github.com/ethereum-optimism/optimism/l2geth@v0.0.0-20230612200230-50b04ade19e3/miner/worker_test.go (about)

     1  // Copyright 2018 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 miner
    18  
    19  import (
    20  	"fmt"
    21  	"math/big"
    22  	"math/rand"
    23  	"sync/atomic"
    24  	"testing"
    25  	"time"
    26  
    27  	"github.com/ethereum-optimism/optimism/l2geth/accounts"
    28  	"github.com/ethereum-optimism/optimism/l2geth/common"
    29  	"github.com/ethereum-optimism/optimism/l2geth/consensus"
    30  	"github.com/ethereum-optimism/optimism/l2geth/consensus/clique"
    31  	"github.com/ethereum-optimism/optimism/l2geth/consensus/ethash"
    32  	"github.com/ethereum-optimism/optimism/l2geth/core"
    33  	"github.com/ethereum-optimism/optimism/l2geth/core/rawdb"
    34  	"github.com/ethereum-optimism/optimism/l2geth/core/types"
    35  	"github.com/ethereum-optimism/optimism/l2geth/core/vm"
    36  	"github.com/ethereum-optimism/optimism/l2geth/crypto"
    37  	"github.com/ethereum-optimism/optimism/l2geth/ethdb"
    38  	"github.com/ethereum-optimism/optimism/l2geth/event"
    39  	"github.com/ethereum-optimism/optimism/l2geth/params"
    40  	"github.com/ethereum-optimism/optimism/l2geth/rollup"
    41  )
    42  
    43  const (
    44  	// testCode is the testing contract binary code which will initialises some
    45  	// variables in constructor
    46  	testCode = "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"
    47  
    48  	// testGas is the gas required for contract deployment.
    49  	testGas = 144109
    50  )
    51  
    52  var (
    53  	// Test chain configurations
    54  	testTxPoolConfig  core.TxPoolConfig
    55  	ethashChainConfig *params.ChainConfig
    56  	cliqueChainConfig *params.ChainConfig
    57  
    58  	// Test accounts
    59  	testBankKey, _  = crypto.GenerateKey()
    60  	testBankAddress = crypto.PubkeyToAddress(testBankKey.PublicKey)
    61  	testBankFunds   = big.NewInt(1000000000000000000)
    62  
    63  	testUserKey, _  = crypto.GenerateKey()
    64  	testUserAddress = crypto.PubkeyToAddress(testUserKey.PublicKey)
    65  
    66  	// Test transactions
    67  	pendingTxs []*types.Transaction
    68  	newTxs     []*types.Transaction
    69  
    70  	testConfig = &Config{
    71  		Recommit: time.Second,
    72  		GasFloor: params.GenesisGasLimit,
    73  		GasCeil:  params.GenesisGasLimit,
    74  	}
    75  )
    76  
    77  func init() {
    78  	testTxPoolConfig = core.DefaultTxPoolConfig
    79  	testTxPoolConfig.Journal = ""
    80  	ethashChainConfig = params.TestChainConfig
    81  	cliqueChainConfig = params.TestChainConfig
    82  	cliqueChainConfig.Clique = &params.CliqueConfig{
    83  		Period: 10,
    84  		Epoch:  30000,
    85  	}
    86  	tx1, _ := types.SignTx(types.NewTransaction(0, testUserAddress, big.NewInt(1000), params.TxGas, nil, nil), types.HomesteadSigner{}, testBankKey)
    87  	pendingTxs = append(pendingTxs, tx1)
    88  	tx2, _ := types.SignTx(types.NewTransaction(1, testUserAddress, big.NewInt(1000), params.TxGas, nil, nil), types.HomesteadSigner{}, testBankKey)
    89  	newTxs = append(newTxs, tx2)
    90  	rand.Seed(time.Now().UnixNano())
    91  }
    92  
    93  // testWorkerBackend implements worker.Backend interfaces and wraps all information needed during the testing.
