github.com/letsencrypt/boulder@v0.20251208.0/grpc/internal/grpcrand/grpcrand.go (about)

     1  /*
     2   *
     3   * Copyright 2018 gRPC authors.
     4   *
     5   * Licensed under the Apache License, Version 2.0 (the "License");
     6   * you may not use this file except in compliance with the License.
     7   * You may obtain a copy of the License at
     8   *
     9   *     http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   *
    17   */
    18  
    19  // Package grpcrand implements math/rand functions in a concurrent-safe way
    20  // with a global random source, independent of math/rand's global source.
    21  package grpcrand
    22  
    23  import (
    24  	"math/rand/v2"
    25  	"sync"
    26  )
    27  
    28  var (
    29  	r  = rand.New(rand.NewPCG(rand.Uint64(), rand.Uint64()))
    30  	mu sync.Mutex
    31  )
    32  
    33  // Int implements rand.Int on the grpcrand global source.
    34  func Int() int {
    35  	mu.Lock()
    36  	defer mu.Unlock()
    37  	return r.Int()
    38  }
    39  
    40  // Int63n implements rand.Int63n on the grpcrand global source.
    41  func Int63n(n int64) int64 {
    42  	mu.Lock()
    43  	defer mu.Unlock()
    44  	return r.Int64N(n)
    45  }
    46  
    47  // Intn implements rand.Intn on the grpcrand global source.
    48  func Intn(n int) int {
    49  	mu.Lock()
    50  	defer mu.Unlock()
    51  	return r.IntN(n)
    52  }
    53  
    54  // Float64 implements rand.Float64 on the grpcrand global source.
    55  func Float64() float64 {
    56  	mu.Lock()
    57  	defer mu.Unlock()
    58  	return r.Float64()
    59  }
    60  
    61  // Uint64 implements rand.Uint64 on the grpcrand global source.
    62  func Uint64() uint64 {
    63  	mu.Lock()
    64  	defer mu.Unlock()
    65  	return r.Uint64()
    66  }