github.com/theQRL/go-zond@v0.1.1/internal/shutdowncheck/shutdown_tracker.go (about)

     1  // Copyright 2021 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package shutdowncheck
    18  
    19  import (
    20  	"time"
    21  
    22  	"github.com/theQRL/go-zond/common"
    23  	"github.com/theQRL/go-zond/core/rawdb"
    24  	"github.com/theQRL/go-zond/zonddb"
    25  	"github.com/theQRL/go-zond/log"
    26  )
    27  
    28  // ShutdownTracker is a service that reports previous unclean shutdowns
    29  // upon start. It needs to be started after a successful start-up and stopped
    30  // after a successful shutdown, just before the db is closed.
    31  type ShutdownTracker struct {
    32  	db     zonddb.Database
    33  	stopCh chan struct{}
    34  }
    35  
    36  // NewShutdownTracker creates a new ShutdownTracker instance and has
    37  // no other side-effect.
    38  func NewShutdownTracker(db zonddb.Database) *ShutdownTracker {
    39  	return &ShutdownTracker{
    40  		db:     db,
    41  		stopCh: make(chan struct{}),
    42  	}
    43  }
    44  
    45  // MarkStartup is to be called in the beginning when the node starts. It will:
    46  // - Push a new startup marker to the db
    47  // - Report previous unclean shutdowns
    48  func (t *ShutdownTracker) MarkStartup() {
    49  	if uncleanShutdowns, discards, err := rawdb.PushUncleanShutdownMarker(t.db); err != nil {
    50  		log.Error("Could not update unclean-shutdown-marker list", "error", err)
    51  	} else {
    52  		if discards > 0 {
    53  			log.Warn("Old unclean shutdowns found", "count", discards)
    54  		}
    55  		for _, tstamp := range uncleanShutdowns {
    56  			t := time.Unix(int64(tstamp), 0)
    57  			log.Warn("Unclean shutdown detected", "booted", t,
    58  				"age", common.PrettyAge(t))
    59  		}
    60  	}
    61  }
    62  
    63  // Start runs an event loop that updates the current marker's timestamp every 5 minutes.
    64  func (t *ShutdownTracker) Start() {
    65  	go func() {
    66  		ticker := time.NewTicker(5 * time.Minute)
    67  		defer ticker.Stop()
    68  		for {
    69  			select {
    70  			case <-ticker.C:
    71  				rawdb.UpdateUncleanShutdownMarker(t.db)
    72  			case <-t.stopCh:
    73  				return
    74  			}
    75  		}
    76  	}()
    77  }
    78  
    79  // Stop will stop the update loop and clear the current marker.
    80  func (t *ShutdownTracker) Stop() {
    81  	// Stop update loop.
    82  	t.stopCh <- struct{}{}
    83  	// Clear last marker.
    84  	rawdb.PopUncleanShutdownMarker(t.db)
    85  }