    94  type testWorkerBackend struct {
    95  	db         ethdb.Database
    96  	txPool     *core.TxPool
    97  	chain      *core.BlockChain
    98  	testTxFeed event.Feed
    99  	genesis    *core.Genesis
   100  	uncleBlock *types.Block
   101  
   102  	syncService *rollup.SyncService
   103  }
   104  
   105  func newTestWorkerBackend(t *testing.T, chainConfig *params.ChainConfig, engine consensus.Engine, db ethdb.Database, n int) *testWorkerBackend {
   106  	var gspec = core.Genesis{
   107  		Config: chainConfig,
   108  		Alloc:  core.GenesisAlloc{testBankAddress: {Balance: testBankFunds}},
   109  	}
   110  
   111  	switch e := engine.(type) {
   112  	case *clique.Clique:
   113  		gspec.ExtraData = make([]byte, 32+common.AddressLength+crypto.SignatureLength)
   114  		copy(gspec.ExtraData[32:32+common.AddressLength], testBankAddress.Bytes())
   115  		e.Authorize(testBankAddress, func(account accounts.Account, s string, data []byte) ([]byte, error) {
   116  			return crypto.Sign(crypto.Keccak256(data), testBankKey)
   117  		})
   118  	case *ethash.Ethash:
   119  	default:
   120  		t.Fatalf("unexpected consensus engine type: %T", engine)
   121  	}
   122  	genesis := gspec.MustCommit(db)
   123  
   124  	chain, _ := core.NewBlockChain(db, &core.CacheConfig{TrieDirtyDisabled: true}, gspec.Config, engine, vm.Config{}, nil)
   125  	txpool := core.NewTxPool(testTxPoolConfig, chainConfig, chain)
   126  
   127  	// Generate a small n-block chain and an uncle block for it
   128  	if n > 0 {
   129  		blocks, _ := core.GenerateChain(chainConfig, genesis, engine, db, n, func(i int, gen *core.BlockGen) {
   130  			gen.SetCoinbase(testBankAddress)
   131  		})
   132  		if _, err := chain.InsertChain(blocks); err != nil {
   133  			t.Fatalf("failed to insert origin chain: %v", err)
   134  		}
   135  	}
   136  	parent := genesis
   137  	if n > 0 {
   138  		parent = chain.GetBlockByHash(chain.CurrentBlock().ParentHash())
   139  	}
   140  	blocks, _ := core.GenerateChain(chainConfig, parent, engine, db, 1, func(i int, gen *core.BlockGen) {
   141  		gen.SetCoinbase(testUserAddress)
   142  	})
   143  
   144  	return &testWorkerBackend{
   145  		db:         db,
   146  		chain:      chain,
   147  		txPool:     txpool,
   148  		genesis:    &gspec,
   149  		uncleBlock: blocks[0],
   150  
   151  		syncService: &rollup.SyncService{},
   152  	}
   153  }
   154  
   155  func (b *testWorkerBackend) BlockChain() *core.BlockChain { return b.chain }
   156  func (b *testWorkerBackend) TxPool() *core.TxPool         { return b.txPool }
   157  
   158  func (b *testWorkerBackend) SyncService() *rollup.SyncService { return b.syncService }
   159  
   160  func (b *testWorkerBackend) newRandomUncle() *types.Block {
   161  	var parent *types.Block
   162  	cur := b.chain.CurrentBlock()
   163  	if cur.NumberU64() == 0 {
   164  		parent = b.chain.Genesis()
   165  	} else {
   166  		parent = b.chain.GetBlockByHash(b.chain.CurrentBlock().ParentHash())
   167  	}
   168  	blocks, _ := core.GenerateChain(b.chain.Config(), parent, b.chain.Engine(), b.db, 1, func(i int, gen *core.BlockGen) {
   169  		var addr = make([]byte, common.AddressLength)
   170  		rand.Read(addr)
   171  		gen.SetCoinbase(common.BytesToAddress(addr))
   172  	})
   173  	return blocks[0]
   174  }
   175  
   176  func (b *testWorkerBackend) newRandomTx(creation bool) *types.Transaction {
