go lang goroutine concurrency limiter

builds

Example

limit the number of concurrent go routines to 10:

  import "github.com/korovkin/limiter"
  ...
  limit := limiter.NewConcurrencyLimiter(10)
  defer limit.WaitAndClose()
  for i := 0; i < 1000; i++ {
    limit.Execute(func() {
      // do some work
    })
  }

Real World Example:

  import "github.com/korovkin/limiter"
  ...
  limiter := limiter.NewConcurrencyLimiter(10)
  httpGoogle := int(0)
  limiter.Execute(func() {
    resp, err := http.Get("https://www.google.com/")
    Expect(err).To(BeNil())
    defer resp.Body.Close()
    httpGoogle = resp.StatusCode
  })
  httpApple := int(0)
  limiter.Execute(func() {
    resp, err := http.Get("https://www.apple.com/")
    Expect(err).To(BeNil())
    defer resp.Body.Close()
    httpApple = resp.StatusCode
  })
  limiter.WaitAndClose()
  log.Println("httpGoogle:", httpGoogle)
  log.Println("httpApple:", httpApple)

Concurrent IO with Error tracking:

  import "github.com/korovkin/limiter"
  ...
    a := errors.New("error a")
    b := errors.New("error b")
    concurrently := limiter.NewConcurrencyLimiterForIO(limiter.DefaultConcurrencyLimitIO)
    concurrently.Execute(func() {
        // Do some really slow IO ...
        // keep the error:
        concurrently.FirstErrorStore(a)
    })
    concurrently.Execute(func() {
        // Do some really slow IO ...
        // keep the error:
        concurrently.FirstErrorStore(b)
    })
    concurrently.WaitAndClose()
    firstErr := concurrently.FirstErrorGet()
    Expect(firstErr == a || firstErr == b).To(BeTrue())