Merge pull request #4590 from hsjoberg/signal-proper-shutdown-glob

signal: handle shutdown properly
This commit is contained in:
Johan T. Halseth 2021-03-18 19:09:31 +01:00 committed by GitHub
commit b1309277b9
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
11 changed files with 170 additions and 129 deletions

@ -2,20 +2,21 @@ package build
import (
"github.com/btcsuite/btclog"
"github.com/lightningnetwork/lnd/signal"
)
// ShutdownLogger wraps an existing logger with a shutdown function which will
// be called on Critical/Criticalf to prompt shutdown.
type ShutdownLogger struct {
btclog.Logger
shutdown func()
}
// NewShutdownLogger creates a shutdown logger for the log provided which will
// use the signal package to request shutdown on critical errors.
func NewShutdownLogger(logger btclog.Logger) *ShutdownLogger {
func NewShutdownLogger(logger btclog.Logger, shutdown func()) *ShutdownLogger {
return &ShutdownLogger{
Logger: logger,
Logger: logger,
shutdown: shutdown,
}
}
@ -26,6 +27,7 @@ func NewShutdownLogger(logger btclog.Logger) *ShutdownLogger {
// Note: it is part of the btclog.Logger interface.
func (s *ShutdownLogger) Criticalf(format string, params ...interface{}) {
s.Logger.Criticalf(format, params...)
s.Logger.Info("Sending request for shutdown")
s.shutdown()
}
@ -36,18 +38,6 @@ func (s *ShutdownLogger) Criticalf(format string, params ...interface{}) {
// Note: it is part of the btclog.Logger interface.
func (s *ShutdownLogger) Critical(v ...interface{}) {
s.Logger.Critical(v)
s.Logger.Info("Sending request for shutdown")
s.shutdown()
}
// shutdown checks whether we are listening for interrupts, since a shutdown
// request to the signal package will block if it is not running, and requests
// shutdown if possible.
func (s *ShutdownLogger) shutdown() {
if !signal.Listening() {
s.Logger.Info("Request for shutdown ignored")
return
}
s.Logger.Info("Sending request for shutdown")
signal.RequestShutdown()
}

@ -14,10 +14,6 @@ import (
// RotatingLogWriter is a wrapper around the LogWriter that supports log file
// rotation.
type RotatingLogWriter struct {
// GenSubLogger is a function that returns a new logger for a subsystem
// belonging to the current RotatingLogWriter.
GenSubLogger func(string) btclog.Logger
logWriter *LogWriter
backendLog *btclog.Backend
@ -39,16 +35,19 @@ func NewRotatingLogWriter() *RotatingLogWriter {
logWriter := &LogWriter{}
backendLog := btclog.NewBackend(logWriter)
return &RotatingLogWriter{
GenSubLogger: func(tag string) btclog.Logger {
logger := backendLog.Logger(tag)
return NewShutdownLogger(logger)
},
logWriter: logWriter,
backendLog: backendLog,
subsystemLoggers: SubLoggers{},
}
}
// GenSubLogger creates a new sublogger. A shutdown callback function
// is provided to be able to shutdown in case of a critical error.
func (r *RotatingLogWriter) GenSubLogger(tag string, shutdown func()) btclog.Logger {
logger := r.backendLog.Logger(tag)
return NewShutdownLogger(logger, shutdown)
}
// RegisterSubLogger registers a new subsystem logger.
func (r *RotatingLogWriter) RegisterSubLogger(subsystem string,
logger btclog.Logger) {

@ -18,7 +18,6 @@ import (
"github.com/btcsuite/btcutil"
"github.com/lightningnetwork/lnd/lnrpc"
"github.com/lightningnetwork/lnd/lnwallet/chanfunding"
"github.com/lightningnetwork/lnd/signal"
"github.com/urfave/cli"
)
@ -467,7 +466,7 @@ func openChannelPsbt(rpcCtx context.Context, ctx *cli.Context,
// the server.
go func() {
select {
case <-signal.ShutdownChannel():
case <-rpcCtx.Done():
fmt.Printf("\nInterrupt signal received.\n")
close(quit)

@ -41,14 +41,15 @@ const (
)
func getContext() context.Context {
if err := signal.Intercept(); err != nil {
shutdownInterceptor, err := signal.Intercept()
if err != nil {
_, _ = fmt.Fprintln(os.Stderr, err)
os.Exit(1)
}
ctxc, cancel := context.WithCancel(context.Background())
go func() {
<-signal.ShutdownChannel()
<-shutdownInterceptor.ShutdownChannel()
cancel()
}()
return ctxc

