fix semaphore pattern

This commit is contained in:
Edward 2020-05-21 17:45:23 +08:00
parent 6ec8f1ebb5
commit 3877727a5c

View File

@ -5,23 +5,24 @@ import (
"time"
)
//error info
var (
ErrNoTickets = errors.New("semaphore: could not aquire semaphore")
ErrIllegalRelease = errors.New("semaphore: can't release the semaphore without acquiring it first")
ErrNoTickets = errors.New("could not acquire semaphore")
ErrIllegalRelease = errors.New("can't release the semaphore without acquiring it first")
)
// Interface contains the behavior of a semaphore that can be acquired and/or released.
type Interface interface {
// ISemaphore contains the behavior of a semaphore that can be acquired and/or released.
type ISemaphore interface {
Acquire() error
Release() error
}
type implementation struct {
type semp struct {
sem chan struct{}
timeout time.Duration
}
func (s *implementation) Acquire() error {
func (s *semp) Acquire() error {
select {
case s.sem <- struct{}{}:
return nil
@ -30,19 +31,19 @@ func (s *implementation) Acquire() error {
}
}
func (s *implementation) Release() error {
func (s *semp) Release() error {
select {
case _ = <-s.sem:
case <-s.sem:
return nil
case <-time.After(s.timeout):
return ErrIllegalRelease
}
return nil
}
func New(tickets int, timeout time.Duration) Interface {
return &implementation{
//New return a new Semaphore
func New(tickets int, timeout time.Duration) ISemaphore {
return &semp{
sem: make(chan struct{}, tickets),
timeout: timeout,
}