/* Minetest Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com> This program is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #pragma once #include "irrlichttypes.h" #include "threading/thread.h" #include "threading/mutex_auto_lock.h" #include "porting.h" #include "log.h" #include "container.h" template<typename T> class MutexedVariable { public: MutexedVariable(const T &value): m_value(value) {} T get() { MutexAutoLock lock(m_mutex); return m_value; } void set(const T &value) { MutexAutoLock lock(m_mutex); m_value = value; } // You pretty surely want to grab the lock when accessing this T m_value; private: std::mutex m_mutex; }; /* A single worker thread - multiple client threads queue framework. */ template<typename Key, typename T, typename Caller, typename CallerData> class GetResult { public: Key key; T item; std::pair<Caller, CallerData> caller; }; template<typename Key, typename T, typename Caller, typename CallerData> class ResultQueue : public MutexedQueue<GetResult<Key, T, Caller, CallerData> > { }; template<typename Caller, typename Data, typename Key, typename T> class CallerInfo { public: Caller caller; Data data; ResultQueue<Key, T, Caller, Data> *dest; }; template<typename Key, typename T, typename Caller, typename CallerData> class GetRequest { public: GetRequest() = default; ~GetRequest() = default; GetRequest(const Key &a_key): key(a_key) { } Key key; std::list<CallerInfo<Caller, CallerData, Key, T> > callers; }; /** * Notes for RequestQueue usage * @param Key unique key to identify a request for a specific resource * @param T ? * @param Caller unique id of calling thread * @param CallerData data passed back to caller */ template<typename Key, typename T, typename Caller, typename CallerData> class RequestQueue { public: bool empty() { return m_queue.empty(); } void add(const Key &key, Caller caller, CallerData callerdata, ResultQueue<Key, T, Caller, CallerData> *dest) { typename std::deque<GetRequest<Key, T, Caller, CallerData> >::iterator i; typename std::list<CallerInfo<Caller, CallerData, Key, T> >::iterator j; { MutexAutoLock lock(m_queue.getMutex()); /* If the caller is already on the list, only update CallerData */ for (i = m_queue.getQueue().begin(); i != m_queue.getQueue().end(); ++i) { GetRequest<Key, T, Caller, CallerData> &request = *i; if (request.key != key) continue; for (j = request.callers.begin(); j != request.callers.end(); ++j) { CallerInfo<Caller, CallerData, Key, T> &ca = *j; if (ca.caller == caller) { ca.data = callerdata; return; } } CallerInfo<Caller, CallerData, Key, T> ca; ca.caller = caller; ca.data = callerdata; ca.dest = dest; request.callers.push_back(ca); return; } } /* Else add a new request to the queue */ GetRequest<Key, T, Caller, CallerData> request; request.key = key; CallerInfo<Caller, CallerData, Key, T> ca; ca.caller = caller; ca.data = callerdata; ca.dest = dest; request.callers.push_back(ca); m_queue.push_back(request); } GetRequest<Key, T, Caller, CallerData> pop(unsigned int timeout_ms) { return m_queue.pop_front(timeout_ms); } GetRequest<Key, T, Caller, CallerData> pop() { return m_queue.pop_frontNoEx(); } void pushResult(GetRequest<Key, T, Caller, CallerData> req, T res) { for (typename std::list<CallerInfo<Caller, CallerData, Key, T> >::iterator i = req.callers.begin(); i != req.callers.end(); ++i) { CallerInfo<Caller, CallerData, Key, T> &ca = *i; GetResult<Key,T,Caller,CallerData> result; result.key = req.key; result.item = res; result.caller.first = ca.caller; result.caller.second = ca.data; ca.dest->push_back(result); } } private: MutexedQueue<GetRequest<Key, T, Caller, CallerData> > m_queue; }; class UpdateThread : public Thread { public: UpdateThread(const std::string &name) : Thread(name + "Update") {} ~UpdateThread() = default; void deferUpdate() { m_update_sem.post(); } void stop() { Thread::stop(); // give us a nudge m_update_sem.post(); } void *run() { BEGIN_DEBUG_EXCEPTION_HANDLER while (!stopRequested()) { m_update_sem.wait(); // Set semaphore to 0 while (m_update_sem.wait(0)); if (stopRequested()) break; doUpdate(); } END_DEBUG_EXCEPTION_HANDLER return NULL; } protected: virtual void doUpdate() = 0; private: Semaphore m_update_sem; };