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@ -25,9 +25,11 @@ import (
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var (
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port = flag.Int("port", 8000, "Port on which to serve HTTP")
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mu sync.Mutex // Prevent multiple updates in parallel.
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toServe atomic.Value // Always contains valid []byte to serve. May be stale unless wg is zero.
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wgMu sync.Mutex // Prevent multiple calls to wg.Wait() or wg.Add(positive number) in parallel.
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wg sync.WaitGroup // Indicates how many updates are pending.
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mu sync.Mutex // Prevent multiple updates in parallel.
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)
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func main() {
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@ -111,7 +113,9 @@ func filter(e fsnotify.Event) bool {
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}
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func serve(w http.ResponseWriter, req *http.Request) {
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wgMu.Lock()
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wg.Wait()
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wgMu.Unlock()
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b := toServe.Load().([]byte)
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w.Write(b)
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}
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@ -143,7 +147,9 @@ func doPopulate(ch chan struct{}, dir string) {
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select {
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case <-ch:
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if pending == 0 {
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wgMu.Lock()
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wg.Add(1)
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wgMu.Unlock()
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}
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pending++
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case <-time.After(10 * time.Millisecond):
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