unsafe_pointer_test.go raw

   1  // Copyright (c) 2021 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 atomic
  22  
  23  import (
  24  	"testing"
  25  	"unsafe"
  26  
  27  	"github.com/stretchr/testify/require"
  28  )
  29  
  30  func TestUnsafePointer(t *testing.T) {
  31  	i := int64(42)
  32  	j := int64(0)
  33  	k := int64(1)
  34  
  35  	tests := []struct {
  36  		desc      string
  37  		newAtomic func() *UnsafePointer
  38  		initial   unsafe.Pointer
  39  	}{
  40  		{
  41  			desc: "non-empty",
  42  			newAtomic: func() *UnsafePointer {
  43  				return NewUnsafePointer(unsafe.Pointer(&i))
  44  			},
  45  			initial: unsafe.Pointer(&i),
  46  		},
  47  		{
  48  			desc: "nil",
  49  			newAtomic: func() *UnsafePointer {
  50  				var p UnsafePointer
  51  				return &p
  52  			},
  53  			initial: unsafe.Pointer(nil),
  54  		},
  55  	}
  56  
  57  	for _, tt := range tests {
  58  		t.Run(tt.desc, func(t *testing.T) {
  59  			t.Run("Load", func(t *testing.T) {
  60  				atom := tt.newAtomic()
  61  				require.Equal(t, tt.initial, atom.Load(), "Load should report nil.")
  62  			})
  63  
  64  			t.Run("Swap", func(t *testing.T) {
  65  				atom := tt.newAtomic()
  66  				require.Equal(t, tt.initial, atom.Swap(unsafe.Pointer(&k)), "Swap didn't return the old value.")
  67  				require.Equal(t, unsafe.Pointer(&k), atom.Load(), "Swap didn't set the correct value.")
  68  			})
  69  
  70  			t.Run("CAS", func(t *testing.T) {
  71  				atom := tt.newAtomic()
  72  				require.True(t, atom.CAS(tt.initial, unsafe.Pointer(&j)), "CAS didn't report a swap.")
  73  				require.Equal(t, unsafe.Pointer(&j), atom.Load(), "CAS didn't set the correct value.")
  74  			})
  75  
  76  			t.Run("Store", func(t *testing.T) {
  77  				atom := tt.newAtomic()
  78  				atom.Store(unsafe.Pointer(&i))
  79  				require.Equal(t, unsafe.Pointer(&i), atom.Load(), "Store didn't set the correct value.")
  80  			})
  81  		})
  82  	}
  83  }
  84