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Viewing changes to debian/gocode/src/github.com/mholt/caddy/sigtrap.go

  • Committer: Horacio Durán
  • Date: 2016-10-14 14:33:43 UTC
  • Revision ID: horacio.duran@canonical.com-20161014143343-ytyhz5sx7d1cje4q
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debian/gocode/src/github.com/mholt/caddy/sigtrap.go
 
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package caddy
 
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import (
 
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        "log"
 
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        "os"
 
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        "os/signal"
 
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        "sync"
 
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)
 
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// TrapSignals create signal handlers for all applicable signals for this
 
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// system. If your Go program uses signals, this is a rather invasive
 
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// function; best to implement them yourself in that case. Signals are not
 
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// required for the caddy package to function properly, but this is a
 
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// convenient way to allow the user to control this part of your program.
 
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func TrapSignals() {
 
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        trapSignalsCrossPlatform()
 
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        trapSignalsPosix()
 
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}
 
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// trapSignalsCrossPlatform captures SIGINT, which triggers forceful
 
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// shutdown that executes shutdown callbacks first. A second interrupt
 
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// signal will exit the process immediately.
 
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func trapSignalsCrossPlatform() {
 
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        go func() {
 
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                shutdown := make(chan os.Signal, 1)
 
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                signal.Notify(shutdown, os.Interrupt)
 
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                for i := 0; true; i++ {
 
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                        <-shutdown
 
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                        if i > 0 {
 
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                                log.Println("[INFO] SIGINT: Force quit")
 
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                                if PidFile != "" {
 
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                                        os.Remove(PidFile)
 
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                                }
 
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                                os.Exit(1)
 
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                        }
 
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                        log.Println("[INFO] SIGINT: Shutting down")
 
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                        if PidFile != "" {
 
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                                os.Remove(PidFile)
 
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                        }
 
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                        go os.Exit(executeShutdownCallbacks("SIGINT"))
 
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                }
 
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        }()
 
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}
 
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// executeShutdownCallbacks executes the shutdown callbacks as initiated
 
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// by signame. It logs any errors and returns the recommended exit status.
 
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// This function is idempotent; subsequent invocations always return 0.
 
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func executeShutdownCallbacks(signame string) (exitCode int) {
 
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        shutdownCallbacksOnce.Do(func() {
 
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                errs := allShutdownCallbacks()
 
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                if len(errs) > 0 {
 
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                        for _, err := range errs {
 
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                                log.Printf("[ERROR] %s shutdown: %v", signame, err)
 
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                        }
 
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                        exitCode = 1
 
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                }
 
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        })
 
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        return
 
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}
 
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// allShutdownCallbacks executes all the shutdown callbacks
 
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// for all the instances, and returns all the errors generated
 
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// during their execution. An error executing one shutdown
 
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// callback does not stop execution of others. Only one shutdown
 
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// callback is executed at a time.
 
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func allShutdownCallbacks() []error {
 
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        var errs []error
 
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        instancesMu.Lock()
 
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        for _, inst := range instances {
 
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                errs = append(errs, inst.ShutdownCallbacks()...)
 
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        }
 
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        instancesMu.Unlock()
 
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        return errs
 
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}
 
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// shutdownCallbacksOnce ensures that shutdown callbacks
 
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// for all instances are only executed once.
 
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var shutdownCallbacksOnce sync.Once