   177  	var tx *types.Transaction
   178  	if creation {
   179  		tx, _ = types.SignTx(types.NewContractCreation(b.txPool.Nonce(testBankAddress), big.NewInt(0), testGas, nil, common.FromHex(testCode)), types.HomesteadSigner{}, testBankKey)
   180  	} else {
   181  		tx, _ = types.SignTx(types.NewTransaction(b.txPool.Nonce(testBankAddress), testUserAddress, big.NewInt(1000), params.TxGas, nil, nil), types.HomesteadSigner{}, testBankKey)
   182  	}
   183  	return tx
   184  }
   185  
   186  func newTestWorker(t *testing.T, chainConfig *params.ChainConfig, engine consensus.Engine, db ethdb.Database, blocks int) (*worker, *testWorkerBackend) {
   187  	backend := newTestWorkerBackend(t, chainConfig, engine, db, blocks)
   188  	backend.txPool.AddLocals(pendingTxs)
   189  	w := newWorker(testConfig, chainConfig, engine, backend, new(event.TypeMux), nil, false)
   190  	w.setEtherbase(testBankAddress)
   191  	return w, backend
   192  }
   193  
   194  func TestGenerateBlockAndImportEthash(t *testing.T) {
   195  	t.Skip("OVM")
   196  	testGenerateBlockAndImport(t, false)
   197  }
   198  
   199  func TestGenerateBlockAndImportClique(t *testing.T) {
   200  	t.Skip("OVM breaks this since it aborts after first tx fails")
   201  	testGenerateBlockAndImport(t, true)
   202  }
   203  
   204  func testGenerateBlockAndImport(t *testing.T, isClique bool) {
   205  	var (
   206  		engine      consensus.Engine
   207  		chainConfig *params.ChainConfig
   208  		db          = rawdb.NewMemoryDatabase()
   209  	)
   210  	if isClique {
   211  		chainConfig = params.AllCliqueProtocolChanges
   212  		chainConfig.Clique = &params.CliqueConfig{Period: 1, Epoch: 30000}
   213  		engine = clique.New(chainConfig.Clique, db)
   214  	} else {
   215  		chainConfig = params.AllEthashProtocolChanges
   216  		engine = ethash.NewFaker()
   217  	}
   218  
   219  	w, b := newTestWorker(t, chainConfig, engine, db, 0)
   220  	defer w.close()
   221  
   222  	db2 := rawdb.NewMemoryDatabase()
   223  	b.genesis.MustCommit(db2)
   224  	chain, _ := core.NewBlockChain(db2, nil, b.chain.Config(), engine, vm.Config{}, nil)
   225  	defer chain.Stop()
   226  
   227  	loopErr := make(chan error)
   228  	newBlock := make(chan struct{})
   229  	listenNewBlock := func() {
   230  		sub := w.mux.Subscribe(core.NewMinedBlockEvent{})
   231  		defer sub.Unsubscribe()
   232  
   233  		for item := range sub.Chan() {
   234  			block := item.Data.(core.NewMinedBlockEvent).Block
   235  			_, err := chain.InsertChain([]*types.Block{block})
   236  			if err != nil {
   237  				loopErr <- fmt.Errorf("failed to insert new mined block:%d, error:%v", block.NumberU64(), err)
   238  			}
   239  			newBlock <- struct{}{}
   240  		}
   241  	}
   242  	// Ignore empty commit here for less noise
   243  	w.skipSealHook = func(task *task) bool {
   244  		return len(task.receipts) == 0
   245  	}
   246  	w.start() // Start mining!
   247  	go listenNewBlock()
   248  
   249  	for i := 0; i < 5; i++ {
   250  		b.txPool.AddLocal(b.newRandomTx(true))
   251  		b.txPool.AddLocal(b.newRandomTx(false))
   252  		w.postSideBlock(core.ChainSideEvent{Block: b.newRandomUncle()})
   253  		w.postSideBlock(core.ChainSideEvent{Block: b.newRandomUncle()})
   254  		select {
   255  		case e := <-loopErr:
   256  			t.Fatal(e)
   257  		case <-newBlock:
   258  		case <-time.NewTimer(3 * time.Second).C: // Worker needs 1s to include new changes.
