src/util.cpp

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2016 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
   6 #if defined(HAVE_CONFIG_H)
   7 #include "config/bitcoin-config.h"
   8 #endif
   9
  10 #include "util.h"
  11
  12 #include "chainparamsbase.h"
  13 #include "random.h"
  14 #include "serialize.h"
  15 #include "sync.h"
  16 #include "utilstrencodings.h"
  17 #include "utiltime.h"
  18
  19 #include <stdarg.h>
  20
  21 #if (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__))
  22 #include <pthread.h>
  23 #include <pthread_np.h>
  24 #endif
  25
  26 #ifndef WIN32
  27 // for posix_fallocate
  28 #ifdef __linux__
  29
  30 #ifdef _POSIX_C_SOURCE
  31 #undef _POSIX_C_SOURCE
  32 #endif
  33
  34 #define _POSIX_C_SOURCE 200112L
  35
  36 #endif // __linux__
  37
  38 #include <algorithm>
  39 #include <fcntl.h>
  40 #include <sys/resource.h>
  41 #include <sys/stat.h>
  42
  43 #else
  44
  45 #ifdef _MSC_VER
  46 #pragma warning(disable:4786)
  47 #pragma warning(disable:4804)
  48 #pragma warning(disable:4805)
  49 #pragma warning(disable:4717)
  50 #endif
  51
  52 #ifdef _WIN32_WINNT
  53 #undef _WIN32_WINNT
  54 #endif
  55 #define _WIN32_WINNT 0x0501
  56
  57 #ifdef _WIN32_IE
  58 #undef _WIN32_IE
  59 #endif
  60 #define _WIN32_IE 0x0501
  61
  62 #define WIN32_LEAN_AND_MEAN 1
  63 #ifndef NOMINMAX
  64 #define NOMINMAX
  65 #endif
  66
  67 #include <io.h> /* for _commit */
  68 #include <shlobj.h>
  69 #endif
  70
  71 #ifdef HAVE_SYS_PRCTL_H
  72 #include <sys/prctl.h>
  73 #endif
  74
  75 #include <boost/algorithm/string/case_conv.hpp> // for to_lower()
  76 #include <boost/algorithm/string/join.hpp>
  77 #include <boost/algorithm/string/predicate.hpp> // for startswith() and endswith()
  78 #include <boost/filesystem.hpp>
  79 #include <boost/filesystem/fstream.hpp>
  80 #include <boost/foreach.hpp>
  81 #include <boost/program_options/detail/config_file.hpp>
  82 #include <boost/program_options/parsers.hpp>
  83 #include <boost/thread.hpp>
  84 #include <openssl/crypto.h>
  85 #include <openssl/rand.h>
  86 #include <openssl/conf.h>
  87
  88 // Work around clang compilation problem in Boost 1.46:
  89 // /usr/include/boost/program_options/detail/config_file.hpp:163:17: error: call to function 'to_internal' that is neither visible in the template definition nor found by argument-dependent lookup
  90 // See also: http://stackoverflow.com/questions/10020179/compilation-fail-in-boost-librairies-program-options
  91 //           http://clang.debian.net/status.php?version=3.0&key=CANNOT_FIND_FUNCTION
  92 namespace boost {
  93
  94     namespace program_options {
  95         std::string to_internal(const std::string&);
  96     }
  97
  98 } // namespace boost
  99
 100 using namespace std;
 101
 102 const char * const BITCOIN_CONF_FILENAME = "bitcoin.conf";
 103 const char * const BITCOIN_PID_FILENAME = "bitcoind.pid";
 104
 105 CCriticalSection cs_args;
 106 map<string, string> mapArgs;
 107 static map<string, vector<string> > _mapMultiArgs;
 108 const map<string, vector<string> >& mapMultiArgs = _mapMultiArgs;
 109 bool fDebug = false;
 110 bool fPrintToConsole = false;
 111 bool fPrintToDebugLog = true;
 112
 113 bool fLogTimestamps = DEFAULT_LOGTIMESTAMPS;
 114 bool fLogTimeMicros = DEFAULT_LOGTIMEMICROS;