@ -10,9 +10,16 @@ import (
)
func main() {
// Hook interceptor for os signals.
shutdownInterceptor, err := signal.Intercept()
if err != nil {
_, _ = fmt.Fprintln(os.Stderr, err)
os.Exit(1)
}
// Load the configuration, and parse any command line options. This
// function will also set up logging properly.
loadedConfig, err := lnd.LoadConfig()
loadedConfig, err := lnd.LoadConfig(shutdownInterceptor)
if err != nil {
if e, ok := err.(*flags.Error); !ok || e.Type != flags.ErrHelp {
// Print error if not due to help request.
@ -24,16 +31,10 @@ func main() {
os.Exit(0)
}
// Hook interceptor for os signals.
if err := signal.Intercept(); err != nil {
_, _ = fmt.Fprintln(os.Stderr, err)
os.Exit(1)
}
// Call the "real" main in a nested manner so the defers will properly
// be executed in the case of a graceful shutdown.
if err := lnd.Main(
loadedConfig, lnd.ListenerCfg{}, signal.ShutdownChannel(),
if err = lnd.Main(
loadedConfig, lnd.ListenerCfg{}, shutdownInterceptor,
); err != nil {
_, _ = fmt.Fprintln(os.Stderr, err)
os.Exit(1)

@ -36,6 +36,7 @@ import (
"github.com/lightningnetwork/lnd/lnrpc/signrpc"
"github.com/lightningnetwork/lnd/lnwallet"
"github.com/lightningnetwork/lnd/routing"
"github.com/lightningnetwork/lnd/signal"
"github.com/lightningnetwork/lnd/tor"
)
@ -510,7 +511,7 @@ func DefaultConfig() Config {
// 2) Pre-parse the command line to check for an alternative config file
// 3) Load configuration file overwriting defaults with any specified options
// 4) Parse CLI options and overwrite/add any specified options
func LoadConfig() (*Config, error) {
func LoadConfig(interceptor signal.Interceptor) (*Config, error) {
// Pre-parse the command line options to pick up an alternative config
// file.
preCfg := DefaultConfig()
@ -563,7 +564,7 @@ func LoadConfig() (*Config, error) {
}
// Make sure everything we just loaded makes sense.
cleanCfg, err := ValidateConfig(cfg, usageMessage)
cleanCfg, err := ValidateConfig(cfg, usageMessage, interceptor)
if err != nil {
return nil, err
}
@ -581,7 +582,8 @@ func LoadConfig() (*Config, error) {
// ValidateConfig check the given configuration to be sane. This makes sure no
// illegal values or combination of values are set. All file system paths are
// normalized. The cleaned up config is returned on success.
func ValidateConfig(cfg Config, usageMessage string) (*Config, error) {
func ValidateConfig(cfg Config, usageMessage string,
interceptor signal.Interceptor) (*Config, error) {
// If the provided lnd directory is not the default, we'll modify the
// path to all of the files and directories that will live within it.
lndDir := CleanAndExpandPath(cfg.LndDir)
@ -1151,7 +1153,7 @@ func ValidateConfig(cfg Config, usageMessage string) (*Config, error) {
}
// Initialize logging at the default logging level.
SetupLoggers(cfg.LogWriter)
SetupLoggers(cfg.LogWriter, interceptor)
err = cfg.LogWriter.InitLogRotator(
filepath.Join(cfg.LogDir, defaultLogFilename),
cfg.MaxLogFileSize, cfg.MaxLogFiles,

