path: root/src/init.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 http://www.opensource.org/licenses/mit-license.php.

#if defined(HAVE_CONFIG_H)
#include "config/bitcoin-config.h"
#endif

#include "init.h"

#include "addrman.h"
#include "amount.h"
#include "checkpoints.h"
#include "compat/sanity.h"
#include "consensus/validation.h"
#include "key.h"
#include "main.h"
#include "miner.h"
#include "net.h"
#include "rpcserver.h"
#include "script/standard.h"
#include "scheduler.h"
#include "txdb.h"
#include "ui_interface.h"
#include "util.h"
#include "utilmoneystr.h"
#include "validationinterface.h"
#ifdef ENABLE_WALLET
#include "wallet/wallet.h"
#include "wallet/walletdb.h"
#endif

#include <stdint.h>
#include <stdio.h>

#ifndef WIN32
#include <signal.h>
#endif

#include <boost/algorithm/string/predicate.hpp>
#include <boost/algorithm/string/replace.hpp>
#include <boost/bind.hpp>
#include <boost/filesystem.hpp>
#include <boost/function.hpp>
#include <boost/interprocess/sync/file_lock.hpp>
#include <boost/thread.hpp>
#include <openssl/crypto.h>

using namespace std;

#ifdef ENABLE_WALLET
CWallet* pwalletMain = NULL;
#endif
bool fFeeEstimatesInitialized = false;

#ifdef WIN32
// Win32 LevelDB doesn't use filedescriptors, and the ones used for
// accessing block files don't count towards the fd_set size limit
// anyway.
#define MIN_CORE_FILEDESCRIPTORS 0
#else
#define MIN_CORE_FILEDESCRIPTORS 150
#endif

/** Used to pass flags to the Bind() function */
enum BindFlags {
    BF_NONE         = 0,
    BF_EXPLICIT     = (1U << 0),
    BF_REPORT_ERROR = (1U << 1),
    BF_WHITELIST    = (1U << 2),
};

static const char* FEE_ESTIMATES_FILENAME="fee_estimates.dat";
CClientUIInterface uiInterface; // Declared but not defined in ui_interface.h

//////////////////////////////////////////////////////////////////////////////
//
// Shutdown
//

//
// Thread management and startup/shutdown:
//
// The network-processing threads are all part of a thread group
// created by AppInit() or the Qt main() function.
//
// A clean exit happens when StartShutdown() or the SIGTERM
// signal handler sets fRequestShutdown, which triggers
// the DetectShutdownThread(), which interrupts the main thread group.
// DetectShutdownThread() then exits, which causes AppInit() to
// continue (it .joins the shutdown thread).
// Shutdown() is then
// called to clean up database connections, and stop other
// threads that should only be stopped after the main network-processing
// threads have exited.
//
// Note that if running -daemon the parent process returns from AppInit2
// before adding any threads to the threadGroup, so .join_all() returns
// immediately and the parent exits from main().
//
// Shutdown for Qt is very similar, only it uses a QTimer to detect
// fRequestShutdown getting set, and then does the normal Qt
// shutdown thing.
//

volatile bool fRequestShutdown = false;

void StartShutdown()
{
    fRequestShutdown = true;
}
bool ShutdownRequested()
{
    return fRequestShutdown;
}

class CCoinsViewErrorCatcher : public CCoinsViewBacked
{
public:
    CCoinsViewErrorCatcher(CCoinsView* view) : CCoinsViewBacked(view) {}
    bool GetCoins(const uint256 &txid, CCoins &coins) const {
        try {
            return CCoinsViewBacked::GetCoins(txid, coins);
        } catch(const std::runtime_error& e) {
            uiInterface.ThreadSafeMessageBox(_("Error reading from database, shutting down."), "", CClientUIInterface::MSG_ERROR);
            LogPrintf("Error reading from database: %s\n", e.what());
            // Starting the shutdown sequence and returning false to the caller would be
            // interpreted as 'entry not found' (as opposed to unable to read data), and
            // could lead to invalid interpretation. Just exit immediately, as we can't
            // continue anyway, and all writes should be atomic.
            abort();
        }
    }
    // Writes do not need similar protection, as failure to write is handled by the caller.
};

static CCoinsViewDB *pcoinsdbview = NULL;
static CCoinsViewErrorCatcher *pcoinscatcher = NULL;

void Shutdown()
{
    LogPrintf("%s: In progress...\n", __func__);
    static CCriticalSection cs_Shutdown;
    TRY_LOCK(cs_Shutdown, lockShutdown);
    if (!lockShutdown)
        return;

    /// Note: Shutdown() must be able to handle cases in which AppInit2() failed part of the way,
    /// for example if the data directory was found to be locked.
    /// Be sure that anything that writes files or flushes caches only does this if the respective
    /// module was initialized.
    RenameThread("bitcoin-shutoff");
    mempool.AddTransactionsUpdated(1);
    StopRPCThreads();
#ifdef ENABLE_WALLET
    if (pwalletMain)
        pwalletMain->Flush(false);
    GenerateBitcoins(false, NULL, 0);
#endif
    StopNode();
    UnregisterNodeSignals(GetNodeSignals());

    if (fFeeEstimatesInitialized)
    {
        boost::filesystem::path est_path = GetDataDir() / FEE_ESTIMATES_FILENAME;
        CAutoFile est_fileout(fopen(est_path.string().c_str(), "wb"), SER_DISK, CLIENT_VERSION);
        if (!est_fileout.IsNull())
            mempool.WriteFeeEstimates(est_fileout);
        else
            LogPrintf("%s: Failed to write fee estimates to %s\n", __func__, est_path.string());
        fFeeEstimatesInitialized = false;
    }

    {
        LOCK(cs_main);
        if (pcoinsTip != NULL) {
            FlushStateToDisk();
        }
        delete pcoinsTip;
        pcoinsTip = NULL;
        delete pcoinscatcher;
        pcoinscatcher = NULL;
        delete pcoinsdbview;
        pcoinsdbview = NULL;
        delete pblocktree;
        pblocktree = NULL;
    }
#ifdef ENABLE_WALLET
    if (pwalletMain)
        pwalletMain->Flush(true);
#endif
#ifndef WIN32
    try {
        boost::filesystem::remove(GetPidFile());
    } catch (const boost::filesystem::filesystem_error& e) {
        LogPrintf("%s: Unable to remove pidfile: %s\n", __func__, e.what());
    }
#endif
    UnregisterAllValidationInterfaces();
#ifdef ENABLE_WALLET
    delete pwalletMain;
    pwalletMain = NULL;
#endif
    ECC_Stop();
    LogPrintf("%s: done\n", __func__);
}

/**
 * Signal handlers are very limited in what they are allowed to do, so:
 */
void HandleSIGTERM(int)
{
    fRequestShutdown = true;
}

void HandleSIGHUP(int)
{
    fReopenDebugLog = true;
}

bool static InitError(const std::string &str)
{
    uiInterface.ThreadSafeMessageBox(str, "", CClientUIInterface::MSG_ERROR);
    return false;
}

bool static InitWarning(const std::string &str)
{
    uiInterface.ThreadSafeMessageBox(str, "", CClientUIInterface::MSG_WARNING);
    return true;
}

bool static Bind(const CService &addr, unsigned int flags) {
    if (!(flags & BF_EXPLICIT) && IsLimited(addr))
        return false;
    std::string strError;
    if (!BindListenPort(addr, strError, (flags & BF_WHITELIST) != 0)) {
        if (flags & BF_REPORT_ERROR)
            return InitError(strError);
        return false;
    }
    return true;
}

void OnRPCStopped()
{
    cvBlockChange.notify_all();
    LogPrint("rpc", "RPC stopped.\n");
}

void OnRPCPreCommand(const CRPCCommand& cmd)
{
    // Observe safe mode
    string strWarning = GetWarnings("rpc");
    if (strWarning != "" && !GetBoolArg("-disablesafemode", false) &&
        !cmd.okSafeMode)
        throw JSONRPCError(RPC_FORBIDDEN_BY_SAFE_MODE, string("Safe mode: ") + strWarning);
}

std::string HelpMessage(HelpMessageMode mode)
{
    const bool showDebug = GetBoolArg("-help-debug", false);

