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- // Copyright 2018 Google LLC
- //
- // 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 testutil
-
- import (
- "math/rand"
- "sync"
- "time"
- )
-
- // NewRand creates a new *rand.Rand seeded with t. The return value is safe for use
- // with multiple goroutines.
- func NewRand(t time.Time) *rand.Rand {
- s := &lockedSource{src: rand.NewSource(t.UnixNano())}
- return rand.New(s)
- }
-
- // lockedSource makes a rand.Source safe for use by multiple goroutines.
- type lockedSource struct {
- mu sync.Mutex
- src rand.Source
- }
-
- func (ls *lockedSource) Int63() int64 {
- ls.mu.Lock()
- defer ls.mu.Unlock()
- return ls.src.Int63()
- }
-
- func (ls *lockedSource) Seed(int64) {
- panic("shouldn't be calling Seed")
- }
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