15
lnd.go

@ -190,7 +190,7 @@ type ListenerCfg struct {
// validated main configuration struct and an optional listener config struct.
// This function starts all main system components then blocks until a signal
// is received on the shutdownChan at which point everything is shut down again.
func Main(cfg *Config, lisCfg ListenerCfg, shutdownChan <-chan struct{}) error {
func Main(cfg *Config, lisCfg ListenerCfg, interceptor signal.Interceptor) error {
defer func() {
ltndLog.Info("Shutdown complete\n")
err := cfg.LogWriter.Close()
@ -378,6 +378,7 @@ func Main(cfg *Config, lisCfg ListenerCfg, shutdownChan <-chan struct{}) error {
rpcServer := newRPCServer(
cfg, interceptorChain, lisCfg.ExternalRPCSubserverCfg,
lisCfg.ExternalRestRegistrar,
interceptor,
)
err = rpcServer.RegisterWithGrpcServer(grpcServer)
@ -408,7 +409,7 @@ func Main(cfg *Config, lisCfg ListenerCfg, shutdownChan <-chan struct{}) error {
// started with the --noseedbackup flag, we use the default password
// for wallet encryption.
if !cfg.NoSeedBackup {
params, err := waitForWalletPassword(cfg, pwService)
params, err := waitForWalletPassword(cfg, pwService, interceptor.ShutdownChannel())
if err != nil {
err := fmt.Errorf("unable to set up wallet password "+
"listeners: %v", err)
@ -793,7 +794,7 @@ func Main(cfg *Config, lisCfg ListenerCfg, shutdownChan <-chan struct{}) error {
"start_height=%v", bestHeight)
for {
if !signal.Alive() {
if !interceptor.Alive() {
return nil
}
@ -856,7 +857,7 @@ func Main(cfg *Config, lisCfg ListenerCfg, shutdownChan <-chan struct{}) error {
// Wait for shutdown signal from either a graceful server stop or from
// the interrupt handler.
<-shutdownChan
<-interceptor.ShutdownChannel()
return nil
}
@ -1328,7 +1329,8 @@ func startRestProxy(cfg *Config, rpcServer *rpcServer, restDialOpts []grpc.DialO
// waitForWalletPassword blocks until a password is provided by the user to
// this RPC server.
func waitForWalletPassword(cfg *Config,
pwService *walletunlocker.UnlockerService) (*WalletUnlockParams, error) {
pwService *walletunlocker.UnlockerService,
shutdownChan <-chan struct{}) (*WalletUnlockParams, error) {
chainConfig := cfg.Bitcoin
if cfg.registeredChains.PrimaryChain() == chainreg.LitecoinChain {
@ -1430,7 +1432,8 @@ func waitForWalletPassword(cfg *Config,
MacResponseChan: pwService.MacResponseChan,
}, nil
case <-signal.ShutdownChannel():
// If we got a shutdown signal we just return with an error immediately
case <-shutdownChan:
return nil, fmt.Errorf("shutting down")
}
}

