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gitea/modules/graceful/manager.go
wxiaoguang 18f26cfbf7
Improve queue and logger context (#24924)
Before there was a "graceful function": RunWithShutdownFns, it's mainly
for some modules which doesn't support context.

The old queue system doesn't work well with context, so the old queues
need it.

After the queue refactoring, the new queue works with context well, so,
use Golang context as much as possible, the `RunWithShutdownFns` could
be removed (replaced by RunWithCancel for context cancel mechanism), the
related code could be simplified.

This PR also fixes some legacy queue-init problems, eg:

* typo : archiver: "unable to create codes indexer queue" => "unable to
create repo-archive queue"
* no nil check for failed queues, which causes unfriendly panic

After this PR, many goroutines could have better display name:

![image](https://github.com/go-gitea/gitea/assets/2114189/701b2a9b-8065-4137-aeaa-0bda2b34604a)

![image](https://github.com/go-gitea/gitea/assets/2114189/f1d5f50f-0534-40f0-b0be-f2c9daa5fe92)
2023-05-26 07:31:55 +00:00

293 lines
8 KiB
Go

// Copyright 2019 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package graceful
import (
"context"
"runtime/pprof"
"sync"
"time"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/process"
"code.gitea.io/gitea/modules/setting"
)
type state uint8
const (
stateInit state = iota
stateRunning
stateShuttingDown
stateTerminate
)
type RunCanceler interface {
Run()
Cancel()
}
// There are some places that could inherit sockets:
//
// * HTTP or HTTPS main listener
// * HTTP or HTTPS install listener
// * HTTP redirection fallback
// * Builtin SSH listener
//
// If you add a new place you must increment this number
// and add a function to call manager.InformCleanup if it's not going to be used
const numberOfServersToCreate = 4
// Manager represents the graceful server manager interface
var manager *Manager
var initOnce = sync.Once{}
// GetManager returns the Manager
func GetManager() *Manager {
InitManager(context.Background())
return manager
}
// InitManager creates the graceful manager in the provided context
func InitManager(ctx context.Context) {
initOnce.Do(func() {
manager = newGracefulManager(ctx)
// Set the process default context to the HammerContext
process.DefaultContext = manager.HammerContext()
})
}
// RunWithCancel helps to run a function with a custom context, the Cancel function will be called at shutdown
// The Cancel function should stop the Run function in predictable time.
func (g *Manager) RunWithCancel(rc RunCanceler) {
g.RunAtShutdown(context.Background(), rc.Cancel)
g.runningServerWaitGroup.Add(1)
defer g.runningServerWaitGroup.Done()
defer func() {
if err := recover(); err != nil {
log.Critical("PANIC during RunWithCancel: %v\nStacktrace: %s", err, log.Stack(2))
g.doShutdown()
}
}()
rc.Run()
}
// RunWithShutdownContext takes a function that has a context to watch for shutdown.
// After the provided context is Done(), the main function must return once shutdown is complete.
// (Optionally the HammerContext may be obtained and waited for however, this should be avoided if possible.)
func (g *Manager) RunWithShutdownContext(run func(context.Context)) {
g.runningServerWaitGroup.Add(1)
defer g.runningServerWaitGroup.Done()
defer func() {
if err := recover(); err != nil {
log.Critical("PANIC during RunWithShutdownContext: %v\nStacktrace: %s", err, log.Stack(2))
g.doShutdown()
}
}()
ctx := g.ShutdownContext()
pprof.SetGoroutineLabels(ctx) // We don't have a label to restore back to but I think this is fine
run(ctx)
}
// RunAtTerminate adds to the terminate wait group and creates a go-routine to run the provided function at termination
func (g *Manager) RunAtTerminate(terminate func()) {
g.terminateWaitGroup.Add(1)
g.lock.Lock()
defer g.lock.Unlock()
g.toRunAtTerminate = append(g.toRunAtTerminate,
func() {
defer g.terminateWaitGroup.Done()
defer func() {
if err := recover(); err != nil {
log.Critical("PANIC during RunAtTerminate: %v\nStacktrace: %s", err, log.Stack(2))
}
}()
terminate()
})
}
// RunAtShutdown creates a go-routine to run the provided function at shutdown
func (g *Manager) RunAtShutdown(ctx context.Context, shutdown func()) {
g.lock.Lock()
defer g.lock.Unlock()
g.toRunAtShutdown = append(g.toRunAtShutdown,
func() {
defer func() {
if err := recover(); err != nil {
log.Critical("PANIC during RunAtShutdown: %v\nStacktrace: %s", err, log.Stack(2))
}
}()
select {
case <-ctx.Done():
return
default:
shutdown()
}
