39 lines
715 B
Go
39 lines
715 B
Go
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package core
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import (
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"context"
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"time"
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)
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type slots chan struct{}
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func (s slots) acquire(ctx context.Context) bool {
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if ctx.Err() != nil {
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return false
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}
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select {
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case s <- struct{}{}:
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return true
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case <-ctx.Done():
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return false
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}
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}
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// The wait has a deadline of its own, so the work after it keeps its whole budget.
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func (s slots) acquireWithin(parent context.Context, timeout time.Duration) bool {
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ctx, cancel := context.WithTimeout(parent, timeout)
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defer cancel()
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return s.acquire(ctx)
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}
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func (s slots) release() {
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<-s
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}
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func timeoutFromMillis(millis int64, fallback time.Duration) time.Duration {
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if millis <= 0 {
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return fallback
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}
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return time.Duration(millis) * time.Millisecond
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}
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