    // When adding new options to the categories, please keep and ensure alphabetical ordering.
    // Do not translate _(...) -help-debug options, Many technical terms, and only a very small audience, so is unnecessary stress to translators

    string strUsage = HelpMessageGroup(_("Options:"));
    strUsage += HelpMessageOpt("-?", _("This help message"));
    strUsage += HelpMessageOpt("-alerts", strprintf(_("Receive and display P2P network alerts (default: %u)"), DEFAULT_ALERTS));
    strUsage += HelpMessageOpt("-alertnotify=<cmd>", _("Execute command when a relevant alert is received or we see a really long fork (%s in cmd is replaced by message)"));
    strUsage += HelpMessageOpt("-blocknotify=<cmd>", _("Execute command when the best block changes (%s in cmd is replaced by block hash)"));
    strUsage += HelpMessageOpt("-checkblocks=<n>", strprintf(_("How many blocks to check at startup (default: %u, 0 = all)"), 288));
    strUsage += HelpMessageOpt("-checklevel=<n>", strprintf(_("How thorough the block verification of -checkblocks is (0-4, default: %u)"), 3));
    strUsage += HelpMessageOpt("-conf=<file>", strprintf(_("Specify configuration file (default: %s)"), "bitcoin.conf"));
    if (mode == HMM_BITCOIND)
    {
#if !defined(WIN32)
        strUsage += HelpMessageOpt("-daemon", _("Run in the background as a daemon and accept commands"));
#endif
    }
    strUsage += HelpMessageOpt("-datadir=<dir>", _("Specify data directory"));
    strUsage += HelpMessageOpt("-dbcache=<n>", strprintf(_("Set database cache size in megabytes (%d to %d, default: %d)"), nMinDbCache, nMaxDbCache, nDefaultDbCache));
    strUsage += HelpMessageOpt("-loadblock=<file>", _("Imports blocks from external blk000??.dat file") + " " + _("on startup"));
    strUsage += HelpMessageOpt("-maxorphantx=<n>", strprintf(_("Keep at most <n> unconnectable transactions in memory (default: %u)"), DEFAULT_MAX_ORPHAN_TRANSACTIONS));
    strUsage += HelpMessageOpt("-par=<n>", strprintf(_("Set the number of script verification threads (%u to %d, 0 = auto, <0 = leave that many cores free, default: %d)"),
        -(int)boost::thread::hardware_concurrency(), MAX_SCRIPTCHECK_THREADS, DEFAULT_SCRIPTCHECK_THREADS));
#ifndef WIN32
    strUsage += HelpMessageOpt("-pid=<file>", strprintf(_("Specify pid file (default: %s)"), "bitcoind.pid"));
#endif
    strUsage += HelpMessageOpt("-prune=<n>", strprintf(_("Reduce storage requirements by pruning (deleting) old blocks. This mode disables wallet support and is incompatible with -txindex. "
            "Warning: Reverting this setting requires re-downloading the entire blockchain. "
            "(default: 0 = disable pruning blocks, >%u = target size in MiB to use for block files)"), MIN_DISK_SPACE_FOR_BLOCK_FILES / 1024 / 1024));
    strUsage += HelpMessageOpt("-reindex", _("Rebuild block chain index from current blk000??.dat files on startup"));
#if !defined(WIN32)
    strUsage += HelpMessageOpt("-sysperms", _("Create new files with system default permissions, instead of umask 077 (only effective with disabled wallet functionality)"));
#endif
    strUsage += HelpMessageOpt("-txindex", strprintf(_("Maintain a full transaction index, used by the getrawtransaction rpc call (default: %u)"), 0));

    strUsage += HelpMessageGroup(_("Connection options:"));
    strUsage += HelpMessageOpt("-addnode=<ip>", _("Add a node to connect to and attempt to keep the connection open"));
    strUsage += HelpMessageOpt("-banscore=<n>", strprintf(_("Threshold for disconnecting misbehaving peers (default: %u)"), 100));
    strUsage += HelpMessageOpt("-bantime=<n>", strprintf(_("Number of seconds to keep misbehaving peers from reconnecting (default: %u)"), 86400));
    strUsage += HelpMessageOpt("-bind=<addr>", _("Bind to given address and always listen on it. Use [host]:port notation for IPv6"));
    strUsage += HelpMessageOpt("-connect=<ip>", _("Connect only to the specified node(s)"));
    strUsage += HelpMessageOpt("-discover", _("Discover own IP addresses (default: 1 when listening and no -externalip or -proxy)"));
    strUsage += HelpMessageOpt("-dns", _("Allow DNS lookups for -addnode, -seednode and -connect") + " " + _("(default: 1)"));
    strUsage += HelpMessageOpt("-dnsseed", _("Query for peer addresses via DNS lookup, if low on addresses (default: 1 unless -connect)"));
    strUsage += HelpMessageOpt("-externalip=<ip>", _("Specify your own public address"));
    strUsage += HelpMessageOpt("-forcednsseed", strprintf(_("Always query for peer addresses via DNS lookup (default: %u)"), 0));
    strUsage += HelpMessageOpt("-listen", _("Accept connections from outside (default: 1 if no -proxy or -connect)"));
    strUsage += HelpMessageOpt("-maxconnections=<n>", strprintf(_("Maintain at most <n> connections to peers (default: %u)"), 125));
    strUsage += HelpMessageOpt("-maxreceivebuffer=<n>", strprintf(_("Maximum per-connection receive buffer, <n>*1000 bytes (default: %u)"), 5000));
    strUsage += HelpMessageOpt("-maxsendbuffer=<n>", strprintf(_("Maximum per-connection send buffer, <n>*1000 bytes (default: %u)"), 1000));
    strUsage += HelpMessageOpt("-onion=<ip:port>", strprintf(_("Use separate SOCKS5 proxy to reach peers via Tor hidden services (default: %s)"), "-proxy"));
    strUsage += HelpMessageOpt("-onlynet=<net>", _("Only connect to nodes in network <net> (ipv4, ipv6 or onion)"));
    strUsage += HelpMessageOpt("-permitbaremultisig", strprintf(_("Relay non-P2SH multisig (default: %u)"), 1));
    strUsage += HelpMessageOpt("-port=<port>", strprintf(_("Listen for connections on <port> (default: %u or testnet: %u)"), 8333, 18333));
    strUsage += HelpMessageOpt("-proxy=<ip:port>", _("Connect through SOCKS5 proxy"));
    strUsage += HelpMessageOpt("-proxyrandomize", strprintf(_("Randomize credentials for every proxy connection. This enables Tor stream isolation (default: %u)"), 1));
    strUsage += HelpMessageOpt("-seednode=<ip>", _("Connect to a node to retrieve peer addresses, and disconnect"));
    strUsage += HelpMessageOpt("-timeout=<n>", strprintf(_("Specify connection timeout in milliseconds (minimum: 1, default: %d)"), DEFAULT_CONNECT_TIMEOUT));
#ifdef USE_UPNP
#if USE_UPNP
    strUsage += HelpMessageOpt("-upnp", _("Use UPnP to map the listening port (default: 1 when listening)"));
#else
    strUsage += HelpMessageOpt("-upnp", strprintf(_("Use UPnP to map the listening port (default: %u)"), 0));
#endif
#endif
    strUsage += HelpMessageOpt("-whitebind=<addr>", _("Bind to given address and whitelist peers connecting to it. Use [host]:port notation for IPv6"));
    strUsage += HelpMessageOpt("-whitelist=<netmask>", _("Whitelist peers connecting from the given netmask or IP address. Can be specified multiple times.") +
        " " + _("Whitelisted peers cannot be DoS banned and their transactions are always relayed, even if they are already in the mempool, useful e.g. for a gateway"));
        

#ifdef ENABLE_WALLET
    strUsage += HelpMessageGroup(_("Wallet options:"));
    strUsage += HelpMessageOpt("-disablewallet", _("Do not load the wallet and disable wallet RPC calls"));
    strUsage += HelpMessageOpt("-keypool=<n>", strprintf(_("Set key pool size to <n> (default: %u)"), 100));
    if (showDebug)
        strUsage += HelpMessageOpt("-mintxfee=<amt>", strprintf("Fees (in BTC/Kb) smaller than this are considered zero fee for transaction creation (default: %s)",
            FormatMoney(CWallet::minTxFee.GetFeePerK())));
    strUsage += HelpMessageOpt("-paytxfee=<amt>", strprintf(_("Fee (in BTC/kB) to add to transactions you send (default: %s)"), FormatMoney(payTxFee.GetFeePerK())));
    strUsage += HelpMessageOpt("-rescan", _("Rescan the block chain for missing wallet transactions") + " " + _("on startup"));
    strUsage += HelpMessageOpt("-salvagewallet", _("Attempt to recover private keys from a corrupt wallet.dat") + " " + _("on startup"));
    strUsage += HelpMessageOpt("-sendfreetransactions", strprintf(_("Send transactions as zero-fee transactions if possible (default: %u)"), 0));
    strUsage += HelpMessageOpt("-spendzeroconfchange", strprintf(_("Spend unconfirmed change when sending transactions (default: %u)"), 1));
    strUsage += HelpMessageOpt("-txconfirmtarget=<n>", strprintf(_("If paytxfee is not set, include enough fee so transactions begin confirmation on average within n blocks (default: %u)"), DEFAULT_TX_CONFIRM_TARGET));
    strUsage += HelpMessageOpt("-maxtxfee=<amt>", strprintf(_("Maximum total fees to use in a single wallet transaction; setting this too low may abort large transactions (default: %s)"),
        FormatMoney(maxTxFee)));
    strUsage += HelpMessageOpt("-upgradewallet", _("Upgrade wallet to latest format") + " " + _("on startup"));
    strUsage += HelpMessageOpt("-wallet=<file>", _("Specify wallet file (within data directory)") + " " + strprintf(_("(default: %s)"), "wallet.dat"));
    strUsage += HelpMessageOpt("-walletbroadcast", _("Make the wallet broadcast transactions") + " " + strprintf(_("(default: %u)"), true));
    strUsage += HelpMessageOpt("-walletnotify=<cmd>", _("Execute command when a wallet transaction changes (%s in cmd is replaced by TxID)"));
    strUsage += HelpMessageOpt("-zapwallettxes=<mode>", _("Delete all wallet transactions and only recover those parts of the blockchain through -rescan on startup") +
        " " + _("(1 = keep tx meta data e.g. account owner and payment request information, 2 = drop tx meta data)"));
                    
