eth: interrupt chain insertion on shutdown (#21114)

This adds a new API method on core.BlockChain to allow interrupting
running data inserts, and calls the method before shutting down the
downloader.

The BlockChain interrupt checks are now done through a method instead
of inlining the atomic load everywhere. There is no loss of efficiency from
this and it makes the interrupt protocol a lot clearer because the check is
defined next to the method that sets the flag.
This commit is contained in:
Felix Lange 2020-05-26 21:37:37 +02:00 committed by GitHub
parent 4873a9d3c3
commit 9219e0fba4
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 38 additions and 22 deletions

@ -178,11 +178,10 @@ type BlockChain struct {
txLookupCache *lru.Cache // Cache for the most recent transaction lookup data.
futureBlocks *lru.Cache // future blocks are blocks added for later processing
quit chan struct{} // blockchain quit channel
running int32 // running must be called atomically
// procInterrupt must be atomically called
procInterrupt int32 // interrupt signaler for block processing
quit chan struct{} // blockchain quit channel
wg sync.WaitGroup // chain processing wait group for shutting down
running int32 // 0 if chain is running, 1 when stopped
procInterrupt int32 // interrupt signaler for block processing
engine consensus.Engine
validator Validator // Block and state validator interface
@ -239,7 +238,7 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, chainConfig *par
bc.processor = NewStateProcessor(chainConfig, bc, engine)
var err error
bc.hc, err = NewHeaderChain(db, chainConfig, engine, bc.getProcInterrupt)
bc.hc, err = NewHeaderChain(db, chainConfig, engine, bc.insertStopped)
if err != nil {
return nil, err
}
@ -332,10 +331,6 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, chainConfig *par
return bc, nil
}
func (bc *BlockChain) getProcInterrupt() bool {
return atomic.LoadInt32(&bc.procInterrupt) == 1
}
// GetVMConfig returns the block chain VM config.
func (bc *BlockChain) GetVMConfig() *vm.Config {
return &bc.vmConfig
@ -882,8 +877,7 @@ func (bc *BlockChain) Stop() {
// Unsubscribe all subscriptions registered from blockchain
bc.scope.Close()
close(bc.quit)
atomic.StoreInt32(&bc.procInterrupt, 1)
bc.StopInsert()
bc.wg.Wait()
// Ensure that the entirety of the state snapshot is journalled to disk.
@ -928,6 +922,18 @@ func (bc *BlockChain) Stop() {
log.Info("Blockchain stopped")
}
// StopInsert interrupts all insertion methods, causing them to return
// errInsertionInterrupted as soon as possible. Insertion is permanently disabled after
// calling this method.
func (bc *BlockChain) StopInsert() {
atomic.StoreInt32(&bc.procInterrupt, 1)
}
// insertStopped returns true after StopInsert has been called.
func (bc *BlockChain) insertStopped() bool {
return atomic.LoadInt32(&bc.procInterrupt) == 1
}
func (bc *BlockChain) procFutureBlocks() {
blocks := make([]*types.Block, 0, bc.futureBlocks.Len())
for _, hash := range bc.futureBlocks.Keys() {
@ -1113,7 +1119,7 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
var deleted []*numberHash
for i, block := range blockChain {
// Short circuit insertion if shutting down or processing failed
if atomic.LoadInt32(&bc.procInterrupt) == 1 {
if bc.insertStopped() {
return 0, errInsertionInterrupted
}
// Short circuit insertion if it is required(used in testing only)
@ -1260,7 +1266,7 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
batch := bc.db.NewBatch()
for i, block := range blockChain {
// Short circuit insertion if shutting down or processing failed
if atomic.LoadInt32(&bc.procInterrupt) == 1 {
if bc.insertStopped() {
return 0, errInsertionInterrupted
}
// Short circuit if the owner header is unknown
@ -1708,8 +1714,8 @@ func (bc *BlockChain) insertChain(chain types.Blocks, verifySeals bool) (int, er
// No validation errors for the first block (or chain prefix skipped)
for ; block != nil && err == nil || err == ErrKnownBlock; block, err = it.next() {
// If the chain is terminating, stop processing blocks
if atomic.LoadInt32(&bc.procInterrupt) == 1 {
log.Debug("Premature abort during blocks processing")
if bc.insertStopped() {
log.Debug("Abort during block processing")
break
}
// If the header is a banned one, straight out abort
@ -1996,8 +2002,8 @@ func (bc *BlockChain) insertSideChain(block *types.Block, it *insertIterator) (i
blocks, memory = blocks[:0], 0
// If the chain is terminating, stop processing blocks
if atomic.LoadInt32(&bc.procInterrupt) == 1 {
log.Debug("Premature abort during blocks processing")
if bc.insertStopped() {
log.Debug("Abort during blocks processing")
return 0, nil
}
}

@ -199,7 +199,6 @@ func (cs *chainSyncer) loop() {
cs.pm.txFetcher.Start()
defer cs.pm.blockFetcher.Stop()
defer cs.pm.txFetcher.Stop()
defer cs.pm.downloader.Terminate()
// The force timer lowers the peer count threshold down to one when it fires.
// This ensures we'll always start sync even if there aren't enough peers.
@ -222,8 +221,13 @@ func (cs *chainSyncer) loop() {
cs.forced = true
case <-cs.pm.quitSync:
// Disable all insertion on the blockchain. This needs to happen before
// terminating the downloader because the downloader waits for blockchain
// inserts, and these can take a long time to finish.
cs.pm.blockchain.StopInsert()
cs.pm.downloader.Terminate()
if cs.doneCh != nil {
cs.pm.downloader.Terminate() // Double term is fine, Cancel would block until queue is emptied
// Wait for the current sync to end.
<-cs.doneCh
}
return

@ -314,10 +314,16 @@ func (lc *LightChain) Stop() {
return
}
close(lc.quit)
atomic.StoreInt32(&lc.procInterrupt, 1)
lc.StopInsert()
lc.wg.Wait()
log.Info("Blockchain manager stopped")
log.Info("Blockchain stopped")
}
// StopInsert interrupts all insertion methods, causing them to return
// errInsertionInterrupted as soon as possible. Insertion is permanently disabled after
// calling this method.
func (lc *LightChain) StopInsert() {
atomic.StoreInt32(&lc.procInterrupt, 1)
}
// Rollback is designed to remove a chain of links from the database that aren't