forgejo/modules/graceful/manager_windows.go
zeripath cbaa1de9ec Add Graceful shutdown for Windows and hooks for shutdown of goroutines (#8964)
* Graceful Shutdown for windows and others

Restructures modules/graceful, adding shutdown for windows, removing and
replacing the old minwinsvc code.

Creates a new waitGroup - terminate which allows for goroutines to
finish up after the shutdown of the servers.

Shutdown and terminate hooks are added for goroutines.

* Remove unused functions - these can be added in a different PR

* Add startup timeout functionality

* Document STARTUP_TIMEOUT
2019-11-21 13:32:02 -05:00

162 lines
3.7 KiB
Go

// +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.
// This code is heavily inspired by the archived gofacebook/gracenet/net.go handler
package graceful
import (
"os"
"strconv"
"sync"
"time"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/setting"
"golang.org/x/sys/windows/svc"
"golang.org/x/sys/windows/svc/debug"
)
var WindowsServiceName = "gitea"
const (
hammerCode = 128
hammerCmd = svc.Cmd(hammerCode)
acceptHammerCode = svc.Accepted(hammerCode)
)
type gracefulManager struct {
isChild bool
lock *sync.RWMutex
state state
shutdown chan struct{}
hammer chan struct{}
terminate chan struct{}
runningServerWaitGroup sync.WaitGroup
createServerWaitGroup sync.WaitGroup
terminateWaitGroup sync.WaitGroup
}
func newGracefulManager() *gracefulManager {
manager := &gracefulManager{
isChild: false,
lock: &sync.RWMutex{},
}
manager.createServerWaitGroup.Add(numberOfServersToCreate)
manager.Run()
return manager
}
func (g *gracefulManager) Run() {
g.setState(stateRunning)
if skip, _ := strconv.ParseBool(os.Getenv("SKIP_MINWINSVC")); skip {
return
}
run := svc.Run
isInteractive, err := svc.IsAnInteractiveSession()
if err != nil {
log.Error("Unable to ascertain if running as an Interactive Session: %v", err)
return
}
if isInteractive {
run = debug.Run
}
go run(WindowsServiceName, g)
}
// Execute makes gracefulManager implement svc.Handler
func (g *gracefulManager) Execute(args []string, changes <-chan svc.ChangeRequest, status chan<- svc.Status) (svcSpecificEC bool, exitCode uint32) {
if setting.StartupTimeout > 0 {
status <- svc.Status{State: svc.StartPending}
} else {
status <- svc.Status{State: svc.StartPending, WaitHint: uint32(setting.StartupTimeout/time.Millisecond)}
}
// Now need to wait for everything to start...
if !g.awaitServer(setting.StartupTimeout) {
return false, 1
}
// We need to implement some way of svc.AcceptParamChange/svc.ParamChange
status <- svc.Status{
State: svc.Running,
Accepts: svc.AcceptStop | svc.AcceptShutdown | acceptHammerCode,
}
waitTime := 30 * time.Second
loop:
for change := range changes {
switch change.Cmd {
case svc.Interrogate:
status <- change.CurrentStatus
case svc.Stop, svc.Shutdown:
g.doShutdown()
waitTime += setting.GracefulHammerTime
break loop
case hammerCode:
g.doShutdown()
g.doHammerTime(0 *time.Second)
break loop
default:
log.Debug("Unexpected control request: %v", change.Cmd)
}
}
status <- svc.Status{
State: svc.StopPending,
WaitHint: uint32(waitTime/time.Millisecond),
}
hammerLoop:
for {
select {
case change := <-changes:
switch change.Cmd {
case svc.Interrogate:
status <- change.CurrentStatus
case svc.Stop, svc.Shutdown, hammerCmd:
g.doHammerTime(0 * time.Second)
break hammerLoop
default:
log.Debug("Unexpected control request: %v", change.Cmd)
}
case <-g.hammer:
break hammerLoop
}
}
return false, 0
}
func (g *gracefulManager) RegisterServer() {
g.runningServerWaitGroup.Add(1)
}
func (g *gracefulManager) awaitServer(limit time.Duration) bool {
c := make(chan struct{})
go func() {
defer close(c)
g.createServerWaitGroup.Wait()
}()
if limit > 0 {
select {
case <-c:
return true // completed normally
case <-time.After(limit):
return false // timed out
case <-g.IsShutdown():
return false
}
} else {
select {
case <-c:
return true // completed normally
case <-g.IsShutdown():
return false
}
}
}