#endif

    strUsage += HelpMessageGroup(_("Debugging/Testing options:"));
    if (showDebug)
    {
        strUsage += HelpMessageOpt("-checkpoints", strprintf("Only accept block chain matching built-in checkpoints (default: %u)", 1));
        strUsage += HelpMessageOpt("-dblogsize=<n>", strprintf("Flush database activity from memory pool to disk log every <n> megabytes (default: %u)", 100));
        strUsage += HelpMessageOpt("-disablesafemode", strprintf("Disable safemode, override a real safe mode event (default: %u)", 0));
        strUsage += HelpMessageOpt("-testsafemode", strprintf("Force safe mode (default: %u)", 0));
        strUsage += HelpMessageOpt("-dropmessagestest=<n>", "Randomly drop 1 of every <n> network messages");
        strUsage += HelpMessageOpt("-fuzzmessagestest=<n>", "Randomly fuzz 1 of every <n> network messages");
        strUsage += HelpMessageOpt("-flushwallet", strprintf("Run a thread to flush wallet periodically (default: %u)", 1));
        strUsage += HelpMessageOpt("-stopafterblockimport", strprintf("Stop running after importing blocks from disk (default: %u)", 0));
    }
    string debugCategories = "addrman, alert, bench, coindb, db, lock, rand, rpc, selectcoins, mempool, net, proxy, prune"; // Don't translate these and qt below
    if (mode == HMM_BITCOIN_QT)
        debugCategories += ", qt";
    strUsage += HelpMessageOpt("-debug=<category>", strprintf(_("Output debugging information (default: %u, supplying <category> is optional)"), 0) + ". " +
        _("If <category> is not supplied, output all debugging information.") + _("<category> can be:") + " " + debugCategories + ".");
#ifdef ENABLE_WALLET
    strUsage += HelpMessageOpt("-gen", strprintf(_("Generate coins (default: %u)"), 0));
    strUsage += HelpMessageOpt("-genproclimit=<n>", strprintf(_("Set the number of threads for coin generation if enabled (-1 = all cores, default: %d)"), 1));
#endif
    strUsage += HelpMessageOpt("-help-debug", _("Show all debugging options (usage: --help -help-debug)"));
    strUsage += HelpMessageOpt("-logips", strprintf(_("Include IP addresses in debug output (default: %u)"), 0));
    strUsage += HelpMessageOpt("-logtimestamps", strprintf(_("Prepend debug output with timestamp (default: %u)"), 1));
    if (showDebug)
    {
        strUsage += HelpMessageOpt("-limitfreerelay=<n>", strprintf("Continuously rate-limit free transactions to <n>*1000 bytes per minute (default: %u)", 15));
        strUsage += HelpMessageOpt("-relaypriority", strprintf("Require high priority for relaying free or low-fee transactions (default: %u)", 1));
        strUsage += HelpMessageOpt("-maxsigcachesize=<n>", strprintf("Limit size of signature cache to <n> entries (default: %u)", 50000));
    }
    strUsage += HelpMessageOpt("-minrelaytxfee=<amt>", strprintf(_("Fees (in BTC/Kb) smaller than this are considered zero fee for relaying (default: %s)"), FormatMoney(::minRelayTxFee.GetFeePerK())));
    strUsage += HelpMessageOpt("-printtoconsole", _("Send trace/debug info to console instead of debug.log file"));
    if (showDebug)
    {
        strUsage += HelpMessageOpt("-printpriority", strprintf("Log transaction priority and fee per kB when mining blocks (default: %u)", 0));
        strUsage += HelpMessageOpt("-privdb", strprintf("Sets the DB_PRIVATE flag in the wallet db environment (default: %u)", 1));
        strUsage += HelpMessageOpt("-regtest", "Enter regression test mode, which uses a special chain in which blocks can be solved instantly. "
            "This is intended for regression testing tools and app development.");
    }
    strUsage += HelpMessageOpt("-shrinkdebugfile", _("Shrink debug.log file on client startup (default: 1 when no -debug)"));
    strUsage += HelpMessageOpt("-testnet", _("Use the test network"));

    strUsage += HelpMessageGroup(_("Node relay options:"));
    strUsage += HelpMessageOpt("-datacarrier", strprintf(_("Relay and mine data carrier transactions (default: %u)"), 1));
    strUsage += HelpMessageOpt("-datacarriersize", strprintf(_("Maximum size of data in data carrier transactions we relay and mine (default: %u)"), MAX_OP_RETURN_RELAY));

    strUsage += HelpMessageGroup(_("Block creation options:"));
    strUsage += HelpMessageOpt("-blockminsize=<n>", strprintf(_("Set minimum block size in bytes (default: %u)"), 0));
    strUsage += HelpMessageOpt("-blockmaxsize=<n>", strprintf(_("Set maximum block size in bytes (default: %d)"), DEFAULT_BLOCK_MAX_SIZE));
    strUsage += HelpMessageOpt("-blockprioritysize=<n>", strprintf(_("Set maximum size of high-priority/low-fee transactions in bytes (default: %d)"), DEFAULT_BLOCK_PRIORITY_SIZE));

    strUsage += HelpMessageGroup(_("RPC server options:"));
    strUsage += HelpMessageOpt("-server", _("Accept command line and JSON-RPC commands"));
    strUsage += HelpMessageOpt("-rest", strprintf(_("Accept public REST requests (default: %u)"), 0));
    strUsage += HelpMessageOpt("-rpcbind=<addr>", _("Bind to given address to listen for JSON-RPC connections. Use [host]:port notation for IPv6. This option can be specified multiple times (default: bind to all interfaces)"));
    strUsage += HelpMessageOpt("-rpcuser=<user>", _("Username for JSON-RPC connections"));
    strUsage += HelpMessageOpt("-rpcpassword=<pw>", _("Password for JSON-RPC connections"));
    strUsage += HelpMessageOpt("-rpcport=<port>", strprintf(_("Listen for JSON-RPC connections on <port> (default: %u or testnet: %u)"), 8332, 18332));
    strUsage += HelpMessageOpt("-rpcallowip=<ip>", _("Allow JSON-RPC connections from specified source. Valid for <ip> are a single IP (e.g. 1.2.3.4), a network/netmask (e.g. 1.2.3.4/255.255.255.0) or a network/CIDR (e.g. 1.2.3.4/24). This option can be specified multiple times"));
    strUsage += HelpMessageOpt("-rpcthreads=<n>", strprintf(_("Set the number of threads to service RPC calls (default: %d)"), 4));
    strUsage += HelpMessageOpt("-rpckeepalive", strprintf(_("RPC support for HTTP persistent connections (default: %d)"), 1));

    strUsage += HelpMessageGroup(_("RPC SSL options: (see the Bitcoin Wiki for SSL setup instructions)"));
    strUsage += HelpMessageOpt("-rpcssl", _("Use OpenSSL (https) for JSON-RPC connections"));
    strUsage += HelpMessageOpt("-rpcsslcertificatechainfile=<file.cert>", strprintf(_("Server certificate file (default: %s)"), "server.cert"));
    strUsage += HelpMessageOpt("-rpcsslprivatekeyfile=<file.pem>", strprintf(_("Server private key (default: %s)"), "server.pem"));
    strUsage += HelpMessageOpt("-rpcsslciphers=<ciphers>", strprintf(_("Acceptable ciphers (default: %s)"), "TLSv1.2+HIGH:TLSv1+HIGH:!SSLv2:!aNULL:!eNULL:!3DES:@STRENGTH"));

    if (mode == HMM_BITCOIN_QT)
    {
        strUsage += HelpMessageGroup(_("UI Options:"));
        if (showDebug) {
            strUsage += HelpMessageOpt("-allowselfsignedrootcertificates", "Allow self signed root certificates (default: 0)");
        }
        strUsage += HelpMessageOpt("-choosedatadir", _("Choose data directory on startup (default: 0)"));
        strUsage += HelpMessageOpt("-lang=<lang>", _("Set language, for example \"de_DE\" (default: system locale)"));
        strUsage += HelpMessageOpt("-min", _("Start minimized"));
        strUsage += HelpMessageOpt("-rootcertificates=<file>", _("Set SSL root certificates for payment request (default: -system-)"));
        strUsage += HelpMessageOpt("-splash", _("Show splash screen on startup (default: 1)"));
    }

    return strUsage;
}

std::string LicenseInfo()
{
    return FormatParagraph(strprintf(_("Copyright (C) 2009-%i The Bitcoin Core Developers"), COPYRIGHT_YEAR)) + "\n" +
           "\n" +
           FormatParagraph(_("This is experimental software.")) + "\n" +
           "\n" +
           FormatParagraph(_("Distributed under the MIT software license, see the accompanying file COPYING or <http://www.opensource.org/licenses/mit-license.php>.")) + "\n" +
           "\n" +
           FormatParagraph(_("This product includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit <https://www.openssl.org/> and cryptographic software written by Eric Young and UPnP software written by Thomas Bernard.")) +
           "\n";
}

static void BlockNotifyCallback(const uint256& hashNewTip)
{
    std::string strCmd = GetArg("-blocknotify", "");

    boost::replace_all(strCmd, "%s", hashNewTip.GetHex());
    boost::thread t(runCommand, strCmd); // thread runs free
}

struct CImportingNow
{
    CImportingNow() {
        assert(fImporting == false);
        fImporting = true;
    }

