github.com/m3db/m3@v1.5.0/src/query/util/execution/parallel_test.go (about)

     1  // Copyright (c) 2018 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package execution
    22  
    23  import (
    24  	"context"
    25  	"fmt"
    26  	"testing"
    27  
    28  	"github.com/fortytw2/leaktest"
    29  	"github.com/stretchr/testify/assert"
    30  	"github.com/stretchr/testify/require"
    31  )
    32  
    33  type request struct {
    34  	order     int
    35  	processed bool
    36  	err       error
    37  	wait      <-chan bool
    38  	ack       chan<- bool
    39  }
    40  
    41  func (f *request) Process(ctx context.Context) error {
    42  	defer func() {
    43  		if f.ack != nil {
    44  			f.ack <- true
    45  		}
    46  	}()
    47  
    48  	if f.err != nil {
    49  		return f.err
    50  	}
    51  
    52  	if f.wait != nil {
    53  		<-f.wait
    54  	}
    55  
    56  	select {
    57  	case <-ctx.Done():
    58  		return ctx.Err()
    59  	default:
    60  		f.processed = true
    61  		return nil
    62  	}
    63  }
    64  
    65  func (f *request) String() string {
    66  	return fmt.Sprintf("%v %v %v", f.order, f.processed, f.err)
    67  }
    68  
    69  func TestOrderedParallel(t *testing.T) {
    70  	requests := make([]Request, 3)
    71  	signalChan := make(chan bool)
    72  	requests[0] = &request{order: 0, wait: signalChan}
    73  	requests[1] = &request{order: 1, ack: signalChan}
    74  	requests[2] = &request{order: 2}
    75  
    76  	err := ExecuteParallel(context.Background(), requests)
    77  	require.NoError(t, err, "no error during parallel execute")
    78  	assert.True(t, requests[0].(*request).processed, "slowest request processed")
    79  }
    80  
    81  func TestSingleError(t *testing.T) {
    82  	defer leaktest.Check(t)()
    83  	requests := make([]Request, 3)
    84  	signalChan := make(chan bool)
    85  
    86  	var cancelErr error
    87  	requests[0] = funcRequest(func(ctx context.Context) error {
    88  		// wait for the second goroutine to finish
    89  		<-signalChan
    90  
    91  		// wait for cancellation. This will hang if there's a bug here (i.e. the context doesn't get cancelled);
    92  		// we rely on leaktest to catch that case.
    93  		<-ctx.Done()
    94  
    95  		cancelErr = ctx.Err()
    96  		return nil
    97  	})
    98  	requests[1] = &request{order: 1, err: fmt.Errorf("problem executing"), ack: signalChan}
    99  	requests[2] = &request{order: 2}
   100  
   101  	err := ExecuteParallel(context.Background(), requests)
   102  	assert.Error(t, err, "error in second request")
   103  
   104  	assert.EqualError(t, cancelErr, "context canceled",
   105  		"context should be cancelled in case of any request error")
   106  }
   107  
   108  type funcRequest func(ctx context.Context) error
   109  
   110  func (f funcRequest) Process(ctx context.Context) error {
   111  	return f(ctx)
   112  }