result_pool_test.go

Documentation: github.com/sourcegraph/conc/pool

     1  package pool
     2  
     3  import (
     4  	"fmt"
     5  	"sort"
     6  	"strconv"
     7  	"sync/atomic"
     8  	"testing"
     9  	"time"
    10  
    11  	"github.com/stretchr/testify/require"
    12  )
    13  
    14  func ExampleResultPool() {
    15  	p := NewWithResults[int]()
    16  	for i := 0; i < 10; i++ {
    17  		i := i
    18  		p.Go(func() int {
    19  			return i * 2
    20  		})
    21  	}
    22  	res := p.Wait()
    23  	// Result order is nondeterministic, so sort them first
    24  	sort.Ints(res)
    25  	fmt.Println(res)
    26  
    27  	// Output:
    28  	// [0 2 4 6 8 10 12 14 16 18]
    29  }
    30  
    31  func TestResultGroup(t *testing.T) {
    32  	t.Parallel()
    33  
    34  	t.Run("panics on configuration after init", func(t *testing.T) {
    35  		t.Run("before wait", func(t *testing.T) {
    36  			t.Parallel()
    37  			g := NewWithResults[int]()
    38  			g.Go(func() int { return 0 })
    39  			require.Panics(t, func() { g.WithMaxGoroutines(10) })
    40  		})
    41  
    42  		t.Run("after wait", func(t *testing.T) {
    43  			t.Parallel()
    44  			g := NewWithResults[int]()
    45  			g.Go(func() int { return 0 })
    46  			require.Panics(t, func() { g.WithMaxGoroutines(10) })
    47  		})
    48  	})
    49  
    50  	t.Run("basic", func(t *testing.T) {
    51  		t.Parallel()
    52  		g := NewWithResults[int]()
    53  		expected := []int{}
    54  		for i := 0; i < 100; i++ {
    55  			i := i
    56  			expected = append(expected, i)
    57  			g.Go(func() int {
    58  				return i
    59  			})
    60  		}
    61  		res := g.Wait()
    62  		sort.Ints(res)
    63  		require.Equal(t, expected, res)
    64  	})
    65  
    66  	t.Run("limit", func(t *testing.T) {
    67  		t.Parallel()
    68  		for _, maxGoroutines := range []int{1, 10, 100} {
    69  			t.Run(strconv.Itoa(maxGoroutines), func(t *testing.T) {
    70  				g := NewWithResults[int]().WithMaxGoroutines(maxGoroutines)
    71  
    72  				var currentConcurrent atomic.Int64
    73  				var errCount atomic.Int64
    74  				taskCount := maxGoroutines * 10
    75  				expected := make([]int, taskCount)
    76  				for i := 0; i < taskCount; i++ {
    77  					i := i
    78  					expected[i] = i
    79  					g.Go(func() int {
    80  						cur := currentConcurrent.Add(1)
    81  						if cur > int64(maxGoroutines) {
    82  							errCount.Add(1)
    83  						}
    84  						time.Sleep(time.Millisecond)
    85  						currentConcurrent.Add(-1)
    86  						return i
    87  					})
    88  				}
    89  				res := g.Wait()
    90  				sort.Ints(res)
    91  				require.Equal(t, expected, res)
    92  				require.Equal(t, int64(0), errCount.Load())
    93  				require.Equal(t, int64(0), currentConcurrent.Load())
    94  			})
    95  		}
    96  	})
    97  }
    98
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