src/util/thread.h

   1 /*
   2 Minetest
   3 Copyright (C) 2010-2013 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 #ifndef UTIL_THREAD_HEADER
  21 #define UTIL_THREAD_HEADER
  22
  23 #include "../irrlichttypes.h"
  24 #include <jthread.h>
  25 #include <jmutex.h>
  26 #include <jmutexautolock.h>
  27
  28 template<typename T>
  29 class MutexedVariable
  30 {
  31 public:
  32         MutexedVariable(T value):
  33                 m_value(value)
  34         {
  35                 m_mutex.Init();
  36         }
  37
  38         T get()
  39         {
  40                 JMutexAutoLock lock(m_mutex);
  41                 return m_value;
  42         }
  43
  44         void set(T value)
  45         {
  46                 JMutexAutoLock lock(m_mutex);
  47                 m_value = value;
  48         }
  49
  50         // You'll want to grab this in a SharedPtr
  51         JMutexAutoLock * getLock()
  52         {
  53                 return new JMutexAutoLock(m_mutex);
  54         }
  55
  56         // You pretty surely want to grab the lock when accessing this
  57         T m_value;
  58
  59 private:
  60         JMutex m_mutex;
  61 };
  62
  63 /*
  64         A base class for simple background thread implementation
  65 */
  66
  67 class SimpleThread : public JThread
  68 {
  69         bool run;
  70         JMutex run_mutex;
  71
  72 public:
  73
  74         SimpleThread():
  75                 JThread(),
  76                 run(true)
  77         {
  78                 run_mutex.Init();
  79         }
  80
  81         virtual ~SimpleThread()
  82         {}
  83
  84         virtual void * Thread() = 0;
  85
  86         bool getRun()
  87         {
  88                 JMutexAutoLock lock(run_mutex);
  89                 return run;
  90         }
  91         void setRun(bool a_run)
  92         {
  93                 JMutexAutoLock lock(run_mutex);
  94                 run = a_run;
  95         }
  96
  97         void stop()
  98         {
  99                 setRun(false);
 100                 while(IsRunning())
 101                         sleep_ms(100);
 102         }
 103 };
 104
 105 /*
 106         A single worker thread - multiple client threads queue framework.
 107 */
 108
 109 template<typename Caller, typename Data>
 110 class CallerInfo
 111 {
 112 public:
 113         Caller caller;
 114         Data data;
 115 };
 116
 117 template<typename Key, typename T, typename Caller, typename CallerData>
 118 class GetResult
 119 {
 120 public:
 121         Key key;
 122         T item;
 123         core::list<CallerInfo<Caller, CallerData> > callers;
 124 };
 125
 126 template<typename Key, typename T, typename Caller, typename CallerData>
 127 class ResultQueue: public MutexedQueue< GetResult<Key, T, Caller, CallerData> >
 128 {
 129 };
 130
 131 template<typename Key, typename T, typename Caller, typename CallerData>
 132 class GetRequest
 133 {
 134 public:
 135         GetRequest()
 136         {
 137                 dest = NULL;
 138         }
 139         GetRequest(ResultQueue<Key,T, Caller, CallerData> *a_dest)
 140         {
 141                 dest = a_dest;
 142         }
 143         GetRequest(ResultQueue<Key,T, Caller, CallerData> *a_dest,
 144                         Key a_key)
 145         {
 146                 dest = a_dest;
 147                 key = a_key;
 148         }
 149         ~GetRequest()
 150         {
 151         }
 152
 153         Key key;
 154         ResultQueue<Key, T, Caller, CallerData> *dest;
 155         core::list<CallerInfo<Caller, CallerData> > callers;
 156 };
 157
 158 template<typename Key, typename T, typename Caller, typename CallerData>
 159 class RequestQueue
 160 {
 161 public:
 162         u32 size()
 163         {
 164                 return m_queue.size();
 165         }
 166
 167         void add(Key key, Caller caller, CallerData callerdata,
 168                         ResultQueue<Key, T, Caller, CallerData> *dest)
 169         {
 170                 JMutexAutoLock lock(m_queue.getMutex());
 171
 172                 /*
 173                         If the caller is already on the list, only update CallerData
 174                 */
 175                 for(typename core::list< GetRequest<Key, T, Caller, CallerData> >::Iterator
 176                                 i = m_queue.getList().begin();
 177                                 i != m_queue.getList().end(); i++)
 178                 {
 179                         GetRequest<Key, T, Caller, CallerData> &request = *i;
 180
 181                         if(request.key == key)
 182                         {
 183                                 for(typename core::list< CallerInfo<Caller, CallerData> >::Iterator
 184                                                 i = request.callers.begin();
 185                                                 i != request.callers.end(); i++)
 186                                 {
 187                                         CallerInfo<Caller, CallerData> &ca = *i;
 188                                         if(ca.caller == caller)
 189                                         {
 190                                                 ca.data = callerdata;
 191                                                 return;
 192                                         }
 193                                 }
 194                                 CallerInfo<Caller, CallerData> ca;
 195                                 ca.caller = caller;
 196                                 ca.data = callerdata;
 197                                 request.callers.push_back(ca);
 198                                 return;
 199                         }
 200                 }
 201
 202                 /*
 203                         Else add a new request to the queue
 204                 */
 205
 206                 GetRequest<Key, T, Caller, CallerData> request;
 207                 request.key = key;
 208                 CallerInfo<Caller, CallerData> ca;
 209                 ca.caller = caller;
 210                 ca.data = callerdata;
 211                 request.callers.push_back(ca);
 212                 request.dest = dest;
 213
 214                 m_queue.getList().push_back(request);
 215         }
 216
 217         GetRequest<Key, T, Caller, CallerData> pop(bool wait_if_empty=false)
 218         {
 219                 return m_queue.pop_front(wait_if_empty);
 220         }
 221
 222 private:
 223         MutexedQueue< GetRequest<Key, T, Caller, CallerData> > m_queue;
 224 };
 225
 226 #endif
 227