Merge pull request #1822 from karalabe/contain-pow

core: separate and contain POW verifier, extensive tests
This commit is contained in:
Jeffrey Wilcke 2015-09-21 06:52:11 -07:00
commit 12c0afe4fe
4 changed files with 327 additions and 62 deletions

View File

@ -22,7 +22,6 @@ import (
"fmt"
"io"
"math/big"
"runtime"
"sync"
"sync/atomic"
"time"
@ -616,14 +615,12 @@ func (self *ChainManager) InsertChain(chain types.Blocks) (int, error) {
stats struct{ queued, processed, ignored int }
tstart = time.Now()
nonceDone = make(chan nonceResult, len(chain))
nonceQuit = make(chan struct{})
nonceChecked = make([]bool, len(chain))
)
// Start the parallel nonce verifier.
go verifyNonces(self.pow, chain, nonceQuit, nonceDone)
defer close(nonceQuit)
nonceAbort, nonceResults := verifyNoncesFromBlocks(self.pow, chain)
defer close(nonceAbort)
txcount := 0
for i, block := range chain {
@ -636,11 +633,11 @@ func (self *ChainManager) InsertChain(chain types.Blocks) (int, error) {
// Wait for block i's nonce to be verified before processing
// its state transition.
for !nonceChecked[i] {
r := <-nonceDone
nonceChecked[r.i] = true
r := <-nonceResults
nonceChecked[r.index] = true
if !r.valid {
block := chain[r.i]
return r.i, &BlockNonceErr{Hash: block.Hash(), Number: block.Number(), Nonce: block.Nonce()}
block := chain[r.index]
return r.index, &BlockNonceErr{Hash: block.Hash(), Number: block.Number(), Nonce: block.Nonce()}
}
}
@ -843,40 +840,3 @@ func blockErr(block *types.Block, err error) {
glog.V(logger.Error).Infoln(err)
glog.V(logger.Debug).Infoln(verifyNonces)
}
type nonceResult struct {
i int
valid bool
}
// block verifies nonces of the given blocks in parallel and returns
// an error if one of the blocks nonce verifications failed.
func verifyNonces(pow pow.PoW, blocks []*types.Block, quit <-chan struct{}, done chan<- nonceResult) {
// Spawn a few workers. They listen for blocks on the in channel
// and send results on done. The workers will exit in the
// background when in is closed.
var (
in = make(chan int)
nworkers = runtime.GOMAXPROCS(0)
)
defer close(in)
if len(blocks) < nworkers {
nworkers = len(blocks)
}
for i := 0; i < nworkers; i++ {
go func() {
for i := range in {
done <- nonceResult{i: i, valid: pow.Verify(blocks[i])}
}
}()
}
// Feed block indices to the workers.
for i := range blocks {
select {
case in <- i:
continue
case <-quit:
return
}
}
}

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@ -456,7 +456,7 @@ func TestInsertNonceError(t *testing.T) {
fail := rand.Int() % len(blocks)
failblock := blocks[fail]
bc.pow = failpow{failblock.NumberU64()}
bc.pow = failPow{failblock.NumberU64()}
n, err := bc.InsertChain(blocks)
// Check that the returned error indicates the nonce failure.
@ -499,18 +499,3 @@ func TestGenesisMismatch(t *testing.T) {
}
}
*/
// failpow returns false from Verify for a certain block number.
type failpow struct{ num uint64 }
func (pow failpow) Search(pow.Block, <-chan struct{}) (nonce uint64, mixHash []byte) {
return 0, nil
}
func (pow failpow) Verify(b pow.Block) bool {
return b.NumberU64() != pow.num
}
func (pow failpow) GetHashrate() int64 {
return 0
}
func (pow failpow) Turbo(bool) {
}