104
log.go

@ -84,12 +84,36 @@ var (
atplLog = addLndPkgLogger("ATPL")
)
// genSubLogger creates a logger for a subsystem. We provide an instance of
// a signal.Interceptor to be able to shutdown in the case of a critical error.
func genSubLogger(root *build.RotatingLogWriter,
interceptor signal.Interceptor) func(string) btclog.Logger {
// Create a shutdown function which will request shutdown from our
// interceptor if it is listening.
shutdown := func() {
if !interceptor.Listening() {
return
}
interceptor.RequestShutdown()
}
// Return a function which will create a sublogger from our root
// logger without shutdown fn.
return func(tag string) btclog.Logger {
return root.GenSubLogger(tag, shutdown)
}
}
// SetupLoggers initializes all package-global logger variables.
func SetupLoggers(root *build.RotatingLogWriter) {
func SetupLoggers(root *build.RotatingLogWriter, interceptor signal.Interceptor) {
genLogger := genSubLogger(root, interceptor)
// Now that we have the proper root logger, we can replace the
// placeholder lnd package loggers.
for _, l := range lndPkgLoggers {
l.Logger = build.NewSubLogger(l.subsystem, root.GenSubLogger)
l.Logger = build.NewSubLogger(l.subsystem, genLogger)
SetSubLogger(root, l.subsystem, l.Logger)
}
@ -98,51 +122,55 @@ func SetupLoggers(root *build.RotatingLogWriter) {
signal.UseLogger(ltndLog)
autopilot.UseLogger(atplLog)
AddSubLogger(root, "LNWL", lnwallet.UseLogger)
AddSubLogger(root, "DISC", discovery.UseLogger)
AddSubLogger(root, "NTFN", chainntnfs.UseLogger)
AddSubLogger(root, "CHDB", channeldb.UseLogger)
AddSubLogger(root, "HSWC", htlcswitch.UseLogger)
AddSubLogger(root, "CMGR", connmgr.UseLogger)
AddSubLogger(root, "BTCN", neutrino.UseLogger)
AddSubLogger(root, "CNCT", contractcourt.UseLogger)
AddSubLogger(root, "SPHX", sphinx.UseLogger)
AddSubLogger(root, "SWPR", sweep.UseLogger)
AddSubLogger(root, "SGNR", signrpc.UseLogger)
AddSubLogger(root, "WLKT", walletrpc.UseLogger)
AddSubLogger(root, "ARPC", autopilotrpc.UseLogger)
AddSubLogger(root, "INVC", invoices.UseLogger)
AddSubLogger(root, "NANN", netann.UseLogger)
AddSubLogger(root, "WTWR", watchtower.UseLogger)
AddSubLogger(root, "NTFR", chainrpc.UseLogger)
AddSubLogger(root, "IRPC", invoicesrpc.UseLogger)
AddSubLogger(root, "CHNF", channelnotifier.UseLogger)
AddSubLogger(root, "CHBU", chanbackup.UseLogger)
AddSubLogger(root, "PROM", monitoring.UseLogger)
AddSubLogger(root, "WTCL", wtclient.UseLogger)
AddSubLogger(root, "PRNF", peernotifier.UseLogger)
AddSubLogger(root, "CHFD", chanfunding.UseLogger)
AddSubLogger(root, "PEER", peer.UseLogger)
AddSubLogger(root, "CHCL", chancloser.UseLogger)
AddSubLogger(root, "LNWL", interceptor, lnwallet.UseLogger)
AddSubLogger(root, "DISC", interceptor, discovery.UseLogger)
AddSubLogger(root, "NTFN", interceptor, chainntnfs.UseLogger)
AddSubLogger(root, "CHDB", interceptor, channeldb.UseLogger)
AddSubLogger(root, "HSWC", interceptor, htlcswitch.UseLogger)
AddSubLogger(root, "CMGR", interceptor, connmgr.UseLogger)
AddSubLogger(root, "BTCN", interceptor, neutrino.UseLogger)
AddSubLogger(root, "CNCT", interceptor, contractcourt.UseLogger)
AddSubLogger(root, "SPHX", interceptor, sphinx.UseLogger)
AddSubLogger(root, "SWPR", interceptor, sweep.UseLogger)
AddSubLogger(root, "SGNR", interceptor, signrpc.UseLogger)
AddSubLogger(root, "WLKT", interceptor, walletrpc.UseLogger)
AddSubLogger(root, "ARPC", interceptor, autopilotrpc.UseLogger)
AddSubLogger(root, "INVC", interceptor, invoices.UseLogger)
AddSubLogger(root, "NANN", interceptor, netann.UseLogger)
AddSubLogger(root, "WTWR", interceptor, watchtower.UseLogger)
AddSubLogger(root, "NTFR", interceptor, chainrpc.UseLogger)
AddSubLogger(root, "IRPC", interceptor, invoicesrpc.UseLogger)
AddSubLogger(root, "CHNF", interceptor, channelnotifier.UseLogger)
AddSubLogger(root, "CHBU", interceptor, chanbackup.UseLogger)
AddSubLogger(root, "PROM", interceptor, monitoring.UseLogger)
AddSubLogger(root, "WTCL", interceptor, wtclient.UseLogger)
AddSubLogger(root, "PRNF", interceptor, peernotifier.UseLogger)
AddSubLogger(root, "CHFD", interceptor, chanfunding.UseLogger)
AddSubLogger(root, "PEER", interceptor, peer.UseLogger)
AddSubLogger(root, "CHCL", interceptor, chancloser.UseLogger)
AddSubLogger(root, routing.Subsystem, routing.UseLogger, localchans.UseLogger)
AddSubLogger(root, routerrpc.Subsystem, routerrpc.UseLogger)
AddSubLogger(root, chanfitness.Subsystem, chanfitness.UseLogger)
AddSubLogger(root, verrpc.Subsystem, verrpc.UseLogger)
AddSubLogger(root, healthcheck.Subsystem, healthcheck.UseLogger)
AddSubLogger(root, chainreg.Subsystem, chainreg.UseLogger)
AddSubLogger(root, chanacceptor.Subsystem, chanacceptor.UseLogger)
AddSubLogger(root, funding.Subsystem, funding.UseLogger)
AddSubLogger(root, routing.Subsystem, interceptor, routing.UseLogger, localchans.UseLogger)
AddSubLogger(root, routerrpc.Subsystem, interceptor, routerrpc.UseLogger)
AddSubLogger(root, chanfitness.Subsystem, interceptor, chanfitness.UseLogger)
AddSubLogger(root, verrpc.Subsystem, interceptor, verrpc.UseLogger)
AddSubLogger(root, healthcheck.Subsystem, interceptor, healthcheck.UseLogger)
AddSubLogger(root, chainreg.Subsystem, interceptor, chainreg.UseLogger)
AddSubLogger(root, chanacceptor.Subsystem, interceptor, chanacceptor.UseLogger)
AddSubLogger(root, funding.Subsystem, interceptor, funding.UseLogger)
}
// AddSubLogger is a helper method to conveniently create and register the
// logger of one or more sub systems.
func AddSubLogger(root *build.RotatingLogWriter, subsystem string,
useLoggers ...func(btclog.Logger)) {
interceptor signal.Interceptor, useLoggers ...func(btclog.Logger)) {
// genSubLogger will return a callback for creating a logger instance,
// which we will give to the root logger.
genLogger := genSubLogger(root, interceptor)
// Create and register just a single logger to prevent them from
// overwriting each other internally.
logger := build.NewSubLogger(subsystem, root.GenSubLogger)
logger := build.NewSubLogger(subsystem, genLogger)
SetSubLogger(root, subsystem, logger, useLoggers...)
}

