cogroup

Golang coroutine group

Package cogroup provides an elegant goroutine group with context controls. It's designed to meet the following requirements.

• Tasks can be executed without order
• Group wait command will close the write access to the task queue
• Upstream context can cancel/stop the execution of the tasks
• When the context is canceled, the tasks in queue will be no longer consumed
• Only spawn specified number of goroutines to consume the task queue
• Panic recover for a single task execution
• Custom worker with upstream context and worker id provided.
• Wait will block until tasks are finished or canceled, and return with the queue length

Usage

Start a group and wait till all the tasks are finished.

import  (
  "context"
  "time"

  "github.com/devfans/cogroup"
)

func main() {
  f := func(context.Context) error {
    <-time.After(time.Second)
    return nil
  }

  g := cogroup.Start(context.Background(), 2, 10, false)
  for i := 0; i < 10; i++ {
    g.Add(f)
  }
  g.Wait()
}

Start a group and cancel it later.

import  (
  "context"
  "time"

  "github.com/devfans/cogroup"
)

func main() {
  f := func(ctx context.Context) error {
    <-time.After(time.Second)
    workerID := cogroup.GetWorkerID(ctx)
    println(workerID, " did one task")
    return nil
  }

  ctx, cancel := context.WithCancel(context.Background())
  g := cogroup.Start(ctx, 2, 10, false)
  go func() {
    <-time.After(1 * time.Second)
    cancel()
  }()

  for i := 0; i < 100; i++ {
    g.Add(f)
  }
  println("Tasks left:", g.Wait())
}

Start a group with custom worker

import  (
  "context"
  "time"

  "github.com/devfans/cogroup"
)

func main() {
  f := func(context.Context) error {
    <-time.After(time.Second)
    return nil
  }

  g := cogroup.New(context.Background(), 2, 10, false)
  g.StartWithWorker(func(ctx context.Context, i int, f func(context.Context) error {
    println("Worker is running with id", i)
    f(ctx)
  }))
  for i := 0; i < 10; i++ {
    g.Add(f)
  }
  g.Wait()
}

Misc

Blog：https://blog.devfans.io/create-a-golang-coroutine-group/