104 lines
2.8 KiB
Go
104 lines
2.8 KiB
Go
package usync
|
|
|
|
import "sync"
|
|
|
|
// Monitor guards access to a value. It must not be copied after first use.
|
|
type Monitor[T any] struct {
|
|
value T
|
|
mutex sync.Mutex
|
|
}
|
|
|
|
// NewMonitor creates a new Monitor with the specified value.
|
|
func NewMonitor[T any] (value T) Monitor[T] {
|
|
return Monitor[T] {
|
|
value: value,
|
|
}
|
|
}
|
|
|
|
// Set sets the value of the Monitor.
|
|
func (this *Monitor[T]) Set (value T) {
|
|
this.mutex.Lock()
|
|
defer this.mutex.Unlock()
|
|
this.value = value
|
|
}
|
|
|
|
// Borrow borrows the value from the Monitor, and returns a function that must
|
|
// immediately be deferred, like this:
|
|
//
|
|
// value, done := monitor.Borrow()
|
|
// defer done()
|
|
//
|
|
// From the time Borrow is called to the time the done function is called, it is
|
|
// safe to access the locked object from within the current goroutine.
|
|
func (this *Monitor[T]) Borrow () (T, func ()) {
|
|
this.mutex.Lock()
|
|
return this.value, this.mutex.Unlock
|
|
}
|
|
|
|
// BorrowReturn is like borrow, but returns a "done" function that takes in an
|
|
// updated value. The intended use of this function is like this:
|
|
//
|
|
// value, done := monitor.BorrowReturn()
|
|
// defer done(value)
|
|
func (this *Monitor[T]) BorrowReturn () (T, func (T)) {
|
|
this.mutex.Lock()
|
|
return this.value, func (value T) {
|
|
defer this.mutex.Unlock()
|
|
this.value = value
|
|
}
|
|
}
|
|
|
|
// RWMonitor guards separate read/write access to a value.
|
|
type RWMonitor[T any] struct {
|
|
value T
|
|
mutex sync.RWMutex
|
|
}
|
|
|
|
// NewRWMonitor creates a new Monitor with the specified value. It must not be
|
|
// copied after first use.
|
|
func NewRWMonitor[T any] (value T) RWMonitor[T] {
|
|
return RWMonitor[T] {
|
|
value: value,
|
|
}
|
|
}
|
|
|
|
// Set sets the value of the Monitor.
|
|
func (this *RWMonitor[T]) Set (value T) {
|
|
this.mutex.Lock()
|
|
defer this.mutex.Unlock()
|
|
this.value = value
|
|
}
|
|
|
|
// Borrow borrows the value from the Monitor for write access, and returns a
|
|
// function that must immediately be deferred, like this:
|
|
//
|
|
// value, done := monitor.Borrow()
|
|
// defer done()
|
|
//
|
|
// From the time Borrow is called to the time the done function is called, it is
|
|
// safe to access the locked object from within the current goroutine.
|
|
func (this *RWMonitor[T]) Borrow () (T, func ()) {
|
|
this.mutex.Lock()
|
|
return this.value, this.mutex.Unlock
|
|
}
|
|
|
|
// BorrowReturn is like borrow, but returns a "done" function that takes in an
|
|
// updated value. The intended use of this function is like this:
|
|
//
|
|
// value, done := monitor.BorrowReturn()
|
|
// defer done(value)
|
|
func (this *RWMonitor[T]) BorrowReturn () (T, func (T)) {
|
|
this.mutex.Lock()
|
|
return this.value, func (value T) {
|
|
defer this.mutex.Unlock()
|
|
this.value = value
|
|
}
|
|
}
|
|
|
|
// RBorrow is like Borrow, but returns the item for read access only. Do not
|
|
// under any circumstances modify anything returned by this method.
|
|
func (this *RWMonitor[T]) RBorrow () (T, func ()) {
|
|
this.mutex.Lock()
|
|
return this.value, this.mutex.Unlock
|
|
}
|