   259  			t.Fatalf("timeout")
   260  		}
   261  	}
   262  }
   263  
   264  func TestEmptyWorkEthash(t *testing.T) {
   265  	testEmptyWork(t, ethashChainConfig, ethash.NewFaker())
   266  }
   267  func TestEmptyWorkClique(t *testing.T) {
   268  	testEmptyWork(t, cliqueChainConfig, clique.New(cliqueChainConfig.Clique, rawdb.NewMemoryDatabase()))
   269  }
   270  
   271  func testEmptyWork(t *testing.T, chainConfig *params.ChainConfig, engine consensus.Engine) {
   272  	t.Skip("OVM breaks this with `account balance mismatch`, probably because transfers don't work.")
   273  
   274  	defer engine.Close()
   275  
   276  	w, _ := newTestWorker(t, chainConfig, engine, rawdb.NewMemoryDatabase(), 0)
   277  	defer w.close()
   278  
   279  	var (
   280  		taskIndex int
   281  		taskCh    = make(chan struct{}, 2)
   282  	)
   283  	checkEqual := func(t *testing.T, task *task, index int) {
   284  		// The first empty work without any txs included
   285  		receiptLen, balance := 0, big.NewInt(0)
   286  		if index == 1 {
   287  			// The second full work with 1 tx included
   288  			receiptLen, balance = 1, big.NewInt(1000)
   289  		}
   290  		if len(task.receipts) != receiptLen {
   291  			t.Fatalf("receipt number mismatch: have %d, want %d", len(task.receipts), receiptLen)
   292  		}
   293  		if task.state.GetBalance(testUserAddress).Cmp(balance) != 0 {
   294  			t.Fatalf("account balance mismatch: have %d, want %d", task.state.GetBalance(testUserAddress), balance)
   295  		}
   296  	}
   297  	w.newTaskHook = func(task *task) {
   298  		if task.block.NumberU64() == 1 {
   299  			checkEqual(t, task, taskIndex)
   300  			taskIndex += 1
   301  			taskCh <- struct{}{}
   302  		}
   303  	}
   304  	w.skipSealHook = func(task *task) bool { return true }
   305  	w.fullTaskHook = func() {
   306  		// Arch64 unit tests are running in a VM on travis, they must
   307  		// be given more time to execute.
   308  		time.Sleep(time.Second)
   309  	}
   310  	w.start() // Start mining!
   311  	for i := 0; i < 2; i += 1 {
   312  		select {
   313  		case <-taskCh:
   314  		case <-time.NewTimer(3 * time.Second).C:
   315  			t.Error("new task timeout")
   316  		}
   317  	}
   318  }
   319  
   320  func TestStreamUncleBlock(t *testing.T) {
   321  	ethash := ethash.NewFaker()
   322  	defer ethash.Close()
   323  
   324  	w, b := newTestWorker(t, ethashChainConfig, ethash, rawdb.NewMemoryDatabase(), 1)
   325  	defer w.close()
   326  
   327  	var taskCh = make(chan struct{})
   328  
   329  	taskIndex := 0
   330  	w.newTaskHook = func(task *task) {
   331  		if task.block.NumberU64() == 2 {
   332  			// The first task has 1 pending tx, the second one has 1
   333  			// tx and 1 uncle.