@ -45,17 +45,18 @@ func Start(extraArgs string, unlockerReady, rpcReady Callback) {
// LoadConfig below.
os.Args = append(os.Args, splitArgs...)
// Load the configuration, and parse the extra arguments as command
// line options. This function will also set up logging properly.
loadedConfig, err := lnd.LoadConfig()
// Hook interceptor for os signals.
shutdownInterceptor, err := signal.Intercept()
if err != nil {
_, _ = fmt.Fprintln(os.Stderr, err)
rpcReady.OnError(err)
return
}
// Hook interceptor for os signals.
if err := signal.Intercept(); err != nil {
// Load the configuration, and parse the extra arguments as command
// line options. This function will also set up logging properly.
loadedConfig, err := lnd.LoadConfig(shutdownInterceptor)
if err != nil {
_, _ = fmt.Fprintln(os.Stderr, err)
rpcReady.OnError(err)
return
@ -85,7 +86,7 @@ func Start(extraArgs string, unlockerReady, rpcReady Callback) {
// be executed in the case of a graceful shutdown.
go func() {
if err := lnd.Main(
loadedConfig, cfg, signal.ShutdownChannel(),
loadedConfig, cfg, shutdownInterceptor,
); err != nil {
if e, ok := err.(*flags.Error); ok &&
e.Type == flags.ErrHelp {

@ -520,6 +520,9 @@ type rpcServer struct {
// extRestRegistrar is optional and specifies the registration
// callback to register external REST subservers.
extRestRegistrar RestRegistrar
// interceptor is used to be able to request a shutdown
interceptor signal.Interceptor
}
// A compile time check to ensure that rpcServer fully implements the
@ -531,7 +534,8 @@ var _ lnrpc.LightningServer = (*rpcServer)(nil)
// be used to register the LightningService with the gRPC server.
func newRPCServer(cfg *Config, interceptorChain *rpcperms.InterceptorChain,
extSubserverCfg *RPCSubserverConfig,
extRestRegistrar RestRegistrar) *rpcServer {
extRestRegistrar RestRegistrar,
interceptor signal.Interceptor) *rpcServer {
// We go trhough the list of registered sub-servers, and create a gRPC
// handler for each. These are used to register with the gRPC server
@ -552,6 +556,7 @@ func newRPCServer(cfg *Config, interceptorChain *rpcperms.InterceptorChain,
extSubserverCfg: extSubserverCfg,
extRestRegistrar: extRestRegistrar,
quit: make(chan struct{}, 1),
interceptor: interceptor,
}
}
@ -5383,8 +5388,7 @@ func (r *rpcServer) GetNetworkInfo(ctx context.Context,
// a graceful shutdown of the daemon.
func (r *rpcServer) StopDaemon(ctx context.Context,
_ *lnrpc.StopRequest) (*lnrpc.StopResponse, error) {
signal.RequestShutdown()
r.interceptor.RequestShutdown()
return &lnrpc.StopResponse{}, nil
}

