forked from aws/amazon-ecs-agent
/
ticker.go
52 lines (45 loc) · 1.31 KB
/
ticker.go
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// Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License"). You may
// not use this file except in compliance with the License. A copy of the
// License is located at
//
// http://aws.amazon.com/apache2.0/
//
// or in the "license" file accompanying this file. This file is distributed
// on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
// express or implied. See the License for the specific language governing
// permissions and limitations under the License.
package utils
import (
"context"
"math/rand"
"time"
)
// NewJitteredTicker works like a time.Ticker except with randomly distributed ticks
// between start and end duration.
func NewJitteredTicker(ctx context.Context, start, end time.Duration) <-chan time.Time {
ticker := make(chan time.Time, 1)
go func() {
defer close(ticker)
for {
select {
case <-ctx.Done():
return
default:
time.Sleep(randomDuration(start, end))
sendNow(ticker)
}
}
}()
return ticker
}
func randomDuration(start, end time.Duration) time.Duration {
return time.Duration(start.Nanoseconds()+rand.Int63n(end.Nanoseconds()-start.Nanoseconds())) * time.Nanosecond
}
func sendNow(ticker chan<- time.Time) {
select {
case ticker <- time.Now():
default:
}
}