src/script/cpp_api/s_async.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2013 sapier, <sapier AT gmx DOT net>
   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 #include <stdio.h>
  21 #include <stdlib.h>
  22
  23 extern "C" {
  24 #include "lua.h"
  25 #include "lauxlib.h"
  26 #include "lualib.h"
  27 }
  28
  29 #include "server.h"
  30 #include "s_async.h"
  31 #include "log.h"
  32 #include "filesys.h"
  33 #include "porting.h"
  34 #include "common/c_internal.h"
  35
  36 /******************************************************************************/
  37 AsyncEngine::AsyncEngine() :
  38         initDone(false),
  39         jobIdCounter(0)
  40 {
  41 }
  42
  43 /******************************************************************************/
  44 AsyncEngine::~AsyncEngine()
  45 {
  46
  47         // Request all threads to stop
  48         for (std::vector<AsyncWorkerThread *>::iterator it = workerThreads.begin();
  49                         it != workerThreads.end(); it++) {
  50                 (*it)->Stop();
  51         }
  52
  53
  54         // Wake up all threads
  55         for (std::vector<AsyncWorkerThread *>::iterator it = workerThreads.begin();
  56                         it != workerThreads.end(); it++) {
  57                 jobQueueCounter.Post();
  58         }
  59
  60         // Wait for threads to finish
  61         for (std::vector<AsyncWorkerThread *>::iterator it = workerThreads.begin();
  62                         it != workerThreads.end(); it++) {
  63                 (*it)->Wait();
  64         }
  65
  66         // Force kill all threads
  67         for (std::vector<AsyncWorkerThread *>::iterator it = workerThreads.begin();
  68                         it != workerThreads.end(); it++) {
  69                 (*it)->Kill();
  70                 delete *it;
  71         }
  72
  73         jobQueueMutex.Lock();
  74         jobQueue.clear();
  75         jobQueueMutex.Unlock();
  76         workerThreads.clear();
  77 }
  78
  79 /******************************************************************************/
  80 bool AsyncEngine::registerFunction(const char* name, lua_CFunction func)
  81 {
  82         if (initDone) {
  83                 return false;
  84         }
  85         functionList[name] = func;
  86         return true;
  87 }
  88
  89 /******************************************************************************/
  90 void AsyncEngine::initialize(unsigned int numEngines)
  91 {
  92         initDone = true;
  93
  94         for (unsigned int i = 0; i < numEngines; i++) {
  95                 AsyncWorkerThread *toAdd = new AsyncWorkerThread(this, i);
  96                 workerThreads.push_back(toAdd);
  97                 toAdd->Start();
  98         }
  99 }
 100
 101 /******************************************************************************/
 102 unsigned int AsyncEngine::queueAsyncJob(std::string func, std::string params)
 103 {
 104         jobQueueMutex.Lock();
 105         LuaJobInfo toAdd;
 106         toAdd.id = jobIdCounter++;
 107         toAdd.serializedFunction = func;
 108         toAdd.serializedParams = params;
 109
 110         jobQueue.push_back(toAdd);
 111
 112         jobQueueCounter.Post();
 113
 114         jobQueueMutex.Unlock();
 115
 116         return toAdd.id;
 117 }
 118
 119 /******************************************************************************/
 120 LuaJobInfo AsyncEngine::getJob()
 121 {
 122         jobQueueCounter.Wait();
 123         jobQueueMutex.Lock();
 124
 125         LuaJobInfo retval;
 126         retval.valid = false;
 127
 128         if (!jobQueue.empty()) {
 129                 retval = jobQueue.front();
 130                 jobQueue.pop_front();
 131                 retval.valid = true;
 132         }
 133         jobQueueMutex.Unlock();
 134
 135         return retval;
 136 }
 137
 138 /******************************************************************************/
 139 void AsyncEngine::putJobResult(LuaJobInfo result)
 140 {
 141         resultQueueMutex.Lock();
 142         resultQueue.push_back(result);
 143         resultQueueMutex.Unlock();
 144 }
 145
 146 /******************************************************************************/
 147 void AsyncEngine::step(lua_State *L, int errorhandler)
 148 {
 149         lua_getglobal(L, "core");
 150         resultQueueMutex.Lock();
 151         while (!resultQueue.empty()) {
 152                 LuaJobInfo jobDone = resultQueue.front();
 153                 resultQueue.pop_front();
 154
 155                 lua_getfield(L, -1, "async_event_handler");
 156
 157                 if (lua_isnil(L, -1)) {
 158                         FATAL_ERROR("Async event handler does not exist!");
 159                 }
 160
 161                 luaL_checktype(L, -1, LUA_TFUNCTION);
 162
 163                 lua_pushinteger(L, jobDone.id);
 164                 lua_pushlstring(L, jobDone.serializedResult.data(),
 165                                 jobDone.serializedResult.size());
 166
 167                 PCALL_RESL(L, lua_pcall(L, 2, 0, errorhandler));
 168         }
 169         resultQueueMutex.Unlock();
 170         lua_pop(L, 1); // Pop core
 171 }
 172
 173 /******************************************************************************/
 174 void AsyncEngine::pushFinishedJobs(lua_State* L) {
