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50 lines
1.6 KiB
Go
50 lines
1.6 KiB
Go
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package main
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import "fmt"
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// The goroutine has a few paths to termination:
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// • When it has completed its work.
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// • When it cannot continue its work due to an unrecoverable error.
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// • When it’s told to stop working
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/**
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We get the first two paths for free—these paths are your algorithm—but what about
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work cancellation? This turns out to be the most important bit because of the net‐
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work effect: if you’ve begun a goroutine, it’s most likely cooperating with several other
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goroutines in some sort of organized fashion.
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**/
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func main() {
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}
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// Here we see that the main goroutine passes a nil channel into doWork. Therefore, the
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// strings channel will never actually gets any strings written onto it, and the goroutine
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// containing doWork will remain in memory for the lifetime of this process (we would
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// even deadlock if we joined the goroutine within doWork and the main goroutine).
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// In this example, the lifetime of the process is very short, but in a real program, gorou‐
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// tines could easily be started at the beginning of a long-lived program. In the worst
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// case, the main goroutine could continue to spin up goroutines throughout its life,
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// causing creep in memory utilization.
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func resourceLeak() {
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doWork := func(strings <-chan string) <-chan interface{} {
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completed := make(chan interface{})
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go func() {
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defer fmt.Println("doWork exited.")
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defer close(completed)
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for s := range strings {
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// Do something interesting
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fmt.Println(s)
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}
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}()
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return completed
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}
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doWork(nil)
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// Perhaps more work is done here
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fmt.Println("Done.")
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}
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func cancellationSignal() {
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}
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