 115 bool fLogIPs = DEFAULT_LOGIPS;
 116 std::atomic<bool> fReopenDebugLog(false);
 117 CTranslationInterface translationInterface;
 118
 119 /** Init OpenSSL library multithreading support */
 120 static CCriticalSection** ppmutexOpenSSL;
 121 void locking_callback(int mode, int i, const char* file, int line) NO_THREAD_SAFETY_ANALYSIS
 122 {
 123     if (mode & CRYPTO_LOCK) {
 124         ENTER_CRITICAL_SECTION(*ppmutexOpenSSL[i]);
 125     } else {
 126         LEAVE_CRITICAL_SECTION(*ppmutexOpenSSL[i]);
 127     }
 128 }
 129
 130 // Init
 131 class CInit
 132 {
 133 public:
 134     CInit()
 135     {
 136         // Init OpenSSL library multithreading support
 137         ppmutexOpenSSL = (CCriticalSection**)OPENSSL_malloc(CRYPTO_num_locks() * sizeof(CCriticalSection*));
 138         for (int i = 0; i < CRYPTO_num_locks(); i++)
 139             ppmutexOpenSSL[i] = new CCriticalSection();
 140         CRYPTO_set_locking_callback(locking_callback);
 141
 142         // OpenSSL can optionally load a config file which lists optional loadable modules and engines.
 143         // We don't use them so we don't require the config. However some of our libs may call functions
 144         // which attempt to load the config file, possibly resulting in an exit() or crash if it is missing
 145         // or corrupt. Explicitly tell OpenSSL not to try to load the file. The result for our libs will be
 146         // that the config appears to have been loaded and there are no modules/engines available.
 147         OPENSSL_no_config();
 148
 149 #ifdef WIN32
 150         // Seed OpenSSL PRNG with current contents of the screen
 151         RAND_screen();
 152 #endif
 153
 154         // Seed OpenSSL PRNG with performance counter
 155         RandAddSeed();
 156     }
 157     ~CInit()
 158     {
 159         // Securely erase the memory used by the PRNG
 160         RAND_cleanup();
 161         // Shutdown OpenSSL library multithreading support
 162         CRYPTO_set_locking_callback(NULL);
 163         for (int i = 0; i < CRYPTO_num_locks(); i++)
 164             delete ppmutexOpenSSL[i];
 165         OPENSSL_free(ppmutexOpenSSL);
 166     }
 167 }
 168 instance_of_cinit;
 169
 170 /**
 171  * LogPrintf() has been broken a couple of times now
 172  * by well-meaning people adding mutexes in the most straightforward way.
 173  * It breaks because it may be called by global destructors during shutdown.
 174  * Since the order of destruction of static/global objects is undefined,
 175  * defining a mutex as a global object doesn't work (the mutex gets
 176  * destroyed, and then some later destructor calls OutputDebugStringF,
 177  * maybe indirectly, and you get a core dump at shutdown trying to lock
 178  * the mutex).
 179  */
 180
 181 static boost::once_flag debugPrintInitFlag = BOOST_ONCE_INIT;
 182
 183 /**
 184  * We use boost::call_once() to make sure mutexDebugLog and
 185  * vMsgsBeforeOpenLog are initialized in a thread-safe manner.
 186  *
 187  * NOTE: fileout, mutexDebugLog and sometimes vMsgsBeforeOpenLog
 188  * are leaked on exit. This is ugly, but will be cleaned up by
 189  * the OS/libc. When the shutdown sequence is fully audited and
 190  * tested, explicit destruction of these objects can be implemented.
