func TestBufferedSub(t *testing.T) {
	l := events.NewLogger()

	s := l.Subscribe(events.AllEvents)
	defer l.Unsubscribe(s)
	bs := events.NewBufferedSubscription(s, 10*events.BufferSize)

	go func() {
		for i := 0; i < 10*events.BufferSize; i++ {
			l.Log(events.DeviceConnected, fmt.Sprintf("event-%d", i))
			if i%30 == 0 {
				// Give the buffer routine time to pick up the events
				time.Sleep(20 * time.Millisecond)
			}
		}
	}()

	recv := 0
	for recv < 10*events.BufferSize {
		evs := bs.Since(recv, nil)
		for _, ev := range evs {
			if ev.ID != recv+1 {
				t.Fatalf("Incorrect ID; %d != %d", ev.ID, recv+1)
			}
			recv = ev.ID
		}
	}

}

func TestSinceUsesSubscriptionId(t *testing.T) {
	l := events.NewLogger()

	s := l.Subscribe(events.DeviceConnected)
	defer l.Unsubscribe(s)
	bs := events.NewBufferedSubscription(s, 10*events.BufferSize)

	l.Log(events.DeviceConnected, "a") // SubscriptionID = 1
	l.Log(events.DeviceDisconnected, "b")
	l.Log(events.DeviceDisconnected, "c")
	l.Log(events.DeviceConnected, "d") // SubscriptionID = 2

	// We need to loop for the events, as they may not all have been
	// delivered to the buffered subscription when we get here.
	t0 := time.Now()
	for time.Since(t0) < time.Second {
		events := bs.Since(0, nil)
		if len(events) == 2 {
			break
		}
		if len(events) > 2 {
			t.Fatal("Incorrect number of events:", len(events))
		}
	}

	events := bs.Since(1, nil)
	if len(events) != 1 {
		t.Fatal("Incorrect number of events:", len(events))
	}
}

func BenchmarkBufferedSub(b *testing.B) {
	l := events.NewLogger()

	s := l.Subscribe(events.AllEvents)
	defer l.Unsubscribe(s)
	bufferSize := events.BufferSize
	bs := events.NewBufferedSubscription(s, bufferSize)

	// The coord channel paces the sender according to the receiver,
	// ensuring that no events are dropped. The benchmark measures sending +
	// receiving + synchronization overhead.

	coord := make(chan struct{}, bufferSize)
	for i := 0; i < bufferSize-1; i++ {
		coord <- struct{}{}
	}

	// Receive the events
	done := make(chan struct{})
	go func() {
		defer close(done)
		recv := 0
		var evs []events.Event
		for i := 0; i < b.N; {
			evs = bs.Since(recv, evs[:0])
			for _, ev := range evs {
				if ev.GlobalID != recv+1 {
					b.Fatal("skipped event", ev.GlobalID, recv)
				}
				recv = ev.GlobalID
				coord <- struct{}{}
			}
			i += len(evs)
		}
	}()

	// Send the events
	eventData := map[string]string{
		"foo":   "bar",
		"other": "data",
		"and":   "something else",
	}
	for i := 0; i < b.N; i++ {
		l.Log(events.DeviceConnected, eventData)
		<-coord
	}

	<-done
	b.ReportAllocs()
}

func syncthingMain() {
	// Create a main service manager. We'll add things to this as we go along.
	// We want any logging it does to go through our log system.
	mainSvc := suture.New("main", suture.Spec{
		Log: func(line string) {
			l.Debugln(line)
		},
	})
	mainSvc.ServeBackground()

	// Set a log prefix similar to the ID we will have later on, or early log
	// lines look ugly.
	l.SetPrefix("[start] ")

	if auditEnabled {
		startAuditing(mainSvc)
	}

	if verbose {
		mainSvc.Add(newVerboseSvc())
	}

	errors := logger.NewRecorder(l, logger.LevelWarn, maxSystemErrors, 0)
	systemLog := logger.NewRecorder(l, logger.LevelDebug, maxSystemLog, initialSystemLog)

	// Event subscription for the API; must start early to catch the early events.
	apiSub := events.NewBufferedSubscription(events.Default.Subscribe(events.AllEvents), 1000)

	if len(os.Getenv("GOMAXPROCS")) == 0 {
		runtime.GOMAXPROCS(runtime.NumCPU())
	}

	// Attempt to increase the limit on number of open files to the maximum
	// allowed, in case we have many peers. We don't really care enough to
	// report the error if there is one.
	osutil.MaximizeOpenFileLimit()

	// Ensure that that we have a certificate and key.
	cert, err := tls.LoadX509KeyPair(locations[locCertFile], locations[locKeyFile])
	if err != nil {
		l.Infof("Generating RSA key and certificate for %s...", tlsDefaultCommonName)
		cert, err = tlsutil.NewCertificate(locations[locCertFile], locations[locKeyFile], tlsDefaultCommonName, tlsRSABits)
		if err != nil {
			l.Fatalln(err)
		}
	}

