cyclicbarrier
CyclicBarrier is a synchronizer that allows a set of goroutines to wait for each other to reach a common execution point, also called a barrier.
Inspired by Java CyclicBarrier https://docs.oracle.com/javase/9/docs/api/java/util/concurrent/CyclicBarrier.html and C# Barrier https://msdn.microsoft.com/en-us/library/system.threading.barrier(v=vs.110).aspx
Usage
Initiate
import "github.com/marusama/cyclicbarrier"
...
b1 := cyclicbarrier.New(10) // new cyclic barrier with parties = 10
...
b2 := cyclicbarrier.NewWithAction(10, func() error { return nil }) // new cyclic barrier with parties = 10 and with defined barrier action
Await
b.Await(ctx) // await other parties
Reset
b.Reset() // reset the barrier
Simple example
// create a barrier for 10 parties with an action that increments counter
// this action will be called each time when all goroutines reach the barrier
cnt := 0
b := cyclicbarrier.NewWithAction(10, func() error {
cnt++
return nil
})
wg := sync.WaitGroup{}
for i := 0; i < 10; i++ { // create 10 goroutines (the same count as barrier parties)
wg.Add(1)
go func() {
for j := 0; j < 5; j++ {
// do some hard work 5 times
time.Sleep(100 * time.Millisecond)
err := b.Await(context.TODO()) // ..and wait for other parties on the barrier.
// Last arrived goroutine will do the barrier action
// and then pass all other goroutines to the next round
if err != nil {
panic(err)
}
}
wg.Done()
}()
}
wg.Wait()
fmt.Println(cnt) // cnt = 5, it means that the barrier was passed 5 times
For more documentation see https://godoc.org/github.com/marusama/cyclicbarrier
