增加获取当前锁状态方法

redisLock/redis.go

@@ -5,6 +5,8 @@ import (
 	"log"
 	"time"
 
+	"github.com/google/uuid"
+
 	"github.com/go-redis/redis/v8"
 )
 
@@ -22,8 +24,8 @@ type RedisLock struct {
 	kvt             redisCommInfo
 }
 
-func CreateRedisLock(c *redis.Client, ctx context.Context, k, v string, ttl int) *RedisLock {
+func CreateRedisLock(c *redis.Client, ctx context.Context, k string, ttl int) *RedisLock {
-	return &RedisLock{c, ctx, make(chan struct{}, 1), make(chan struct{}), redisCommInfo{k, v, ttl}}
+	return &RedisLock{c, ctx, make(chan struct{}, 1), make(chan struct{}), redisCommInfo{k, uuid.New().String(), ttl}}
 }
 
 func (r *RedisLock) Lock() {
@@ -82,6 +84,10 @@ func (r *RedisLock) Unlock() {
 	}
 }
 
+func (r *RedisLock) IsHeld() bool {
+	return r.client.HExists(r.ctx, r.kvt.key, r.kvt.value).Val()
+}
+
 func (r *RedisLock) autoReNewExpire() {
 	defer func() {
 		<-r.lockKeepAliveCh

worker/rpc.go

@@ -3,6 +3,7 @@ package worker
 import (
 	"context"
 	"errors"
+	"fmt"
 	"goRedisDLM/engine"
 	"goRedisDLM/redisLock"
 	"log"
@@ -11,7 +12,6 @@ import (
 	"time"
 
 	"github.com/go-redis/redis/v8"
-	"github.com/google/uuid"
 )
 
 type Inventory struct {
@@ -19,13 +19,9 @@ type Inventory struct {
 }
 
 func (i *Inventory) Work(request engine.Request, response *engine.Response) error {
-	value := uuid.New()
-
-	//log.Printf("uuid: %s, lock key: %s\n", value.String(), request.Dlock)
-
 	ctx := context.Background()
 
-	lock := redisLock.CreateRedisLock(i.Client, ctx, request.Dlock, value.String(), 100)
+	lock := redisLock.CreateRedisLock(i.Client, ctx, request.Dlock, 100)
 	lock.Lock()
 
 	time.Sleep(time.Duration(rand.Int31n(100)) * time.Millisecond)
@@ -41,16 +37,22 @@ func (i *Inventory) Work(request engine.Request, response *engine.Response) erro
 	if inventory >= 0 {
 		//这里应该使用lua脚本，再检测一下当前是否获取到锁，获取到之后再进行扣减。类似双检加锁的思想，因为此时可能会续期失败。
 		//i.Client.Set(ctx, "inventory", fmt.Sprintf("%d", inventory), redis.KeepTTL)
-		script := `if redis.call('hexists',KEYS[1],ARGV[1]) == 1 then return redis.call('set',KEYS[2],ARGV[2])
+		//script := `if redis.call('hexists',KEYS[1],ARGV[1]) == 1 then return redis.call('set',KEYS[2],ARGV[2])
-					else return 0 end`
+		//			else return 0 end`
-
+		//
-		val := i.Client.Eval(ctx, script, []string{request.Dlock, "inventory"}, value.String(), inventory).Val()
+		//val := i.Client.Eval(ctx, script, []string{request.Dlock, "inventory"}, value.String(), inventory).Val()
-		if res, ok := val.(string); ok && res == "OK" {
 
+		if lock.IsHeld() {
+			setString := fmt.Sprintf("%d", inventory)
+			if i.Client.Set(ctx, "inventory", setString, redis.KeepTTL).Val() != "OK" {
+				log.Println("error set inventory")
+				err = errors.New("inventory err")
+				goto Error
+			}
 		} else {
 			//任务执行失败需要通知调用者，让调用者自己决策是否需要重新调度还是放弃，这样worker和主线程实现了解偶
-			log.Println("error set inventory")
+			log.Println("error lock is not held")
-			err = errors.New("inventory err")
+			err = errors.New("error lock is not held")
 			goto Error
 		}
 	} else {