 191  */
 192 static FILE* fileout = NULL;
 193 static boost::mutex* mutexDebugLog = NULL;
 194 static list<string> *vMsgsBeforeOpenLog;
 195
 196 static int FileWriteStr(const std::string &str, FILE *fp)
 197 {
 198     return fwrite(str.data(), 1, str.size(), fp);
 199 }
 200
 201 static void DebugPrintInit()
 202 {
 203     assert(mutexDebugLog == NULL);
 204     mutexDebugLog = new boost::mutex();
 205     vMsgsBeforeOpenLog = new list<string>;
 206 }
 207
 208 void OpenDebugLog()
 209 {
 210     boost::call_once(&DebugPrintInit, debugPrintInitFlag);
 211     boost::mutex::scoped_lock scoped_lock(*mutexDebugLog);
 212
 213     assert(fileout == NULL);
 214     assert(vMsgsBeforeOpenLog);
 215     boost::filesystem::path pathDebug = GetDataDir() / "debug.log";
 216     fileout = fopen(pathDebug.string().c_str(), "a");
 217     if (fileout) setbuf(fileout, NULL); // unbuffered
 218
 219     // dump buffered messages from before we opened the log
 220     while (!vMsgsBeforeOpenLog->empty()) {
 221         FileWriteStr(vMsgsBeforeOpenLog->front(), fileout);
 222         vMsgsBeforeOpenLog->pop_front();
 223     }
 224
 225     delete vMsgsBeforeOpenLog;
 226     vMsgsBeforeOpenLog = NULL;
 227 }
 228
 229 bool LogAcceptCategory(const char* category)
 230 {
 231     if (category != NULL)
 232     {
 233         if (!fDebug)
 234             return false;
 235
 236         // Give each thread quick access to -debug settings.
 237         // This helps prevent issues debugging global destructors,
 238         // where mapMultiArgs might be deleted before another
 239         // global destructor calls LogPrint()
 240         static boost::thread_specific_ptr<set<string> > ptrCategory;
 241         if (ptrCategory.get() == NULL)
 242         {
 243             if (mapMultiArgs.count("-debug")) {
 244                 const vector<string>& categories = mapMultiArgs.at("-debug");
 245                 ptrCategory.reset(new set<string>(categories.begin(), categories.end()));
 246                 // thread_specific_ptr automatically deletes the set when the thread ends.
 247             } else
 248                 ptrCategory.reset(new set<string>());
 249         }
 250         const set<string>& setCategories = *ptrCategory.get();
 251
 252         // if not debugging everything and not debugging specific category, LogPrint does nothing.
 253         if (setCategories.count(string("")) == 0 &&
 254             setCategories.count(string("1")) == 0 &&
 255             setCategories.count(string(category)) == 0)
 256             return false;
 257     }
 258     return true;
 259 }
 260
 261 /**
 262  * fStartedNewLine is a state variable held by the calling context that will
 263  * suppress printing of the timestamp when multiple calls are made that don't
 264  * end in a newline. Initialize it to true, and hold it, in the calling context.
 265  */
 266 static std::string LogTimestampStr(const std::string &str, std::atomic_bool *fStartedNewLine)
 267 {
 268     string strStamped;
 269
 270     if (!fLogTimestamps)
 271         return str;
 272
 273     if (*fStartedNewLine) {
 274         int64_t nTimeMicros = GetLogTimeMicros();
 275         strStamped = DateTimeStrFormat("%Y-%m-%d %H:%M:%S", nTimeMicros/1000000);
 276         if (fLogTimeMicros)
 277             strStamped += strprintf(".%06d", nTimeMicros%1000000);
 278         strStamped += ' ' + str;
 279     } else
 280         strStamped = str;
 281
 282     if (!str.empty() && str[str.size()-1] == '\n')
 283         *fStartedNewLine = true;
 284     else
 285         *fStartedNewLine = false;
 286
 287     return strStamped;
 288 }
 289
 290 int LogPrintStr(const std::string &str)
 291 {
