github.com/pingcap/tiflow@v0.0.0-20240520035814-5bf52d54e205/pkg/util/atomic_test.go (about)

     1  // Copyright 2024 PingCAP, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package util
    15  
    16  import (
    17  	"context"
    18  	"math/rand"
    19  	"sync"
    20  	"sync/atomic"
    21  	"testing"
    22  
    23  	"github.com/stretchr/testify/require"
    24  )
    25  
    26  func TestMustCompareAndIncrease(t *testing.T) {
    27  	t.Parallel()
    28  
    29  	var target atomic.Int64
    30  	target.Store(10)
    31  
    32  	ctx, cancel := context.WithCancel(context.Background())
    33  	wg := sync.WaitGroup{}
    34  
    35  	doIncrease := func() {
    36  		for {
    37  			select {
    38  			case <-ctx.Done():
    39  				return
    40  			default:
    41  				delta := rand.Int63n(100)
    42  				v := target.Load() + delta
    43  				MustCompareAndMonotonicIncrease(&target, v)
    44  				require.GreaterOrEqual(t, target.Load(), v)
    45  			}
    46  		}
    47  	}
    48  
    49  	// Test target increase.
    50  	wg.Add(2)
    51  	go func() {
    52  		defer wg.Done()
    53  		doIncrease()
    54  	}()
    55  	go func() {
    56  		defer wg.Done()
    57  		doIncrease()
    58  	}()
    59  
    60  	wg.Add(1)
    61  	// Test target never decrease.
    62  	go func() {
    63  		defer wg.Done()
    64  		for {
    65  			select {
    66  			case <-ctx.Done():
    67  				return
    68  			default:
    69  				v := target.Load() - 1
    70  				MustCompareAndMonotonicIncrease(&target, v)
    71  				require.Greater(t, target.Load(), v)
    72  			}
    73  		}
    74  	}()
    75  
    76  	cancel()
    77  	wg.Wait()
    78  }
    79  
    80  func TestCompareAndIncrease(t *testing.T) {
    81  	t.Parallel()
    82  
    83  	var target atomic.Int64
    84  	target.Store(10)
    85  	require.True(t, CompareAndIncrease(&target, 10))
    86  	require.Equal(t, int64(10), target.Load())
    87  
    88  	require.True(t, CompareAndIncrease(&target, 20))
    89  	require.Equal(t, int64(20), target.Load())
    90  	require.False(t, CompareAndIncrease(&target, 19))
    91  	require.Equal(t, int64(20), target.Load())
    92  }
    93  
    94  func TestCompareAndMonotonicIncrease(t *testing.T) {
    95  	t.Parallel()
    96  
    97  	var target atomic.Int64
    98  	target.Store(10)
    99  	require.False(t, CompareAndMonotonicIncrease(&target, 10))
   100  	require.Equal(t, int64(10), target.Load())
   101  
   102  	require.True(t, CompareAndMonotonicIncrease(&target, 11))
   103  	require.Equal(t, int64(11), target.Load())
   104  	require.False(t, CompareAndMonotonicIncrease(&target, 10))
   105  	require.Equal(t, int64(11), target.Load())
   106  }