109 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			109 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| // Copyright 2023 The Gitea Authors. All rights reserved.
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| // SPDX-License-Identifier: MIT
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| 
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| package graceful
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| 
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| import (
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| 	"context"
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| 	"runtime/pprof"
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| 	"sync"
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| 	"time"
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| )
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| 
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| // FIXME: it seems that there is a bug when using systemd Type=notify: the "Install Page" (INSTALL_LOCK=false) doesn't notify properly.
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| // At the moment, no idea whether it also affects Windows Service, or whether it's a regression bug. It needs to be investigated later.
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| 
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| type systemdNotifyMsg string
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| 
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| const (
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| 	readyMsg     systemdNotifyMsg = "READY=1"
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| 	stoppingMsg  systemdNotifyMsg = "STOPPING=1"
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| 	reloadingMsg systemdNotifyMsg = "RELOADING=1"
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| 	watchdogMsg  systemdNotifyMsg = "WATCHDOG=1"
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| )
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| 
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| func statusMsg(msg string) systemdNotifyMsg {
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| 	return systemdNotifyMsg("STATUS=" + msg)
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| }
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| 
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| // Manager manages the graceful shutdown process
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| type Manager struct {
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| 	ctx                    context.Context
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| 	isChild                bool
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| 	forked                 bool
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| 	lock                   sync.RWMutex
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| 	state                  state
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| 	shutdownCtx            context.Context
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| 	hammerCtx              context.Context
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| 	terminateCtx           context.Context
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| 	managerCtx             context.Context
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| 	shutdownCtxCancel      context.CancelFunc
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| 	hammerCtxCancel        context.CancelFunc
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| 	terminateCtxCancel     context.CancelFunc
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| 	managerCtxCancel       context.CancelFunc
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| 	runningServerWaitGroup sync.WaitGroup
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| 	terminateWaitGroup     sync.WaitGroup
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| 	createServerCond       sync.Cond
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| 	createdServer          int
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| 	shutdownRequested      chan struct{}
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| 
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| 	toRunAtShutdown  []func()
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| 	toRunAtTerminate []func()
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| }
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| 
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| func newGracefulManager(ctx context.Context) *Manager {
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| 	manager := &Manager{ctx: ctx, shutdownRequested: make(chan struct{})}
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| 	manager.createServerCond.L = &sync.Mutex{}
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| 	manager.prepare(ctx)
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| 	manager.start()
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| 	return manager
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| }
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| 
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| func (g *Manager) prepare(ctx context.Context) {
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| 	g.terminateCtx, g.terminateCtxCancel = context.WithCancel(ctx)
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| 	g.shutdownCtx, g.shutdownCtxCancel = context.WithCancel(ctx)
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| 	g.hammerCtx, g.hammerCtxCancel = context.WithCancel(ctx)
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| 	g.managerCtx, g.managerCtxCancel = context.WithCancel(ctx)
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| 
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| 	g.terminateCtx = pprof.WithLabels(g.terminateCtx, pprof.Labels("graceful-lifecycle", "with-terminate"))
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| 	g.shutdownCtx = pprof.WithLabels(g.shutdownCtx, pprof.Labels("graceful-lifecycle", "with-shutdown"))
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| 	g.hammerCtx = pprof.WithLabels(g.hammerCtx, pprof.Labels("graceful-lifecycle", "with-hammer"))
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| 	g.managerCtx = pprof.WithLabels(g.managerCtx, pprof.Labels("graceful-lifecycle", "with-manager"))
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| 
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| 	if !g.setStateTransition(stateInit, stateRunning) {
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| 		panic("invalid graceful manager state: transition from init to running failed")
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| 	}
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| }
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| 
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| // DoImmediateHammer causes an immediate hammer
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| func (g *Manager) DoImmediateHammer() {
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| 	g.notify(statusMsg("Sending immediate hammer"))
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| 	g.doHammerTime(0 * time.Second)
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| }
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| 
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| // DoGracefulShutdown causes a graceful shutdown
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| func (g *Manager) DoGracefulShutdown() {
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| 	g.lock.Lock()
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| 	select {
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| 	case <-g.shutdownRequested:
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| 	default:
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| 		close(g.shutdownRequested)
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| 	}
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| 	forked := g.forked
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| 	g.lock.Unlock()
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| 
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| 	if !forked {
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| 		g.notify(stoppingMsg)
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| 	} else {
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| 		g.notify(statusMsg("Shutting down after fork"))
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| 	}
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| 	g.doShutdown()
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| }
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| 
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| // RegisterServer registers the running of a listening server, in the case of unix this means that the parent process can now die.
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| // Any call to RegisterServer must be matched by a call to ServerDone
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| func (g *Manager) RegisterServer() {
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| 	KillParent()
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| 	g.runningServerWaitGroup.Add(1)
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| }
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