 292     int ret = 0; // Returns total number of characters written
 293     static std::atomic_bool fStartedNewLine(true);
 294
 295     string strTimestamped = LogTimestampStr(str, &fStartedNewLine);
 296
 297     if (fPrintToConsole)
 298     {
 299         // print to console
 300         ret = fwrite(strTimestamped.data(), 1, strTimestamped.size(), stdout);
 301         fflush(stdout);
 302     }
 303     else if (fPrintToDebugLog)
 304     {
 305         boost::call_once(&DebugPrintInit, debugPrintInitFlag);
 306         boost::mutex::scoped_lock scoped_lock(*mutexDebugLog);
 307
 308         // buffer if we haven't opened the log yet
 309         if (fileout == NULL) {
 310             assert(vMsgsBeforeOpenLog);
 311             ret = strTimestamped.length();
 312             vMsgsBeforeOpenLog->push_back(strTimestamped);
 313         }
 314         else
 315         {
 316             // reopen the log file, if requested
 317             if (fReopenDebugLog) {
 318                 fReopenDebugLog = false;
 319                 boost::filesystem::path pathDebug = GetDataDir() / "debug.log";
 320                 if (freopen(pathDebug.string().c_str(),"a",fileout) != NULL)
 321                     setbuf(fileout, NULL); // unbuffered
 322             }
 323
 324             ret = FileWriteStr(strTimestamped, fileout);
 325         }
 326     }
 327     return ret;
 328 }
 329
 330 /** Interpret string as boolean, for argument parsing */
 331 static bool InterpretBool(const std::string& strValue)
 332 {
 333     if (strValue.empty())
 334         return true;
 335     return (atoi(strValue) != 0);
 336 }
 337
 338 /** Turn -noX into -X=0 */
 339 static void InterpretNegativeSetting(std::string& strKey, std::string& strValue)
 340 {
 341     if (strKey.length()>3 && strKey[0]=='-' && strKey[1]=='n' && strKey[2]=='o')
 342     {
 343         strKey = "-" + strKey.substr(3);
 344         strValue = InterpretBool(strValue) ? "0" : "1";
 345     }
 346 }
 347
 348 void ParseParameters(int argc, const char* const argv[])
 349 {
 350     LOCK(cs_args);
 351     mapArgs.clear();
 352     _mapMultiArgs.clear();
 353
 354     for (int i = 1; i < argc; i++)
 355     {
 356         std::string str(argv[i]);
 357         std::string strValue;
 358         size_t is_index = str.find('=');
 359         if (is_index != std::string::npos)
 360         {
 361             strValue = str.substr(is_index+1);
 362             str = str.substr(0, is_index);
 363         }
 364 #ifdef WIN32
 365         boost::to_lower(str);
 366         if (boost::algorithm::starts_with(str, "/"))
 367             str = "-" + str.substr(1);
 368 #endif
 369
 370         if (str[0] != '-')
 371             break;
 372
 373         // Interpret --foo as -foo.
 374         // If both --foo and -foo are set, the last takes effect.
 375         if (str.length() > 1 && str[1] == '-')
 376             str = str.substr(1);
 377         InterpretNegativeSetting(str, strValue);
 378
 379         mapArgs[str] = strValue;
 380         _mapMultiArgs[str].push_back(strValue);
 381     }
 382 }
 383
 384 bool IsArgSet(const std::string& strArg)
 385 {
 386     LOCK(cs_args);
 387     return mapArgs.count(strArg);
 388 }
 389
 390 std::string GetArg(const std::string& strArg, const std::string& strDefault)
 391 {
 392     LOCK(cs_args);
 393     if (mapArgs.count(strArg))
 394         return mapArgs[strArg];
 395     return strDefault;
 396 }
 397
 398 int64_t GetArg(const std::string& strArg, int64_t nDefault)
 399 {
 400     LOCK(cs_args);
 401     if (mapArgs.count(strArg))
 402         return atoi64(mapArgs[strArg]);
 403     return nDefault;
 404 }
 405
 406 bool GetBoolArg(const std::string& strArg, bool fDefault)
 407 {