   334  			numTxs := len(task.block.Transactions())
   335  			numUncles := len(task.block.Uncles())
   336  
   337  			switch taskIndex {
   338  			case 0:
   339  				if numTxs != 1 {
   340  					t.Errorf("expected 1 tx in first task, got: %d", numTxs)
   341  				}
   342  				if numUncles != 0 {
   343  					t.Errorf("expected no uncles in first task, got: %d", numUncles)
   344  				}
   345  
   346  			case 1:
   347  				if numTxs != 1 {
   348  					t.Errorf("expected 1 tx in second task, got: %d", numTxs)
   349  				}
   350  				if numUncles != 1 {
   351  					t.Errorf("expected 1 uncle in second task, got: %d", numUncles)
   352  				}
   353  				have := task.block.Header().UncleHash
   354  				want := types.CalcUncleHash([]*types.Header{b.uncleBlock.Header()})
   355  				if have != want {
   356  					t.Errorf("uncle hash mismatch: have %s, want %s", have.Hex(), want.Hex())
   357  				}
   358  
   359  			default:
   360  				t.Errorf("only expected two tasks")
   361  			}
   362  			taskCh <- struct{}{}
   363  			taskIndex += 1
   364  		}
   365  	}
   366  	w.skipSealHook = func(task *task) bool {
   367  		return true
   368  	}
   369  	w.fullTaskHook = func() {
   370  		time.Sleep(100 * time.Millisecond)
   371  	}
   372  	w.start()
   373  
   374  	select {
   375  	case <-taskCh:
   376  	case <-time.NewTimer(time.Second).C:
   377  		t.Error("new task timeout")
   378  	}
   379  
   380  	w.postSideBlock(core.ChainSideEvent{Block: b.uncleBlock})
   381  
   382  	select {
   383  	case <-taskCh:
   384  	case <-time.NewTimer(time.Second).C:
   385  		t.Error("new task timeout")
   386  	}
   387  }
   388  
   389  func TestRegenerateMiningBlockEthash(t *testing.T) {
   390  	testRegenerateMiningBlock(t, ethashChainConfig, ethash.NewFaker())
   391  }
   392  
   393  func TestRegenerateMiningBlockClique(t *testing.T) {
   394  	testRegenerateMiningBlock(t, cliqueChainConfig, clique.New(cliqueChainConfig.Clique, rawdb.NewMemoryDatabase()))
   395  }
   396  
   397  func testRegenerateMiningBlock(t *testing.T, chainConfig *params.ChainConfig, engine consensus.Engine) {
   398  	t.Skip("OVM breaks this with `account balance mismatch`, probably because transfers don't work.")
   399  
   400  	defer engine.Close()
   401  
   402  	w, b := newTestWorker(t, chainConfig, engine, rawdb.NewMemoryDatabase(), 0)
   403  	defer w.close()
   404  
   405  	var taskCh = make(chan struct{})
   406  
   407  	taskIndex := 0
   408  	w.newTaskHook = func(task *task) {
   409  		if task.block.NumberU64() == 1 {
   410  			// The first task is an empty task, the second
   411  			// one has 1 pending tx, the third one has 2 txs
   412  			if taskIndex == 2 {
   413  				receiptLen, balance := 1, big.NewInt(1000)
   414  				if len(task.receipts) != receiptLen {
   415  					t.Errorf("receipt number mismatch: have %d, want %d", len(task.receipts), receiptLen)
   416  				}
   417  				if task.state.GetBalance(testUserAddress).Cmp(balance) != 0 {
   418  					t.Errorf("account balance mismatch: have %d, want %d", task.state.GetBalance(testUserAddress), balance)
   419  				}
   420  			}
   421  			taskCh <- struct{}{}
   422  			taskIndex += 1
   423  		}
   424  		if task.block.NumberU64() == 2 {
   425  			// The first task is an empty task, the second
   426  			// one has 1 pending tx, the third one has 2 txs
   427  			if taskIndex == 2 {
   428  				receiptLen, balance := 2, big.NewInt(2000)
   429  				if len(task.receipts) != receiptLen {
   430  					t.Errorf("receipt number mismatch: have %d, want %d", len(task.receipts), receiptLen)
   431  				}
   432  				if task.state.GetBalance(testUserAddress).Cmp(balance) != 0 {
   433  					t.Errorf("account balance mismatch: have %d, want %d", task.state.GetBalance(testUserAddress), balance)
   434  				}
   435  			}
   436  			taskCh <- struct{}{}
   437  			taskIndex += 1
   438  		}
   439  	}
   440  	w.skipSealHook = func(task *task) bool {
   441  		return true
   442  	}
   443  	w.fullTaskHook = func() {
   444  		time.Sleep(100 * time.Millisecond)
   445  	}
   446  
   447  	w.start()
   448  	// Ignore the first two works
   449  	for i := 0; i < 2; i += 1 {
   450  		select {
   451  		case <-taskCh:
   452  		case <-time.NewTimer(time.Second).C:
   453  			t.Error("new task timeout")
   454  		}
   455  	}
   456  	b.txPool.AddLocals(newTxs)
   457  	time.Sleep(time.Second)
   458  
   459  	select {
   460  	case <-taskCh:
   461  	case <-time.NewTimer(time.Second).C:
   462  		t.Error("new task timeout")
   463  	}
   464  }
   465  
   466  func TestAdjustIntervalEthash(t *testing.T) {
   467  	testAdjustInterval(t, ethashChainConfig, ethash.NewFaker())
   468  }
   469  
   470  func TestAdjustIntervalClique(t *testing.T) {
   471  	testAdjustInterval(t, cliqueChainConfig, clique.New(cliqueChainConfig.Clique, rawdb.NewMemoryDatabase()))
   472  }
   473  
   474  func testAdjustInterval(t *testing.T, chainConfig *params.ChainConfig, engine consensus.Engine) {
   475  	defer engine.Close()
   476  
   477  	w, _ := newTestWorker(t, chainConfig, engine, rawdb.NewMemoryDatabase(), 0)
   478  	defer w.close()
   479  
   480  	w.skipSealHook = func(task *task) bool {
   481  		return true
   482  	}
   483  	w.fullTaskHook = func() {
   484  		time.Sleep(100 * time.Millisecond)
   485  	}
   486  	var (
   487  		progress = make(chan struct{}, 10)
   488  		result   = make([]float64, 0, 10)
   489  		index    = 0
   490  		start    uint32
   491  	)
   492  	w.resubmitHook = func(minInterval time.Duration, recommitInterval time.Duration) {
   493  		// Short circuit if interval checking hasn't started.
