gohive

README

gohive

Package gohive implements a simple and easy to use goroutine pool for Go

Features

• Pool can be created with a specific size as per the requirement
• Accepts tasks which implements Runner interface
• Uses channels to accepts tasks and gets them executed via workers
• Uses synchronization among workers to avoid race conditions

Installation

Use go get to install and update:

$ go get -u github.com/loveleshsharma/gohive

Usage

• Create an instance of Pool type first

hive := gohive.NewFixedPool(5)

• Invoke the Submit() function and pass the task to execute

hive.Submit(object Runner)

Submit function accepts a Runner object as an argument, which it passes to the pool if a worker is available, otherwise it will wait for the worker to be available

• To close the pool we can invoke the Close() function

hive.Close()

Once the pool is closed, we cannot assign any task to it

Example

Let's get into a full program where we can see how to use the gohive package in order to execute many goroutines simultaneously

package main

import (
   "fmt"
   "github.com/loveleshsharma/gohive"
   "sync"
)

func main() {
   var wg sync.WaitGroup
   pool := gohive.NewFixedPool(5)

   for i := 1; i <= 20; i++ {
      if err := pool.Submit(NewMyStruct(i, &wg)); err != nil {
         fmt.Println("error: ", err)
         break
      }
   }

   wg.Wait()
}

type MyStruct struct {
   num int
   wg  *sync.WaitGroup
}

func NewMyStruct(num int, wg *sync.WaitGroup) MyStruct {
   myStruct := MyStruct{
      num: num,
      wg:  wg,
   }
   wg.Add(1)
   return myStruct
}

func (s MyStruct) Run() {
   defer s.wg.Done()
   val := s.num
   fact := s.num
   for i := s.num - 1; i > 0; i-- {
      fact *= i
   }

   fmt.Printf("Factorial of %d: %d\n", val, fact)
}

Important : Always keep sync.WaitGroup in your struct and put defer wg.Done() as the first statement of your Run() function. It will wait for your task to complete.

TODO

1. Maintain a waiting queue to stop blocking submit method when all goroutines are busy.
2. Submitting priority tasks which takes priority over other tasks.
3. Handling panics inside goroutines to prevent them from crashing.
4. Implement dynamic pool which will scale the number of goroutines as per requirement and scales down when they are idle.
5. Submitting multiple tasks together.

Documentation

Index

• Constants
• type Pool
  • func NewFixedPool(size int) *Pool
  • func (p *Pool) Close() error
  • func (p *Pool) IsPoolClosed() bool
  • func (p *Pool) Submit(r Runner) error
• type Runner

Constants

const (
	OPEN = iota
	CLOSED
)

Types

type Pool

type Pool struct {
	// contains filtered or unexported fields
}

func NewFixedPool

func NewFixedPool(size int) *Pool

func (*Pool) Close

func (p *Pool) Close() error

func (*Pool) IsPoolClosed

func (p *Pool) IsPoolClosed() bool

func (*Pool) Submit

func (p *Pool) Submit(r Runner) error

type Runner

type Runner interface {
	Run()
}