 408     LOCK(cs_args);
 409     if (mapArgs.count(strArg))
 410         return InterpretBool(mapArgs[strArg]);
 411     return fDefault;
 412 }
 413
 414 bool SoftSetArg(const std::string& strArg, const std::string& strValue)
 415 {
 416     LOCK(cs_args);
 417     if (mapArgs.count(strArg))
 418         return false;
 419     mapArgs[strArg] = strValue;
 420     return true;
 421 }
 422
 423 bool SoftSetBoolArg(const std::string& strArg, bool fValue)
 424 {
 425     if (fValue)
 426         return SoftSetArg(strArg, std::string("1"));
 427     else
 428         return SoftSetArg(strArg, std::string("0"));
 429 }
 430
 431 void ForceSetArg(const std::string& strArg, const std::string& strValue)
 432 {
 433     LOCK(cs_args);
 434     mapArgs[strArg] = strValue;
 435 }
 436
 437
 438
 439 static const int screenWidth = 79;
 440 static const int optIndent = 2;
 441 static const int msgIndent = 7;
 442
 443 std::string HelpMessageGroup(const std::string &message) {
 444     return std::string(message) + std::string("\n\n");
 445 }
 446
 447 std::string HelpMessageOpt(const std::string &option, const std::string &message) {
 448     return std::string(optIndent,' ') + std::string(option) +
 449            std::string("\n") + std::string(msgIndent,' ') +
 450            FormatParagraph(message, screenWidth - msgIndent, msgIndent) +
 451            std::string("\n\n");
 452 }
 453
 454 static std::string FormatException(const std::exception* pex, const char* pszThread)
 455 {
 456 #ifdef WIN32
 457     char pszModule[MAX_PATH] = "";
 458     GetModuleFileNameA(NULL, pszModule, sizeof(pszModule));
 459 #else
 460     const char* pszModule = "bitcoin";
 461 #endif
 462     if (pex)
 463         return strprintf(
 464             "EXCEPTION: %s       \n%s       \n%s in %s       \n", typeid(*pex).name(), pex->what(), pszModule, pszThread);
 465     else
 466         return strprintf(
 467             "UNKNOWN EXCEPTION       \n%s in %s       \n", pszModule, pszThread);
 468 }
 469
 470 void PrintExceptionContinue(const std::exception* pex, const char* pszThread)
 471 {
 472     std::string message = FormatException(pex, pszThread);
 473     LogPrintf("\n\n************************\n%s\n", message);
 474     fprintf(stderr, "\n\n************************\n%s\n", message.c_str());
 475 }
 476
 477 boost::filesystem::path GetDefaultDataDir()
 478 {
 479     namespace fs = boost::filesystem;
 480     // Windows < Vista: C:\Documents and Settings\Username\Application Data\Bitcoin
 481     // Windows >= Vista: C:\Users\Username\AppData\Roaming\Bitcoin
 482     // Mac: ~/Library/Application Support/Bitcoin
 483     // Unix: ~/.bitcoin
 484 #ifdef WIN32
 485     // Windows
 486     return GetSpecialFolderPath(CSIDL_APPDATA) / "Bitcoin";
 487 #else
 488     fs::path pathRet;
 489     char* pszHome = getenv("HOME");
 490     if (pszHome == NULL || strlen(pszHome) == 0)
 491         pathRet = fs::path("/");
 492     else
 493         pathRet = fs::path(pszHome);
 494 #ifdef MAC_OSX
 495     // Mac
 496     return pathRet / "Library/Application Support/Bitcoin";
 497 #else
 498     // Unix
 499     return pathRet / ".bitcoin";
 500 #endif
 501 #endif
 502 }
 503
 504 static boost::filesystem::path pathCached;
 505 static boost::filesystem::path pathCachedNetSpecific;
 506 static CCriticalSection csPathCached;
 507
 508 const boost::filesystem::path &GetDataDir(bool fNetSpecific)
 509 {
 510     namespace fs = boost::filesystem;
 511
 512     LOCK(csPathCached);
 513
 514     fs::path &path = fNetSpecific ? pathCachedNetSpecific : pathCached;
 515
 516     // This can be called during exceptions by LogPrintf(), so we cache the
 517     // value so we don't have to do memory allocations after that.
