1505d282ac
* Regenerate code to update copyright end year to 2023 * Test behaviour of default values initialized in different ways This adds repro tests for #126 and #129 * Fix Swap and CompareAndSwap for Value wrappers Fixes #126, #129 All atomic types can be used without initialization, e.g., `var v <AtomicType>`. This works fine for integer types as the initialized value of 0 matches the default value for the user-facing type. However, for Value wrappers, they are initialized to `nil`, which is a value that can't be set (triggers a panic) so the default value for the user-facing type is forced to be stored as a different value. This leads to multiple possible values representing the default user-facing type. E.g., an `atomic.String` with value `""` may be represented by the underlying atomic as either `nil`, or `""`. This causes issues when we don't handle the `nil` value correctly, causing to panics in `Swap` and incorrectly not swapping values in `CompareAndSwap`. This change fixes the above issues by: * Requiring `pack` and `unpack` function in gen-atomicwrapper as the only place we weren't supplying them was for `String`, and the branching adds unnecessary complexity, especially with added `nil` handling. * Extending `CompareAndSwap` for `Value` wrappers to try an additional `CompareAndSwap(nil, <new>)` only if the original `CompareAndSwap` fails and the old value is the zero value.
110 lines
3.1 KiB
Go
110 lines
3.1 KiB
Go
// @generated Code generated by gen-atomicint.
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// Copyright (c) 2020-2023 Uber Technologies, Inc.
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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package atomic
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import (
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"encoding/json"
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"strconv"
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"sync/atomic"
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)
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// Int64 is an atomic wrapper around int64.
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type Int64 struct {
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_ nocmp // disallow non-atomic comparison
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v int64
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}
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// NewInt64 creates a new Int64.
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func NewInt64(val int64) *Int64 {
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return &Int64{v: val}
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}
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// Load atomically loads the wrapped value.
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func (i *Int64) Load() int64 {
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return atomic.LoadInt64(&i.v)
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}
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// Add atomically adds to the wrapped int64 and returns the new value.
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func (i *Int64) Add(delta int64) int64 {
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return atomic.AddInt64(&i.v, delta)
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}
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// Sub atomically subtracts from the wrapped int64 and returns the new value.
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func (i *Int64) Sub(delta int64) int64 {
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return atomic.AddInt64(&i.v, -delta)
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}
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// Inc atomically increments the wrapped int64 and returns the new value.
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func (i *Int64) Inc() int64 {
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return i.Add(1)
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}
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// Dec atomically decrements the wrapped int64 and returns the new value.
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func (i *Int64) Dec() int64 {
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return i.Sub(1)
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}
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// CAS is an atomic compare-and-swap.
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//
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// Deprecated: Use CompareAndSwap.
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func (i *Int64) CAS(old, new int64) (swapped bool) {
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return i.CompareAndSwap(old, new)
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}
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// CompareAndSwap is an atomic compare-and-swap.
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func (i *Int64) CompareAndSwap(old, new int64) (swapped bool) {
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return atomic.CompareAndSwapInt64(&i.v, old, new)
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}
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// Store atomically stores the passed value.
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func (i *Int64) Store(val int64) {
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atomic.StoreInt64(&i.v, val)
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}
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// Swap atomically swaps the wrapped int64 and returns the old value.
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func (i *Int64) Swap(val int64) (old int64) {
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return atomic.SwapInt64(&i.v, val)
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}
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// MarshalJSON encodes the wrapped int64 into JSON.
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func (i *Int64) MarshalJSON() ([]byte, error) {
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return json.Marshal(i.Load())
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}
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// UnmarshalJSON decodes JSON into the wrapped int64.
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func (i *Int64) UnmarshalJSON(b []byte) error {
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var v int64
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if err := json.Unmarshal(b, &v); err != nil {
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return err
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}
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i.Store(v)
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return nil
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}
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// String encodes the wrapped value as a string.
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func (i *Int64) String() string {
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v := i.Load()
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return strconv.FormatInt(int64(v), 10)
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}
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