From fd46136dfaf68a7046cf7b8693824d73ac6b1caf Mon Sep 17 00:00:00 2001 From: Gregory Maxwell Date: Sat, 22 Oct 2016 05:33:25 +0000 Subject: [PATCH 1/3] IBD check uses minimumchain work instead of checkpoints. This introduces a 'minimum chain work' chainparam which is intended to be the known amount of work in the chain for the network at the time of software release. If you don't have this much work, you're not yet caught up. This is used instead of the count of blocks test from checkpoints. This criteria is trivial to keep updated as there is no element of subjectivity, trust, or position dependence to it. It is also a more reliable metric of sync status than a block count. --- doc/release-process.md | 1 + src/chainparams.cpp | 10 ++++++++++ src/consensus/params.h | 1 + src/main.cpp | 6 ++++-- 4 files changed, 16 insertions(+), 2 deletions(-) diff --git a/doc/release-process.md b/doc/release-process.md index 63f75fb3992..85cf160f47a 100644 --- a/doc/release-process.md +++ b/doc/release-process.md @@ -12,6 +12,7 @@ Before every minor and major release: * Update [bips.md](bips.md) to account for changes since the last release. * Update version in sources (see below) * Write release notes (see below) +* Update `src/chainparams.cpp` nMinimumChainWork with information from the getblockchaininfo rpc. Before every major release: diff --git a/src/chainparams.cpp b/src/chainparams.cpp index 5850016ae27..a57ab632e4c 100644 --- a/src/chainparams.cpp +++ b/src/chainparams.cpp @@ -96,6 +96,9 @@ public: consensus.vDeployments[Consensus::DEPLOYMENT_SEGWIT].nStartTime = 1479168000; // November 15th, 2016. consensus.vDeployments[Consensus::DEPLOYMENT_SEGWIT].nTimeout = 1510704000; // November 15th, 2017. + // The best chain should have at least this much work. + consensus.nMinimumChainWork = uint256S("0x0000000000000000000000000000000000000000002cb971dd56d1c583c20f90"); + /** * The message start string is designed to be unlikely to occur in normal data. * The characters are rarely used upper ASCII, not valid as UTF-8, and produce @@ -191,6 +194,9 @@ public: consensus.vDeployments[Consensus::DEPLOYMENT_SEGWIT].nStartTime = 1462060800; // May 1st 2016 consensus.vDeployments[Consensus::DEPLOYMENT_SEGWIT].nTimeout = 1493596800; // May 1st 2017 + // The best chain should have at least this much work. + consensus.nMinimumChainWork = uint256S("0x0000000000000000000000000000000000000000000000198b4def2baa9338d6"); + pchMessageStart[0] = 0x0b; pchMessageStart[1] = 0x11; pchMessageStart[2] = 0x09; @@ -224,6 +230,7 @@ public: fRequireStandard = false; fMineBlocksOnDemand = false; + checkpointData = (CCheckpointData) { boost::assign::map_list_of ( 546, uint256S("000000002a936ca763904c3c35fce2f3556c559c0214345d31b1bcebf76acb70")), @@ -265,6 +272,9 @@ public: consensus.vDeployments[Consensus::DEPLOYMENT_SEGWIT].nStartTime = 0; consensus.vDeployments[Consensus::DEPLOYMENT_SEGWIT].nTimeout = 999999999999ULL; + // The best chain should have at least this much work. + consensus.nMinimumChainWork = uint256S("0x00"); + pchMessageStart[0] = 0xfa; pchMessageStart[1] = 0xbf; pchMessageStart[2] = 0xb5; diff --git a/src/consensus/params.h b/src/consensus/params.h index 0e73cace831..20efc68ade8 100644 --- a/src/consensus/params.h +++ b/src/consensus/params.h @@ -61,6 +61,7 @@ struct Params { int64_t nPowTargetSpacing; int64_t nPowTargetTimespan; int64_t DifficultyAdjustmentInterval() const { return nPowTargetTimespan / nPowTargetSpacing; } + uint256 nMinimumChainWork; }; } // namespace Consensus diff --git a/src/main.cpp b/src/main.cpp index 5e17ec6251e..6b33539a2ef 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -1740,7 +1740,9 @@ bool IsInitialBlockDownload() return false; if (fImporting || fReindex) return true; - if (fCheckpointsEnabled && chainActive.Height() < Checkpoints::GetTotalBlocksEstimate(chainParams.Checkpoints())) + if (chainActive.Tip() == NULL) + return true; + if (chainActive.Tip()->nChainWork < UintToArith256(chainParams.GetConsensus().nMinimumChainWork)) return true; bool state = (chainActive.Height() < pindexBestHeader->nHeight - 24 * 6 || std::max(chainActive.Tip()->GetBlockTime(), pindexBestHeader->GetBlockTime()) < GetTime() - nMaxTipAge); @@ -1774,7 +1776,7 @@ void CheckForkWarningConditions() { AssertLockHeld(cs_main); // Before we get past initial download, we cannot reliably alert