87 lines
2.0 KiB
Go
87 lines
2.0 KiB
Go
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package clock
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import (
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"context"
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"fmt"
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"sync"
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"time"
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)
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func (m *Mock) WithTimeout(parent context.Context, timeout time.Duration) (context.Context, context.CancelFunc) {
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return m.WithDeadline(parent, m.Now().Add(timeout))
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}
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func (m *Mock) WithDeadline(parent context.Context, deadline time.Time) (context.Context, context.CancelFunc) {
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if cur, ok := parent.Deadline(); ok && cur.Before(deadline) {
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// The current deadline is already sooner than the new one.
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return context.WithCancel(parent)
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}
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ctx := &timerCtx{clock: m, parent: parent, deadline: deadline, done: make(chan struct{})}
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propagateCancel(parent, ctx)
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dur := m.Until(deadline)
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if dur <= 0 {
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ctx.cancel(context.DeadlineExceeded) // deadline has already passed
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return ctx, func() {}
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}
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ctx.Lock()
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defer ctx.Unlock()
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if ctx.err == nil {
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ctx.timer = m.AfterFunc(dur, func() {
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ctx.cancel(context.DeadlineExceeded)
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})
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}
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return ctx, func() { ctx.cancel(context.Canceled) }
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}
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// propagateCancel arranges for child to be canceled when parent is.
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func propagateCancel(parent context.Context, child *timerCtx) {
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if parent.Done() == nil {
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return // parent is never canceled
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}
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go func() {
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select {
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case <-parent.Done():
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child.cancel(parent.Err())
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case <-child.Done():
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}
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}()
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}
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type timerCtx struct {
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sync.Mutex
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clock Clock
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parent context.Context
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deadline time.Time
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done chan struct{}
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err error
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timer *Timer
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}
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func (c *timerCtx) cancel(err error) {
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c.Lock()
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defer c.Unlock()
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if c.err != nil {
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return // already canceled
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}
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c.err = err
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close(c.done)
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if c.timer != nil {
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c.timer.Stop()
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c.timer = nil
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}
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}
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func (c *timerCtx) Deadline() (deadline time.Time, ok bool) { return c.deadline, true }
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func (c *timerCtx) Done() <-chan struct{} { return c.done }
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func (c *timerCtx) Err() error { return c.err }
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func (c *timerCtx) Value(key interface{}) interface{} { return c.parent.Value(key) }
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func (c *timerCtx) String() string {
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return fmt.Sprintf("clock.WithDeadline(%s [%s])", c.deadline, c.deadline.Sub(c.clock.Now()))
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}
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