mining_getblocktemplate_longpoll.py

#!/usr/bin/env python3
# Copyright (c) 2014-2020 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
"""Test longpolling with getblocktemplate."""

from decimal import Decimal
import random
import threading

from test_framework.authproxy import JSONRPCException
from test_framework.blocktools import COINBASE_MATURITY
from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import advance_time_for_pos, get_rpc_proxy
from test_framework.wallet import MiniWallet


class LongpollThread(threading.Thread):
    def __init__(self, node):
        threading.Thread.__init__(self)
        # query current longpollid
        template = node.getblocktemplate({'rules': ['segwit']})
        self.longpollid = template['longpollid']
        # create a new connection to the node, we can't use the same
        # connection from two threads
        self.node = get_rpc_proxy(node.url, 1, timeout=600, coveragedir=node.coverage_dir)

    def run(self):
        try:
            self.node.getblocktemplate({'longpollid': self.longpollid, 'rules': ['segwit']})
        except JSONRPCException:
            # In PoS, the longpoll correctly unblocks when a change is detected,
            # but creating the response template may fail if nLastCoinStakeSearchTime
            # was consumed by a recent generate() call on the same node.
            # The test validates longpoll detection, not template creation.
            pass

class GetBlockTemplateLPTest(BitcoinTestFramework):
    def set_test_params(self):
        self.num_nodes = 2
        self.supports_cli = False
        # Whitelist prevents P2P disconnections from mocktime/realtime mismatch
        self.extra_args = [['-whitelist=127.0.0.1']] * self.num_nodes

    def skip_test_if_missing_module(self):
        self.skip_if_no_wallet()

    def run_test(self):
        self.log.info("Warning: this test will take about 70 seconds in the best case. Be patient.")
        self.log.info("Test that longpollid doesn't change between successive getblocktemplate() invocations if nothing else happens")
        self.nodes[0].generate(10)
        # Advance mocktime so getblocktemplate can find a new coinstake
        # (PoS requires GetAdjustedTime() > nLastCoinStakeSearchTime)
        advance_time_for_pos(self.nodes, seconds=120)
        template = self.nodes[0].getblocktemplate({'rules': ['segwit']})
        longpollid = template['longpollid']
        template2 = self.nodes[0].getblocktemplate({'rules': ['segwit']})
        assert template2['longpollid'] == longpollid

        self.log.info("Test that longpoll waits if we do nothing")
        thr = LongpollThread(self.nodes[0])
        thr.start()
        # check that thread still lives
        thr.join(5)  # wait 5 seconds or until thread exits
        assert thr.is_alive()

        miniwallets = [ MiniWallet(node) for node in self.nodes ]
        self.log.info("Test that longpoll will terminate if another node generates a block")
        miniwallets[1].generate(1)  # generate a block on another node
        # check that thread will exit now that new transaction entered mempool
        thr.join(5)  # wait 5 seconds or until thread exits
        assert not thr.is_alive()

        self.log.info("Test that longpoll will terminate if we generate a block ourselves")
        advance_time_for_pos(self.nodes, seconds=120)
        thr = LongpollThread(self.nodes[0])
        thr.start()
        miniwallets[0].generate(1)  # generate a block on own node
        thr.join(5)  # wait 5 seconds or until thread exits
        assert not thr.is_alive()

        # Add enough mature utxos to the wallets, so that all txs spend confirmed coins
        self.nodes[0].generate(COINBASE_MATURITY)
        self.sync_blocks()

        self.log.info("Test that introducing a new transaction into the mempool will terminate the longpoll")
        advance_time_for_pos(self.nodes, seconds=120)
        thr = LongpollThread(self.nodes[0])
        thr.start()
        # generate a random transaction and submit it
        min_relay_fee = self.nodes[0].getnetworkinfo()["relayfee"]
        fee_rate = min_relay_fee + Decimal('0.00000010') * random.randint(0,20)
        miniwallets[0].send_self_transfer(from_node=self.nodes[0],
                                          fee_rate=fee_rate)
        # after one minute, every 10 seconds the mempool is probed, so in 80 seconds it should have returned
        thr.join(60 + 20)
        assert not thr.is_alive()

if __name__ == '__main__':
    GetBlockTemplateLPTest().main()