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- // Copyright (c) 2017 Uber Technologies, Inc.
- //
- // Licensed under the Apache License, Version 2.0 (the "License");
- // you may not use this file except in compliance with the License.
- // You may obtain a copy of the License at
- //
- // http://www.apache.org/licenses/LICENSE-2.0
- //
- // Unless required by applicable law or agreed to in writing, software
- // distributed under the License 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 (
- "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()
- }
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