 518     if (!path.empty())
 519         return path;
 520
 521     if (IsArgSet("-datadir")) {
 522         path = fs::system_complete(GetArg("-datadir", ""));
 523         if (!fs::is_directory(path)) {
 524             path = "";
 525             return path;
 526         }
 527     } else {
 528         path = GetDefaultDataDir();
 529     }
 530     if (fNetSpecific)
 531         path /= BaseParams().DataDir();
 532
 533     fs::create_directories(path);
 534
 535     return path;
 536 }
 537
 538 void ClearDatadirCache()
 539 {
 540     LOCK(csPathCached);
 541
 542     pathCached = boost::filesystem::path();
 543     pathCachedNetSpecific = boost::filesystem::path();
 544 }
 545
 546 boost::filesystem::path GetConfigFile(const std::string& confPath)
 547 {
 548     boost::filesystem::path pathConfigFile(confPath);
 549     if (!pathConfigFile.is_complete())
 550         pathConfigFile = GetDataDir(false) / pathConfigFile;
 551
 552     return pathConfigFile;
 553 }
 554
 555 void ReadConfigFile(const std::string& confPath)
 556 {
 557     boost::filesystem::ifstream streamConfig(GetConfigFile(confPath));
 558     if (!streamConfig.good())
 559         return; // No bitcoin.conf file is OK
 560
 561     {
 562         LOCK(cs_args);
 563         set<string> setOptions;
 564         setOptions.insert("*");
 565
 566         for (boost::program_options::detail::config_file_iterator it(streamConfig, setOptions), end; it != end; ++it)
 567         {
 568             // Don't overwrite existing settings so command line settings override bitcoin.conf
 569             string strKey = string("-") + it->string_key;
 570             string strValue = it->value[0];
 571             InterpretNegativeSetting(strKey, strValue);
 572             if (mapArgs.count(strKey) == 0)
 573                 mapArgs[strKey] = strValue;
 574             _mapMultiArgs[strKey].push_back(strValue);
 575         }
 576     }
 577     // If datadir is changed in .conf file:
 578     ClearDatadirCache();
 579 }
 580
 581 #ifndef WIN32
 582 boost::filesystem::path GetPidFile()
 583 {
 584     boost::filesystem::path pathPidFile(GetArg("-pid", BITCOIN_PID_FILENAME));
 585     if (!pathPidFile.is_complete()) pathPidFile = GetDataDir() / pathPidFile;
 586     return pathPidFile;
 587 }
 588
 589 void CreatePidFile(const boost::filesystem::path &path, pid_t pid)
 590 {
 591     FILE* file = fopen(path.string().c_str(), "w");
 592     if (file)
 593     {
 594         fprintf(file, "%d\n", pid);
 595         fclose(file);
 596     }
 597 }
 598 #endif
 599
 600 bool RenameOver(boost::filesystem::path src, boost::filesystem::path dest)
 601 {
 602 #ifdef WIN32
 603     return MoveFileExA(src.string().c_str(), dest.string().c_str(),
 604                        MOVEFILE_REPLACE_EXISTING) != 0;
 605 #else
 606     int rc = std::rename(src.string().c_str(), dest.string().c_str());
 607     return (rc == 0);
 608 #endif /* WIN32 */
 609 }
 610
 611 /**
 612  * Ignores exceptions thrown by Boost's create_directory if the requested directory exists.
 613  * Specifically handles case where path p exists, but it wasn't possible for the user to
 614  * write to the parent directory.
 615  */
 616 bool TryCreateDirectory(const boost::filesystem::path& p)
 617 {
 618     try
 619     {
 620         return boost::filesystem::create_directory(p);
 621     } catch (const boost::filesystem::filesystem_error&) {
 622         if (!boost::filesystem::exists(p) || !boost::filesystem::is_directory(p))
 623             throw;
 624     }
 625
 626     // create_directory didn't create the directory, it had to have existed already
 627     return false;
 628 }
 629
 630 void FileCommit(FILE *file)
 631 {
 632     fflush(file); // harmless if redundantly called
 633 #ifdef WIN32
 634     HANDLE hFile = (HANDLE)_get_osfhandle(_fileno(file));
 635     FlushFileBuffers(hFile);
 636 #else
 637     #if defined(__linux__) || defined(__NetBSD__)
 638     fdatasync(fileno(file));
 639     #elif defined(__APPLE__) && defined(F_FULLFSYNC)
 640     fcntl(fileno(file), F_FULLFSYNC, 0);
 641     #else
 642     fsync(fileno(file));
 643     #endif
 644 #endif
 645 }
 646
 647 bool TruncateFile(FILE *file, unsigned int length) {
 648 #if defined(WIN32)
 649     return _chsize(_fileno(file), length) == 0;
 650 #else
 651     return ftruncate(fileno(file), length) == 0;
 652 #endif
 653 }
 654
 655 /**
 656  * this function tries to raise the file descriptor limit to the requested number.
