46 lines
1.3 KiB
Go
46 lines
1.3 KiB
Go
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// Package deadline implements the deadline (also known as "timeout") resiliency pattern for Go.
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package deadline
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import (
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"errors"
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"time"
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)
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// ErrTimedOut is the error returned from Run when the deadline expires.
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var ErrTimedOut = errors.New("timed out waiting for function to finish")
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// Deadline implements the deadline/timeout resiliency pattern.
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type Deadline struct {
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timeout time.Duration
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}
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// New constructs a new Deadline with the given timeout.
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func New(timeout time.Duration) *Deadline {
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return &Deadline{
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timeout: timeout,
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}
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}
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// Run runs the given function, passing it a stopper channel. If the deadline passes before
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// the function finishes executing, Run returns ErrTimeOut to the caller and closes the stopper
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// channel so that the work function can attempt to exit gracefully. It does not (and cannot)
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// simply kill the running function, so if it doesn't respect the stopper channel then it may
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// keep running after the deadline passes. If the function finishes before the deadline, then
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// the return value of the function is returned from Run.
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func (d *Deadline) Run(work func(<-chan struct{}) error) error {
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result := make(chan error)
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stopper := make(chan struct{})
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go func() {
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result <- work(stopper)
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}()
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select {
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case ret := <-result:
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return ret
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case <-time.After(d.timeout):
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close(stopper)
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return ErrTimedOut
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}
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}
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