github.com/bytedance/gopkg@v0.0.0-20240514070511-01b2cbcf35e1/util/gctuner/finalizer_test.go (about)

     1  // Copyright 2022 ByteDance 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 gctuner
    16  
    17  import (
    18  	"runtime"
    19  	"runtime/debug"
    20  	"sync/atomic"
    21  	"testing"
    22  
    23  	"github.com/stretchr/testify/assert"
    24  )
    25  
    26  func TestFinalizer(t *testing.T) {
    27  	// disable gc
    28  	debug.SetGCPercent(-1)
    29  	defer debug.SetGCPercent(100)
    30  
    31  	maxCount := int32(16)
    32  	is := assert.New(t)
    33  	var count int32
    34  	f := newFinalizer(func() {
    35  		n := atomic.AddInt32(&count, 1)
    36  		if n > maxCount {
    37  			t.Fatalf("cannot exec finalizer callback after f has been gc")
    38  		}
    39  	})
    40  	for atomic.LoadInt32(&count) < maxCount {
    41  		runtime.GC()
    42  	}
    43  	is.Nil(f.ref)
    44  	f.stop()
    45  	// when f stopped, finalizer callback will not be called
    46  	lastCount := atomic.LoadInt32(&count)
    47  	for i := 0; i < 10; i++ {
    48  		runtime.GC()
    49  		is.Equal(lastCount, atomic.LoadInt32(&count))
    50  	}
    51  }