path: root/consensus/ethash/ethash_test.go

// Copyright 2017 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 ethash

import (
    "io/ioutil"
    "math/big"
    "math/rand"
    "os"
    "sync"
    "testing"

    "github.com/ethereum/go-ethereum/core/types"
)

// Tests that ethash works correctly in test mode.
func TestTestMode(t *testing.T) {
    head := &types.Header{Number: big.NewInt(1), Difficulty: big.NewInt(100)}

    ethash := NewTester()
    block, err := ethash.Seal(nil, types.NewBlockWithHeader(head), nil)
    if err != nil {
        t.Fatalf("failed to seal block: %v", err)
    }
    head.Nonce = types.EncodeNonce(block.Nonce())
    head.MixDigest = block.MixDigest()
    if err := ethash.VerifySeal(nil, head); err != nil {
        t.Fatalf("unexpected verification error: %v", err)
    }
}

// This test checks that cache lru logic doesn't crash under load.
// It reproduces https://github.com/ethereum/go-ethereum/issues/14943
func TestCacheFileEvict(t *testing.T) {
    tmpdir, err := ioutil.TempDir("", "ethash-test")
    if err != nil {
        t.Fatal(err)
    }
    defer os.RemoveAll(tmpdir)
    e := New(Config{CachesInMem: 3, CachesOnDisk: 10, CacheDir: tmpdir, PowMode: ModeTest})

    workers := 8
    epochs := 100
    var wg sync.WaitGroup
    wg.Add(workers)
    for i := 0; i < workers; i++ {
        go verifyTest(&wg, e, i, epochs)
    }
    wg.Wait()
}

func verifyTest(wg *sync.WaitGroup, e *Ethash, workerIndex, epochs int) {
    defer wg.Done()

    const wiggle = 4 * epochLength
    r := rand.New(rand.NewSource(int64(workerIndex)))
    for epoch := 0; epoch < epochs; epoch++ {
        block := int64(epoch)*epochLength - wiggle/2 + r.Int63n(wiggle)
        if block < 0 {
            block = 0
        }
        head := &types.Header{Number: big.NewInt(block), Difficulty: big.NewInt(100)}
        e.VerifySeal(nil, head)
    }
}