 657  * It returns the actual file descriptor limit (which may be more or less than nMinFD)
 658  */
 659 int RaiseFileDescriptorLimit(int nMinFD) {
 660 #if defined(WIN32)
 661     return 2048;
 662 #else
 663     struct rlimit limitFD;
 664     if (getrlimit(RLIMIT_NOFILE, &limitFD) != -1) {
 665         if (limitFD.rlim_cur < (rlim_t)nMinFD) {
 666             limitFD.rlim_cur = nMinFD;
 667             if (limitFD.rlim_cur > limitFD.rlim_max)
 668                 limitFD.rlim_cur = limitFD.rlim_max;
 669             setrlimit(RLIMIT_NOFILE, &limitFD);
 670             getrlimit(RLIMIT_NOFILE, &limitFD);
 671         }
 672         return limitFD.rlim_cur;
 673     }
 674     return nMinFD; // getrlimit failed, assume it's fine
 675 #endif
 676 }
 677
 678 /**
 679  * this function tries to make a particular range of a file allocated (corresponding to disk space)
 680  * it is advisory, and the range specified in the arguments will never contain live data
 681  */
 682 void AllocateFileRange(FILE *file, unsigned int offset, unsigned int length) {
 683 #if defined(WIN32)
 684     // Windows-specific version
 685     HANDLE hFile = (HANDLE)_get_osfhandle(_fileno(file));
 686     LARGE_INTEGER nFileSize;
 687     int64_t nEndPos = (int64_t)offset + length;
 688     nFileSize.u.LowPart = nEndPos & 0xFFFFFFFF;
 689     nFileSize.u.HighPart = nEndPos >> 32;
 690     SetFilePointerEx(hFile, nFileSize, 0, FILE_BEGIN);
 691     SetEndOfFile(hFile);
 692 #elif defined(MAC_OSX)
 693     // OSX specific version
 694     fstore_t fst;
 695     fst.fst_flags = F_ALLOCATECONTIG;
 696     fst.fst_posmode = F_PEOFPOSMODE;
 697     fst.fst_offset = 0;
 698     fst.fst_length = (off_t)offset + length;
 699     fst.fst_bytesalloc = 0;
 700     if (fcntl(fileno(file), F_PREALLOCATE, &fst) == -1) {
 701         fst.fst_flags = F_ALLOCATEALL;
 702         fcntl(fileno(file), F_PREALLOCATE, &fst);
 703     }
 704     ftruncate(fileno(file), fst.fst_length);
 705 #elif defined(__linux__)
 706     // Version using posix_fallocate
 707     off_t nEndPos = (off_t)offset + length;
 708     posix_fallocate(fileno(file), 0, nEndPos);
 709 #else
 710     // Fallback version
 711     // TODO: just write one byte per block
 712     static const char buf[65536] = {};
 713     fseek(file, offset, SEEK_SET);
 714     while (length > 0) {
 715         unsigned int now = 65536;
 716         if (length < now)
 717             now = length;
 718         fwrite(buf, 1, now, file); // allowed to fail; this function is advisory anyway
 719         length -= now;
 720     }
 721 #endif
 722 }
 723
 724 void ShrinkDebugFile()
 725 {
 726     // Amount of debug.log to save at end when shrinking (must fit in memory)
 727     constexpr size_t RECENT_DEBUG_HISTORY_SIZE = 10 * 1000000;
 728     // Scroll debug.log if it's getting too big
 729     boost::filesystem::path pathLog = GetDataDir() / "debug.log";
 730     FILE* file = fopen(pathLog.string().c_str(), "r");
 731     // If debug.log file is more than 10% bigger the RECENT_DEBUG_HISTORY_SIZE
 732     // trim it down by saving only the last RECENT_DEBUG_HISTORY_SIZE bytes
 733     if (file && boost::filesystem::file_size(pathLog) > 11 * (RECENT_DEBUG_HISTORY_SIZE / 10))
 734     {
 735         // Restart the file with some of the end
 736         std::vector<char> vch(RECENT_DEBUG_HISTORY_SIZE, 0);
 737         fseek(file, -((long)vch.size()), SEEK_END);
 738         int nBytes = fread(vch.data(), 1, vch.size(), file);
 739         fclose(file);
 740
 741         file = fopen(pathLog.string().c_str(), "w");
 742         if (file)
