[TOC] > https://mp.weixin.qq.com/s/kWpQSJNWoOqV64Ol1sIeow ## 概述 ``` // 棧元素節點 type directItem struct { next unsafe.Pointer v interface{} } // CAS 操作實現的棧 (無鎖編程) type LockFreeStack struct { // 棧元素容器用鏈表表示 top unsafe.Pointer // 棧長度 len uint64 } func NewLockFreeStack() *LockFreeStack { return &LockFreeStack{} } func (s *LockFreeStack) Push(v interface{}) { item := directItem{v: v} var top unsafe.Pointer for { top = atomic.LoadPointer(&s.top) item.next = top if atomic.CompareAndSwapPointer(&s.top, top, unsafe.Pointer(&item)) { // 只有 1 個 goroutine 可以執行到這里 // 棧元素數量 + 1 atomic.AddUint64(&s.len, 1) return } } } func (s *LockFreeStack) Pop() interface{} { var top, next unsafe.Pointer var item *directItem for { top = atomic.LoadPointer(&s.top) if top == nil { return nil } item = (*directItem)(top) next = atomic.LoadPointer(&item.next) if atomic.CompareAndSwapPointer(&s.top, top, next) { // 只有 1 個 goroutine 可以執行到這里 // 棧元素數量 - 1 atomic.AddUint64(&s.len, ^uint64(0)) return item.v } } } ```