src/emerge.cpp

   1 /*
   2 Minetest-c55
   3 Copyright (C) 2010-2011 celeron55, Perttu Ahola <celeron55@gmail.com>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20
  21 #include "server.h"
  22 #include <iostream>
  23 #include <queue>
  24 #include "clientserver.h"
  25 #include "map.h"
  26 #include "jmutexautolock.h"
  27 #include "main.h"
  28 #include "constants.h"
  29 #include "voxel.h"
  30 #include "config.h"
  31 #include "mapblock.h"
  32 #include "serverobject.h"
  33 #include "settings.h"
  34 #include "script.h"
  35 #include "scriptapi.h"
  36 #include "profiler.h"
  37 #include "log.h"
  38 #include "nodedef.h"
  39 #include "biome.h"
  40 #include "emerge.h"
  41 #include "mapgen_v6.h"
  42
  43
  44 EmergeManager::EmergeManager(IGameDef *gamedef, BiomeDefManager *bdef) {
  45         //register built-in mapgens
  46         registerMapgen("v6", new MapgenFactoryV6());
  47
  48         this->biomedef = bdef ? bdef : new BiomeDefManager(gamedef);
  49         this->params   = NULL;
  50         this->mapgen   = NULL;
  51
  52         queuemutex.Init();
  53         emergethread = new EmergeThread((Server *)gamedef);
  54 }
  55
  56
  57 EmergeManager::~EmergeManager() {
  58         emergethread->setRun(false);
  59         emergethread->stop();
  60
  61         delete emergethread;
  62         delete biomedef;
  63         delete mapgen;
  64         delete params;
  65 }
  66
  67
  68 void EmergeManager::initMapgens(MapgenParams *mgparams) {
  69         if (mapgen)
  70                 return;
  71
  72         this->params = mgparams;
  73         this->mapgen = getMapgen(); //only one mapgen for now!
  74 }
  75
  76
  77 Mapgen *EmergeManager::getMapgen() {
  78         if (!mapgen) {
  79                 mapgen = createMapgen(params->mg_name, 0, params, this);
  80                 if (!mapgen) {
  81                         infostream << "EmergeManager: falling back to mapgen v6" << std::endl;
  82                         delete params;
  83                         params = createMapgenParams("v6");
  84                         mapgen = createMapgen("v6", 0, params, this);
  85                 }
  86         }
  87         return mapgen;
  88 }
  89
  90
  91 bool EmergeManager::enqueueBlockEmerge(u16 peer_id, v3s16 p, bool allow_generate) {
  92         std::map<v3s16, BlockEmergeData *>::const_iterator iter;
  93         BlockEmergeData *bedata;
  94         u16 count;
  95         u8 flags = 0;
  96
  97         if (allow_generate)
  98                 flags |= BLOCK_EMERGE_ALLOWGEN;
  99
 100         //TODO:
 101         // add logic to select which emergethread to add it to
 102         //  - one with the least queue contents?
 103         //  - if a queue is too full, move onto another one
 104         //  - use the peer id sometime
 105
 106         {
 107                 JMutexAutoLock queuelock(queuemutex);
 108
 109                 count = blocks_enqueued.size();
 110                 u16 queuelimit_total = 256;
 111                 if (count >= queuelimit_total)
 112                         return false;
 113
 114                 count = peer_queue_count[peer_id];
 115                 u16 queuelimit_peer = allow_generate ? 1 : 5;
 116                 if (count >= queuelimit_peer)
 117                         return false;
 118
 119                 iter = blocks_enqueued.find(p);
 120                 if (iter != blocks_enqueued.end()) {
 121                         bedata = iter->second;
 122                         bedata->flags |= flags;
 123                         return true;
 124                 }
 125
 126                 bedata = new BlockEmergeData;
 127                 bedata->flags = flags;
 128                 bedata->peer_requested = peer_id;
 129                 blocks_enqueued.insert(std::make_pair(p, bedata));
 130
 131                 peer_queue_count[peer_id] = count + 1;
 132
 133                 emergethread->blockqueue.push(p);
 134         }
 135         emergethread->qevent.signal();
 136
 137         return true;
 138 }
 139
 140
 141 bool EmergeManager::popBlockEmerge(v3s16 *pos, u8 *flags) {
 142         std::map<v3s16, BlockEmergeData *>::iterator iter;
 143         JMutexAutoLock queuelock(queuemutex);
 144
 145         if (emergethread->blockqueue.empty())
 146                 return false;
 147         v3s16 p = emergethread->blockqueue.front();
 148         emergethread->blockqueue.pop();
 149
 150         *pos = p;
 151
 152         iter = blocks_enqueued.find(p);
 153         if (iter == blocks_enqueued.end())
 154                 return false; //uh oh, queue and map out of sync!!