})
}
func (g *Manager) doShutdown() {
if !g.setStateTransition(stateRunning, stateShuttingDown) {
g.DoImmediateHammer()
return
}
g.lock.Lock()
g.shutdownCtxCancel()
atShutdownCtx := pprof.WithLabels(g.hammerCtx, pprof.Labels("graceful-lifecycle", "post-shutdown"))
pprof.SetGoroutineLabels(atShutdownCtx)
for _, fn := range g.toRunAtShutdown {
go fn()
}
g.lock.Unlock()
if setting.GracefulHammerTime >= 0 {
go g.doHammerTime(setting.GracefulHammerTime)
}
go func() {
g.WaitForServers()
// Mop up any remaining unclosed events.
g.doHammerTime(0)
<-time.After(1 * time.Second)
g.doTerminate()
g.WaitForTerminate()
g.lock.Lock()
g.managerCtxCancel()
g.lock.Unlock()
}()
}
func (g *Manager) doHammerTime(d time.Duration) {
time.Sleep(d)
g.lock.Lock()
select {
case <-g.hammerCtx.Done():
default:
log.Warn("Setting Hammer condition")
g.hammerCtxCancel()
atHammerCtx := pprof.WithLabels(g.terminateCtx, pprof.Labels("graceful-lifecycle", "post-hammer"))
pprof.SetGoroutineLabels(atHammerCtx)
}
g.lock.Unlock()
}
func (g *Manager) doTerminate() {
if !g.setStateTransition(stateShuttingDown, stateTerminate) {
return
}
g.lock.Lock()
select {
case <-g.terminateCtx.Done():
default:
log.Warn("Terminating")
g.terminateCtxCancel()
atTerminateCtx := pprof.WithLabels(g.managerCtx, pprof.Labels("graceful-lifecycle", "post-terminate"))
pprof.SetGoroutineLabels(atTerminateCtx)
for _, fn := range g.toRunAtTerminate {
go fn()
}
}
g.lock.Unlock()
}
// IsChild returns if the current process is a child of previous Gitea process
func (g *Manager) IsChild() bool {
return g.isChild
}
// IsShutdown returns a channel which will be closed at shutdown.
// The order of closure is IsShutdown, IsHammer (potentially), IsTerminate
func (g *Manager) IsShutdown() <-chan struct{} {
return g.shutdownCtx.Done()
}
// IsHammer returns a channel which will be closed at hammer
// The order of closure is IsShutdown, IsHammer (potentially), IsTerminate
// Servers running within the running server wait group should respond to IsHammer
// if not shutdown already
func (g *Manager) IsHammer() <-chan struct{} {
return g.hammerCtx.Done()
}
// IsTerminate returns a channel which will be closed at terminate
// The order of closure is IsShutdown, IsHammer (potentially), IsTerminate
// IsTerminate will only close once all running servers have stopped
func (g *Manager) IsTerminate() <-chan struct{} {
return g.terminateCtx.Done()
}
// ServerDone declares a running server done and subtracts one from the
// running server wait group. Users probably do not want to call this
// and should use one of the RunWithShutdown* functions
func (g *Manager) ServerDone() {
g.runningServerWaitGroup.Done()
}
// WaitForServers waits for all running servers to finish. Users should probably
// instead use AtTerminate or IsTerminate
func (g *Manager) WaitForServers() {
g.runningServerWaitGroup.Wait()
}
// WaitForTerminate waits for all terminating actions to finish.
// Only the main go-routine should use this
func (g *Manager) WaitForTerminate() {
g.terminateWaitGroup.Wait()
}
func (g *Manager) getState() state {
g.lock.RLock()
defer g.lock.RUnlock()
return g.state
}
func (g *Manager) setStateTransition(old, new state) bool {
if old != g.getState() {
return false
}
g.lock.Lock()
if g.state != old {
g.lock.Unlock()
return false
}
g.state = new
g.lock.Unlock()
return true
}
func (g *Manager) setState(st state) {
g.lock.Lock()
defer g.lock.Unlock()
g.state = st
}
// InformCleanup tells the cleanup wait group that we have either taken a listener or will not be taking a listener.
// At the moment the total number of servers (numberOfServersToCreate) are pre-defined as a const before global init,
// so this function MUST be called if a server is not used.
func (g *Manager) InformCleanup() {
g.createServerWaitGroup.Done()
}
// Done allows the manager to be viewed as a context.Context, it returns a channel that is closed when the server is finished terminating
func (g *Manager) Done() <-chan struct{} {
return g.managerCtx.Done()
}
// Err allows the manager to be viewed as a context.Context done at Terminate
func (g *Manager) Err() error {
return g.managerCtx.Err()
}
// Value allows the manager to be viewed as a context.Context done at Terminate
func (g *Manager) Value(key interface{}) interface{} {
return g.managerCtx.Value(key)
}
// Deadline returns nil as there is no fixed Deadline for the manager, it allows the manager to be viewed as a context.Context
func (g *Manager) Deadline() (deadline time.Time, ok bool) {
return g.managerCtx.Deadline()
}