finalizer_test.go

     1  // Copyright 2012 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package race_test
     6  
     7  import (
     8  	"runtime"
     9  	"sync"
    10  	"testing"
    11  	"time"
    12  	"unsafe"
    13  )
    14  
    15  func TestNoRaceFin(t *testing.T) {
    16  	c := make(chan bool)
    17  	go func() {
    18  		x := new(string)
    19  		runtime.SetFinalizer(x, func(x *string) {
    20  			*x = "foo"
    21  		})
    22  		*x = "bar"
    23  		c <- true
    24  	}()
    25  	<-c
    26  	runtime.GC()
    27  	time.Sleep(100 * time.Millisecond)
    28  }
    29  
    30  var finVar struct {
    31  	sync.Mutex
    32  	cnt int
    33  }
    34  
    35  func TestNoRaceFinGlobal(t *testing.T) {
    36  	c := make(chan bool)
    37  	go func() {
    38  		x := new(string)
    39  		runtime.SetFinalizer(x, func(x *string) {
    40  			finVar.Lock()
    41  			finVar.cnt++
    42  			finVar.Unlock()
    43  		})
    44  		c <- true
    45  	}()
    46  	<-c
    47  	runtime.GC()
    48  	time.Sleep(100 * time.Millisecond)
    49  	finVar.Lock()
    50  	finVar.cnt++
    51  	finVar.Unlock()
    52  }
    53  
    54  func TestRaceFin(t *testing.T) {
    55  	c := make(chan bool)
    56  	y := 0
    57  	_ = y
    58  	go func() {
    59  		x := new(string)
    60  		runtime.SetFinalizer(x, func(x *string) {
    61  			y = 42
    62  		})
    63  		c <- true
    64  	}()
    65  	<-c
    66  	runtime.GC()
    67  	time.Sleep(100 * time.Millisecond)
    68  	y = 66
    69  }
    70  
    71  func TestNoRaceCleanup(t *testing.T) {
    72  	c := make(chan bool)
    73  	go func() {
    74  		x := new(string)
    75  		y := new(string)
    76  		runtime.AddCleanup(x, func(y *string) {
    77  			*y = "foo"
    78  		}, y)
    79  		*y = "bar"
    80  		runtime.KeepAlive(x)
    81  		c <- true
    82  	}()
    83  	<-c
    84  	runtime.GC()
    85  	time.Sleep(100 * time.Millisecond)
    86  }
    87  
    88  func TestRaceBetweenCleanups(t *testing.T) {
    89  	// Allocate struct with pointer to avoid hitting tinyalloc.
    90  	// Otherwise we can't be sure when the allocation will
    91  	// be freed.
    92  	type T struct {
    93  		v int
    94  		p unsafe.Pointer
    95  	}
    96  	sharedVar := new(int)
    97  	v0 := new(T)
    98  	v1 := new(T)
    99  	cleanup := func(x int) {
   100  		*sharedVar = x
   101  	}
   102  	runtime.AddCleanup(v0, cleanup, 0)
   103  	runtime.AddCleanup(v1, cleanup, 0)
   104  	v0 = nil
   105  	v1 = nil
   106  
   107  	runtime.GC()
   108  	time.Sleep(100 * time.Millisecond)
   109  }
   110
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