 155
 156         BlockEmergeData *bedata = iter->second;
 157         *flags = bedata->flags;
 158
 159         peer_queue_count[bedata->peer_requested]--;
 160
 161         delete bedata;
 162         blocks_enqueued.erase(iter);
 163
 164         return true;
 165 }
 166
 167
 168 int EmergeManager::getGroundLevelAtPoint(v2s16 p) {
 169         if (!mapgen)
 170                 return 0;
 171         return mapgen->getGroundLevelAtPoint(p);
 172 }
 173
 174
 175 bool EmergeManager::isBlockUnderground(v3s16 blockpos) {
 176         /*
 177         v2s16 p = v2s16((blockpos.X * MAP_BLOCKSIZE) + MAP_BLOCKSIZE / 2,
 178                                         (blockpos.Y * MAP_BLOCKSIZE) + MAP_BLOCKSIZE / 2);
 179         int ground_level = getGroundLevelAtPoint(p);
 180         return blockpos.Y * (MAP_BLOCKSIZE + 1) <= min(water_level, ground_level);
 181         */
 182
 183         //yuck, but then again, should i bother being accurate?
 184         //the height of the nodes in a single block is quite variable
 185         return blockpos.Y * (MAP_BLOCKSIZE + 1) <= params->water_level;
 186 }
 187
 188
 189 u32 EmergeManager::getBlockSeed(v3s16 p) {
 190         return (u32)(params->seed & 0xFFFFFFFF) +
 191                 p.Z * 38134234 +
 192                 p.Y * 42123 +
 193                 p.Y * 23;
 194 }
 195
 196
 197 Mapgen *EmergeManager::createMapgen(std::string mgname, int mgid,
 198                                                                         MapgenParams *mgparams, EmergeManager *emerge) {
 199         std::map<std::string, MapgenFactory *>::const_iterator iter = mglist.find(mgname);
 200         if (iter == mglist.end()) {
 201                 errorstream << "EmergeManager; mapgen " << mgname <<
 202                  " not registered" << std::endl;
 203                 return NULL;
 204         }
 205
 206         MapgenFactory *mgfactory = iter->second;
 207         return mgfactory->createMapgen(mgid, mgparams, emerge);
 208 }
 209
 210
 211 MapgenParams *EmergeManager::createMapgenParams(std::string mgname) {
 212         std::map<std::string, MapgenFactory *>::const_iterator iter = mglist.find(mgname);
 213         if (iter == mglist.end()) {
 214                 errorstream << "EmergeManager: mapgen " << mgname <<
 215                  " not registered" << std::endl;
 216                 return NULL;
 217         }
 218
 219         MapgenFactory *mgfactory = iter->second;
 220         return mgfactory->createMapgenParams();
 221 }
 222
 223
 224 MapgenParams *EmergeManager::getParamsFromSettings(Settings *settings) {
 225         std::string mg_name = settings->get("mg_name");
 226         MapgenParams *mgparams = createMapgenParams(mg_name);
 227
 228         mgparams->mg_name     = mg_name;
 229         mgparams->seed        = settings->getU64(settings == g_settings ? "fixed_map_seed" : "seed");
 230         mgparams->water_level = settings->getS16("water_level");
 231         mgparams->chunksize   = settings->getS16("chunksize");
 232         mgparams->flags       = settings->getS32("mg_flags");
 233
 234         if (!mgparams->readParams(settings)) {
 235                 delete mgparams;
 236                 return NULL;
 237         }
 238         return mgparams;
 239 }
 240
 241
 242 void EmergeManager::setParamsToSettings(Settings *settings) {
 243         settings->set("mg_name",         params->mg_name);
 244         settings->setU64("seed",         params->seed);
 245         settings->setS16("water_level",  params->water_level);
 246         settings->setS16("chunksize",    params->chunksize);
 247         settings->setFlagStr("mg_flags", params->flags, flagdesc_mapgen);
 248
 249         params->writeParams(settings);
 250 }
 251
 252
 253 bool EmergeManager::registerMapgen(std::string mgname, MapgenFactory *mgfactory) {