    ~CImportingNow() {
        assert(fImporting == true);
        fImporting = false;
    }
};


// If we're using -prune with -reindex, then delete block files that will be ignored by the
// reindex.  Since reindexing works by starting at block file 0 and looping until a blockfile
// is missing, do the same here to delete any later block files after a gap.  Also delete all
// rev files since they'll be rewritten by the reindex anyway.  This ensures that vinfoBlockFile
// is in sync with what's actually on disk by the time we start downloading, so that pruning
// works correctly.
void CleanupBlockRevFiles()
{
    using namespace boost::filesystem;
    map<string, path> mapBlockFiles;

    // Glob all blk?????.dat and rev?????.dat files from the blocks directory.
    // Remove the rev files immediately and insert the blk file paths into an
    // ordered map keyed by block file index.
    LogPrintf("Removing unusable blk?????.dat and rev?????.dat files for -reindex with -prune\n");
    path blocksdir = GetDataDir() / "blocks";
    for (directory_iterator it(blocksdir); it != directory_iterator(); it++) {
        if (is_regular_file(*it) &&
            it->path().filename().string().length() == 12 &&
            it->path().filename().string().substr(8,4) == ".dat")
        {
            if (it->path().filename().string().substr(0,3) == "blk")
                mapBlockFiles[it->path().filename().string().substr(3,5)] = it->path();
            else if (it->path().filename().string().substr(0,3) == "rev")
                remove(it->path());
        }
    }

    // Remove all block files that aren't part of a contiguous set starting at
    // zero by walking the ordered map (keys are block file indices) by
    // keeping a separate counter.  Once we hit a gap (or if 0 doesn't exist)
    // start removing block files.
    int nContigCounter = 0;
    BOOST_FOREACH(const PAIRTYPE(string, path)& item, mapBlockFiles) {
        if (atoi(item.first) == nContigCounter) {
            nContigCounter++;
            continue;
        }
        remove(item.second);
    }
}

void ThreadImport(std::vector<boost::filesystem::path> vImportFiles)
{
    RenameThread("bitcoin-loadblk");
    // -reindex
    if (fReindex) {
        CImportingNow imp;
        int nFile = 0;
        while (true) {
            CDiskBlockPos pos(nFile, 0);
            if (!boost::filesystem::exists(GetBlockPosFilename(pos, "blk")))
                break; // No block files left to reindex
            FILE *file = OpenBlockFile(pos, true);
            if (!file)
                break; // This error is logged in OpenBlockFile
            LogPrintf("Reindexing block file blk%05u.dat...\n", (unsigned int)nFile);
            LoadExternalBlockFile(file, &pos);
            nFile++;
        }
        pblocktree->WriteReindexing(false);
        fReindex = false;
        LogPrintf("Reindexing finished\n");
        // To avoid ending up in a situation without genesis block, re-try initializing (no-op if reindexing worked):
        InitBlockIndex();
    }

    // hardcoded $DATADIR/bootstrap.dat
    boost::filesystem::path pathBootstrap = GetDataDir() / "bootstrap.dat";
    if (boost::filesystem::exists(pathBootstrap)) {
        FILE *file = fopen(pathBootstrap.string().c_str(), "rb");
        if (file) {
            CImportingNow imp;
            boost::filesystem::path pathBootstrapOld = GetDataDir() / "bootstrap.dat.old";
            LogPrintf("Importing bootstrap.dat...\n");
            LoadExternalBlockFile(file);
            RenameOver(pathBootstrap, pathBootstrapOld);
        } else {
            LogPrintf("Warning: Could not open bootstrap file %s\n", pathBootstrap.string());
        }
    }

    // -loadblock=
    BOOST_FOREACH(boost::filesystem::path &path, vImportFiles) {
        FILE *file = fopen(path.string().c_str(), "rb");
        if (file) {
            CImportingNow imp;
            LogPrintf("Importing blocks file %s...\n", path.string());
            LoadExternalBlockFile(file);
        } else {
            LogPrintf("Warning: Could not open blocks file %s\n", path.string());
        }
    }

    if (GetBoolArg("-stopafterblockimport", false)) {
        LogPrintf("Stopping after block import\n");
        StartShutdown();
    }
}

/** Sanity checks
 *  Ensure that Bitcoin is running in a usable environment with all
 *  necessary library support.
 */
bool InitSanityCheck(void)
{
    if(!ECC_InitSanityCheck()) {
        InitError("OpenSSL appears to lack support for elliptic curve cryptography. For more "
                  "information, visit https://en.bitcoin.it/wiki/OpenSSL_and_EC_Libraries");
        return false;
    }
    if (!glibc_sanity_test() || !glibcxx_sanity_test())
        return false;

    return true;
}

/** Initialize bitcoin.
 *  @pre Parameters should be parsed and config file should be read.
 */
bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
{
    // ********************************************************* Step 1: setup
#ifdef _MSC_VER
    // Turn off Microsoft heap dump noise
    _CrtSetReportMode(_CRT_WARN, _CRTDBG_MODE_FILE);
    _CrtSetReportFile(_CRT_WARN, CreateFileA("NUL", GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, 0));
#endif
#if _MSC_VER >= 1400
    // Disable confusing "helpful" text message on abort, Ctrl-C
    _set_abort_behavior(0, _WRITE_ABORT_MSG | _CALL_REPORTFAULT);
#endif
#ifdef WIN32
    // Enable Data Execution Prevention (DEP)
    // Minimum supported OS versions: WinXP SP3, WinVista >= SP1, Win Server 2008
    // A failure is non-critical and needs no further attention!
#ifndef PROCESS_DEP_ENABLE
    // We define this here, because GCCs winbase.h limits this to _WIN32_WINNT >= 0x0601 (Windows 7),
    // which is not correct. Can be removed, when GCCs winbase.h is fixed!
#define PROCESS_DEP_ENABLE 0x00000001
#endif
    typedef BOOL (WINAPI *PSETPROCDEPPOL)(DWORD);
    PSETPROCDEPPOL setProcDEPPol = (PSETPROCDEPPOL)GetProcAddress(GetModuleHandleA("Kernel32.dll"), "SetProcessDEPPolicy");
    if (setProcDEPPol != NULL) setProcDEPPol(PROCESS_DEP_ENABLE);

    // Initialize Windows Sockets
    WSADATA wsadata;
    int ret = WSAStartup(MAKEWORD(2,2), &wsadata);
    if (ret != NO_ERROR || LOBYTE(wsadata.wVersion ) != 2 || HIBYTE(wsadata.wVersion) != 2)
    {
        return InitError(strprintf("Error: Winsock library failed to start (WSAStartup returned error %d)", ret));
    }
#endif
#ifndef WIN32

    if (GetBoolArg("-sysperms", false)) {
#ifdef ENABLE_WALLET
        if (!GetBoolArg("-disablewallet", false))
            return InitError("Error: -sysperms is not allowed in combination with enabled wallet functionality");
#endif
    } else {
        umask(077);
    }

    // Clean shutdown on SIGTERM
    struct sigaction sa;
    sa.sa_handler = HandleSIGTERM;
    sigemptyset(&sa.sa_mask);
    sa.sa_flags = 0;
    sigaction(SIGTERM, &sa, NULL);
    sigaction(SIGINT, &sa, NULL);

    // Reopen debug.log on SIGHUP
    struct sigaction sa_hup;
    sa_hup.sa_handler = HandleSIGHUP;
    sigemptyset(&sa_hup.sa_mask);
    sa_hup.sa_flags = 0;
    sigaction(SIGHUP, &sa_hup, NULL);

#if defined (__SVR4) && defined (__sun)
    // ignore SIGPIPE on Solaris
    signal(SIGPIPE, SIG_IGN);
#endif
#endif

    // ********************************************************* Step 2: parameter interactions
    const CChainParams& chainparams = Params();

    // Set this early so that parameter interactions go to console
    fPrintToConsole = GetBoolArg("-printtoconsole", false);
    fLogTimestamps = GetBoolArg("-logtimestamps", true);
    fLogIPs = GetBoolArg("-logips", false);

