go/src/cmd/vendor/golang.org/x/sync/semaphore/semaphore.go

type waiter …

// NewWeighted creates a new weighted semaphore with the given
// maximum combined weight for concurrent access.
func NewWeighted(n int64) *Weighted { … }

type Weighted …

// Acquire acquires the semaphore with a weight of n, blocking until resources
// are available or ctx is done. On success, returns nil. On failure, returns
// ctx.Err() and leaves the semaphore unchanged.
func (s *Weighted) Acquire(ctx context.Context, n int64) error { … }

// TryAcquire acquires the semaphore with a weight of n without blocking.
// On success, returns true. On failure, returns false and leaves the semaphore unchanged.
func (s *Weighted) TryAcquire(n int64) bool { … }

// Release releases the semaphore with a weight of n.
func (s *Weighted) Release(n int64) { … }

func (s *Weighted) notifyWaiters() { … }