about forks - // (we assume we don't get stuck on a fork before the last checkpoint) + // (we assume we don't get stuck on a fork before finishing our initial sync) if (IsInitialBlockDownload()) return; From 2082b5574cec783f4ff99941492d92e05680b293 Mon Sep 17 00:00:00 2001 From: Gregory Maxwell Date: Wed, 2 Nov 2016 01:49:45 +0000 Subject: [PATCH 2/3] Remove GetTotalBlocksEstimate and checkpoint tests that test nothing. GetTotalBlocksEstimate is no longer used and it was the only thing the checkpoint tests were testing. Since checkpoints are on their way out it makes more sense to remove the test file than to cook up a new pointless test. --- src/Makefile.test.include | 1 - src/checkpoints.cpp | 10 ---------- src/checkpoints.h | 3 --- src/test/Checkpoints_tests.cpp | 27 --------------------------- 4 files changed, 41 deletions(-) delete mode 100644 src/test/Checkpoints_tests.cpp diff --git a/src/Makefile.test.include b/src/Makefile.test.include index 5ce1bbb8963..4e4cca14caf 100644 --- a/src/Makefile.test.include +++ b/src/Makefile.test.include @@ -50,7 +50,6 @@ BITCOIN_TESTS =\ test/bip32_tests.cpp \ test/blockencodings_tests.cpp \ test/bloom_tests.cpp \ - test/Checkpoints_tests.cpp \ test/coins_tests.cpp \ test/compress_tests.cpp \ test/crypto_tests.cpp \ diff --git a/src/checkpoints.cpp b/src/checkpoints.cpp index aefddce4641..d22c188c16e 100644 --- a/src/checkpoints.cpp +++ b/src/checkpoints.cpp @@ -55,16 +55,6 @@ namespace Checkpoints { return fWorkBefore / (fWorkBefore + fWorkAfter); } - int GetTotalBlocksEstimate(const CCheckpointData& data) - { - const MapCheckpoints& checkpoints = data.mapCheckpoints; - - if (checkpoints.empty()) - return 0; - - return checkpoints.rbegin()->first; - } - CBlockIndex* GetLastCheckpoint(const CCheckpointData& data) { const MapCheckpoints& checkpoints = data.mapCheckpoints; diff --git a/src/checkpoints.h b/src/checkpoints.h index cd25ea5379d..04346f35ffa 100644 --- a/src/checkpoints.h +++ b/src/checkpoints.h @@ -19,9 +19,6 @@ struct CCheckpointData; namespace Checkpoints { -//! Return conservative estimate of total number of blocks, 0 if unknown -int GetTotalBlocksEstimate(const CCheckpointData& data); - //! Returns last CBlockIndex* in mapBlockIndex that is a checkpoint CBlockIndex* GetLastCheckpoint(const CCheckpointData& data); diff --git a/src/test/Checkpoints_tests.cpp b/src/test/Checkpoints_tests.cpp deleted file mode 100644 index 1b7d368e13e..00000000000 --- a/src/test/Checkpoints_tests.cpp +++ /dev/null @@ -1,27 +0,0 @@ -// Copyright (c) 2011-2015 The Bitcoin Core developers -// Distributed under the MIT software license, see the accompanying -// file COPYING or http://www.opensource.org/licenses/mit-license.php. - -// -// Unit tests for block-chain checkpoints -// - -#include "checkpoints.h" - -#include "uint256.h" -#include "test/test_bitcoin.h" -#include "chainparams.h" - -#include - -using namespace std; - -BOOST_FIXTURE_TEST_SUITE(Checkpoints_tests, BasicTestingSetup) - -BOOST_AUTO_TEST_CASE(sanity) -{ - const CCheckpointData& checkpoints = Params(CBaseChainParams::MAIN).Checkpoints(); - BOOST_CHECK(Checkpoints::GetTotalBlocksEstimate(checkpoints) >= 134444); -} - -BOOST_AUTO_TEST_SUITE_END() From e141beb6a9816b7e1e680fb0a8bae16d42a3e557 Mon Sep 17 00:00:00 2001 From: Gregory Maxwell Date: Tue, 1 Nov 2016 00:37:54 +0000 Subject: [PATCH 3/3] IsInitialBlockDownload no longer uses header-only timestamps. This avoids a corner case (mostly visible on testnet) where bogus headers can keep nodes in IsInitialBlockDownload. --- src/main.cpp | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/src/main.cpp b/src/main.cpp index 6b33539a2ef..46320604eff 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -1744,11 +1744,10 @@ bool IsInitialBlockDownload() return true; if (chainActive.Tip()->nChainWork < UintToArith256(chainParams.GetConsensus().nMinimumChainWork)) return true; - bool state = (chainActive.Height() < pindexBestHeader->nHeight - 24 * 6 || - std::max(chainActive.Tip()->GetBlockTime(), pindexBestHeader->GetBlockTime()) < GetTime() - nMaxTipAge); - if (!state) - latchToFalse.store(true, std::memory_order_relaxed); - return state; + if (chainActive.Tip()->GetBlockTime() < (GetTime() - nMaxTipAge)) + return true; + latchToFalse.store(true, std::memory_order_relaxed); + return false; } bool fLargeWorkForkFound = false;