github.com/pingcap/tiflow@v0.0.0-20240520035814-5bf52d54e205/dm/pkg/checker/worker_pool_test.go (about)

     1  // Copyright 2022 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 checker
    15  
    16  import (
    17  	"context"
    18  	"errors"
    19  	"sync/atomic"
    20  	"testing"
    21  	"time"
    22  
    23  	"github.com/stretchr/testify/require"
    24  )
    25  
    26  type slowIncrementer struct {
    27  	atomic.Int64
    28  }
    29  
    30  func (i *slowIncrementer) Inc() int64 {
    31  	time.Sleep(100 * time.Millisecond)
    32  	return i.Add(1)
    33  }
    34  
    35  type job struct {
    36  	inc *slowIncrementer
    37  }
    38  
    39  type baseAdder struct {
    40  	base   int64
    41  	closed atomic.Bool
    42  }
    43  
    44  func (a *baseAdder) add(_ context.Context, j job) (int64, error) {
    45  	i := j.inc.Inc()
    46  	return a.base + i, nil
    47  }
    48  
    49  func TestExampleWorkerPool(t *testing.T) {
    50  	sum := int64(0)
    51  	concurrency := 100
    52  	jobNum := 1000
    53  	incrementer := slowIncrementer{}
    54  
    55  	pool := NewWorkerPool[job, int64](func(result int64) {
    56  		sum += result
    57  	})
    58  	for i := 0; i < concurrency; i++ {
    59  		worker := &baseAdder{base: 666}
    60  		pool.Go(worker.add)
    61  	}
    62  	for i := 0; i < jobNum; i++ {
    63  		pool.PutJob(job{inc: &incrementer})
    64  	}
    65  
    66  	err := pool.Wait()
    67  	require.NoError(t, err)
    68  	// sum 1 to 1000 = 500500
    69  	require.Equal(t, int64(666*jobNum+500500), sum)
    70  }
    71  
    72  var (
    73  	errMock = errors.New("mock error")
    74  	errorAt = int64(500)
    75  )
    76  
    77  func (a *baseAdder) addAndError(_ context.Context, j job) (int64, error) {
    78  	i := j.inc.Inc()
    79  	if i == errorAt {
    80  		if a.closed.Load() {
    81  			panic("worker is used after closed")
    82  		}
    83  		a.closed.Store(true)
    84  		return 0, errMock
    85  	}
    86  	return a.base + i, nil
    87  }
    88  
    89  func TestExampleWorkerPoolError(t *testing.T) {
    90  	sum := int64(0)
    91  	concurrency := 100
    92  	jobNum := 1000
    93  	incrementer := slowIncrementer{}
    94  
    95  	pool := NewWorkerPool[job, int64](func(result int64) {
    96  		sum += result
    97  	})
    98  	for i := 0; i < concurrency; i++ {
    99  		worker := &baseAdder{base: 666}
   100  		pool.Go(worker.addAndError)
   101  	}
   102  	for i := 0; i < jobNum; i++ {
   103  		ok := pool.PutJob(job{inc: &incrementer})
   104  		if !ok {
   105  			require.GreaterOrEqual(t, int64(i), errorAt)
   106  			break
   107  		}
   108  	}
   109  
   110  	err := pool.Wait()
   111  	require.ErrorIs(t, err, errMock)
   112  }