   494  		if atomic.LoadUint32(&start) == 0 {
   495  			return
   496  		}
   497  		var wantMinInterval, wantRecommitInterval time.Duration
   498  
   499  		switch index {
   500  		case 0:
   501  			wantMinInterval, wantRecommitInterval = 3*time.Second, 3*time.Second
   502  		case 1:
   503  			origin := float64(3 * time.Second.Nanoseconds())
   504  			estimate := origin*(1-intervalAdjustRatio) + intervalAdjustRatio*(origin/0.8+intervalAdjustBias)
   505  			wantMinInterval, wantRecommitInterval = 3*time.Second, time.Duration(estimate)*time.Nanosecond
   506  		case 2:
   507  			estimate := result[index-1]
   508  			min := float64(3 * time.Second.Nanoseconds())
   509  			estimate = estimate*(1-intervalAdjustRatio) + intervalAdjustRatio*(min-intervalAdjustBias)
   510  			wantMinInterval, wantRecommitInterval = 3*time.Second, time.Duration(estimate)*time.Nanosecond
   511  		case 3:
   512  			wantMinInterval, wantRecommitInterval = time.Second, time.Second
   513  		}
   514  
   515  		// Check interval
   516  		if minInterval != wantMinInterval {
   517  			t.Errorf("resubmit min interval mismatch: have %v, want %v ", minInterval, wantMinInterval)
   518  		}
   519  		if recommitInterval != wantRecommitInterval {
   520  			t.Errorf("resubmit interval mismatch: have %v, want %v", recommitInterval, wantRecommitInterval)
   521  		}
   522  		result = append(result, float64(recommitInterval.Nanoseconds()))
   523  		index += 1
   524  		progress <- struct{}{}
   525  	}
   526  	w.start()
   527  
   528  	time.Sleep(time.Second) // Ensure two tasks have been summitted due to start opt
   529  	atomic.StoreUint32(&start, 1)
   530  
   531  	w.setRecommitInterval(3 * time.Second)
   532  	select {
   533  	case <-progress:
   534  	case <-time.NewTimer(time.Second).C:
   535  		t.Error("interval reset timeout")
   536  	}
   537  
   538  	w.resubmitAdjustCh <- &intervalAdjust{inc: true, ratio: 0.8}
   539  	select {
   540  	case <-progress:
   541  	case <-time.NewTimer(time.Second).C:
   542  		t.Error("interval reset timeout")
   543  	}
   544  
   545  	w.resubmitAdjustCh <- &intervalAdjust{inc: false}
   546  	select {
   547  	case <-progress:
   548  	case <-time.NewTimer(time.Second).C:
   549  		t.Error("interval reset timeout")
   550  	}
   551  
   552  	w.setRecommitInterval(500 * time.Millisecond)
   553  	select {
   554  	case <-progress:
   555  	case <-time.NewTimer(time.Second).C:
   556  		t.Error("interval reset timeout")
   557  	}
   558  }