 175         // Result Table
 176         resultQueueMutex.Lock();
 177
 178         unsigned int index = 1;
 179         lua_createtable(L, resultQueue.size(), 0);
 180         int top = lua_gettop(L);
 181
 182         while (!resultQueue.empty()) {
 183                 LuaJobInfo jobDone = resultQueue.front();
 184                 resultQueue.pop_front();
 185
 186                 lua_createtable(L, 0, 2);  // Pre-allocate space for two map fields
 187                 int top_lvl2 = lua_gettop(L);
 188
 189                 lua_pushstring(L, "jobid");
 190                 lua_pushnumber(L, jobDone.id);
 191                 lua_settable(L, top_lvl2);
 192
 193                 lua_pushstring(L, "retval");
 194                 lua_pushlstring(L, jobDone.serializedResult.data(),
 195                         jobDone.serializedResult.size());
 196                 lua_settable(L, top_lvl2);
 197
 198                 lua_rawseti(L, top, index++);
 199         }
 200
 201         resultQueueMutex.Unlock();
 202 }
 203
 204 /******************************************************************************/
 205 void AsyncEngine::prepareEnvironment(lua_State* L, int top)
 206 {
 207         for (std::map<std::string, lua_CFunction>::iterator it = functionList.begin();
 208                         it != functionList.end(); it++) {
 209                 lua_pushstring(L, it->first.c_str());
 210                 lua_pushcfunction(L, it->second);
 211                 lua_settable(L, top);
 212         }
 213 }
 214
 215 /******************************************************************************/
 216 AsyncWorkerThread::AsyncWorkerThread(AsyncEngine* jobDispatcher,
 217                 unsigned int threadNum) :
 218         ScriptApiBase(),
 219         jobDispatcher(jobDispatcher),
 220         threadnum(threadNum)
 221 {
 222         lua_State *L = getStack();
 223
 224         // Prepare job lua environment
 225         lua_getglobal(L, "core");
 226         int top = lua_gettop(L);
 227
 228         // Push builtin initialization type
 229         lua_pushstring(L, "async");
 230         lua_setglobal(L, "INIT");
 231
 232         jobDispatcher->prepareEnvironment(L, top);
 233 }
 234
 235 /******************************************************************************/
 236 AsyncWorkerThread::~AsyncWorkerThread()
 237 {
 238         sanity_check(IsRunning() == false);
 239 }
 240
 241 /******************************************************************************/
 242 void* AsyncWorkerThread::Thread()
 243 {
 244         ThreadStarted();
 245
 246         // Register thread for error logging
 247         char number[21];
 248         snprintf(number, sizeof(number), "%u", threadnum);
 249         log_register_thread(std::string("AsyncWorkerThread_") + number);
 250
 251         porting::setThreadName((std::string("AsyncWorkTh_") + number).c_str());
 252
 253         lua_State *L = getStack();
 254
 255         std::string script = getServer()->getBuiltinLuaPath() + DIR_DELIM + "init.lua";
 256         if (!loadScript(script)) {
 257                 errorstream
 258                         << "AsyncWorkerThread execution of async base environment failed!"
 259                         << std::endl;
 260                 abort();
 261         }
 262
 263         lua_getglobal(L, "core");
 264         if (lua_isnil(L, -1)) {
 265                 errorstream << "Unable to find core within async environment!";
 266                 abort();
 267         }
 268
 269         // Main loop
 270         while (!StopRequested()) {
 271                 // Wait for job
 272                 LuaJobInfo toProcess = jobDispatcher->getJob();
 273
 274                 if (toProcess.valid == false || StopRequested()) {
 275                         continue;
 276                 }
 277
 278                 lua_getfield(L, -1, "job_processor");
 279                 if (lua_isnil(L, -1)) {
 280                         errorstream << "Unable to get async job processor!" << std::endl;
 281                         abort();
 282                 }
 283
 284                 luaL_checktype(L, -1, LUA_TFUNCTION);
 285
 286                 // Call it
 287                 lua_pushlstring(L,
 288                                 toProcess.serializedFunction.data(),
 289                                 toProcess.serializedFunction.size());
 290                 lua_pushlstring(L,
 291                                 toProcess.serializedParams.data(),
 292                                 toProcess.serializedParams.size());
 293
 294                 int result = lua_pcall(L, 2, 1, m_errorhandler);
 295                 if (result) {
 296                         PCALL_RES(result);
 297                         toProcess.serializedResult = "";
 298                 } else {
 299                         // Fetch result
 300                         size_t length;
 301                         const char *retval = lua_tolstring(L, -1, &length);
 302                         toProcess.serializedResult = std::string(retval, length);
 303                 }
 304
 305                 lua_pop(L, 1);  // Pop retval
 306
 307                 // Put job result
 308                 jobDispatcher->putJobResult(toProcess);
 309         }
 310
 311         lua_pop(L, 1);  // Pop core
 312
 313         log_deregister_thread();
 314
 315         return 0;
 316 }
 317