87
core/chain_pow.go Normal file
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@ -0,0 +1,87 @@
// Copyright 2015 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 core
import (
"runtime"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/pow"
)
// nonceCheckResult contains the result of a nonce verification.
type nonceCheckResult struct {
index int // Index of the item verified from an input array
valid bool // Result of the nonce verification
}
// verifyNoncesFromHeaders starts a concurrent header nonce verification,
// returning a quit channel to abort the operations and a results channel
// to retrieve the async verifications.
func verifyNoncesFromHeaders(checker pow.PoW, headers []*types.Header) (chan<- struct{}, <-chan nonceCheckResult) {
items := make([]pow.Block, len(headers))
for i, header := range headers {
items[i] = types.NewBlockWithHeader(header)
}
return verifyNonces(checker, items)
}
// verifyNoncesFromBlocks starts a concurrent block nonce verification,
// returning a quit channel to abort the operations and a results channel
// to retrieve the async verifications.
func verifyNoncesFromBlocks(checker pow.PoW, blocks []*types.Block) (chan<- struct{}, <-chan nonceCheckResult) {
items := make([]pow.Block, len(blocks))
for i, block := range blocks {
items[i] = block
}
return verifyNonces(checker, items)
}
// verifyNonces starts a concurrent nonce verification, returning a quit channel
// to abort the operations and a results channel to retrieve the async checks.
func verifyNonces(checker pow.PoW, items []pow.Block) (chan<- struct{}, <-chan nonceCheckResult) {
// Spawn as many workers as allowed threads
workers := runtime.GOMAXPROCS(0)
if len(items) < workers {
workers = len(items)
}
// Create a task channel and spawn the verifiers
tasks := make(chan int, workers)
results := make(chan nonceCheckResult, len(items)) // Buffered to make sure all workers stop
for i := 0; i < workers; i++ {
go func() {
for index := range tasks {
results <- nonceCheckResult{index: index, valid: checker.Verify(items[index])}
}
}()
}
// Feed item indices to the workers until done or aborted
abort := make(chan struct{})
go func() {
defer close(tasks)
for i := range items {
select {
case tasks <- i:
continue
case <-abort:
return
}
}
}()
return abort, results
}

