The memory lock module, also known as the dynamic mutex lock module, supports dynamically generating mutex locks based on given key names, ensuring concurrency safety and supporting the Try*Lock feature.

In scenarios where a large number of dynamic mutex locks are maintained, please manually call the Remove method to delete mutex lock objects that are no longer in use.

Usage:

import "github.com/gogf/gf/v2/os/gmlock"

Usage scenarios: Scenarios that require dynamic creation of mutex locks, or need to maintain a large number of dynamic locks;

Interface documentation:

https://pkg.go.dev/github.com/gogf/gf/v2/os/gmlock

func Lock(key string)
func LockFunc(key string, f func())
func RLock(key string)
func RLockFunc(key string, f func())
func RUnlock(key string)
func Remove(key string)
func TryLock(key string) bool
func TryLockFunc(key string, f func()) bool
func TryRLock(key string) bool
func TryRLockFunc(key string, f func()) bool
func Unlock(key string)
type Locker
    func New() *Locker
    func (l *Locker) Clear()
    func (l *Locker) Lock(key string)
    func (l *Locker) LockFunc(key string, f func())
    func (l *Locker) RLock(key string)
    func (l *Locker) RLockFunc(key string, f func())
    func (l *Locker) RUnlock(key string)
    func (l *Locker) Remove(key string)
    func (l *Locker) TryLock(key string) bool
    func (l *Locker) TryLockFunc(key string, f func()) bool
    func (l *Locker) TryRLock(key string) bool
    func (l *Locker) TryRLockFunc(key string, f func()) bool
    func (l *Locker) Unlock(key string)

Example 1: Basic Usage

package main

import (
    "time"
    "sync"
    "github.com/gogf/gf/v2/os/glog"
    "github.com/gogf/gf/v2/os/gmlock"
)

func main() {
    key := "lock"
    wg  := sync.WaitGroup{}
    for i := 0; i < 10; i++ {
        wg.Add(1)
        go func(i int) {
            gmlock.Lock(key)
            glog.Println(i)
            time.Sleep(time.Second)
            gmlock.Unlock(key)
            wg.Done()
        }(i)
    }
    wg.Wait()
}

In this example, it simulates opening 10 goroutines simultaneously, but at any one time only one goroutine can acquire the lock. The goroutine with the lock will execute for 1 second before exiting, allowing other goroutines to acquire the lock.

After execution, the output is:

2018-10-15 23:57:28.295 9
2018-10-15 23:57:29.296 0
2018-10-15 23:57:30.296 1
2018-10-15 23:57:31.296 2
2018-10-15 23:57:32.296 3
2018-10-15 23:57:33.297 4
2018-10-15 23:57:34.297 5
2018-10-15 23:57:35.297 6
2018-10-15 23:57:36.298 7
2018-10-15 23:57:37.298 8

Example 2: TryLock Non-blocking Lock

The TryLock method returns a value, indicating whether the lock was successfully acquired. If successful, it returns true; if the lock is already acquired by another goroutine, it returns false.

package main

import (
    "sync"
    "github.com/gogf/gf/v2/os/glog"
    "time"
    "github.com/gogf/gf/v2/os/gmlock"
)

func main() {
    key := "lock"
    wg  := sync.WaitGroup{}
    for i := 0; i < 10; i++ {
        wg.Add(1)
        go func(i int) {
            if gmlock.TryLock(key) {
                glog.Println(i)
                time.Sleep(time.Second)
                gmlock.Unlock(key)
            } else {
                glog.Println(false)
            }
            wg.Done()
        }(i)
    }
    wg.Wait()
}

Similarly, in this example, only 1 goroutine can acquire the lock at the same time, and other goroutines will exit immediately if TryLock fails.

After execution, the output is:

2018-10-16 00:01:59.172 9
2018-10-16 00:01:59.172 false
2018-10-16 00:01:59.172 false
2018-10-16 00:01:59.172 false
2018-10-16 00:01:59.172 false
2018-10-16 00:01:59.172 false
2018-10-16 00:01:59.172 false
2018-10-16 00:01:59.172 false
2018-10-16 00:01:59.172 false
2018-10-16 00:01:59.176 false