test/functional/minchainwork.py

   1 #!/usr/bin/env python3
   2 # Copyright (c) 2017 The Bitcoin Core developers
   3 # Distributed under the MIT software license, see the accompanying
   4 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5 """Test logic for setting nMinimumChainWork on command line.
   6
   7 Nodes don't consider themselves out of "initial block download" until
   8 their active chain has more work than nMinimumChainWork.
   9
  10 Nodes don't download blocks from a peer unless the peer's best known block
  11 has more work than nMinimumChainWork.
  12
  13 While in initial block download, nodes won't relay blocks to their peers, so
  14 test that this parameter functions as intended by verifying that block relay
  15 only succeeds past a given node once its nMinimumChainWork has been exceeded.
  16 """
  17
  18 import time
  19
  20 from test_framework.test_framework import BitcoinTestFramework
  21 from test_framework.util import sync_blocks, connect_nodes, assert_equal
  22
  23 # 2 hashes required per regtest block (with no difficulty adjustment)
  24 REGTEST_WORK_PER_BLOCK = 2
  25
  26 class MinimumChainWorkTest(BitcoinTestFramework):
  27     def set_test_params(self):
  28         self.setup_clean_chain = True
  29         self.num_nodes = 3
  30         self.extra_args = [[], ["-minimumchainwork=0x65"], ["-minimumchainwork=0x65"]]
  31         self.node_min_work = [0, 101, 101]
  32
  33     def setup_network(self):
  34         # This test relies on the chain setup being:
  35         # node0 <- node1 <- node2
  36         # Before leaving IBD, nodes prefer to download blocks from outbound
  37         # peers, so ensure that we're mining on an outbound peer and testing
  38         # block relay to inbound peers.
  39         self.setup_nodes()
  40         for i in range(self.num_nodes-1):
  41             connect_nodes(self.nodes[i+1], i)
  42
  43     def run_test(self):
  44         # Start building a chain on node0.  node2 shouldn't be able to sync until node1's
  45         # minchainwork is exceeded
  46         starting_chain_work = REGTEST_WORK_PER_BLOCK # Genesis block's work
  47         self.log.info("Testing relay across node %d (minChainWork = %d)", 1, self.node_min_work[1])
  48
  49         starting_blockcount = self.nodes[2].getblockcount()
  50
  51         num_blocks_to_generate = int((self.node_min_work[1] - starting_chain_work) / REGTEST_WORK_PER_BLOCK)
  52         self.log.info("Generating %d blocks on node0", num_blocks_to_generate)
  53         hashes = self.nodes[0].generate(num_blocks_to_generate)
  54
  55         self.log.info("Node0 current chain work: %s", self.nodes[0].getblockheader(hashes[-1])['chainwork'])
  56
  57         # Sleep a few seconds and verify that node2 didn't get any new blocks
  58         # or headers.  We sleep, rather than sync_blocks(node0, node1) because
  59         # it's reasonable either way for node1 to get the blocks, or not get
  60         # them (since they're below node1's minchainwork).
  61         time.sleep(3)
  62
  63         self.log.info("Verifying node 2 has no more blocks than before")
  64         self.log.info("Blockcounts: %s", [n.getblockcount() for n in self.nodes])
  65         # Node2 shouldn't have any new headers yet, because node1 should not
  66         # have relayed anything.
  67         assert_equal(len(self.nodes[2].getchaintips()), 1)
  68         assert_equal(self.nodes[2].getchaintips()[0]['height'], 0)
  69
  70         assert self.nodes[1].getbestblockhash() != self.nodes[0].getbestblockhash()
  71         assert_equal(self.nodes[2].getblockcount(), starting_blockcount)
  72
  73         self.log.info("Generating one more block")
  74         self.nodes[0].generate(1)
  75
  76         self.log.info("Verifying nodes are all synced")
  77         self.sync_all()
  78         self.log.info("Blockcounts: %s", [n.getblockcount() for n in self.nodes])
  79
  80 if __name__ == '__main__':
  81     MinimumChainWorkTest().main()