 254         mglist.insert(std::make_pair(mgname, mgfactory));
 255         infostream << "EmergeManager: registered mapgen " << mgname << std::endl;
 256 }
 257
 258
 259
 260 class MapEditEventIgnorer
 261 {
 262 public:
 263         MapEditEventIgnorer(bool *flag):
 264                 m_flag(flag)
 265         {
 266                 if(*m_flag == false)
 267                         *m_flag = true;
 268                 else
 269                         m_flag = NULL;
 270         }
 271
 272         ~MapEditEventIgnorer()
 273         {
 274                 if(m_flag)
 275                 {
 276                         assert(*m_flag);
 277                         *m_flag = false;
 278                 }
 279         }
 280
 281 private:
 282         bool *m_flag;
 283 };
 284
 285 class MapEditEventAreaIgnorer
 286 {
 287 public:
 288         MapEditEventAreaIgnorer(VoxelArea *ignorevariable, const VoxelArea &a):
 289                 m_ignorevariable(ignorevariable)
 290         {
 291                 if(m_ignorevariable->getVolume() == 0)
 292                         *m_ignorevariable = a;
 293                 else
 294                         m_ignorevariable = NULL;
 295         }
 296
 297         ~MapEditEventAreaIgnorer()
 298         {
 299                 if(m_ignorevariable)
 300                 {
 301                         assert(m_ignorevariable->getVolume() != 0);
 302                         *m_ignorevariable = VoxelArea();
 303                 }
 304         }
 305
 306 private:
 307         VoxelArea *m_ignorevariable;
 308 };
 309
 310
 311 #if 1
 312
 313 #define EMERGE_DBG_OUT(x) \
 314         { if (enable_mapgen_debug_info) \
 315         infostream << "EmergeThread: " x << std::endl; }
 316
 317 bool EmergeThread::getBlockOrStartGen(v3s16 p, MapBlock **b,
 318                                                                         BlockMakeData *data, bool allow_gen) {
 319         v2s16 p2d(p.X, p.Z);
 320         //envlock: usually takes <=1ms, sometimes 90ms or ~400ms to acquire
 321         JMutexAutoLock envlock(m_server->m_env_mutex);
 322
 323         // Load sector if it isn't loaded
 324         if (map->getSectorNoGenerateNoEx(p2d) == NULL)
 325                 map->loadSectorMeta(p2d);
 326
 327         // Attempt to load block
 328         MapBlock *block = map->getBlockNoCreateNoEx(p);
 329         if (!block || block->isDummy() || !block->isGenerated()) {
 330                 EMERGE_DBG_OUT("not in memory, attempting to load from disk");
 331                 block = map->loadBlock(p);
 332         }
 333
 334         // If could not load and allowed to generate,
 335         // start generation inside this same envlock
 336         if (allow_gen && (block == NULL || !block->isGenerated())) {
 337                 EMERGE_DBG_OUT("generating");
 338                 map->initBlockMake(data, p);
 339                 return true;
 340         }
 341
 342         *b = block;
 343         return false;
 344 }
 345
 346
 347 void *EmergeThread::Thread() {
 348         ThreadStarted();
 349         log_register_thread("EmergeThread");
 350         DSTACK(__FUNCTION_NAME);
 351         BEGIN_DEBUG_EXCEPTION_HANDLER
 352
 353         v3s16 last_tried_pos(-32768,-32768,-32768); // For error output
 354         v3s16 p;
 355         u8 flags;
 356
 357         map    = (ServerMap *)&(m_server->m_env->getMap());
 358         emerge = m_server->m_emerge;
 359         mapgen = emerge->getMapgen();
 360
 361         while (getRun())
 362         try {
 363                 while (!emerge->popBlockEmerge(&p, &flags))
 364                         qevent.wait();
 365
 366                 last_tried_pos = p;
 367                 if (blockpos_over_limit(p))
 368                         continue;
 369
 370                 bool allow_generate = flags & BLOCK_EMERGE_ALLOWGEN;
