Drumline

Drumline provides a synchronization primitive for keeping multiple goroutines in lock step.

The original use case was a process that consumed a Kafka topic consisting of multiple partitions. If the goroutine processing one partition got too far ahead or behind the goroutines processing other partitions, it could cause problems if the process was disrupted and needed to be resumed later. Drumline was created to ensure that no process could get too far ahead of the others.

Example

package main

import
  (
    "fmt"
    "github.com/openrelayxyz/drumline"
  )

func main (){
  dl := drumline.NewDrumline(1)

  for i := 0 ; i < 3; i++ {
    dl.Add(1)
    go func() {
      for j := 0; j < 10; j++ {
        fmt.Printf("%v: %v", i, j)
        dl.Step(i)
      }
    }()
  }
}