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                 delete *it;
  70         }
  71
  72         jobQueueMutex.lock();
  73         jobQueue.clear();
  74         jobQueueMutex.unlock();
  75         workerThreads.clear();
  76 }
  77
  78 /******************************************************************************/
  79 bool AsyncEngine::registerFunction(const char* name, lua_CFunction func)
  80 {
  81         if (initDone) {
  82                 return false;
  83         }
  84         functionList[name] = func;
  85         return true;
  86 }
  87
  88 /******************************************************************************/
  89 void AsyncEngine::initialize(unsigned int numEngines)
  90 {
  91         initDone = true;
  92
  93         for (unsigned int i = 0; i < numEngines; i++) {
  94                 AsyncWorkerThread *toAdd = new AsyncWorkerThread(this,
  95                         std::string("AsyncWorker-") + itos(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         MutexAutoLock l(resultQueueMutex);
 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
 202 /******************************************************************************/
 203 void AsyncEngine::prepareEnvironment(lua_State* L, int top)
 204 {
 205         for (std::map<std::string, lua_CFunction>::iterator it = functionList.begin();
 206                         it != functionList.end(); it++) {
 207                 lua_pushstring(L, it->first.c_str());
 208                 lua_pushcfunction(L, it->second);
 209                 lua_settable(L, top);
 210         }
 211 }
 212
 213 /******************************************************************************/
 214 AsyncWorkerThread::AsyncWorkerThread(AsyncEngine* jobDispatcher,
 215                 const std::string &name) :
 216         Thread(name),
 217         ScriptApiBase(),
 218         jobDispatcher(jobDispatcher)
 219 {
 220         lua_State *L = getStack();
 221
 222         // Prepare job lua environment
 223         lua_getglobal(L, "core");
 224         int top = lua_gettop(L);
 225
 226         // Push builtin initialization type
 227         lua_pushstring(L, "async");
 228         lua_setglobal(L, "INIT");
 229
 230         jobDispatcher->prepareEnvironment(L, top);
 231 }
 232
 233 /******************************************************************************/
 234 AsyncWorkerThread::~AsyncWorkerThread()
 235 {
 236         sanity_check(!isRunning());
 237 }
 238
 239 /******************************************************************************/
 240 void* AsyncWorkerThread::run()
 241 {
 242         lua_State *L = getStack();
 243
 244         std::string script = getServer()->getBuiltinLuaPath() + DIR_DELIM + "init.lua";
 245         if (!loadScript(script)) {
 246                 errorstream << "execution of async base environment failed!"
 247                         << std::endl;
 248                 abort();
 249         }
 250
 251         lua_getglobal(L, "core");
 252         if (lua_isnil(L, -1)) {
 253                 errorstream << "Unable to find core within async environment!";
 254                 abort();
 255         }
 256
 257         // Main loop
 258         while (!stopRequested()) {
 259                 // Wait for job
 260                 LuaJobInfo toProcess = jobDispatcher->getJob();
 261
 262                 if (toProcess.valid == false || stopRequested()) {
 263                         continue;
 264                 }
 265
 266                 lua_getfield(L, -1, "job_processor");
 267                 if (lua_isnil(L, -1)) {
 268                         errorstream << "Unable to get async job processor!" << std::endl;
 269                         abort();
 270                 }
 271
 272                 luaL_checktype(L, -1, LUA_TFUNCTION);
 273
 274                 // Call it
 275                 lua_pushlstring(L,
 276                                 toProcess.serializedFunction.data(),
 277                                 toProcess.serializedFunction.size());
 278                 lua_pushlstring(L,
 279                                 toProcess.serializedParams.data(),
 280                                 toProcess.serializedParams.size());
 281
 282                 int result = lua_pcall(L, 2, 1, m_errorhandler);
 283                 if (result) {
 284                         PCALL_RES(result);
 285                         toProcess.serializedResult = "";
 286                 } else {
 287                         // Fetch result
 288                         size_t length;
 289                         const char *retval = lua_tolstring(L, -1, &length);
 290                         toProcess.serializedResult = std::string(retval, length);
 291                 }
 292
 293                 lua_pop(L, 1);  // Pop retval
 294
 295                 // Put job result
 296                 jobDispatcher->putJobResult(toProcess);
 297         }
 298
 299         lua_pop(L, 1);  // Pop core
 300
 301         return 0;
 302 }
 303