233
core/chain_pow_test.go Normal file
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@ -0,0 +1,233 @@
// Copyright 2015 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 core
import (
"math/big"
"runtime"
"testing"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/pow"
)
// failPow is a non-validating proof of work implementation, that returns true
// from Verify for all but one block.
type failPow struct {
failing uint64
}
func (pow failPow) Search(pow.Block, <-chan struct{}) (uint64, []byte) {
return 0, nil
}
func (pow failPow) Verify(block pow.Block) bool { return block.NumberU64() != pow.failing }
func (pow failPow) GetHashrate() int64 { return 0 }
func (pow failPow) Turbo(bool) {}
// delayedPow is a non-validating proof of work implementation, that returns true
// from Verify for all blocks, but delays them the configured amount of time.
type delayedPow struct {
delay time.Duration
}
func (pow delayedPow) Search(pow.Block, <-chan struct{}) (uint64, []byte) {
return 0, nil
}
func (pow delayedPow) Verify(block pow.Block) bool { time.Sleep(pow.delay); return true }
func (pow delayedPow) GetHashrate() int64 { return 0 }
func (pow delayedPow) Turbo(bool) {}
// Tests that simple POW verification works, for both good and bad blocks.
func TestPowVerification(t *testing.T) {
// Create a simple chain to verify
var (
testdb, _ = ethdb.NewMemDatabase()
genesis = GenesisBlockForTesting(testdb, common.Address{}, new(big.Int))
blocks = GenerateChain(genesis, testdb, 8, nil)
)
headers := make([]*types.Header, len(blocks))
for i, block := range blocks {
headers[i] = block.Header()
}
// Run the POW checker for blocks one-by-one, checking for both valid and invalid nonces
for i := 0; i < len(blocks); i++ {
for j, full := range []bool{true, false} {
for k, valid := range []bool{true, false} {
var results <-chan nonceCheckResult
switch {
case full && valid:
_, results = verifyNoncesFromBlocks(FakePow{}, []*types.Block{blocks[i]})
case full && !valid:
_, results = verifyNoncesFromBlocks(failPow{blocks[i].NumberU64()}, []*types.Block{blocks[i]})
case !full && valid:
_, results = verifyNoncesFromHeaders(FakePow{}, []*types.Header{headers[i]})
case !full && !valid:
_, results = verifyNoncesFromHeaders(failPow{headers[i].Number.Uint64()}, []*types.Header{headers[i]})
}
// Wait for the verification result
select {
case result := <-results:
if result.index != 0 {
t.Errorf("test %d.%d.%d: invalid index: have %d, want 0", i, j, k, result.index)
}
if result.valid != valid {
t.Errorf("test %d.%d.%d: validity mismatch: have %v, want %v", i, j, k, result.valid, valid)
}
case <-time.After(time.Second):
t.Fatalf("test %d.%d.%d: verification timeout", i, j, k)
}
// Make sure no more data is returned
select {
case result := <-results:
t.Fatalf("test %d.%d.%d: unexpected result returned: %v", i, j, k, result)
case <-time.After(25 * time.Millisecond):
}
}
}
}
}
// Tests that concurrent POW verification works, for both good and bad blocks.
func TestPowConcurrentVerification2(t *testing.T) { testPowConcurrentVerification(t, 2) }
func TestPowConcurrentVerification8(t *testing.T) { testPowConcurrentVerification(t, 8) }
func TestPowConcurrentVerification32(t *testing.T) { testPowConcurrentVerification(t, 32) }
func testPowConcurrentVerification(t *testing.T, threads int) {
// Create a simple chain to verify
var (
testdb, _ = ethdb.NewMemDatabase()
genesis = GenesisBlockForTesting(testdb, common.Address{}, new(big.Int))
blocks = GenerateChain(genesis, testdb, 8, nil)
)
headers := make([]*types.Header, len(blocks))
for i, block := range blocks {
headers[i] = block.Header()
}
// Set the number of threads to verify on
old := runtime.GOMAXPROCS(threads)
defer runtime.GOMAXPROCS(old)
// Run the POW checker for the entire block chain at once both for a valid and
// also an invalid chain (enough if one is invalid, last but one (arbitrary)).
for i, full := range []bool{true, false} {
for j, valid := range []bool{true, false} {
var results <-chan nonceCheckResult
switch {
case full && valid:
_, results = verifyNoncesFromBlocks(FakePow{}, blocks)
case full && !valid:
_, results = verifyNoncesFromBlocks(failPow{uint64(len(blocks) - 1)}, blocks)
case !full && valid:
_, results = verifyNoncesFromHeaders(FakePow{}, headers)
case !full && !valid:
_, results = verifyNoncesFromHeaders(failPow{uint64(len(headers) - 1)}, headers)
}
// Wait for all the verification results
checks := make(map[int]bool)
for k := 0; k < len(blocks); k++ {
select {
case result := <-results:
if _, ok := checks[result.index]; ok {
t.Fatalf("test %d.%d.%d: duplicate results for %d", i, j, k, result.index)
}
if result.index < 0 || result.index >= len(blocks) {
t.Fatalf("test %d.%d.%d: result %d out of bounds [%d, %d]", i, j, k, result.index, 0, len(blocks)-1)
}
checks[result.index] = result.valid
case <-time.After(time.Second):
t.Fatalf("test %d.%d.%d: verification timeout", i, j, k)
}
}
// Check nonce check validity
for k := 0; k < len(blocks); k++ {
want := valid || (k != len(blocks)-2) // We chose the last but one nonce in the chain to fail
if checks[k] != want {
t.Errorf("test %d.%d.%d: validity mismatch: have %v, want %v", i, j, k, checks[k], want)
}
}
// Make sure no more data is returned
select {
case result := <-results:
t.Fatalf("test %d.%d: unexpected result returned: %v", i, j, result)
case <-time.After(25 * time.Millisecond):
}
}
}
}
// Tests that aborting a POW validation indeed prevents further checks from being
// run, as well as checks that no left-over goroutines are leaked.
func TestPowConcurrentAbortion2(t *testing.T) { testPowConcurrentAbortion(t, 2) }
func TestPowConcurrentAbortion8(t *testing.T) { testPowConcurrentAbortion(t, 8) }
func TestPowConcurrentAbortion32(t *testing.T) { testPowConcurrentAbortion(t, 32) }
func testPowConcurrentAbortion(t *testing.T, threads int) {
// Create a simple chain to verify
var (
testdb, _ = ethdb.NewMemDatabase()
genesis = GenesisBlockForTesting(testdb, common.Address{}, new(big.Int))
blocks = GenerateChain(genesis, testdb, 1024, nil)
)
headers := make([]*types.Header, len(blocks))
for i, block := range blocks {
headers[i] = block.Header()
}
// Set the number of threads to verify on
old := runtime.GOMAXPROCS(threads)
defer runtime.GOMAXPROCS(old)
// Run the POW checker for the entire block chain at once
for i, full := range []bool{true, false} {
var abort chan<- struct{}
var results <-chan nonceCheckResult
// Start the verifications and immediately abort
if full {
abort, results = verifyNoncesFromBlocks(delayedPow{time.Millisecond}, blocks)
} else {
abort, results = verifyNoncesFromHeaders(delayedPow{time.Millisecond}, headers)
}
close(abort)
// Deplete the results channel
verified := make(map[int]struct{})
for depleted := false; !depleted; {
select {
case result := <-results:
verified[result.index] = struct{}{}
case <-time.After(50 * time.Millisecond):
depleted = true
}
}
// Check that abortion was honored by not processing too many POWs
if len(verified) > 2*threads {
t.Errorf("test %d: verification count too large: have %d, want below %d", i, len(verified), 2*threads)
}
// Check that there are no gaps in the results
for j := 0; j < len(verified); j++ {
if _, ok := verified[j]; !ok {
t.Errorf("test %d.%d: gap found in verification results", i, j)
}
}
}
}