增加立即执行的定时器示例

ticker/ticker.go

@@ -0,0 +1,43 @@
+package ticker
+
+import "time"
+
+type Ticker struct {
+	C      chan time.Time
+	ticker *time.Ticker
+	close  chan struct{}
+}
+
+func NewTicker(d time.Duration) *Ticker {
+	return &Ticker{
+		C:      make(chan time.Time, 1),
+		ticker: time.NewTicker(d),
+		close:  make(chan struct{}),
+	}
+}
+
+func (t *Ticker) Start() {
+	// 首次直接触发
+	t.C <- time.Now()
+	go func() {
+		for {
+			select {
+			case <-t.close:
+				// 关闭时停止goroutine
+				return
+			case tc := <-t.ticker.C:
+				// 把go原生定时器 push 的时间推送到我们定义的 time channel 中
+				t.C <- tc
+			}
+		}
+	}()
+}
+
+func (t *Ticker) Reset(d time.Duration) {
+	t.ticker.Reset(d)
+}
+
+func (t *Ticker) Stop() {
+	t.ticker.Stop()
+	close(t.close)
+}

ticker/ticker_test.go

@@ -0,0 +1,48 @@
+package ticker
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+	"time"
+)
+
+func TestTicker(t *testing.T) {
+	now := time.Now()
+	// 记录初始时间
+	data := []int64{
+		now.Unix(),
+	}
+	expected := []int64{
+		now.Unix(),
+	}
+
+	// 预期每隔一秒收到一个信号
+	for i := 0; i < 3; i++ {
+		expected = append(expected, now.Add(time.Duration(i)*time.Second).Unix())
+	}
+
+	done := make(chan struct{})
+	ticker := NewTicker(time.Second)
+	ticker.Start()
+
+	go func() {
+		for {
+			select {
+			case <-done:
+				return
+			case t := <-ticker.C:
+				data = append(data, t.Unix())
+			}
+		}
+	}()
+
+	go func() {
+		// 设置成3秒有时候会有误差
+		time.Sleep(2500 * time.Millisecond)
+		ticker.Stop()
+		close(done)
+	}()
+
+	time.Sleep(3 * time.Second)
+	assert.Equal(t, expected, data)
+}