52 lines
1.8 KiB
Go
52 lines
1.8 KiB
Go
// Copyright (c) 2016 Uber Technologies, Inc.
|
|
|
|
// Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
// of this software and associated documentation files (the "Software"), to deal
|
|
// in the Software without restriction, including without limitation the rights
|
|
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
// copies of the Software, and to permit persons to whom the Software is
|
|
// furnished to do so, subject to the following conditions:
|
|
//
|
|
// The above copyright notice and this permission notice shall be included in
|
|
// all copies or substantial portions of the Software.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
// THE SOFTWARE.
|
|
|
|
package utils
|
|
|
|
import (
|
|
"math/rand"
|
|
"sync"
|
|
)
|
|
|
|
// lockedSource allows a random number generator to be used by multiple goroutines concurrently.
|
|
// The code is very similar to math/rand.lockedSource, which is unfortunately not exposed.
|
|
type lockedSource struct {
|
|
mut sync.Mutex
|
|
src rand.Source
|
|
}
|
|
|
|
// NewRand returns a rand.Rand that is threadsafe.
|
|
func NewRand(seed int64) *rand.Rand {
|
|
return rand.New(&lockedSource{src: rand.NewSource(seed)})
|
|
}
|
|
|
|
func (r *lockedSource) Int63() (n int64) {
|
|
r.mut.Lock()
|
|
n = r.src.Int63()
|
|
r.mut.Unlock()
|
|
return
|
|
}
|
|
|
|
// Seed implements Seed() of Source
|
|
func (r *lockedSource) Seed(seed int64) {
|
|
r.mut.Lock()
|
|
r.src.Seed(seed)
|
|
r.mut.Unlock()
|
|
}
|