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// +build !windows
// Copyright 2019 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package graceful
import (
"context"
"errors"
"os"
"os/signal"
"sync"
"syscall"
"time"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/setting"
)
// Manager manages the graceful shutdown process
type Manager struct {
isChild bool
forked bool
lock *sync.RWMutex
state state
shutdown chan struct{}
hammer chan struct{}
terminate chan struct{}
done chan struct{}
runningServerWaitGroup sync.WaitGroup
createServerWaitGroup sync.WaitGroup
terminateWaitGroup sync.WaitGroup
}
func newGracefulManager(ctx context.Context) *Manager {
manager := &Manager{
isChild: len(os.Getenv(listenFDs)) > 0 && os.Getppid() > 1,
lock: &sync.RWMutex{},
}
manager.createServerWaitGroup.Add(numberOfServersToCreate)
manager.start(ctx)
return manager
}
func (g *Manager) start(ctx context.Context) {
// Make channels
g.terminate = make(chan struct{})
g.shutdown = make(chan struct{})
g.hammer = make(chan struct{})
g.done = make(chan struct{})
// Set the running state & handle signals
g.setState(stateRunning)
go g.handleSignals(ctx)
// Handle clean up of unused provided listeners and delayed start-up
startupDone := make(chan struct{})
go func() {
defer close(startupDone)
// Wait till we're done getting all of the listeners and then close
// the unused ones
g.createServerWaitGroup.Wait()
// Ignore the error here there's not much we can do with it
// They're logged in the CloseProvidedListeners function
_ = CloseProvidedListeners()
}()
if setting.StartupTimeout > 0 {
go func() {
select {
case <-startupDone:
return
case <-g.IsShutdown():
func() {
// When waitgroup counter goes negative it will panic - we don't care about this so we can just ignore it.
defer func() {
_ = recover()
}()
// Ensure that the createServerWaitGroup stops waiting
for {
g.createServerWaitGroup.Done()
}
}()
return
case <-time.After(setting.StartupTimeout):
log.Error("Startup took too long! Shutting down")
g.doShutdown()
}
}()
}
}
func (g *Manager) handleSignals(ctx context.Context) {
signalChannel := make(chan os.Signal, 1)
signal.Notify(
signalChannel,
syscall.SIGHUP,
syscall.SIGUSR1,
syscall.SIGUSR2,
syscall.SIGINT,
syscall.SIGTERM,
syscall.SIGTSTP,
)
pid := syscall.Getpid()
for {
select {
case sig := <-signalChannel:
switch sig {
case syscall.SIGHUP:
log.Info("PID: %d. Received SIGHUP. Attempting GracefulRestart...", pid)
g.DoGracefulRestart()
case syscall.SIGUSR1:
log.Warn("PID %d. Received SIGUSR1. Releasing and reopening logs", pid)
if err := log.ReleaseReopen(); err != nil {
log.Error("Error whilst releasing and reopening logs: %v", err)
}
case syscall.SIGUSR2:
log.Warn("PID %d. Received SIGUSR2. Hammering...", pid)
g.DoImmediateHammer()
case syscall.SIGINT:
log.Warn("PID %d. Received SIGINT. Shutting down...", pid)
g.DoGracefulShutdown()
case syscall.SIGTERM:
log.Warn("PID %d. Received SIGTERM. Shutting down...", pid)
g.DoGracefulShutdown()
case syscall.SIGTSTP:
log.Info("PID %d. Received SIGTSTP.", pid)
default:
log.Info("PID %d. Received %v.", pid, sig)
}
case <-ctx.Done():
log.Warn("PID: %d. Background context for manager closed - %v - Shutting down...", pid, ctx.Err())
g.DoGracefulShutdown()
}
}
}
func (g *Manager) doFork() error {
g.lock.Lock()
if g.forked {
g.lock.Unlock()
return errors.New("another process already forked. Ignoring this one")
}
g.forked = true
g.lock.Unlock()
// We need to move the file logs to append pids
setting.RestartLogsWithPIDSuffix()
_, err := RestartProcess()
return err
}
// DoGracefulRestart causes a graceful restart
func (g *Manager) DoGracefulRestart() {
if setting.GracefulRestartable {
log.Info("PID: %d. Forking...", os.Getpid())
err := g.doFork()
if err != nil && err.Error() != "another process already forked. Ignoring this one" {
log.Error("Error whilst forking from PID: %d : %v", os.Getpid(), err)
}
} else {
log.Info("PID: %d. Not set restartable. Shutting down...", os.Getpid())
g.doShutdown()
}
}
// DoImmediateHammer causes an immediate hammer
func (g *Manager) DoImmediateHammer() {
g.doHammerTime(0 * time.Second)
}
// DoGracefulShutdown causes a graceful shutdown
func (g *Manager) DoGracefulShutdown() {
g.doShutdown()
}
// RegisterServer registers the running of a listening server, in the case of unix this means that the parent process can now die.
// Any call to RegisterServer must be matched by a call to ServerDone
func (g *Manager) RegisterServer() {
KillParent()
g.runningServerWaitGroup.Add(1)
}
|
