78 lines
2.0 KiB
Go
78 lines
2.0 KiB
Go
package usync
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import "sync"
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// Locker guards access to a value. It must not be copied after first use.
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type Locker[T any] struct {
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value T
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mutex sync.Mutex
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}
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// NewLocker creates a new locker with the specified value.
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func NewLocker[T any] (value T) Locker[T] {
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return Locker[T] {
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value: value,
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}
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}
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// Set sets the value of the locker.
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func (this *Locker[T]) Set (value T) {
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this.mutex.Lock()
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defer this.mutex.Unlock()
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this.value = value
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}
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// Borrow borrows the value from the locker, and returns a function that must
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// immediately be deferred, like this:
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//
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// value, done := locker.Borrow()
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// defer done()
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//
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// From the time Borrow is called to the time the done function is called, it is
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// safe to access the locked object from within the current goroutine.
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func (this *Locker[T]) Borrow () (T, func ()) {
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this.mutex.Lock()
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return this.value, this.mutex.Unlock
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}
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// RWLocker guards separate read/write access to a value.
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type RWLocker[T any] struct {
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value T
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mutex sync.RWMutex
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}
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// NewRWLocker creates a new locker with the specified value. It must not be
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// copied after first use.
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func NewRWLocker[T any] (value T) RWLocker[T] {
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return RWLocker[T] {
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value: value,
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}
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}
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// Set sets the value of the locker.
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func (this *RWLocker[T]) Set (value T) {
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this.mutex.Lock()
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defer this.mutex.Unlock()
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this.value = value
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}
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// Borrow borrows the value from the locker for write access, and returns a
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// function that must immediately be deferred, like this:
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//
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// value, done := locker.Borrow()
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// defer done()
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//
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// From the time Borrow is called to the time the done function is called, it is
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// safe to access the locked object from within the current goroutine.
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func (this *RWLocker[T]) Borrow () (T, func ()) {
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this.mutex.Lock()
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return this.value, this.mutex.Unlock
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}
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// RBorrow is like Borrow, but returns the item for read access only. Do not
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// under any circumstances write to an item returned from this method.
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func (this *RWLocker[T]) RBorrow () (T, func ()) {
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this.mutex.Lock()
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return this.value, this.mutex.Unlock
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}
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