replace lock with atomic

internal/scheduler/task.go

@@ -3,36 +3,33 @@ package scheduler
 import (
 	"context"
 	"cycle-scheduler/internal/job"
-	"sync"
 	"sync/atomic"
 	"time"
 )
 
-// safeTime wraps a `time.Timer` with a lock to be thread safe.
-type safeTimer struct {
-	l     sync.Mutex
-	timer *time.Timer
+// atomicTimer wraps a `time.Timer`.
+type atomicTimer struct {
+	atomic.Pointer[time.Timer]
 }
 
-func (st *safeTimer) stop() {
-	if st.timer != nil {
-		st.timer.Stop()
+func (at *atomicTimer) stop() {
+	timer := at.Load()
+	if timer != nil {
+		timer.Stop()
 	}
 }
 
 // set replaces the current timer.
 // It also ensures that the current timer is stopped.
-func (st *safeTimer) set(t *time.Timer) {
-	st.l.Lock()
-	defer st.l.Unlock()
-
-	if st.timer != nil {
-		st.timer.Stop()
-		st.timer = t
+func (at *atomicTimer) set(t *time.Timer) {
+	timer := at.Load()
+	if timer != nil {
+		timer.Stop()
+		at.Swap(t)
 		return
 	}
 
-	st.timer = t
+	at.Swap(t)
 }
 
 type TaskDetails struct {
@@ -43,23 +40,21 @@ type TaskDetails struct {
 type task struct {
 	*job.Job
 	attempts atomic.Uint32
-	timer    *safeTimer
+	timer    atomicTimer
 }
 
 func newTask(f job.FnJob) *task {
 	j := job.NewJob(f)
 	t := task{
 		Job:   &j,
-		timer: &safeTimer{},
+		timer: atomicTimer{},
 	}
 
 	return &t
 }
 
 func (t *task) abort() {
-	if t.timer != nil {
-		t.timer.stop()
-	}
+	t.timer.stop()
 	t.Job.Abort()
 }