doc: fix README

Author: thinkgos

README.md

@@ -39,7 +39,126 @@ Then import the package into your own code.
 - [repetition](./_examples/repetition/main.go)
 - [sample](./_examples/sample/main.go)
 
-use global `timer` instance.
+#### monitor
+
+[embedmd]:# (_examples/monitor/main.go go)
+```go
+package main
+
+import (
+	"log"
+	"math"
+	"math/rand/v2"
+	"net/http"
+	"sync/atomic"
+	"time"
+
+	_ "net/http/pprof"
+
+	"github.com/thinkgos/timer"
+)
+
+// almost 1,000,000 task
+func main() {
+	go func() {
+		sum := &atomic.Int64{}
+		t := time.NewTicker(time.Second)
+		for {
+			<-t.C
+			added := 0
+			ranv := rand.IntN(10)
+			max := int(rand.Uint32N(math.MaxUint16 << 2))
+			for i := 100; i < max; i += 200 {
+				added++
+				ii := i + ranv
+
+				timer.Go(func() {
+					sum.Add(1)
+					delayms := int64(ii) * 20
+					task := timer.NewTask(time.Duration(delayms) * time.Millisecond).WithJob(&job{
+						sum:          sum,
+						expirationMs: time.Now().UnixMilli() + delayms,
+					})
+					timer.AddTask(task)
+
+					// for test race
+					// if ii%0x03 == 0x00 {
+					// 	timer.Go(func() {
+					// 		task.Cancel()
+					// 	})
+					// }
+				})
+			}
+			log.Printf("task: %v - %v added: %d", timer.TaskCounter(), sum.Load(), added)
+		}
+	}()
+
+	addr := ":9990"
+	log.Printf("http stated '%v'\n", addr)
+	log.Println(http.ListenAndServe(addr, nil))
+}
+
+type job struct {
+	sum          *atomic.Int64
+	expirationMs int64
+}
+
+func (j *job) Run() {
+	j.sum.Add(-1)
+	now := time.Now().UnixMilli()
+	if diff := now - j.expirationMs; diff > 1 {
+		log.Printf("this task no equal, diff: %d %d %d\n", now, j.expirationMs, diff)
+	}
+}
+```
+
+#### repetition
+
+[embedmd]:# (_examples/repetition/main.go go)
+```go
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/thinkgos/timer"
+)
+
+// one or two second delay repetition example
+func main() {
+	job := NewRepetitionJob()
+	_ = timer.AddDerefTask(job)
+	select {}
+}
+
+type RepetitionJob struct {
+	task *timer.Task
+	i    int
+}
+
+var _ timer.TaskContainer = (*RepetitionJob)(nil)
+
+func NewRepetitionJob() *RepetitionJob {
+	j := &RepetitionJob{
+		task: timer.NewTask(time.Second),
+		i:    1,
+	}
+	j.task.WithJob(j)
+	return j
+}
+
+func (j *RepetitionJob) Run() {
+	now := time.Now().String()
+	j.i++
+	_ = timer.AddTask(j.task.SetDelay(time.Second * time.Duration((j.i%2 + 1))))
+	fmt.Printf("%s: repetition executed,\n", now)
+}
+
+func (j *RepetitionJob) DerefTask() *timer.Task { return j.task }
+```
+
+#### sample
 
 [embedmd]:# (_examples/sample/main.go go)
 ```go
@@ -67,6 +186,8 @@ func main() {
 }
 ```
 
+
+
 ## How it works
 
 - [How it works](./how_it_works.md)