 743         {
 744             fwrite(vch.data(), 1, nBytes, file);
 745             fclose(file);
 746         }
 747     }
 748     else if (file != NULL)
 749         fclose(file);
 750 }
 751
 752 #ifdef WIN32
 753 boost::filesystem::path GetSpecialFolderPath(int nFolder, bool fCreate)
 754 {
 755     namespace fs = boost::filesystem;
 756
 757     char pszPath[MAX_PATH] = "";
 758
 759     if(SHGetSpecialFolderPathA(NULL, pszPath, nFolder, fCreate))
 760     {
 761         return fs::path(pszPath);
 762     }
 763
 764     LogPrintf("SHGetSpecialFolderPathA() failed, could not obtain requested path.\n");
 765     return fs::path("");
 766 }
 767 #endif
 768
 769 void runCommand(const std::string& strCommand)
 770 {
 771     int nErr = ::system(strCommand.c_str());
 772     if (nErr)
 773         LogPrintf("runCommand error: system(%s) returned %d\n", strCommand, nErr);
 774 }
 775
 776 void RenameThread(const char* name)
 777 {
 778 #if defined(PR_SET_NAME)
 779     // Only the first 15 characters are used (16 - NUL terminator)
 780     ::prctl(PR_SET_NAME, name, 0, 0, 0);
 781 #elif (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__))
 782     pthread_set_name_np(pthread_self(), name);
 783
 784 #elif defined(MAC_OSX)
 785     pthread_setname_np(name);
 786 #else
 787     // Prevent warnings for unused parameters...
 788     (void)name;
 789 #endif
 790 }
 791
 792 void SetupEnvironment()
 793 {
 794     // On most POSIX systems (e.g. Linux, but not BSD) the environment's locale
 795     // may be invalid, in which case the "C" locale is used as fallback.
 796 #if !defined(WIN32) && !defined(MAC_OSX) && !defined(__FreeBSD__) && !defined(__OpenBSD__)
 797     try {
 798         std::locale(""); // Raises a runtime error if current locale is invalid
 799     } catch (const std::runtime_error&) {
 800         setenv("LC_ALL", "C", 1);
 801     }
 802 #endif
 803     // The path locale is lazy initialized and to avoid deinitialization errors
 804     // in multithreading environments, it is set explicitly by the main thread.
 805     // A dummy locale is used to extract the internal default locale, used by
 806     // boost::filesystem::path, which is then used to explicitly imbue the path.
 807     std::locale loc = boost::filesystem::path::imbue(std::locale::classic());
 808     boost::filesystem::path::imbue(loc);
 809 }
 810
 811 bool SetupNetworking()
 812 {
 813 #ifdef WIN32
 814     // Initialize Windows Sockets
 815     WSADATA wsadata;
 816     int ret = WSAStartup(MAKEWORD(2,2), &wsadata);
 817     if (ret != NO_ERROR || LOBYTE(wsadata.wVersion ) != 2 || HIBYTE(wsadata.wVersion) != 2)
 818         return false;
 819 #endif
 820     return true;
 821 }
 822
 823 int GetNumCores()
 824 {
 825 #if BOOST_VERSION >= 105600
 826     return boost::thread::physical_concurrency();
 827 #else // Must fall back to hardware_concurrency, which unfortunately counts virtual cores
 828     return boost::thread::hardware_concurrency();
 829 #endif
 830 }
 831
 832 std::string CopyrightHolders(const std::string& strPrefix)
 833 {
 834     std::string strCopyrightHolders = strPrefix + strprintf(_(COPYRIGHT_HOLDERS), _(COPYRIGHT_HOLDERS_SUBSTITUTION));
 835
 836     // Check for untranslated substitution to make sure Bitcoin Core copyright is not removed by accident
 837     if (strprintf(COPYRIGHT_HOLDERS, COPYRIGHT_HOLDERS_SUBSTITUTION).find("Bitcoin Core") == std::string::npos) {
 838         strCopyrightHolders += "\n" + strPrefix + "The Bitcoin Core developers";
 839     }
 840     return strCopyrightHolders;
 841 }