bugfix 修复周期性定时器不准的问题

Author: guonaihong

time_wheel.go

@@ -114,7 +114,6 @@ func (t *timeWheel) add(node *timeNode, jiffies uint64) *timeNode {
 				break
 			}
 		}
-		//fmt.Printf("idx:%d i:%p\n", idx, head)
 	}
 
 	if head == nil {
@@ -202,18 +201,18 @@ func (t *timeWheel) moveAndExec() {
 		// return
 	}
 
-	//如果本层的盘子没有定时器，这时候和上层的盘子移动一些过来
+	//如果本层的盘子没有定时器，这时候从上层的盘子移动一些过来
 	index := t.jiffies & nearMask
 	if index == 0 {
 		for i := 0; i <= 3; i++ {
 			index2 := t.index(i)
+			t.cascade(i, int(index2))
 			if index2 != 0 {
-				t.cascade(i, int(index2))
 				break
 			}
 		}
 	}
-	
+
 	atomic.AddUint64(&t.jiffies, 1)
 
 	t.t1[index].Lock()
@@ -228,8 +227,7 @@ func (t *timeWheel) moveAndExec() {
 	atomic.AddUint64(&t1.version, 1)
 	t.t1[index].Unlock()
 
-	// 执行
-
+	// 执行,链表中的定时器
 	offset := unsafe.Offsetof(head.Head)
 
 	head.ForEachSafe(func(pos *list.Head) {
@@ -244,7 +242,10 @@ func (t *timeWheel) moveAndExec() {
 
 		if val.isSchedule {
 			jiffies := t.jiffies
-			val.expire = uint64(getExpire(val.userExpire, jiffies))
+			// 这里的jiffies必须要减去1
+			// 当前的callback被调用，已经包含一个时间片,如果不把这个时间片减去，
+			// 每次多一个时间片，就变成累加器, 最后周期定时器慢慢会变得不准
+			val.expire = uint64(getExpire(val.userExpire, jiffies-1))
 			t.add(val, jiffies)
 		}
 	})

time_wheel_test.go

@@ -1,7 +1,9 @@
 package timer
 
 import (
+	"context"
 	"math"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -24,6 +26,7 @@ func Test_GenVersion(t *testing.T) {
 	assert.Equal(t, genVersionHeight(1, 64), uint64(0x0001004000000000))
 }
 
+// 测试1小时
 func Test_hour(t *testing.T) {
 	tw := newTimeWheel()
 
@@ -48,3 +51,109 @@ func Test_hour(t *testing.T) {
 	}
 	assert.True(t, *testHour)
 }
+
+// 测试周期性定时器, 5s
+func Test_ScheduleFunc_5s(t *testing.T) {
+	tw := newTimeWheel()
+
+	var first5 int32
+	ctx, cancel := context.WithCancel(context.Background())
+
+	const total = int32(1000)
+
+	testTime := time.Second * 5
+
+	tw.ScheduleFunc(testTime, func() {
+		atomic.AddInt32(&first5, 1)
+		if atomic.LoadInt32(&first5) == total {
+			cancel()
+		}
+
+	})
+
+	expire := getExpire(testTime*time.Duration(total), 0)
+	for i := 0; i <= int(expire)+10; i++ {
+		get10Ms := func() time.Duration {
+			return tw.curTimePoint + 1
+		}
+		tw.run(get10Ms)
+	}
+
+	select {
+	case <-ctx.Done():
+	case <-time.After(time.Second / 100):
+	}
+
+	assert.Equal(t, total, first5)
+
+}
+
+// 测试周期性定时器, 1hour
+func Test_ScheduleFunc_hour(t *testing.T) {
+	tw := newTimeWheel()
+
+	var first5 int32
+	ctx, cancel := context.WithCancel(context.Background())
+
+	const total = int32(100)
+	testTime := time.Hour
+
+	tw.ScheduleFunc(testTime, func() {
+		atomic.AddInt32(&first5, 1)
+		if atomic.LoadInt32(&first5) == total {
+			cancel()
+		}
+
+	})
+
+	expire := getExpire(testTime*time.Duration(total), 0)
+	for i := 0; i <= int(expire)+10; i++ {
+		get10Ms := func() time.Duration {
+			return tw.curTimePoint + 1
+		}
+		tw.run(get10Ms)
+	}
+
+	select {
+	case <-ctx.Done():
+	case <-time.After(time.Second / 100):
+	}
+
+	assert.Equal(t, total, first5)
+
+}
+
+// 测试周期性定时器, 1day
+func Test_ScheduleFunc_day(t *testing.T) {
+	tw := newTimeWheel()
+
+	var first5 int32
+	ctx, cancel := context.WithCancel(context.Background())
+
+	const total = int32(10)
+	testTime := time.Hour * 24
+
+	tw.ScheduleFunc(testTime, func() {
+		atomic.AddInt32(&first5, 1)
+		if atomic.LoadInt32(&first5) == total {
+			cancel()
+		}
+
+	})
+
+	expire := getExpire(testTime*time.Duration(total), 0)
+	for i := 0; i <= int(expire)+10; i++ {
+		get10Ms := func() time.Duration {
+			return tw.curTimePoint + 1
+		}
+		tw.run(get10Ms)
+	}
+
+	select {
+	case <-ctx.Done():
+	case <-time.After(time.Second / 100):
+	}
+
+	assert.Equal(t, total, first5)
+
+}