github.com/dolthub/dolt/go@v0.40.5-0.20240520175717-68db7794bea6/libraries/doltcore/sqle/read_replica_database_test.go (about)

     1  // Copyright 2022 Dolthub, 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  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package sqle
    16  
    17  import (
    18  	"context"
    19  	"runtime"
    20  	"sync"
    21  	"sync/atomic"
    22  	"testing"
    23  	"time"
    24  
    25  	"github.com/stretchr/testify/assert"
    26  	"golang.org/x/sync/semaphore"
    27  )
    28  
    29  func TestLimiter(t *testing.T) {
    30  	t.Run("NoConcurrency", func(t *testing.T) {
    31  		l := newLimiter()
    32  		for i := 0; i < 16; i++ {
    33  			l.Run(context.Background(), "key_one", func() (any, error) {
    34  				return 1, nil
    35  			})
    36  			l.Run(context.Background(), "key_two", func() (any, error) {
    37  				return 1, nil
    38  			})
    39  			l.Run(context.Background(), "key_three", func() (any, error) {
    40  				return 1, nil
    41  			})
    42  		}
    43  	})
    44  	t.Run("ConcurrentRuns", func(t *testing.T) {
    45  		l := newLimiter()
    46  		var wg sync.WaitGroup
    47  		sema := semaphore.NewWeighted(16)
    48  		sema.Acquire(context.Background(), 16)
    49  		var numRuns int32
    50  		v, err := l.Run(context.Background(), "one", func() (any, error) {
    51  			for i := 0; i < 16; i++ {
    52  				wg.Add(1)
    53  				go func() {
    54  					defer wg.Done()
    55  					sema.Release(1)
    56  					v, err := l.Run(context.Background(), "one", func() (any, error) {
    57  						atomic.AddInt32(&numRuns, 1)
    58  						return 2, nil
    59  					})
    60  					assert.NoError(t, err)
    61  					assert.Equal(t, 2, v)
    62  				}()
    63  			}
    64  
    65  			// TODO: This is some jank to reduce flakiness.
    66  			sema.Acquire(context.Background(), 16)
    67  			time.Sleep(10 * time.Millisecond)
    68  			for i := 0; i < 128; i++ {
    69  				runtime.Gosched()
    70  			}
    71  			time.Sleep(10 * time.Millisecond)
    72  
    73  			return 1, nil
    74  		})
    75  		assert.NoError(t, err)
    76  		assert.Equal(t, 1, v)
    77  		wg.Wait()
    78  		assert.Equal(t, int32(1), numRuns)
    79  	})
    80  }