Function NewBreaker

pkg/proxy/breaker.go:57–80

NewBreaker creates a Breaker with the desired queue depth, concurrency limit and initial capacity.

(params BreakerParams)

// NewBreaker creates a Breaker with the desired queue depth,
// concurrency limit and initial capacity.
func NewBreaker(params BreakerParams) *Breaker {
	if params.QueueDepth <= 0 {
		panic(fmt.Sprintf("Queue depth must be greater than 0. Got %v.", params.QueueDepth))
	}
	if params.MaxConcurrency < 0 {
		panic(fmt.Sprintf("Max concurrency must be 0 or greater. Got %v.", params.MaxConcurrency))
	}
	if params.InitialCapacity < 0 || params.InitialCapacity > params.MaxConcurrency {
		panic(fmt.Sprintf("Initial capacity must be between 0 and max concurrency. Got %v.", params.InitialCapacity))
	}

	b := &Breaker{
		totalSlots: int64(params.QueueDepth + params.MaxConcurrency),
		sem:        newSemaphore(params.MaxConcurrency, params.InitialCapacity),
	}

	// Allocating the closure returned by Reserve here avoids an allocation in Reserve.
	b.release = func() {
		b.sem.release()
		b.releasePending()
	}

	return b
}

// tryAcquirePending tries to acquire a slot on the pending "queue".
func (b *Breaker) tryAcquirePending() bool {