62 lines
1.5 KiB
Go
62 lines
1.5 KiB
Go
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// +build !solution
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package cond
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// A Locker represents an object that can be locked and unlocked.
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type Locker interface {
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Lock()
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Unlock()
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}
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// Cond implements a condition variable, a rendezvous point
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// for goroutines waiting for or announcing the occurrence
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// of an event.
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//
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// Each Cond has an associated Locker L (often a *sync.Mutex or *sync.RWMutex),
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// which must be held when changing the condition and
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// when calling the Wait method.
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type Cond struct {
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L Locker
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}
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// New returns a new Cond with Locker l.
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func New(l Locker) *Cond {
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return &Cond{L: l}
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}
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// Wait atomically unlocks c.L and suspends execution
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// of the calling goroutine. After later resuming execution,
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// Wait locks c.L before returning. Unlike in other systems,
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// Wait cannot return unless awoken by Broadcast or Signal.
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//
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// Because c.L is not locked when Wait first resumes, the caller
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// typically cannot assume that the condition is true when
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// Wait returns. Instead, the caller should Wait in a loop:
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//
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// c.L.Lock()
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// for !condition() {
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// c.Wait()
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// }
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// ... make use of condition ...
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// c.L.Unlock()
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//
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func (c *Cond) Wait() {
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}
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// Signal wakes one goroutine waiting on c, if there is any.
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//
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// It is allowed but not required for the caller to hold c.L
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// during the call.
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func (c *Cond) Signal() {
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}
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// Broadcast wakes all goroutines waiting on c.
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//
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// It is allowed but not required for the caller to hold c.L
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// during the call.
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func (c *Cond) Broadcast() {
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}
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