 371                 EMERGE_DBG_OUT("p=" PP(p) " allow_generate=" << allow_generate);
 372
 373                 /*
 374                         Try to fetch block from memory or disk.
 375                         If not found and asked to generate, initialize generator.
 376                 */
 377                 BlockMakeData data;
 378                 MapBlock *block = NULL;
 379                 core::map<v3s16, MapBlock *> modified_blocks;
 380
 381                 if (getBlockOrStartGen(p, &block, &data, allow_generate)) {
 382                         {
 383                                 ScopeProfiler sp(g_profiler, "EmergeThread: Mapgen::makeChunk", SPT_AVG);
 384                                 TimeTaker t("mapgen::make_block()");
 385
 386                                 mapgen->makeChunk(&data);
 387
 388                                 if (enable_mapgen_debug_info == false)
 389                                         t.stop(true); // Hide output
 390                         }
 391
 392                         {
 393                                 //envlock: usually 0ms, but can take either 30 or 400ms to acquire
 394                                 JMutexAutoLock envlock(m_server->m_env_mutex);
 395                                 ScopeProfiler sp(g_profiler, "EmergeThread: after "
 396                                                 "mapgen::make_block (envlock)", SPT_AVG);
 397
 398                                 map->finishBlockMake(&data, modified_blocks);
 399
 400                                 block = map->getBlockNoCreateNoEx(p);
 401                                 if (block) {
 402                                         /*
 403                                                 Do some post-generate stuff
 404                                         */
 405                                         v3s16 minp = data.blockpos_min * MAP_BLOCKSIZE;
 406                                         v3s16 maxp = data.blockpos_max * MAP_BLOCKSIZE +
 407                                                                  v3s16(1,1,1) * (MAP_BLOCKSIZE - 1);
 408
 409                                         // Ignore map edit events, they will not need to be sent
 410                                         // to anybody because the block hasn't been sent to anybody
 411                                         MapEditEventAreaIgnorer
 412                                                 ign(&m_server->m_ignore_map_edit_events_area,
 413                                                 VoxelArea(minp, maxp));
 414                                         {  // takes about 90ms with -O1 on an e3-1230v2
 415                                                 scriptapi_environment_on_generated(m_server->m_lua,
 416                                                                 minp, maxp, emerge->getBlockSeed(minp));
 417                                         }
 418
 419                                         EMERGE_DBG_OUT("ended up with: " << analyze_block(block));
 420
 421                                         m_server->m_env->activateBlock(block, 0);
 422                                 }
 423                         }
 424                 }
 425
 426                 /*
 427                         Set sent status of modified blocks on clients
 428                 */
 429
 430                 // NOTE: Server's clients are also behind the connection mutex
 431                 //conlock: consistently takes 30-40ms to acquire
 432                 JMutexAutoLock lock(m_server->m_con_mutex);
 433                 // Add the originally fetched block to the modified list
 434                 if (block)
 435                         modified_blocks.insert(p, block);
 436
 437                 // Set the modified blocks unsent for all the clients
 438                 for (core::map<u16, RemoteClient*>::Iterator
 439                          i = m_server->m_clients.getIterator();
 440                          i.atEnd() == false; i++) {
 441                         RemoteClient *client = i.getNode()->getValue();
 442                         if (modified_blocks.size() > 0) {
 443                                 // Remove block from sent history
 444                                 client->SetBlocksNotSent(modified_blocks);
 445                         }
 446                 }
 447         }
 448         catch (VersionMismatchException &e) {
 449                 std::ostringstream err;
 450                 err << "World data version mismatch in MapBlock "<<PP(last_tried_pos)<<std::endl;
 451                 err << "----"<<std::endl;
 452                 err << "\""<<e.what()<<"\""<<std::endl;
 453                 err << "See debug.txt."<<std::endl;
 454                 err << "World probably saved by a newer version of Minetest."<<std::endl;
 455                 m_server->setAsyncFatalError(err.str());
 456         }
 457         catch (SerializationError &e) {
 458                 std::ostringstream err;
 459                 err << "Invalid data in MapBlock "<<PP(last_tried_pos)<<std::endl;
 460                 err << "----"<<std::endl;
 461                 err << "\""<<e.what()<<"\""<<std::endl;
 462                 err << "See debug.txt."<<std::endl;
 463                 err << "You can ignore this using [ignore_world_load_errors = true]."<<std::endl;
 464                 m_server->setAsyncFatalError(err.str());
 465         }
 466
 467         END_DEBUG_EXCEPTION_HANDLER(errorstream)
 468         log_deregister_thread();
 469         return NULL;
 470 }
 471
 472 #else
 473
 474 void *EmergeThread::Thread() {
 475         ThreadStarted();
 476         log_register_thread("EmergeThread");
 477         DSTACK(__FUNCTION_NAME);
 478         BEGIN_DEBUG_EXCEPTION_HANDLER
 479
 480         bool enable_mapgen_debug_info = g_settings->getBool("enable_mapgen_debug_info");
 481
 482         v3s16 last_tried_pos(-32768,-32768,-32768); // For error output
 483         ServerMap &map = ((ServerMap&)m_server->m_env->getMap());
 484         EmergeManager *emerge = m_server->m_emerge;
 485         Mapgen *mapgen = emerge->getMapgen();
 486
 487         while(getRun())
 488         try {
 489                 QueuedBlockEmerge *qptr = m_server->m_emerge_queue.pop();
 490                 if(qptr == NULL)
 491                         break;
 492                 SharedPtr<QueuedBlockEmerge> q(qptr);
 493
 494                 v3s16 &p = q->pos;
 495                 v2s16 p2d(p.X,p.Z);
 496
 497                 last_tried_pos = p;
 498
 499                 /*
 500                         Do not generate over-limit
 501                 */
 502                 if (blockpos_over_limit(p))
 503                         continue;
 504
 505                 //infostream<<"EmergeThread::Thread(): running"<<std::endl;
 506
 507                 //TimeTaker timer("block emerge");
