zcashd/src/validationinterface.cpp

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2014 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or https://www.opensource.org/licenses/mit-license.php .

#include "validationinterface.h"

#include "chainparams.h"
#include "txmempool.h"

#include <boost/thread.hpp>

#include <chrono>
#include <thread>

static CMainSignals g_signals;

CMainSignals& GetMainSignals()
{
    return g_signals;
}

void RegisterValidationInterface(CValidationInterface* pwalletIn) {
    g_signals.UpdatedBlockTip.connect(boost::bind(&CValidationInterface::UpdatedBlockTip, pwalletIn, _1));
    g_signals.SyncTransaction.connect(boost::bind(&CValidationInterface::SyncTransaction, pwalletIn, _1, _2));
    g_signals.EraseTransaction.connect(boost::bind(&CValidationInterface::EraseFromWallet, pwalletIn, _1));
    g_signals.UpdatedTransaction.connect(boost::bind(&CValidationInterface::UpdatedTransaction, pwalletIn, _1));
    g_signals.ChainTip.connect(boost::bind(&CValidationInterface::ChainTip, pwalletIn, _1, _2, _3));
    g_signals.SetBestChain.connect(boost::bind(&CValidationInterface::SetBestChain, pwalletIn, _1));
    g_signals.Inventory.connect(boost::bind(&CValidationInterface::Inventory, pwalletIn, _1));
    g_signals.Broadcast.connect(boost::bind(&CValidationInterface::ResendWalletTransactions, pwalletIn, _1));
    g_signals.BlockChecked.connect(boost::bind(&CValidationInterface::BlockChecked, pwalletIn, _1, _2));
    g_signals.ScriptForMining.connect(boost::bind(&CValidationInterface::GetScriptForMining, pwalletIn, _1));
    g_signals.BlockFound.connect(boost::bind(&CValidationInterface::ResetRequestCount, pwalletIn, _1));
}

void UnregisterValidationInterface(CValidationInterface* pwalletIn) {
    g_signals.BlockFound.disconnect(boost::bind(&CValidationInterface::ResetRequestCount, pwalletIn, _1));
    g_signals.ScriptForMining.disconnect(boost::bind(&CValidationInterface::GetScriptForMining, pwalletIn, _1));
    g_signals.BlockChecked.disconnect(boost::bind(&CValidationInterface::BlockChecked, pwalletIn, _1, _2));
    g_signals.Broadcast.disconnect(boost::bind(&CValidationInterface::ResendWalletTransactions, pwalletIn, _1));
    g_signals.Inventory.disconnect(boost::bind(&CValidationInterface::Inventory, pwalletIn, _1));
    g_signals.ChainTip.disconnect(boost::bind(&CValidationInterface::ChainTip, pwalletIn, _1, _2, _3));
    g_signals.SetBestChain.disconnect(boost::bind(&CValidationInterface::SetBestChain, pwalletIn, _1));
    g_signals.UpdatedTransaction.disconnect(boost::bind(&CValidationInterface::UpdatedTransaction, pwalletIn, _1));
    g_signals.EraseTransaction.disconnect(boost::bind(&CValidationInterface::EraseFromWallet, pwalletIn, _1));
    g_signals.SyncTransaction.disconnect(boost::bind(&CValidationInterface::SyncTransaction, pwalletIn, _1, _2));
    g_signals.UpdatedBlockTip.disconnect(boost::bind(&CValidationInterface::UpdatedBlockTip, pwalletIn, _1));
}

void UnregisterAllValidationInterfaces() {
    g_signals.BlockFound.disconnect_all_slots();
    g_signals.ScriptForMining.disconnect_all_slots();
    g_signals.BlockChecked.disconnect_all_slots();
    g_signals.Broadcast.disconnect_all_slots();
    g_signals.Inventory.disconnect_all_slots();
    g_signals.ChainTip.disconnect_all_slots();
    g_signals.SetBestChain.disconnect_all_slots();
    g_signals.UpdatedTransaction.disconnect_all_slots();
    g_signals.EraseTransaction.disconnect_all_slots();
    g_signals.SyncTransaction.disconnect_all_slots();
    g_signals.UpdatedBlockTip.disconnect_all_slots();
}

void SyncWithWallets(const CTransaction &tx, const CBlock *pblock) {
    g_signals.SyncTransaction(tx, pblock);
}

extern CTxMemPool mempool;

void ThreadNotifyWallets()
{
    while (true) {
        // Run the notifier on an integer second in the steady clock.
        auto now = std::chrono::steady_clock::now().time_since_epoch();
        auto nextFire = std::chrono::duration_cast<std::chrono::seconds>(
            now + std::chrono::seconds(1));
        std::this_thread::sleep_until(
            std::chrono::time_point<std::chrono::steady_clock>(nextFire));

        boost::this_thread::interruption_point();

        // Collect all the state we require

        auto recentlyAdded = mempool.DrainRecentlyAdded();

        // Execute wallet logic based on the collected state. We MUST NOT take
        // the cs_main or mempool.cs locks again until after the next sleep.

        // A race condition can occur here between these SyncWithWallets calls, and
        // the ones triggered by block logic (in ConnectTip and DisconnectTip). It
        // is harmless because calling SyncWithWallets(_, NULL) does not alter the
        // wallet transaction's block information.
        for (auto tx : recentlyAdded.first) {
            try {
                SyncWithWallets(tx, NULL);
            } catch (const boost::thread_interrupted&) {
                throw;
            } catch (const std::exception& e) {
                PrintExceptionContinue(&e, "ThreadNotifyWallets()");
            } catch (...) {
                PrintExceptionContinue(NULL, "ThreadNotifyWallets()");
            }
        }

        // Update the notified sequence number. We only need this in regtest mode,
        // and should not lock on cs between calls to DrainRecentlyAdded otherwise.
        if (Params().NetworkIDString() == "regtest") {
            mempool.SetNotifiedSequence(recentlyAdded.second);
        }
    }
}