    // when specifying an explicit binding address, you want to listen on it
    // even when -connect or -proxy is specified
    if (mapArgs.count("-bind")) {
        if (SoftSetBoolArg("-listen", true))
            LogPrintf("%s: parameter interaction: -bind set -> setting -listen=1\n", __func__);
    }
    if (mapArgs.count("-whitebind")) {
        if (SoftSetBoolArg("-listen", true))
            LogPrintf("%s: parameter interaction: -whitebind set -> setting -listen=1\n", __func__);
    }

    if (mapArgs.count("-connect") && mapMultiArgs["-connect"].size() > 0) {
        // when only connecting to trusted nodes, do not seed via DNS, or listen by default
        if (SoftSetBoolArg("-dnsseed", false))
            LogPrintf("%s: parameter interaction: -connect set -> setting -dnsseed=0\n", __func__);
        if (SoftSetBoolArg("-listen", false))
            LogPrintf("%s: parameter interaction: -connect set -> setting -listen=0\n", __func__);
    }

    if (mapArgs.count("-proxy")) {
        // to protect privacy, do not listen by default if a default proxy server is specified
        if (SoftSetBoolArg("-listen", false))
            LogPrintf("%s: parameter interaction: -proxy set -> setting -listen=0\n", __func__);
        // to protect privacy, do not use UPNP when a proxy is set. The user may still specify -listen=1
        // to listen locally, so don't rely on this happening through -listen below.
        if (SoftSetBoolArg("-upnp", false))
            LogPrintf("%s: parameter interaction: -proxy set -> setting -upnp=0\n", __func__);
        // to protect privacy, do not discover addresses by default
        if (SoftSetBoolArg("-discover", false))
            LogPrintf("%s: parameter interaction: -proxy set -> setting -discover=0\n", __func__);
    }

    if (!GetBoolArg("-listen", DEFAULT_LISTEN)) {
        // do not map ports or try to retrieve public IP when not listening (pointless)
        if (SoftSetBoolArg("-upnp", false))
            LogPrintf("%s: parameter interaction: -listen=0 -> setting -upnp=0\n", __func__);
        if (SoftSetBoolArg("-discover", false))
            LogPrintf("%s: parameter interaction: -listen=0 -> setting -discover=0\n", __func__);
    }

    if (mapArgs.count("-externalip")) {
        // if an explicit public IP is specified, do not try to find others
        if (SoftSetBoolArg("-discover", false))
            LogPrintf("%s: parameter interaction: -externalip set -> setting -discover=0\n", __func__);
    }

    if (GetBoolArg("-salvagewallet", false)) {
        // Rewrite just private keys: rescan to find transactions
        if (SoftSetBoolArg("-rescan", true))
            LogPrintf("%s: parameter interaction: -salvagewallet=1 -> setting -rescan=1\n", __func__);
    }

    // -zapwallettx implies a rescan
    if (GetBoolArg("-zapwallettxes", false)) {
        if (SoftSetBoolArg("-rescan", true))
            LogPrintf("%s: parameter interaction: -zapwallettxes=<mode> -> setting -rescan=1\n", __func__);
    }

    // Make sure enough file descriptors are available
    int nBind = std::max((int)mapArgs.count("-bind") + (int)mapArgs.count("-whitebind"), 1);
    nMaxConnections = GetArg("-maxconnections", 125);
    nMaxConnections = std::max(std::min(nMaxConnections, (int)(FD_SETSIZE - nBind - MIN_CORE_FILEDESCRIPTORS)), 0);
    int nFD = RaiseFileDescriptorLimit(nMaxConnections + MIN_CORE_FILEDESCRIPTORS);
    if (nFD < MIN_CORE_FILEDESCRIPTORS)
        return InitError(_("Not enough file descriptors available."));
    if (nFD - MIN_CORE_FILEDESCRIPTORS < nMaxConnections)
        nMaxConnections = nFD - MIN_CORE_FILEDESCRIPTORS;

    // if using block pruning, then disable txindex
    // also disable the wallet (for now, until SPV support is implemented in wallet)
    if (GetArg("-prune", 0)) {
        if (GetBoolArg("-txindex", false))
            return InitError(_("Prune mode is incompatible with -txindex."));
#ifdef ENABLE_WALLET
        if (!GetBoolArg("-disablewallet", false)) {
            if (SoftSetBoolArg("-disablewallet", true))
                LogPrintf("%s : parameter interaction: -prune -> setting -disablewallet=1\n", __func__);
            else
                return InitError(_("Can't run with a wallet in prune mode."));
        }
#endif
    }

    // ********************************************************* Step 3: parameter-to-internal-flags

    fDebug = !mapMultiArgs["-debug"].empty();
    // Special-case: if -debug=0/-nodebug is set, turn off debugging messages
    const vector<string>& categories = mapMultiArgs["-debug"];
    if (GetBoolArg("-nodebug", false) || find(categories.begin(), categories.end(), string("0")) != categories.end())
        fDebug = false;

    // Check for -debugnet
    if (GetBoolArg("-debugnet", false))
        InitWarning(_("Warning: Unsupported argument -debugnet ignored, use -debug=net."));
    // Check for -socks - as this is a privacy risk to continue, exit here
    if (mapArgs.count("-socks"))
        return InitError(_("Error: Unsupported argument -socks found. Setting SOCKS version isn't possible anymore, only SOCKS5 proxies are supported."));
    // Check for -tor - as this is a privacy risk to continue, exit here
    if (GetBoolArg("-tor", false))
        return InitError(_("Error: Unsupported argument -tor found, use -onion."));

    if (GetBoolArg("-benchmark", false))
        InitWarning(_("Warning: Unsupported argument -benchmark ignored, use -debug=bench."));

    // Checkmempool and checkblockindex default to true in regtest mode
    mempool.setSanityCheck(GetBoolArg("-checkmempool", chainparams.DefaultConsistencyChecks()));
    fCheckBlockIndex = GetBoolArg("-checkblockindex", chainparams.DefaultConsistencyChecks());
    fCheckpointsEnabled = GetBoolArg("-checkpoints", true);

    // -par=0 means autodetect, but nScriptCheckThreads==0 means no concurrency
    nScriptCheckThreads = GetArg("-par", DEFAULT_SCRIPTCHECK_THREADS);
    if (nScriptCheckThreads <= 0)
        nScriptCheckThreads += boost::thread::hardware_concurrency();
    if (nScriptCheckThreads <= 1)
        nScriptCheckThreads = 0;
    else if (nScriptCheckThreads > MAX_SCRIPTCHECK_THREADS)
        nScriptCheckThreads = MAX_SCRIPTCHECK_THREADS;

    fServer = GetBoolArg("-server", false);

    // block pruning; get the amount of disk space (in MB) to allot for block & undo files
    int64_t nSignedPruneTarget = GetArg("-prune", 0) * 1024 * 1024;
    if (nSignedPruneTarget < 0) {
        return InitError(_("Prune cannot be configured with a negative value."));
    }
    nPruneTarget = (uint64_t) nSignedPruneTarget;
    if (nPruneTarget) {
        if (nPruneTarget < MIN_DISK_SPACE_FOR_BLOCK_FILES) {
            return InitError(strprintf(_("Prune configured below the minimum of %d MB.  Please use a higher number."), MIN_DISK_SPACE_FOR_BLOCK_FILES / 1024 / 1024));
        }
        LogPrintf("Prune configured to target %uMiB on disk for block and undo files.\n", nPruneTarget / 1024 / 1024);
        fPruneMode = true;
    }

#ifdef ENABLE_WALLET
    bool fDisableWallet = GetBoolArg("-disablewallet", false);
#endif

    nConnectTimeout = GetArg("-timeout", DEFAULT_CONNECT_TIMEOUT);
    if (nConnectTimeout <= 0)
        nConnectTimeout = DEFAULT_CONNECT_TIMEOUT;

    // Fee-per-kilobyte amount considered the same as "free"
    // If you are mining, be careful setting this:
    // if you set it to zero then
    // a transaction spammer can cheaply fill blocks using
    // 1-satoshi-fee transactions. It should be set above the real
    // cost to you of processing a transaction.
    if (mapArgs.count("-minrelaytxfee"))
    {
        CAmount n = 0;
        if (ParseMoney(mapArgs["-minrelaytxfee"], n) && n > 0)
            ::minRelayTxFee = CFeeRate(n);
        else
            return InitError(strprintf(_("Invalid amount for -minrelaytxfee=<amount>: '%s'"), mapArgs["-minrelaytxfee"]));
    }

