溧阳网站设计,外国知名个人网站,营销型网站(易网拓),洛卡博网站谁做的1.sync.Mutex互斥锁底层实现 2.sync.RwMutex读写锁底层实现 1.sync.Mutex互斥锁底层实现 通过cas原子操作加锁#xff0c;通过信号量实现协程唤醒 锁有两种模式#xff0c;正常模式和饥饿模式 正常模式(非公平锁)#xff1a;所有阻塞在等待队列的go协程会按顺序获取锁通过信号量实现协程唤醒 锁有两种模式正常模式和饥饿模式 正常模式(非公平锁)所有阻塞在等待队列的go协程会按顺序获取锁通常新请求的go协程会更容易获取锁 饥饿模式(公平锁)新请求锁的go协程不会获取锁而是加入队列尾部阻塞等待 饥饿模式触发条件当一个go协程等待锁的时间超过1ms 2.sync.RwMutex读写锁底层实现 支持并发读读锁不阻塞读阻塞写 写锁 会阻塞读和写 适合读多写少 type Mutex struct {state int32 // cas加锁sema uint32 // 信号量实现协程阻塞和唤醒 } const (mutexLocked 1 iota // mutex is lockedmutexWokenmutexStarvingmutexWaiterShift iota ) func (m *Mutex) Lock() {// Fast path: grab unlocked mutex.if atomic.CompareAndSwapInt32(m.state, 0, mutexLocked) {if race.Enabled {race.Acquire(unsafe.Pointer(m))}return}// Slow path (outlined so that the fast path can be inlined)m.lockSlow() }type RWMutex struct {w Mutex // held if there are pending writerswriterSem uint32 // semaphore for writers to wait for completing readersreaderSem uint32 // semaphore for readers to wait for completing writersreaderCount int32 // number of pending readersreaderWait int32 // number of departing readers }