	// We reinitialize the predictable RNG with our device ID, to get a
	// sequence that is always the same but unique to this syncthing instance.
	predictableRandom.Seed(seedFromBytes(cert.Certificate[0]))

	myID = protocol.NewDeviceID(cert.Certificate[0])
	l.SetPrefix(fmt.Sprintf("[%s] ", myID.String()[:5]))

	l.Infoln(LongVersion)
	l.Infoln("My ID:", myID)

	// Emit the Starting event, now that we know who we are.

	events.Default.Log(events.Starting, map[string]string{
		"home": baseDirs["config"],
		"myID": myID.String(),
	})

	// Prepare to be able to save configuration

	cfgFile := locations[locConfigFile]

	// Load the configuration file, if it exists.
	// If it does not, create a template.

	cfg, myName, err := loadConfig(cfgFile)
	if err != nil {
		if os.IsNotExist(err) {
			l.Infoln("No config file; starting with empty defaults")
			myName, _ = os.Hostname()
			newCfg := defaultConfig(myName)
			cfg = config.Wrap(cfgFile, newCfg)
			cfg.Save()
			l.Infof("Edit %s to taste or use the GUI\n", cfgFile)
		} else {
			l.Fatalln("Loading config:", err)
		}
	}

	if cfg.Raw().OriginalVersion != config.CurrentVersion {
		l.Infoln("Archiving a copy of old config file format")
		// Archive a copy
		osutil.Rename(cfgFile, cfgFile+fmt.Sprintf(".v%d", cfg.Raw().OriginalVersion))
		// Save the new version
		cfg.Save()
	}

	if err := checkShortIDs(cfg); err != nil {
		l.Fatalln("Short device IDs are in conflict. Unlucky!\n  Regenerate the device ID of one if the following:\n  ", err)
	}

	if len(profiler) > 0 {
		go func() {
			l.Debugln("Starting profiler on", profiler)
//.........这里部分代码省略.........

func syncthingMain() {
	// Create a main service manager. We'll add things to this as we go along.
	// We want any logging it does to go through our log system.
	mainSvc := suture.New("main", suture.Spec{
		Log: func(line string) {
			if debugSuture {
				l.Debugln(line)
			}
		},
	})
	mainSvc.ServeBackground()

	// Set a log prefix similar to the ID we will have later on, or early log
	// lines look ugly.
	l.SetPrefix("[start] ")

	if auditEnabled {
		startAuditing(mainSvc)
	}

	if verbose {
		mainSvc.Add(newVerboseSvc())
	}

	// Event subscription for the API; must start early to catch the early events.
	apiSub := events.NewBufferedSubscription(events.Default.Subscribe(events.AllEvents), 1000)

	if len(os.Getenv("GOMAXPROCS")) == 0 {
		runtime.GOMAXPROCS(runtime.NumCPU())
	}

	// Ensure that that we have a certificate and key.
	cert, err := tls.LoadX509KeyPair(locations[locCertFile], locations[locKeyFile])
	if err != nil {
		cert, err = newCertificate(locations[locCertFile], locations[locKeyFile], tlsDefaultCommonName)
		if err != nil {
			l.Fatalln("load cert:", err)
		}
	}

	// We reinitialize the predictable RNG with our device ID, to get a
	// sequence that is always the same but unique to this syncthing instance.
	predictableRandom.Seed(seedFromBytes(cert.Certificate[0]))

	myID = protocol.NewDeviceID(cert.Certificate[0])
	l.SetPrefix(fmt.Sprintf("[%s] ", myID.String()[:5]))

	l.Infoln(LongVersion)
	l.Infoln("My ID:", myID)

	// Emit the Starting event, now that we know who we are.

	events.Default.Log(events.Starting, map[string]string{
		"home": baseDirs["config"],
		"myID": myID.String(),
	})

	// Prepare to be able to save configuration

	cfgFile := locations[locConfigFile]

	var myName string

	// Load the configuration file, if it exists.
	// If it does not, create a template.

	if info, err := os.Stat(cfgFile); err == nil {
		if !info.Mode().IsRegular() {
			l.Fatalln("Config file is not a file?")
		}
		cfg, err = config.Load(cfgFile, myID)
		if err == nil {
			myCfg := cfg.Devices()[myID]
			if myCfg.Name == "" {
				myName, _ = os.Hostname()
			} else {
				myName = myCfg.Name
			}
		} else {
			l.Fatalln("Configuration:", err)
		}
	} else {
		l.Infoln("No config file; starting with empty defaults")
		myName, _ = os.Hostname()
		newCfg := defaultConfig(myName)
		cfg = config.Wrap(cfgFile, newCfg)
		cfg.Save()
		l.Infof("Edit %s to taste or use the GUI\n", cfgFile)
	}

	if cfg.Raw().OriginalVersion != config.CurrentVersion {
		l.Infoln("Archiving a copy of old config file format")
		// Archive a copy
		osutil.Rename(cfgFile, cfgFile+fmt.Sprintf(".v%d", cfg.Raw().OriginalVersion))
		// Save the new version
		cfg.Save()
	}

	if err := checkShortIDs(cfg); err != nil {
		l.Fatalln("Short device IDs are in conflict. Unlucky!\n  Regenerate the device ID of one if the following:\n  ", err)
//.........这里部分代码省略.........