 508
 509                 /*
 510                         Try to emerge it from somewhere.
 511
 512                         If it is only wanted as optional, only loading from disk
 513                         will be allowed.
 514                 */
 515
 516                 /*
 517                         Check if any peer wants it as non-optional. In that case it
 518                         will be generated.
 519
 520                         Also decrement the emerge queue count in clients.
 521                 */
 522
 523                 bool only_from_disk = true;
 524                 {
 525                         core::map<u16, u8>::Iterator i;
 526                         for (i=q->s.getIterator(); !i.atEnd(); i++) {
 527                                 u8 flags = i.getNode()->getValue();
 528                                 if (!(flags & BLOCK_EMERGE_FLAG_FROMDISK)) {
 529                                         only_from_disk = false;
 530                                         break;
 531                                 }
 532                         }
 533                 }
 534
 535                 if (enable_mapgen_debug_info)
 536                         infostream<<"EmergeThread: p="
 537                                         <<"("<<p.X<<","<<p.Y<<","<<p.Z<<") "
 538                                         <<"only_from_disk="<<only_from_disk<<std::endl;
 539
 540                 MapBlock *block = NULL;
 541                 bool got_block = true;
 542                 core::map<v3s16, MapBlock*> modified_blocks;
 543
 544                 /*
 545                         Try to fetch block from memory or disk.
 546                         If not found and asked to generate, initialize generator.
 547                 */
 548
 549                 bool started_generate = false;
 550                 BlockMakeData data;
 551                 {
 552                         JMutexAutoLock envlock(m_server->m_env_mutex);
 553
 554                         // Load sector if it isn't loaded
 555                         if(map.getSectorNoGenerateNoEx(p2d) == NULL)
 556                                 map.loadSectorMeta(p2d);
 557
 558                         // Attempt to load block
 559                         block = map.getBlockNoCreateNoEx(p);
 560                         if(!block || block->isDummy() || !block->isGenerated()) {
 561                                 if(enable_mapgen_debug_info)
 562                                         infostream<<"EmergeThread: not in memory, "
 563                                                         <<"attempting to load from disk"<<std::endl;
 564
 565                                 block = map.loadBlock(p);
 566                         }
 567
 568                         // If could not load and allowed to generate, start generation
 569                         // inside this same envlock
 570                         if(only_from_disk == false &&
 571                                         (block == NULL || block->isGenerated() == false)){
 572                                 if(enable_mapgen_debug_info)
 573                                         infostream<<"EmergeThread: generating"<<std::endl;
 574                                 started_generate = true;
 575
 576                                 map.initBlockMake(&data, p);
