forgejo/modules/graceful/manager_windows.go
JonRB cb37c6ba5c
call builtinUnused() if internal SSH is disabled (#20877)
The graceful manager waits for 4 listeners to be created or to be told that they are not needed. If it is not told about them it will indefinitely and timeout. 

This leads to SVC hosts not being told of being in the readyState but on Unix would lead to the termination of the process.

There was an unfortunate regression in #20299 which missed this subtly and in the case whereby SSH is disabled the `builtinUnused()` is not called.

This PR adds a call to `builtinUnused()` when not using the builtin ssh to allow `createServerWaitGroup.Done()` to be called. 

In addition it was noted that the if/else clauses for timeout informing of the SVC host were in the wrong order. These have been swapped.

Fix #20609
2022-08-20 22:09:41 +01:00

251 lines
6.7 KiB
Go

// 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
//go:build windows
package graceful
import (
"context"
"os"
"runtime/pprof"
"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
shutdownCtx context.Context
hammerCtx context.Context
terminateCtx context.Context
managerCtx context.Context
shutdownCtxCancel context.CancelFunc
hammerCtxCancel context.CancelFunc
terminateCtxCancel context.CancelFunc
managerCtxCancel context.CancelFunc
runningServerWaitGroup sync.WaitGroup
createServerWaitGroup sync.WaitGroup
terminateWaitGroup sync.WaitGroup
shutdownRequested chan struct{}
toRunAtShutdown []func()
toRunAtHammer []func()
toRunAtTerminate []func()
}
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 contexts
g.terminateCtx, g.terminateCtxCancel = context.WithCancel(g.ctx)
g.shutdownCtx, g.shutdownCtxCancel = context.WithCancel(g.ctx)
g.hammerCtx, g.hammerCtxCancel = context.WithCancel(g.ctx)
g.managerCtx, g.managerCtxCancel = context.WithCancel(g.ctx)
// Next add pprof labels to these contexts
g.terminateCtx = pprof.WithLabels(g.terminateCtx, pprof.Labels("graceful-lifecycle", "with-terminate"))
g.shutdownCtx = pprof.WithLabels(g.shutdownCtx, pprof.Labels("graceful-lifecycle", "with-shutdown"))
g.hammerCtx = pprof.WithLabels(g.hammerCtx, pprof.Labels("graceful-lifecycle", "with-hammer"))
g.managerCtx = pprof.WithLabels(g.managerCtx, pprof.Labels("graceful-lifecycle", "with-manager"))
// Now label this and all goroutines created by this goroutine with the graceful-lifecycle manager
pprof.SetGoroutineLabels(g.managerCtx)
defer pprof.SetGoroutineLabels(g.ctx)
// Make channels
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
//lint:ignore SA1019 We use IsAnInteractiveSession because IsWindowsService has a different permissions profile
isAnInteractiveSession, err := svc.IsAnInteractiveSession()
if err != nil {
log.Error("Unable to ascertain if running as an Windows Service: %v", err)
return
}
if isAnInteractiveSession {
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, WaitHint: uint32(setting.StartupTimeout / time.Millisecond)}
} else {
status <- svc.Status{State: svc.StartPending}
}
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.hammerCtx.Done():
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
}
}
}