map-manager.cpp

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/*
 * map-manager.cpp
 *
 * Copyright (C) 2009  Thomas A. Vaughan
 * All rights reserved.
 *
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the <organization> nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THOMAS A. VAUGHAN ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THOMAS A. VAUGHAN BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Map management.  See map-manager.h
 */

// includes -------------------------------------------------------------------
#include "map-manager.h"                // always include our own header first!

#include "common/wave_ex.h"

#include "threadsafe/smart_mutex.h"
#include "threadsafe/threadsafe_queue.h"


namespace aesop {


MapManager::~MapManager(void) throw() { }


static const useconds_t s_sleepMicroseconds             = 2000; // 2ms



//
//      MapMgr -- object that implements the MapManager interface
//

class MapMgr : public MapManager {
public:
        MapMgr(void) throw();
        ~MapMgr(void) throw() { }

        // public class methods ------------------------------------------------
        void initialize(IN smart_ptr<Datahash>& params,
                                IN smart_ptr<story::Story>& story);

        // aesop::MapManager class interface methods --------------------------
        void clear(void);
        void requestLoad(IN const char * id);
        smart_ptr<MapDynamics> getMap(IN const char * id);
        void tickMaps(IN float seconds);
        void getIterator(OUT iterator_t& i);
        bool getNextMap(IO iterator_t& i,
                                OUT smart_ptr<MapDynamics>& map);

private:
        // private typedefs ----------------------------------------------------
        typedef std::map<std::string, smart_ptr<MapDynamics> > id_map_t;

        typedef threadsafe_queue<std::string> id_queue_t;

        struct real_iter_t {
                dword_t                 rvn;
                id_map_t::iterator      iter;
        };

        // private helper methods ----------------------------------------------
        void doThread(void);
        static void * threadStart(void *);
        static real_iter_t * getRealIterator(IN iterator_t& i) throw()
                { return (real_iter_t *) &i; }

        // private member data -------------------------------------------------
        smart_mutex                     m_mutex;
        smart_ptr<Datahash>             m_params;
        smart_ptr<story::Story>         m_story;
        id_queue_t                      m_loadQueue;
        pthread_t                       m_thread;
        id_map_t                        m_maps;         // ID --> map
        dword_t                         m_rvn;
};



MapMgr::MapMgr(void)
throw()
{
        m_rvn = 4381;           // random
}



void
MapMgr::initialize
(
IN smart_ptr<Datahash>& params,
IN smart_ptr<story::Story>& story
)
{
        ASSERT(params, "null");
        ASSERT(story, "null");

        m_params = params;
        m_story = story;

        // create worker thread
        ASSERT(!pthread_create(&m_thread, NULL, threadStart, this),
            "Failed to create map manager worker thread");
        DPRINTF("Thread id = 0x%08lx", m_thread);
}



//
//      MapMgr -- aesop::MapManager class interface methods
//

void
MapMgr::clear
(
void
)
{
        DPRINTF("WARNING: requested to clear all map state!");

        // brutally easy...  entire ecosystems wiped away here...
        mlock l(m_mutex);
        ++m_rvn;
        m_maps.clear();
}



void
MapMgr::requestLoad
(
IN const char * id
)
{
        ASSERT(id, "null");
        ASSERT(m_story, "null");

        std::string str_id = id;

        // threadsafe!  push request onto threadsafe queue...
        m_loadQueue.push_back(str_id);
}



smart_ptr<MapDynamics>
MapMgr::getMap
(
IN const char * id
)
{
        ASSERT(id, "null");

        // threadsafe!
        mlock l(m_mutex);

        // do we have this map?
        id_map_t::iterator i = m_maps.find(id);
        if (m_maps.end() == i) {
                DPRINTF("No such map!");
                return NULL;
        }
        ASSERT(i->second, "null");

        return i->second;
}



void
MapMgr::tickMaps
(
IN float seconds
)
{
        ASSERT(seconds > 0, "Bad seconds: %f", seconds);

        // lock!
        mlock l(m_mutex);

        // iterate over all maps and tick
        for (id_map_t::iterator i = m_maps.begin(); i != m_maps.end(); ++i) {
                MapDynamics * md = i->second;
                ASSERT(md, "null");

                md->tickMap(seconds);
        }
}



void
MapMgr::getIterator
(
OUT iterator_t& i
)
{
        real_iter_t * ri = getRealIterator(i);

        // lock!
        mlock l(m_mutex);
        ri->rvn = m_rvn;
        ri->iter = m_maps.begin();
}



bool
MapMgr::getNextMap
(
IO iterator_t& i,
OUT smart_ptr<MapDynamics>& map
)
{
        map = NULL;
        real_iter_t * ri = getRealIterator(i);

        // lock!
        mlock l(m_mutex);

        if (m_rvn != ri->rvn)
                return false;   // something has changed

        if (m_maps.end() == ri->iter)
                return false;   // at end of iteration

        // have a valid iterator!
        map = ri->iter->second;
        ASSERT(map, "null dynamics object?");
        ++ri->iter;
        return true;
}



//
//      MapMgr -- private helper methods
//

void
MapMgr::doThread
(
void
)
{
        // infinite loop, waiting for work!
        for (;;) {
                usleep(s_sleepMicroseconds);

                // anything to do?
                std::string id;
                if (!m_loadQueue.pop_front(id))
                        continue;       // nope

                // okay, have an ID to load! 
                // quick lock to check some data points
                std::string path;
                {
                        mlock l(m_mutex);
                        if (m_maps.end() != m_maps.find(id)) {
                                // already loaded!
                                continue;
                        }

                        // not yet loaded
                        path = m_story->getObjectPath("map", id.c_str());
                }

                // load here, on thread, outside mutex
                DPRINTF("******* Loading map: %s", id.c_str());
                smart_ptr<Map> map = loadMap(id.c_str(), path.c_str());
                ASSERT(map, "null");

                smart_ptr<MapDynamics> dyn = MapDynamics::create(map, m_params);
                ASSERT(dyn, "null");

                // okay!  add to our map
                {
                        mlock l(m_mutex);
                        ++m_rvn;
                        m_maps[id] = dyn;
                }
        }
}



void *
MapMgr::threadStart
(
IN void * ctx
)
{
        MapMgr * pThis = (MapMgr *) ctx;
        for (;;) {
                try {
                        pThis->doThread();
                } catch (std::exception& e) {
                        DPRINTF("Exception from MapMgr worker thread:\n  %s",
                            e.what());
                }
        }
        return NULL;
}



//
//      public API
//

smart_ptr<MapManager>
MapManager::create
(
IN smart_ptr<Datahash>& params,
IN smart_ptr<story::Story>& story
)
{
        ASSERT(params, "null");
        ASSERT(story, "null");

        smart_ptr<MapMgr> local = new MapMgr;
        ASSERT(local, "out of memory");

        local->initialize(params, story);

        return local;
}



};      // aesop namespace