forked from mirror/abool
69 lines
1.5 KiB
Go
69 lines
1.5 KiB
Go
// Package abool provides atomic Boolean type for cleaner code and
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// better performance.
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package abool
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import "sync/atomic"
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// New creates an AtomicBool with default to false
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func New() *AtomicBool {
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return new(AtomicBool)
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}
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// NewBool creates an AtomicBool with given default value
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func NewBool(ok bool) *AtomicBool {
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ab := New()
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if ok {
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ab.Set()
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}
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return ab
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}
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// AtomicBool is an atomic Boolean
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// Its methods are all atomic, thus safe to be called by
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// multiple goroutines simultaneously
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// Note: When embedding into a struct, one should always use
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// *AtomicBool to avoid copy
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type AtomicBool int32
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// Set sets the Boolean to true
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func (ab *AtomicBool) Set() {
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atomic.StoreInt32((*int32)(ab), 1)
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}
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// UnSet sets the Boolean to false
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func (ab *AtomicBool) UnSet() {
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atomic.StoreInt32((*int32)(ab), 0)
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}
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// IsSet returns whether the Boolean is true
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func (ab *AtomicBool) IsSet() bool {
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return atomic.LoadInt32((*int32)(ab)) == 1
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}
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// SetTo sets the Boolean with given Boolean.
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func (ab *AtomicBool) SetTo(yes bool) {
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if yes {
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atomic.StoreInt32((*int32)(ab), 1)
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} else {
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atomic.StoreInt32((*int32)(ab), 0)
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}
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}
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// Toggle negates boolean atomically and returns the previous value.
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func (ab *AtomicBool) Toggle() bool {
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return (atomic.AddInt32((*int32)(ab), 1)-1)&1 == 1
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}
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// SetToIf sets the Boolean to new only if the Boolean matches the old
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// Returns whether the set was done
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func (ab *AtomicBool) SetToIf(old, new bool) (set bool) {
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var o, n int32
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if old {
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o = 1
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}
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if new {
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n = 1
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}
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return atomic.CompareAndSwapInt32((*int32)(ab), o, n)
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}
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