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# SizedWaitGroup
[](https://godoc.org/github.com/remeh/sizedwaitgroup)
`SizedWaitGroup` has the same role and API as `sync.WaitGroup` but it adds a limit of the amount of goroutines started concurrently.
`SizedWaitGroup` adds the feature of limiting the maximum number of concurrently started routines. It could for example be used to start multiples routines querying a database but without sending too much queries in order to not overload the given database.
# Example
```
package main
import (
"fmt"
"math/rand"
"time"
"github.com/remeh/sizedwaitgroup"
)
func main() {
rand.Seed(time.Now().UnixNano())
// Typical use-case:
// 50 queries must be executed as quick as possible
// but without overloading the database, so only
// 8 routines should be started concurrently.
swg := sizedwaitgroup.New(8)
for i := 0; i < 50; i++ {
swg.Add()
go func(i int) {
defer swg.Done()
query(i)
}(i)
}
swg.Wait()
}
func query(i int) {
fmt.Println(i)
ms := i + 500 + rand.Intn(500)
time.Sleep(time.Duration(ms) * time.Millisecond)
}
```
# License
MIT
# Copyright
Rémy Mathieu © 2016
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