51 lines
1.1 KiB
Go
51 lines
1.1 KiB
Go
package mutexes
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import (
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"sync/atomic"
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)
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// WithSafety wrapps the supplied Mutex to protect unlock fns
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// from being called multiple times
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func WithSafety(mu Mutex) Mutex {
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return &safeMutex{mu: mu}
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}
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// WithSafetyRW wrapps the supplied RWMutex to protect unlock
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// fns from being called multiple times
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func WithSafetyRW(mu RWMutex) RWMutex {
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return &safeRWMutex{mu: mu}
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}
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// safeMutex simply wraps a Mutex to add multi-unlock safety
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type safeMutex struct{ mu Mutex }
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func (mu *safeMutex) Lock() func() {
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unlock := mu.mu.Lock()
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return once(unlock)
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}
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// safeRWMutex simply wraps a RWMutex to add multi-unlock safety
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type safeRWMutex struct{ mu RWMutex }
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func (mu *safeRWMutex) Lock() func() {
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unlock := mu.mu.Lock()
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return once(unlock)
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}
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func (mu *safeRWMutex) RLock() func() {
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unlock := mu.mu.RLock()
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return once(unlock)
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}
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// once will perform 'do' only once, this is safe for unlocks
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// as 2 functions calling 'unlock()' don't need absolute guarantees
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// that by the time it is completed the unlock was finished.
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func once(do func()) func() {
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var done uint32
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return func() {
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if atomic.CompareAndSwapUint32(&done, 0, 1) {
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do()
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}
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}
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}
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