Golang Concurrency Manager 
Golang Concurrency Manager package limits the number of goroutines that are allowed to run concurrently.
Installation
Run the following command to install this package:
$ go get -u github.com/zenthangplus/goccm
Example
package main
import (
"fmt"
"goccm"
"time"
)
func main() {
// Limit 3 goroutines to run concurrently.
c := goccm.New(3)
for i := 1; i <= 10; i++ {
// This function have to call before any goroutine
c.Wait()
go func(i int) {
fmt.Printf("Job %d is running\n", i)
time.Sleep(2 * time.Second)
// This function have to when a goroutine has finished
// Or you can use `defer c.Done()` at the top of goroutine.
c.Done()
}(i)
}
// This function have to call to ensure all goroutines have finished
// after close the main program.
c.WaitAllDone()
}
List of supported functions
package main
import "goccm"
func main() {
// Create the concurrency manager
// The first argument is the maximum number of goroutines to run concurrently.
c := goccm.New(10)
// Wait until a slot is available for the new goroutine.
c.Wait()
// Mark a goroutine as finished
c.Done()
// Wait for all goroutines are done
c.WaitAllDone()
// Close the manager manually
c.Close()
// Returns the number of goroutines which are running
c.RunningCount()
}
