eth, les: update unclean shutdown markers regularly (#24077)

Fixes #22580

Co-authored-by: Felix Lange <fjl@twurst.com>

internal/shutdowncheck/shutdown_tracker.go

@@ -0,0 +1,85 @@
+// Copyright 2021 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package shutdowncheck
+
+import (
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+// ShutdownTracker is a service that reports previous unclean shutdowns
+// upon start. It needs to be started after a successful start-up and stopped
+// after a successful shutdown, just before the db is closed.
+type ShutdownTracker struct {
+	db     ethdb.Database
+	stopCh chan struct{}
+}
+
+// NewShutdownTracker creates a new ShutdownTracker instance and has
+// no other side-effect.
+func NewShutdownTracker(db ethdb.Database) *ShutdownTracker {
+	return &ShutdownTracker{
+		db:     db,
+		stopCh: make(chan struct{}),
+	}
+}
+
+// MarkStartup is to be called in the beginning when the node starts. It will:
+// - Push a new startup marker to the db
+// - Report previous unclean shutdowns
+func (t *ShutdownTracker) MarkStartup() {
+	if uncleanShutdowns, discards, err := rawdb.PushUncleanShutdownMarker(t.db); err != nil {
+		log.Error("Could not update unclean-shutdown-marker list", "error", err)
+	} else {
+		if discards > 0 {
+			log.Warn("Old unclean shutdowns found", "count", discards)
+		}
+		for _, tstamp := range uncleanShutdowns {
+			t := time.Unix(int64(tstamp), 0)
+			log.Warn("Unclean shutdown detected", "booted", t,
+				"age", common.PrettyAge(t))
+		}
+	}
+}
+
+// Start runs an event loop that updates the current marker's timestamp every 5 minutes.
+func (t *ShutdownTracker) Start() {
+	go func() {
+		ticker := time.NewTicker(5 * time.Minute)
+		defer ticker.Stop()
+		for {
+			select {
+			case <-ticker.C:
+				rawdb.UpdateUncleanShutdownMarker(t.db)
+			case <-t.stopCh:
+				return
+			}
+		}
+	}()
+}
+
+// Stop will stop the update loop and clear the current marker.
+func (t *ShutdownTracker) Stop() {
+	// Stop update loop.
+	t.stopCh <- struct{}{}
+	// Clear last marker.
+	rawdb.PopUncleanShutdownMarker(t.db)
+}