 577                         }
 578                 }
 579
 580                 /*
 581                         If generator was initialized, generate now when envlock is free.
 582                 */
 583                 if(started_generate) {
 584                         {
 585                                 ScopeProfiler sp(g_profiler, "EmergeThread: mapgen::make_block",
 586                                                 SPT_AVG);
 587                                 TimeTaker t("mapgen::make_block()");
 588
 589                                 mapgen->makeChunk(&data);
 590
 591                                 if (enable_mapgen_debug_info == false)
 592                                         t.stop(true); // Hide output
 593                         }
 594
 595                         do{ // enable break
 596                                 // Lock environment again to access the map
 597                                 JMutexAutoLock envlock(m_server->m_env_mutex);
 598
 599                                 ScopeProfiler sp(g_profiler, "EmergeThread: after "
 600                                                 "mapgen::make_block (envlock)", SPT_AVG);
 601
 602                                 // Blit data back on map, update lighting, add mobs and
 603                                 // whatever this does
 604                                 map.finishBlockMake(&data, modified_blocks);
 605
 606                                 // Get central block
 607                                 block = map.getBlockNoCreateNoEx(p);
 608
 609                                 // If block doesn't exist, don't try doing anything with it
 610                                 // This happens if the block is not in generation boundaries
 611                                 if(!block)
 612                                         break;
 613
 614                                 /*
 615                                         Do some post-generate stuff
 616                                 */
 617                                 v3s16 minp = data.blockpos_min * MAP_BLOCKSIZE;
 618                                 v3s16 maxp = data.blockpos_max * MAP_BLOCKSIZE +
 619                                                 v3s16(1,1,1) * (MAP_BLOCKSIZE - 1);
 620
 621                                 /*
 622                                         Ignore map edit events, they will not need to be
 623                                         sent to anybody because the block hasn't been sent
 624                                         to anybody
 625                                 */
 626                                 MapEditEventAreaIgnorer ign(
 627                                                 &m_server->m_ignore_map_edit_events_area,
 628                                                 VoxelArea(minp, maxp));
 629                                 {
 630                                         TimeTaker timer("on_generated");
 631                                         scriptapi_environment_on_generated(m_server->m_lua,
 632                                                         minp, maxp, emerge->getBlockSeed(minp));
 633                                         //int t = timer.stop(true);
 634                                         //dstream<<"on_generated took "<<t<<"ms"<<std::endl;
 635                                 }
 636
 637                                 if (enable_mapgen_debug_info)
 638                                         infostream << "EmergeThread: ended up with: "
 639                                                         << analyze_block(block) << std::endl;
 640
 641                                 // Activate objects and stuff
 642                                 m_server->m_env->activateBlock(block, 0);
 643                         }while(false);
 644                 }
 645
 646                 if(block == NULL)
 647                         got_block = false;
 648
 649                 /*
 650                         Set sent status of modified blocks on clients
 651                 */
 652
 653                 // NOTE: Server's clients are also behind the connection mutex
 654                 JMutexAutoLock lock(m_server->m_con_mutex);
 655
 656                 /*
 657                         Add the originally fetched block to the modified list
 658                 */
 659                 if(got_block)
 660                         modified_blocks.insert(p, block);
 661
 662                 /*
 663                         Set the modified blocks unsent for all the clients
 664                 */
 665                 for(core::map<u16, RemoteClient*>::Iterator
 666                                 i = m_server->m_clients.getIterator();
 667                                 i.atEnd() == false; i++) {
 668                         RemoteClient *client = i.getNode()->getValue();
 669                         if(modified_blocks.size() > 0) {
 670                                 // Remove block from sent history
 671                                 client->SetBlocksNotSent(modified_blocks);
 672                         }
 673                 }
 674
 675
 676 niters++;
 677         }
 678         catch (VersionMismatchException &e) {
 679                 std::ostringstream err;
 680                 err << "World data version mismatch in MapBlock "<<PP(last_tried_pos)<<std::endl;
 681                 err << "----"<<std::endl;
 682                 err << "\""<<e.what()<<"\""<<std::endl;
 683                 err << "See debug.txt."<<std::endl;
 684                 err << "World probably saved by a newer version of Minetest."<<std::endl;
 685                 m_server->setAsyncFatalError(err.str());
 686         }
 687         catch (SerializationError &e) {
 688                 std::ostringstream err;
 689                 err << "Invalid data in MapBlock "<<PP(last_tried_pos)<<std::endl;
 690                 err << "----"<<std::endl;
 691                 err << "\""<<e.what()<<"\""<<std::endl;
 692                 err << "See debug.txt."<<std::endl;
 693                 err << "You can ignore this using [ignore_world_load_errors = true]."<<std::endl;
 694                 m_server->setAsyncFatalError(err.str());
 695         }
 696 printf("emergethread iterated %d times\n", niters);
 697         END_DEBUG_EXCEPTION_HANDLER(errorstream)
 698         log_deregister_thread();
 699         return NULL;
 700 }
 701
 702 #endif