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| 1 | +// Copyright (c) 2023 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 pool_test |
| 22 | + |
| 23 | +import ( |
| 24 | + "runtime/debug" |
| 25 | + "sync" |
| 26 | + "testing" |
| 27 | + |
| 28 | + "github.com/go-faster/sdk/internal/pool" |
| 29 | + "github.com/stretchr/testify/require" |
| 30 | +) |
| 31 | + |
| 32 | +type pooledValue[T any] struct { |
| 33 | + value T |
| 34 | +} |
| 35 | + |
| 36 | +func TestNew(t *testing.T) { |
| 37 | + // Disable GC to avoid the victim cache during the test. |
| 38 | + defer debug.SetGCPercent(debug.SetGCPercent(-1)) |
| 39 | + |
| 40 | + p := pool.New(func() *pooledValue[string] { |
| 41 | + return &pooledValue[string]{ |
| 42 | + value: "new", |
| 43 | + } |
| 44 | + }) |
| 45 | + |
| 46 | + // Probabilistically, 75% of sync.Pool.Put calls will succeed when -race |
| 47 | + // is enabled (see ref below); attempt to make this quasi-deterministic by |
| 48 | + // brute force (i.e., put significantly more objects in the pool than we |
| 49 | + // will need for the test) in order to avoid testing without race enabled. |
| 50 | + // |
| 51 | + // ref: https://cs.opensource.google/go/go/+/refs/tags/go1.20.2:src/sync/pool.go;l=100-103 |
| 52 | + for i := 0; i < 1_000; i++ { |
| 53 | + p.Put(&pooledValue[string]{ |
| 54 | + value: t.Name(), |
| 55 | + }) |
| 56 | + } |
| 57 | + |
| 58 | + // Ensure that we always get the expected value. Note that this must only |
| 59 | + // run a fraction of the number of times that Put is called above. |
| 60 | + for i := 0; i < 10; i++ { |
| 61 | + func() { |
| 62 | + x := p.Get() |
| 63 | + defer p.Put(x) |
| 64 | + require.Equal(t, t.Name(), x.value) |
| 65 | + }() |
| 66 | + } |
| 67 | + |
| 68 | + // Depool all objects that might be in the pool to ensure that it's empty. |
| 69 | + for i := 0; i < 1_000; i++ { |
| 70 | + p.Get() |
| 71 | + } |
| 72 | + |
| 73 | + // Now that the pool is empty, it should use the value specified in the |
| 74 | + // underlying sync.Pool.New func. |
| 75 | + require.Equal(t, "new", p.Get().value) |
| 76 | +} |
| 77 | + |
| 78 | +func TestNew_Race(t *testing.T) { |
| 79 | + p := pool.New(func() *pooledValue[int] { |
| 80 | + return &pooledValue[int]{ |
| 81 | + value: -1, |
| 82 | + } |
| 83 | + }) |
| 84 | + |
| 85 | + var wg sync.WaitGroup |
| 86 | + defer wg.Wait() |
| 87 | + |
| 88 | + // Run a number of goroutines that read and write pool object fields to |
| 89 | + // tease out races. |
| 90 | + for i := 0; i < 1_000; i++ { |
| 91 | + i := i |
| 92 | + |
| 93 | + wg.Add(1) |
| 94 | + go func() { |
| 95 | + defer wg.Done() |
| 96 | + |
| 97 | + x := p.Get() |
| 98 | + defer p.Put(x) |
| 99 | + |
| 100 | + // Must both read and write the field. |
| 101 | + if n := x.value; n >= -1 { |
| 102 | + x.value = i |
| 103 | + } |
| 104 | + }() |
| 105 | + } |
| 106 | +} |
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