@ -14,29 +14,40 @@ import (
)
var (
// interruptChannel is used to receive SIGINT (Ctrl+C) signals.
interruptChannel = make(chan os.Signal, 1)
// shutdownRequestChannel is used to request the daemon to shutdown
// gracefully, similar to when receiving SIGINT.
shutdownRequestChannel = make(chan struct{})
// started indicates whether we have started our main interrupt handler.
// This field should be used atomically.
started int32
// quit is closed when instructing the main interrupt handler to exit.
quit = make(chan struct{})
// shutdownChannel is closed once the main interrupt handler exits.
shutdownChannel = make(chan struct{})
)
// Intercept starts the interception of interrupt signals. Note that this
// function can only be called once.
func Intercept() error {
// Interceptor contains channels and methods regarding application shutdown
// and interrupt signals
type Interceptor struct {
// interruptChannel is used to receive SIGINT (Ctrl+C) signals.
interruptChannel chan os.Signal
// shutdownChannel is closed once the main interrupt handler exits.
shutdownChannel chan struct{}
// shutdownRequestChannel is used to request the daemon to shutdown
// gracefully, similar to when receiving SIGINT.
shutdownRequestChannel chan struct{}
// quit is closed when instructing the main interrupt handler to exit.
quit chan struct{}
}
// Intercept starts the interception of interrupt signals and returns an `Interceptor` instance.
// Note that any previous active interceptor must be stopped before a new one can be created
func Intercept() (Interceptor, error) {
if !atomic.CompareAndSwapInt32(&started, 0, 1) {
return errors.New("intercept already started")
return Interceptor{}, errors.New("intercept already started")
}
channels := Interceptor{
interruptChannel: make(chan os.Signal, 1),
shutdownChannel: make(chan struct{}),
shutdownRequestChannel: make(chan struct{}),
quit: make(chan struct{}),
}
signalsToCatch := []os.Signal{
@ -45,10 +56,10 @@ func Intercept() error {
syscall.SIGTERM,
syscall.SIGQUIT,
}
signal.Notify(interruptChannel, signalsToCatch...)
go mainInterruptHandler()
signal.Notify(channels.interruptChannel, signalsToCatch...)
go channels.mainInterruptHandler()
return nil
return channels, nil
}
// mainInterruptHandler listens for SIGINT (Ctrl+C) signals on the
@ -56,7 +67,8 @@ func Intercept() error {
// invokes the registered interruptCallbacks accordingly. It also listens for
// callback registration.
// It must be run as a goroutine.
func mainInterruptHandler() {
func (c *Interceptor) mainInterruptHandler() {
defer atomic.StoreInt32(&started, 0)
// isShutdown is a flag which is used to indicate whether or not
// the shutdown signal has already been received and hence any future
// attempts to add a new interrupt handler should invoke them
@ -76,22 +88,23 @@ func mainInterruptHandler() {
// Signal the main interrupt handler to exit, and stop accept
// post-facto requests.
close(quit)
close(c.quit)
}
for {
select {
case signal := <-interruptChannel:
case signal := <-c.interruptChannel:
log.Infof("Received %v", signal)
shutdown()
case <-shutdownRequestChannel:
case <-c.shutdownRequestChannel:
log.Infof("Received shutdown request.")
shutdown()
case <-quit:
case <-c.quit:
log.Infof("Gracefully shutting down.")
close(shutdownChannel)
close(c.shutdownChannel)
signal.Stop(c.interruptChannel)
return
}
}
@ -99,7 +112,7 @@ func mainInterruptHandler() {
// Listening returns true if the main interrupt handler has been started, and
// has not been killed.
func Listening() bool {
func (c *Interceptor) Listening() bool {
// If our started field is not set, we are not yet listening for
// interrupts.
if atomic.LoadInt32(&started) != 1 {
@ -108,13 +121,13 @@ func Listening() bool {
// If we have started our main goroutine, we check whether we have
// stopped it yet.
return Alive()
return c.Alive()
}
// Alive returns true if the main interrupt handler has not been killed.
func Alive() bool {
func (c *Interceptor) Alive() bool {
select {
case <-quit:
case <-c.quit:
return false
default:
return true
@ -122,15 +135,15 @@ func Alive() bool {
}
// RequestShutdown initiates a graceful shutdown from the application.
func RequestShutdown() {
func (c *Interceptor) RequestShutdown() {
select {
case shutdownRequestChannel <- struct{}{}:
case <-quit:
case c.shutdownRequestChannel <- struct{}{}:
case <-c.quit:
}
}
// ShutdownChannel returns the channel that will be closed once the main
// interrupt handler has exited.
func ShutdownChannel() <-chan struct{} {
return shutdownChannel
func (c *Interceptor) ShutdownChannel() <-chan struct{} {
return c.shutdownChannel
}