#ifdef ENABLE_WALLET
    if (mapArgs.count("-mintxfee"))
    {
        CAmount n = 0;
        if (ParseMoney(mapArgs["-mintxfee"], n) && n > 0)
            CWallet::minTxFee = CFeeRate(n);
        else
            return InitError(strprintf(_("Invalid amount for -mintxfee=<amount>: '%s'"), mapArgs["-mintxfee"]));
    }
    if (mapArgs.count("-paytxfee"))
    {
        CAmount nFeePerK = 0;
        if (!ParseMoney(mapArgs["-paytxfee"], nFeePerK))
            return InitError(strprintf(_("Invalid amount for -paytxfee=<amount>: '%s'"), mapArgs["-paytxfee"]));
        if (nFeePerK > nHighTransactionFeeWarning)
            InitWarning(_("Warning: -paytxfee is set very high! This is the transaction fee you will pay if you send a transaction."));
        payTxFee = CFeeRate(nFeePerK, 1000);
        if (payTxFee < ::minRelayTxFee)
        {
            return InitError(strprintf(_("Invalid amount for -paytxfee=<amount>: '%s' (must be at least %s)"),
                                       mapArgs["-paytxfee"], ::minRelayTxFee.ToString()));
        }
    }
    if (mapArgs.count("-maxtxfee"))
    {
        CAmount nMaxFee = 0;
        if (!ParseMoney(mapArgs["-maxtxfee"], nMaxFee))
            return InitError(strprintf(_("Invalid amount for -maxtxfee=<amount>: '%s'"), mapArgs["-maptxfee"]));
        if (nMaxFee > nHighTransactionMaxFeeWarning)
            InitWarning(_("Warning: -maxtxfee is set very high! Fees this large could be paid on a single transaction."));
        maxTxFee = nMaxFee;
        if (CFeeRate(maxTxFee, 1000) < ::minRelayTxFee)
        {
            return InitError(strprintf(_("Invalid amount for -maxtxfee=<amount>: '%s' (must be at least the minrelay fee of %s to prevent stuck transactions)"),
                                       mapArgs["-maxtxfee"], ::minRelayTxFee.ToString()));
        }
    }
    nTxConfirmTarget = GetArg("-txconfirmtarget", DEFAULT_TX_CONFIRM_TARGET);
    bSpendZeroConfChange = GetBoolArg("-spendzeroconfchange", true);
    fSendFreeTransactions = GetBoolArg("-sendfreetransactions", false);

    std::string strWalletFile = GetArg("-wallet", "wallet.dat");
#endif // ENABLE_WALLET

    fIsBareMultisigStd = GetBoolArg("-permitbaremultisig", true);
    nMaxDatacarrierBytes = GetArg("-datacarriersize", nMaxDatacarrierBytes);

    fAlerts = GetBoolArg("-alerts", DEFAULT_ALERTS);

    // ********************************************************* Step 4: application initialization: dir lock, daemonize, pidfile, debug log

    // Initialize elliptic curve code
    ECC_Start();

    // Sanity check
    if (!InitSanityCheck())
        return InitError(_("Initialization sanity check failed. Bitcoin Core is shutting down."));

    std::string strDataDir = GetDataDir().string();
#ifdef ENABLE_WALLET
    // Wallet file must be a plain filename without a directory
    if (strWalletFile != boost::filesystem::basename(strWalletFile) + boost::filesystem::extension(strWalletFile))
        return InitError(strprintf(_("Wallet %s resides outside data directory %s"), strWalletFile, strDataDir));
#endif
    // Make sure only a single Bitcoin process is using the data directory.
    boost::filesystem::path pathLockFile = GetDataDir() / ".lock";
    FILE* file = fopen(pathLockFile.string().c_str(), "a"); // empty lock file; created if it doesn't exist.
    if (file) fclose(file);

    try {
        static boost::interprocess::file_lock lock(pathLockFile.string().c_str());
        if (!lock.try_lock())
            return InitError(strprintf(_("Cannot obtain a lock on data directory %s. Bitcoin Core is probably already running."), strDataDir));
    } catch(const boost::interprocess::interprocess_exception& e) {
        return InitError(strprintf(_("Cannot obtain a lock on data directory %s. Bitcoin Core is probably already running.") + " %s.", strDataDir, e.what()));
    }

#ifndef WIN32
    CreatePidFile(GetPidFile(), getpid());
#endif
    if (GetBoolArg("-shrinkdebugfile", !fDebug))
        ShrinkDebugFile();
    LogPrintf("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n");
    LogPrintf("Bitcoin version %s (%s)\n", FormatFullVersion(), CLIENT_DATE);
    LogPrintf("Using OpenSSL version %s\n", SSLeay_version(SSLEAY_VERSION));
#ifdef ENABLE_WALLET
    LogPrintf("Using BerkeleyDB version %s\n", DbEnv::version(0, 0, 0));
#endif
    if (!fLogTimestamps)
        LogPrintf("Startup time: %s\n", DateTimeStrFormat("%Y-%m-%d %H:%M:%S", GetTime()));
    LogPrintf("Default data directory %s\n", GetDefaultDataDir().string());
    LogPrintf("Using data directory %s\n", strDataDir);
    LogPrintf("Using config file %s\n", GetConfigFile().string());
    LogPrintf("Using at most %i connections (%i file descriptors available)\n", nMaxConnections, nFD);
    std::ostringstream strErrors;

    LogPrintf("Using %u threads for script verification\n", nScriptCheckThreads);
    if (nScriptCheckThreads) {
        for (int i=0; i<nScriptCheckThreads-1; i++)
            threadGroup.create_thread(&ThreadScriptCheck);
    }

    // Start the lightweight task scheduler thread
    CScheduler::Function serviceLoop = boost::bind(&CScheduler::serviceQueue, &scheduler);
    threadGroup.create_thread(boost::bind(&TraceThread<CScheduler::Function>, "scheduler", serviceLoop));

    /* Start the RPC server already.  It will be started in "warmup" mode
     * and not really process calls already (but it will signify connections
     * that the server is there and will be ready later).  Warmup mode will
     * be disabled when initialisation is finished.
     */
    if (fServer)
    {
        uiInterface.InitMessage.connect(SetRPCWarmupStatus);
        RPCServer::OnStopped(&OnRPCStopped);
        RPCServer::OnPreCommand(&OnRPCPreCommand);
        StartRPCThreads();
    }

    int64_t nStart;

    // ********************************************************* Step 5: verify wallet database integrity
#ifdef ENABLE_WALLET
    if (!fDisableWallet) {
        LogPrintf("Using wallet %s\n", strWalletFile);
        uiInterface.InitMessage(_("Verifying wallet..."));

        std::string warningString;
        std::string errorString;
        
        if (!CWallet::Verify(strWalletFile, warningString, errorString))
            return false;
        
        if (!warningString.empty())
            InitWarning(warningString);
        if (!errorString.empty())
            return InitError(warningString);
        
    } // (!fDisableWallet)
#endif // ENABLE_WALLET
    // ********************************************************* Step 6: network initialization

    RegisterNodeSignals(GetNodeSignals());

    if (mapArgs.count("-onlynet")) {
        std::set<enum Network> nets;
        BOOST_FOREACH(std::string snet, mapMultiArgs["-onlynet"]) {
            enum Network net = ParseNetwork(snet);
            if (net == NET_UNROUTABLE)
                return InitError(strprintf(_("Unknown network specified in -onlynet: '%s'"), snet));
            nets.insert(net);
        }
        for (int n = 0; n < NET_MAX; n++) {
            enum Network net = (enum Network)n;
            if (!nets.count(net))
                SetLimited(net);
        }
    }

    if (mapArgs.count("-whitelist")) {
        BOOST_FOREACH(const std::string& net, mapMultiArgs["-whitelist"]) {
            CSubNet subnet(net);
            if (!subnet.IsValid())
                return InitError(strprintf(_("Invalid netmask specified in -whitelist: '%s'"), net));
            CNode::AddWhitelistedRange(subnet);
        }
    }

    proxyType addrProxy;
    bool fProxy = false;
    if (mapArgs.count("-proxy")) {
        addrProxy = proxyType(CService(mapArgs["-proxy"], 9050), GetBoolArg("-proxyrandomize", true));
        if (!addrProxy.IsValid())
            return InitError(strprintf(_("Invalid -proxy address: '%s'"), mapArgs["-proxy"]));

        SetProxy(NET_IPV4, addrProxy);
        SetProxy(NET_IPV6, addrProxy);
        SetNameProxy(addrProxy);
        fProxy = true;
    }

    // -onion can override normal proxy, -noonion disables connecting to .onion entirely
    if (!(mapArgs.count("-onion") && mapArgs["-onion"] == "0") &&
        (fProxy || mapArgs.count("-onion"))) {
        proxyType addrOnion;
        if (!mapArgs.count("-onion"))
            addrOnion = addrProxy;
        else
            addrOnion = proxyType(CService(mapArgs["-onion"], 9050), GetBoolArg("-proxyrandomize", true));
        if (!addrOnion.IsValid())
            return InitError(strprintf(_("Invalid -onion address: '%s'"), mapArgs["-onion"]));
        SetProxy(NET_TOR, addrOnion);
        SetReachable(NET_TOR);
    }

