Why use distributed lock?
- Some program processes/services may compete for resources, they distributed deployed in different position at many machines, ensure free from side effects such dirty read/write, we should lock those resources before make logic action.
- Some crontab task may distribute deployed, we know they will run at the same time when time reach, ensure crontab task can execute one by one, we make a task lock!
- Other Parallel security.
Some cases: 1.avoid repeated order pay in E-commerce business, we lock the order. 2.multi copy of crontab statistical task run at night, we lock task.
We are support:
- Single Mode Redis: Stand-alone Redis.
- Sentinel Mode Redis: Pseudo Cluster Redis.
Simple：
go get -v github.com/hunterhug/gorlock
Support auto keepAlive:
// LockFactory is main interface
type LockFactory interface {
SetRetryCount(c int64) LockFactory
GetRetryCount() int64
SetUnLockRetryCount(c int64) LockFactory
GetUnLockRetryCount() int64
SetKeepAlive(isKeepAlive bool) LockFactory
IsKeepAlive() bool
SetRetryMillSecondDelay(c int64) LockFactory
GetRetryMillSecondDelay() int64
SetUnLockRetryMillSecondDelay(c int64) LockFactory
GetUnLockRetryMillSecondDelay() int64
LockFactoryCore
}
// LockFactoryCore is core interface
type LockFactoryCore interface {
// Lock ,lock resource default keepAlive depend on LockFactory
Lock(ctx context.Context, resourceName string, lockMillSecond int) (lock *Lock, err error)
// LockForceKeepAlive lock resource force keepAlive
LockForceKeepAlive(ctx context.Context, resourceName string, lockMillSecond int) (lock *Lock, err error)
// LockForceNotKeepAlive lock resource force not keepAlive
LockForceNotKeepAlive(ctx context.Context, resourceName string, lockMillSecond int) (lock *Lock, err error)
// UnLock ,unlock resource
UnLock(ctx context.Context, lock *Lock) (isUnLock bool, err error)
// Done asynchronous see lock whether is release
Done(lock *Lock) chan error
}If you keepAlive the lock, you must call defer UnLock() every time you make a Lock.
package main
import (
"context"
"fmt"
"github.com/hunterhug/gorlock"
"time"
)
func main() {
gorlock.SetDebug()
// 1. config redis
redisHost := "127.0.0.1:6379"
redisDb := 0
redisPass := "hunterhug" // may redis has password
config := gorlock.NewRedisSingleModeConfig(redisHost, redisDb, redisPass)
pool, err := gorlock.NewRedisPool(config)
if err != nil {
fmt.Println("redis init err:", err.Error())
return
}
// 2. new a lock factory
lockFactory := gorlock.New(pool)
// set retry time and delay mill second
lockFactory.SetRetryCount(3).SetRetryMillSecondDelay(200)
// keep alive will auto extend the expire time of lock
lockFactory.SetKeepAlive(true)
// 3. lock a resource
resourceName := "myLock"
// 10s
expireMillSecond := 10 * 1000
lock, err := lockFactory.Lock(context.Background(), resourceName, expireMillSecond)
if err != nil {
fmt.Println("lock err:", err.Error())
return
}
// lock empty point not lock
if lock == nil {
fmt.Println("lock err:", "can not lock")
return
}
// add lock success
fmt.Printf("add lock success:%#v\n", lock)
// wait lock release
//<-lockFactory.Done(lock)
time.Sleep(3 * time.Second)
// 4. unlock a resource
isUnlock, err := lockFactory.UnLock(context.Background(), lock)
if err != nil {
fmt.Println("lock err:", err.Error())
return
}
fmt.Printf("lock unlock: %v, %#v\n", isUnlock, lock)
// unlock a resource again no effect side
isUnlock, err = lockFactory.UnLock(context.Background(), lock)
if err != nil {
fmt.Println("lock err:", err.Error())
return
}
fmt.Println("lock unlock:", isUnlock)
}Result：
add lock success:&gorlock.Lock{CreateMillSecondTime:1627543007573, LiveMillSecondTime:10001, LastKeepAliveMillSecondTime:0, UnlockMillSecondTime:0, ResourceName:"myLock", RandomKey:"a6f438bd9b1f4d759e818dbc78e890f4", IsUnlock:false, isUnlockChan:(chan struct {})(0xc00007a1e0), IsClose:false, OpenKeepAlive:true, closeChan:(chan struct {})(0xc00007a240), keepAliveDealCloseChan:(chan bool)(0xc00007a2a0), mutex:sync.Mutex{state:0, sema:0x0}}
2021-07-29 15:16:48.083 github.com/hunterhug/gorlock:(*redisLockFactory).keepAlive [DEBUG]: start in 2021-07-29 15:16:48.079402 +0800 CST m=+0.518137615 keepAlive myLock with random key:a6f438bd9b1f4d759e818dbc78e890f4 doing
2021-07-29 15:16:48.586 github.com/hunterhug/gorlock:(*redisLockFactory).keepAlive [DEBUG]: start in 2021-07-29 15:16:48.583449 +0800 CST m=+1.022178426 keepAlive myLock with random key:a6f438bd9b1f4d759e818dbc78e890f4 doing
2021-07-29 15:16:49.090 github.com/hunterhug/gorlock:(*redisLockFactory).keepAlive [DEBUG]: start in 2021-07-29 15:16:49.087154 +0800 CST m=+1.525877218 keepAlive myLock with random key:a6f438bd9b1f4d759e818dbc78e890f4 doing
2021-07-29 15:16:49.594 github.com/hunterhug/gorlock:(*redisLockFactory).keepAlive [DEBUG]: start in 2021-07-29 15:16:49.590883 +0800 CST m=+2.029599435 keepAlive myLock with random key:a6f438bd9b1f4d759e818dbc78e890f4 doing
2021-07-29 15:16:50.097 github.com/hunterhug/gorlock:(*redisLockFactory).keepAlive [DEBUG]: start in 2021-07-29 15:16:50.094998 +0800 CST m=+2.533708261 keepAlive myLock with random key:a6f438bd9b1f4d759e818dbc78e890f4 doing
2021-07-29 15:16:50.575 github.com/hunterhug/gorlock:(*redisLockFactory).UnLock [DEBUG]: UnLock send signal to keepAlive ask game over
2021-07-29 15:16:50.575 github.com/hunterhug/gorlock:(*redisLockFactory).keepAlive [DEBUG]: start in 2021-07-29 15:16:50.575115 +0800 CST m=+3.013818937 keepAlive myLock with random key:a6f438bd9b1f4d759e818dbc78e890f4 close
2021-07-29 15:16:50.575 github.com/hunterhug/gorlock:(*redisLockFactory).UnLock [DEBUG]: UnLock receive signal to keepAlive response keepAliveHasBeenClose=false
lock unlock: true, &gorlock.Lock{CreateMillSecondTime:1627543007573, LiveMillSecondTime:10001, LastKeepAliveMillSecondTime:1627543010097, UnlockMillSecondTime:1627543010575, ResourceName:"myLock", RandomKey:"a6f438bd9b1f4d759e818dbc78e890f4", IsUnlock:true, isUnlockChan:(chan struct {})(0xc00007a1e0), IsClose:true, OpenKeepAlive:true, closeChan:(chan struct {})(0xc00007a240), keepAliveDealCloseChan:(chan bool)(0xc00007a2a0), mutex:sync.Mutex{state:0, sema:0x0}}
lock unlock: true
Copyright [2019-2021] [github.com/hunterhug]
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.