encryption"
 	"github.com/pierrec/lz4"
 	"github.com/vmihailenco/msgpack/v4"
-	"io"
-	"io/ioutil"
-	"time"
 )
 
 // SessionState is used to store information about the currently authenticated user session
@@ -29,6 +30,7 @@ type SessionState struct {
 	Groups            []string `msgpack:"g,omitempty"`
 	PreferredUsername string   `msgpack:"pu,omitempty"`
 
+	// Internal helpers, not serialized
 	Clock clock.Clock `msgpack:"-"`
 	Lock  Lock        `msgpack:"-"`
 }

pkg/clock/clock.go

@@ -63,13 +63,10 @@ func Reset() *clockapi.Mock {
 // package.
 type Clock struct {
 	mock *clockapi.Mock
-	sync.Mutex
 }
 
 // Set sets the Clock to a clock.Mock at the given time.Time
 func (c *Clock) Set(t time.Time) {
-	c.Lock()
-	defer c.Unlock()
 	if c.mock == nil {
 		c.mock = clockapi.NewMock()
 	}
@@ -79,8 +76,6 @@ func (c *Clock) Set(t time.Time) {
 // Add moves clock forward time.Duration if it is mocked. It will error
 // if the clock is not mocked.
 func (c *Clock) Add(d time.Duration) error {
-	c.Lock()
-	defer c.Unlock()
 	if c.mock == nil {
 		return errors.New("clock not mocked")
 	}
@@ -91,8 +86,6 @@ func (c *Clock) Add(d time.Duration) error {
 // Reset removes local clock.Mock.  Returns any existing Mock if set in case
 // lingering time operations are attached to it.
 func (c *Clock) Reset() *clockapi.Mock {
-	c.Lock()
-	defer c.Unlock()
 	existing := c.mock
 	c.mock = nil
 	return existing