    // see Step 2: parameter interactions for more information about these
    fListen = GetBoolArg("-listen", DEFAULT_LISTEN);
    fDiscover = GetBoolArg("-discover", true);
    fNameLookup = GetBoolArg("-dns", true);

    bool fBound = false;
    if (fListen) {
        if (mapArgs.count("-bind") || mapArgs.count("-whitebind")) {
            BOOST_FOREACH(std::string strBind, mapMultiArgs["-bind"]) {
                CService addrBind;
                if (!Lookup(strBind.c_str(), addrBind, GetListenPort(), false))
                    return InitError(strprintf(_("Cannot resolve -bind address: '%s'"), strBind));
                fBound |= Bind(addrBind, (BF_EXPLICIT | BF_REPORT_ERROR));
            }
            BOOST_FOREACH(std::string strBind, mapMultiArgs["-whitebind"]) {
                CService addrBind;
                if (!Lookup(strBind.c_str(), addrBind, 0, false))
                    return InitError(strprintf(_("Cannot resolve -whitebind address: '%s'"), strBind));
                if (addrBind.GetPort() == 0)
                    return InitError(strprintf(_("Need to specify a port with -whitebind: '%s'"), strBind));
                fBound |= Bind(addrBind, (BF_EXPLICIT | BF_REPORT_ERROR | BF_WHITELIST));
            }
        }
        else {
            struct in_addr inaddr_any;
            inaddr_any.s_addr = INADDR_ANY;
            fBound |= Bind(CService(in6addr_any, GetListenPort()), BF_NONE);
            fBound |= Bind(CService(inaddr_any, GetListenPort()), !fBound ? BF_REPORT_ERROR : BF_NONE);
        }
        if (!fBound)
            return InitError(_("Failed to listen on any port. Use -listen=0 if you want this."));
    }

    if (mapArgs.count("-externalip")) {
        BOOST_FOREACH(string strAddr, mapMultiArgs["-externalip"]) {
            CService addrLocal(strAddr, GetListenPort(), fNameLookup);
            if (!addrLocal.IsValid())
                return InitError(strprintf(_("Cannot resolve -externalip address: '%s'"), strAddr));
            AddLocal(CService(strAddr, GetListenPort(), fNameLookup), LOCAL_MANUAL);
        }
    }

    BOOST_FOREACH(string strDest, mapMultiArgs["-seednode"])
        AddOneShot(strDest);

    // ********************************************************* Step 7: load block chain

    fReindex = GetBoolArg("-reindex", false);

    // Upgrading to 0.8; hard-link the old blknnnn.dat files into /blocks/
    boost::filesystem::path blocksDir = GetDataDir() / "blocks";
    if (!boost::filesystem::exists(blocksDir))
    {
        boost::filesystem::create_directories(blocksDir);
        bool linked = false;
        for (unsigned int i = 1; i < 10000; i++) {
            boost::filesystem::path source = GetDataDir() / strprintf("blk%04u.dat", i);
            if (!boost::filesystem::exists(source)) break;
            boost::filesystem::path dest = blocksDir / strprintf("blk%05u.dat", i-1);
            try {
                boost::filesystem::create_hard_link(source, dest);
                LogPrintf("Hardlinked %s -> %s\n", source.string(), dest.string());
                linked = true;
            } catch (const boost::filesystem::filesystem_error& e) {
                // Note: hardlink creation failing is not a disaster, it just means
                // blocks will get re-downloaded from peers.
                LogPrintf("Error hardlinking blk%04u.dat: %s\n", i, e.what());
                break;
            }
        }
        if (linked)
        {
            fReindex = true;
        }
    }

    // cache size calculations
    int64_t nTotalCache = (GetArg("-dbcache", nDefaultDbCache) << 20);
    nTotalCache = std::max(nTotalCache, nMinDbCache << 20); // total cache cannot be less than nMinDbCache
    nTotalCache = std::min(nTotalCache, nMaxDbCache << 20); // total cache cannot be greated than nMaxDbcache
    int64_t nBlockTreeDBCache = nTotalCache / 8;
    if (nBlockTreeDBCache > (1 << 21) && !GetBoolArg("-txindex", false))
        nBlockTreeDBCache = (1 << 21); // block tree db cache shouldn't be larger than 2 MiB
    nTotalCache -= nBlockTreeDBCache;
    int64_t nCoinDBCache = std::min(nTotalCache / 2, (nTotalCache / 4) + (1 << 23)); // use 25%-50% of the remainder for disk cache
    nTotalCache -= nCoinDBCache;
    nCoinCacheUsage = nTotalCache; // the rest goes to in-memory cache
    LogPrintf("Cache configuration:\n");
    LogPrintf("* Using %.1fMiB for block index database\n", nBlockTreeDBCache * (1.0 / 1024 / 1024));
    LogPrintf("* Using %.1fMiB for chain state database\n", nCoinDBCache * (1.0 / 1024 / 1024));
    LogPrintf("* Using %.1fMiB for in-memory UTXO set\n", nCoinCacheUsage * (1.0 / 1024 / 1024));

    bool fLoaded = false;
    while (!fLoaded) {
        bool fReset = fReindex;
        std::string strLoadError;

        uiInterface.InitMessage(_("Loading block index..."));

        nStart = GetTimeMillis();
        do {
            try {
                UnloadBlockIndex();
                delete pcoinsTip;
                delete pcoinsdbview;
                delete pcoinscatcher;
                delete pblocktree;

                pblocktree = new CBlockTreeDB(nBlockTreeDBCache, false, fReindex);
                pcoinsdbview = new CCoinsViewDB(nCoinDBCache, false, fReindex);
                pcoinscatcher = new CCoinsViewErrorCatcher(pcoinsdbview);
                pcoinsTip = new CCoinsViewCache(pcoinscatcher);

                if (fReindex) {
                    pblocktree->WriteReindexing(true);
                    //If we're reindexing in prune mode, wipe away unusable block files and all undo data files
                    if (fPruneMode)
                        CleanupBlockRevFiles();
                }

                if (!LoadBlockIndex()) {
                    strLoadError = _("Error loading block database");
                    break;
                }

                // If the loaded chain has a wrong genesis, bail out immediately
                // (we're likely using a testnet datadir, or the other way around).
                if (!mapBlockIndex.empty() && mapBlockIndex.count(chainparams.GetConsensus().hashGenesisBlock) == 0)
                    return InitError(_("Incorrect or no genesis block found. Wrong datadir for network?"));

                // Initialize the block index (no-op if non-empty database was already loaded)
                if (!InitBlockIndex()) {
                    strLoadError = _("Error initializing block database");
                    break;
                }

                // Check for changed -txindex state
                if (fTxIndex != GetBoolArg("-txindex", false)) {
                    strLoadError = _("You need to rebuild the database using -reindex to change -txindex");
                    break;
                }

                // Check for changed -prune state.  What we are concerned about is a user who has pruned blocks
                // in the past, but is now trying to run unpruned.
                if (fHavePruned && !fPruneMode) {
                    strLoadError = _("You need to rebuild the database using -reindex to go back to unpruned mode.  This will redownload the entire blockchain");
                    break;
                }

                uiInterface.InitMessage(_("Verifying blocks..."));
                if (fHavePruned && GetArg("-checkblocks", 288) > MIN_BLOCKS_TO_KEEP) {
                    LogPrintf("Prune: pruned datadir may not have more than %d blocks; -checkblocks=%d may fail\n",
                        MIN_BLOCKS_TO_KEEP, GetArg("-checkblocks", 288));
                }
                if (!CVerifyDB().VerifyDB(pcoinsdbview, GetArg("-checklevel", 3),
                              GetArg("-checkblocks", 288))) {
                    strLoadError = _("Corrupted block database detected");
                    break;
                }
            } catch (const std::exception& e) {
                if (fDebug) LogPrintf("%s\n", e.what());
                strLoadError = _("Error opening block database");
                break;
            }

            fLoaded = true;
        } while(false);

        if (!fLoaded) {
            // first suggest a reindex
            if (!fReset) {
                bool fRet = uiInterface.ThreadSafeMessageBox(
                    strLoadError + ".\n\n" + _("Do you want to rebuild the block database now?"),
                    "", CClientUIInterface::MSG_ERROR | CClientUIInterface::BTN_ABORT);
                if (fRet) {
                    fReindex = true;
                    fRequestShutdown = false;
                } else {
                    LogPrintf("Aborted block database rebuild. Exiting.\n");
                    return false;
                }
            } else {
                return InitError(strLoadError);
            }
        }
    }

    // As LoadBlockIndex can take several minutes, it's possible the user
    // requested to kill the GUI during the last operation. If so, exit.
    // As the program has not fully started yet, Shutdown() is possibly overkill.
    if (fRequestShutdown)
    {
        LogPrintf("Shutdown requested. Exiting.\n");
        return false;
    }
    LogPrintf(" block index %15dms\n", GetTimeMillis() - nStart);

    boost::filesystem::path est_path = GetDataDir() / FEE_ESTIMATES_FILENAME;
    CAutoFile est_filein(fopen(est_path.string().c_str(), "rb"), SER_DISK, CLIENT_VERSION);
    // Allowed to fail as this file IS missing on first startup.
    if (!est_filein.IsNull())
        mempool.ReadFeeEstimates(est_filein);
    fFeeEstimatesInitialized = true;

    // if prune mode, unset NODE_NETWORK and prune block files
    if (fPruneMode) {
        LogPrintf("Unsetting NODE_NETWORK on prune mode\n");
        nLocalServices &= ~NODE_NETWORK;
        if (!fReindex) {
            PruneAndFlush();
        }
    }

    // ********************************************************* Step 8: load wallet
#ifdef ENABLE_WALLET
    if (fDisableWallet) {
        pwalletMain = NULL;
        LogPrintf("Wallet disabled!\n");
    } else {

