semaphore

Documentation

Index

• type Semaphore
  • func New(permits int) *Semaphore
  • func (s *Semaphore) Acquire()
  • func (s *Semaphore) AcquireContext(ctx context.Context, n int) bool
  • func (s *Semaphore) AcquireMany(n int)
  • func (s *Semaphore) AcquireWithin(n int, d time.Duration) bool
  • func (s *Semaphore) AvailablePermits() int
  • func (s *Semaphore) DrainPermits() int
  • func (s *Semaphore) Release()
  • func (s *Semaphore) ReleaseMany(n int)

Types

type Semaphore

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

Semaphore is an implementation of semaphore.

func New

func New(permits int) *Semaphore

New creates a new Semaphore with specified number of permits.

func (*Semaphore) Acquire

func (s *Semaphore) Acquire()

Acquire acquires one permit. If it is not available, the goroutine will block until it is available.

func (*Semaphore) AcquireContext

func (s *Semaphore) AcquireContext(ctx context.Context, n int) bool

AcquireContext is similar to AcquireMany() but takes a context. Returns true if successful or false if the context is done first.

func (*Semaphore) AcquireMany

func (s *Semaphore) AcquireMany(n int)

AcquireMany is similar to Acquire() but for many permits.

The number of permits acquired is at most the number of permits in the semaphore. i.e. if n = 5 and s was created with New(2), at most 2 permits will be acquired.

func (*Semaphore) AcquireWithin

func (s *Semaphore) AcquireWithin(n int, d time.Duration) bool

AcquireWithin is similar to AcquireMany() but cancels if duration elapses before getting the permits. Returns true if successful and false if timeout occurs.

func (*Semaphore) AvailablePermits

func (s *Semaphore) AvailablePermits() int

AvailablePermits gives number of available unacquired permits.

func (*Semaphore) DrainPermits

func (s *Semaphore) DrainPermits() int

DrainPermits acquires all available permits and return the number of permits acquired.

func (*Semaphore) Release

func (s *Semaphore) Release()

Release releases one permit.

func (*Semaphore) ReleaseMany

func (s *Semaphore) ReleaseMany(n int)

ReleaseMany releases n permits.

The number of permits released is at most the number of permits in the semaphore. i.e. if n = 5 and s was created with New(2), at most 2 permits will be released.