unsafe_pointer_test.go

Documentation: go.uber.org/atomic

     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
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