        // needed to restore wallet transaction meta data after -zapwallettxes
        std::vector<CWalletTx> vWtx;

        if (GetBoolArg("-zapwallettxes", false)) {
            uiInterface.InitMessage(_("Zapping all transactions from wallet..."));

            pwalletMain = new CWallet(strWalletFile);
            DBErrors nZapWalletRet = pwalletMain->ZapWalletTx(vWtx);
            if (nZapWalletRet != DB_LOAD_OK) {
                uiInterface.InitMessage(_("Error loading wallet.dat: Wallet corrupted"));
                return false;
            }

            delete pwalletMain;
            pwalletMain = NULL;
        }

        uiInterface.InitMessage(_("Loading wallet..."));

        nStart = GetTimeMillis();
        bool fFirstRun = true;
        pwalletMain = new CWallet(strWalletFile);
        DBErrors nLoadWalletRet = pwalletMain->LoadWallet(fFirstRun);
        if (nLoadWalletRet != DB_LOAD_OK)
        {
            if (nLoadWalletRet == DB_CORRUPT)
                strErrors << _("Error loading wallet.dat: Wallet corrupted") << "\n";
            else if (nLoadWalletRet == DB_NONCRITICAL_ERROR)
            {
                string msg(_("Warning: error reading wallet.dat! All keys read correctly, but transaction data"
                             " or address book entries might be missing or incorrect."));
                InitWarning(msg);
            }
            else if (nLoadWalletRet == DB_TOO_NEW)
                strErrors << _("Error loading wallet.dat: Wallet requires newer version of Bitcoin Core") << "\n";
            else if (nLoadWalletRet == DB_NEED_REWRITE)
            {
                strErrors << _("Wallet needed to be rewritten: restart Bitcoin Core to complete") << "\n";
                LogPrintf("%s", strErrors.str());
                return InitError(strErrors.str());
            }
            else
                strErrors << _("Error loading wallet.dat") << "\n";
        }

        if (GetBoolArg("-upgradewallet", fFirstRun))
        {
            int nMaxVersion = GetArg("-upgradewallet", 0);
            if (nMaxVersion == 0) // the -upgradewallet without argument case
            {
                LogPrintf("Performing wallet upgrade to %i\n", FEATURE_LATEST);
                nMaxVersion = CLIENT_VERSION;
                pwalletMain->SetMinVersion(FEATURE_LATEST); // permanently upgrade the wallet immediately
            }
            else
                LogPrintf("Allowing wallet upgrade up to %i\n", nMaxVersion);
            if (nMaxVersion < pwalletMain->GetVersion())
                strErrors << _("Cannot downgrade wallet") << "\n";
            pwalletMain->SetMaxVersion(nMaxVersion);
        }

        if (fFirstRun)
        {
            // Create new keyUser and set as default key
            RandAddSeedPerfmon();

            CPubKey newDefaultKey;
            if (pwalletMain->GetKeyFromPool(newDefaultKey)) {
                pwalletMain->SetDefaultKey(newDefaultKey);
                if (!pwalletMain->SetAddressBook(pwalletMain->vchDefaultKey.GetID(), "", "receive"))
                    strErrors << _("Cannot write default address") << "\n";
            }

            pwalletMain->SetBestChain(chainActive.GetLocator());
        }

        LogPrintf("%s", strErrors.str());
        LogPrintf(" wallet      %15dms\n", GetTimeMillis() - nStart);

        RegisterValidationInterface(pwalletMain);

        CBlockIndex *pindexRescan = chainActive.Tip();
        if (GetBoolArg("-rescan", false))
            pindexRescan = chainActive.Genesis();
        else
        {
            CWalletDB walletdb(strWalletFile);
            CBlockLocator locator;
            if (walletdb.ReadBestBlock(locator))
                pindexRescan = FindForkInGlobalIndex(chainActive, locator);
            else
                pindexRescan = chainActive.Genesis();
        }
        if (chainActive.Tip() && chainActive.Tip() != pindexRescan)
        {
            uiInterface.InitMessage(_("Rescanning..."));
            LogPrintf("Rescanning last %i blocks (from block %i)...\n", chainActive.Height() - pindexRescan->nHeight, pindexRescan->nHeight);
            nStart = GetTimeMillis();
            pwalletMain->ScanForWalletTransactions(pindexRescan, true);
            LogPrintf(" rescan      %15dms\n", GetTimeMillis() - nStart);
            pwalletMain->SetBestChain(chainActive.GetLocator());
            nWalletDBUpdated++;

            // Restore wallet transaction metadata after -zapwallettxes=1
            if (GetBoolArg("-zapwallettxes", false) && GetArg("-zapwallettxes", "1") != "2")
            {
                CWalletDB walletdb(strWalletFile);

                BOOST_FOREACH(const CWalletTx& wtxOld, vWtx)
                {
                    uint256 hash = wtxOld.GetHash();
                    std::map<uint256, CWalletTx>::iterator mi = pwalletMain->mapWallet.find(hash);
                    if (mi != pwalletMain->mapWallet.end())
                    {
                        const CWalletTx* copyFrom = &wtxOld;
                        CWalletTx* copyTo = &mi->second;
                        copyTo->mapValue = copyFrom->mapValue;
                        copyTo->vOrderForm = copyFrom->vOrderForm;
                        copyTo->nTimeReceived = copyFrom->nTimeReceived;
                        copyTo->nTimeSmart = copyFrom->nTimeSmart;
                        copyTo->fFromMe = copyFrom->fFromMe;
                        copyTo->strFromAccount = copyFrom->strFromAccount;
                        copyTo->nOrderPos = copyFrom->nOrderPos;
                        copyTo->WriteToDisk(&walletdb);
                    }
                }
            }
        }
        pwalletMain->SetBroadcastTransactions(GetBoolArg("-walletbroadcast", true));
    } // (!fDisableWallet)
#else // ENABLE_WALLET
    LogPrintf("No wallet support compiled in!\n");
#endif // !ENABLE_WALLET
    // ********************************************************* Step 9: import blocks

    if (mapArgs.count("-blocknotify"))
        uiInterface.NotifyBlockTip.connect(BlockNotifyCallback);

    uiInterface.InitMessage(_("Activating best chain..."));
    // scan for better chains in the block chain database, that are not yet connected in the active best chain
    CValidationState state;
    if (!ActivateBestChain(state))
        strErrors << "Failed to connect best block";

    std::vector<boost::filesystem::path> vImportFiles;
    if (mapArgs.count("-loadblock"))
    {
        BOOST_FOREACH(string strFile, mapMultiArgs["-loadblock"])
            vImportFiles.push_back(strFile);
    }
    threadGroup.create_thread(boost::bind(&ThreadImport, vImportFiles));
    if (chainActive.Tip() == NULL) {
        LogPrintf("Waiting for genesis block to be imported...\n");
        while (!fRequestShutdown && chainActive.Tip() == NULL)
            MilliSleep(10);
    }

    // ********************************************************* Step 10: start node

    if (!CheckDiskSpace())
        return false;

    if (!strErrors.str().empty())
        return InitError(strErrors.str());

    RandAddSeedPerfmon();

    //// debug print
    LogPrintf("mapBlockIndex.size() = %u\n",   mapBlockIndex.size());
    LogPrintf("nBestHeight = %d\n",                   chainActive.Height());
#ifdef ENABLE_WALLET
    LogPrintf("setKeyPool.size() = %u\n",      pwalletMain ? pwalletMain->setKeyPool.size() : 0);
    LogPrintf("mapWallet.size() = %u\n",       pwalletMain ? pwalletMain->mapWallet.size() : 0);
    LogPrintf("mapAddressBook.size() = %u\n",  pwalletMain ? pwalletMain->mapAddressBook.size() : 0);
#endif

    StartNode(threadGroup, scheduler);
#if 0 // Disable partition check for now, it triggers too often (issue #6251)
    // Monitor the chain, and alert if we get blocks much quicker or slower than expected
    int64_t nPowTargetSpacing = Params().GetConsensus().nPowTargetSpacing;
    CScheduler::Function f = boost::bind(&PartitionCheck, &IsInitialBlockDownload,
                                         boost::ref(cs_main), boost::cref(chainActive), nPowTargetSpacing);
    scheduler.scheduleEvery(f, nPowTargetSpacing);
#endif
#ifdef ENABLE_WALLET
    // Generate coins in the background
    if (pwalletMain)
        GenerateBitcoins(GetBoolArg("-gen", false), pwalletMain, GetArg("-genproclimit", 1));
#endif

    // ********************************************************* Step 11: finished

    SetRPCWarmupFinished();
    uiInterface.InitMessage(_("Done loading"));

#ifdef ENABLE_WALLET
    if (pwalletMain) {
        // Add wallet transactions that aren't already in a block to mapTransactions
        pwalletMain->ReacceptWalletTransactions();

        // Run a thread to flush wallet periodically
        threadGroup.create_thread(boost::bind(&ThreadFlushWalletDB, boost::ref(pwalletMain->strWalletFile)));
    }
#endif

    return !fRequestShutdown;
}