forgejo/modules/graceful/manager_windows.go
zeripath 113c1557ff
Fix regression from #14623 - use debug SVC handler only on interactive sessions (#15210)
Unfortunately #14623 changed from the deprecated IsInteractiveSession to
IsWindowsService without recognising that they are the complement of
each other.

This means that Windows SVC control is not working correctly. This PR
adds some Tracing statements but also fixes the bug.

Fix #15159

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: techknowlogick <techknowlogick@gitea.io>
2021-03-31 22:48:48 +03:00

228 lines
5.5 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 (
"context"
"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"
)
// WindowsServiceName is the name of the Windows service
var WindowsServiceName = "gitea"
const (
hammerCode = 128
hammerCmd = svc.Cmd(hammerCode)
acceptHammerCode = svc.Accepted(hammerCode)
)
// Manager manages the graceful shutdown process
type Manager struct {
ctx context.Context
isChild 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
shutdownRequested chan struct{}
}
func newGracefulManager(ctx context.Context) *Manager {
manager := &Manager{
isChild: false,
lock: &sync.RWMutex{},
ctx: ctx,
}
manager.createServerWaitGroup.Add(numberOfServersToCreate)
manager.start()
return manager
}
func (g *Manager) start() {
// Make channels
g.terminate = make(chan struct{})
g.shutdown = make(chan struct{})
g.hammer = make(chan struct{})
g.done = make(chan struct{})
g.shutdownRequested = make(chan struct{})
// Set the running state
g.setState(stateRunning)
if skip, _ := strconv.ParseBool(os.Getenv("SKIP_MINWINSVC")); skip {
log.Trace("Skipping SVC check as SKIP_MINWINSVC is set")
return
}
// Make SVC process
run := svc.Run
isWindowsService, err := svc.IsWindowsService()
if err != nil {
log.Error("Unable to ascertain if running as an Windows Service: %v", err)
return
}
if !isWindowsService {
log.Trace("Not running a service ... using the debug SVC manager")
run = debug.Run
}
go func() {
_ = run(WindowsServiceName, g)
}()
}
// Execute makes Manager implement svc.Handler
func (g *Manager) 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)}
}
log.Trace("Awaiting server start-up")
// Now need to wait for everything to start...
if !g.awaitServer(setting.StartupTimeout) {
log.Trace("... start-up failed ... Stopped")
return false, 1
}
log.Trace("Sending Running state to SVC")
// We need to implement some way of svc.AcceptParamChange/svc.ParamChange
status <- svc.Status{
State: svc.Running,
Accepts: svc.AcceptStop | svc.AcceptShutdown | acceptHammerCode,
}
log.Trace("Started")
waitTime := 30 * time.Second
loop:
for {
select {
case <-g.ctx.Done():
log.Trace("Shutting down")
g.DoGracefulShutdown()
waitTime += setting.GracefulHammerTime
break loop
case <-g.shutdownRequested:
log.Trace("Shutting down")
waitTime += setting.GracefulHammerTime
break loop
case change := <-changes:
switch change.Cmd {
case svc.Interrogate:
log.Trace("SVC sent interrogate")
status <- change.CurrentStatus
case svc.Stop, svc.Shutdown:
log.Trace("SVC requested shutdown - shutting down")
g.DoGracefulShutdown()
waitTime += setting.GracefulHammerTime
break loop
case hammerCode:
log.Trace("SVC requested hammer - shutting down and hammering immediately")
g.DoGracefulShutdown()
g.DoImmediateHammer()
break loop
default:
log.Debug("Unexpected control request: %v", change.Cmd)
}
}
}
log.Trace("Sending StopPending state to SVC")
status <- svc.Status{
State: svc.StopPending,
WaitHint: uint32(waitTime / time.Millisecond),
}
hammerLoop:
for {
select {
case change := <-changes:
switch change.Cmd {
case svc.Interrogate:
log.Trace("SVC sent interrogate")
status <- change.CurrentStatus
case svc.Stop, svc.Shutdown, hammerCmd:
log.Trace("SVC requested hammer - hammering immediately")
g.DoImmediateHammer()
break hammerLoop
default:
log.Debug("Unexpected control request: %v", change.Cmd)
}
case <-g.hammer:
break hammerLoop
}
}
log.Trace("Stopped")
return false, 0
}
// DoImmediateHammer causes an immediate hammer
func (g *Manager) DoImmediateHammer() {
g.doHammerTime(0 * time.Second)
}
// DoGracefulShutdown causes a graceful shutdown
func (g *Manager) DoGracefulShutdown() {
g.lock.Lock()
select {
case <-g.shutdownRequested:
g.lock.Unlock()
default:
close(g.shutdownRequested)
g.lock.Unlock()
g.doShutdown()
}
}
// RegisterServer registers the running of a listening server.
// Any call to RegisterServer must be matched by a call to ServerDone
func (g *Manager) RegisterServer() {
g.runningServerWaitGroup.Add(1)
}
func (g *Manager) 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
}
}
}