sync

Documentation

Overview

Package sync extends basic synchronization primitives.

Index

• type WaitGroup
  • func NewWaitGroup() *WaitGroup
  • func (wg *WaitGroup) Add(delta int)
  • func (wg *WaitGroup) Done()
  • func (wg *WaitGroup) Wait()

Types

type WaitGroup

type WaitGroup struct {
	// contains filtered or unexported fields
}

A WaitGroup waits for a collection of goroutines to finish. The main goroutine calls Add to set the number of goroutines to wait for. Then each of the goroutines runs and calls Done when finished. At the same time, Wait can be used to block until all goroutines have finished.

WaitGroups in the sync package do not allow adding or subtracting from the counter while another goroutine is waiting, while this one does.

A WaitGroup must not be copied after first use.

In the terminology of the Go memory model, a call to Done

func NewWaitGroup

func NewWaitGroup() *WaitGroup

NewWaitGroup creates a new WaitGroup.

func (*WaitGroup) Add

func (wg *WaitGroup) Add(delta int)

Add adds delta, which may be negative, to the WaitGroup counter. If the counter becomes zero, all goroutines blocked on Wait are released. If the counter goes negative, Add panics.

func (*WaitGroup) Done

func (wg *WaitGroup) Done()

Done decrements the WaitGroup counter by one.

func (*WaitGroup) Wait

func (wg *WaitGroup) Wait()

Wait blocks until the WaitGroup counter is zero.