love2d.love/src/modules/thread/Thread.cpp

/**
 * Copyright (c) 2006-2013 LOVE Development Team
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 **/

#include "common/config.h"

#include "Thread.h"

#ifdef LOVE_BUILD_STANDALONE
extern "C" int luaopen_love(lua_State *L);
#endif // LOVE_BUILD_STANDALONE
extern "C" int luaopen_love_thread(lua_State *L);

namespace love
{
namespace thread
{

Thread::ThreadThread::ThreadThread(ThreadData *comm)
	: comm(comm)
{
}

void Thread::ThreadThread::main()
{
	lua_State *L = lua_open();
	luaL_openlibs(L);
#ifdef LOVE_BUILD_STANDALONE
	love::luax_preload(L, luaopen_love, "love");
	luaopen_love(L);
#endif // LOVE_BUILD_STANDALONE
	luaopen_love_thread(L);
	{
		size_t len;
		const char *name = comm->getName(&len);
		lua_pushlstring(L, name, len);
	}
	luax_convobj(L, lua_gettop(L), "thread", "getThread");
	lua_getglobal(L, "love");
	lua_pushvalue(L, -2);
	lua_setfield(L, -2, "_curthread");
	if (luaL_dostring(L, comm->getCode()) == 1)
	{
		{
			Lock lock((Mutex *) comm->mutex);
			Variant *v = new Variant(lua_tostring(L, -1), lua_strlen(L, -1));
			comm->setValue("error", v);
			v->release();
		}
		((Conditional *) comm->cond)->broadcast();
	}
	lua_close(L);
}

ThreadData::ThreadData(const char *name, size_t len, const char *code, void *mutex, void *cond)
	: mutex(mutex), cond(cond), len(len)
{
	this->name = new char[len+1];
	memset(this->name, 0, len+1);
	memcpy(this->name, name, len);
	if (code)
	{
		len = strlen(code);
		this->code = new char[len+1];
		memset(this->code, 0, len+1);
		memcpy(this->code, code, len);
	}
	else
		this->code = 0;
}

ThreadData::~ThreadData()
{
	delete[] name;
	delete[] code;
}

const char *ThreadData::getCode()
{
	return code;
}

const char *ThreadData::getName(size_t *len)
{
	if (len)
		 *len = this->len;
	return name;
}

Variant *ThreadData::getValue(const std::string &name)
{
	if (shared.count(name) == 0)
		return 0;
	return shared[name];
}

void ThreadData::clearValue(const std::string &name)
{
	if (shared.count(name) == 0)
		return;
	shared[name]->release();
	shared.erase(name);
}

void ThreadData::setValue(const std::string &name, Variant *v)
{
	if (shared.count(name) != 0)
		shared[name]->release();
	v->retain();
	shared[name] = v;
}

std::vector<std::string> ThreadData::getKeys()
{
	std::vector<std::string> keys;
	for (std::map<std::string, Variant *>::iterator it = shared.begin(); it != shared.end(); it++)
	{
		keys.push_back(it->first);
	}
	return keys;
}

Thread::Thread(love::thread::ThreadModule *module, const std::string &name, love::Data *data)
	: handle(0), module(module), name(name), isThread(true)
{
	module->retain();
	unsigned int len = data->getSize();
	this->data = new char[len+1];
	memset(this->data, 0, len+1);
	memcpy(this->data, data->getData(), len);
	mutex = new Mutex();
	cond = new Conditional();
	comm = new ThreadData(name.c_str(), name.length(), this->data, mutex, cond);
}

Thread::Thread(love::thread::ThreadModule *module, const std::string &name)
	: handle(0), module(module), name(name), data(0), isThread(false)
{
	module->retain();
	mutex = new Mutex();
	cond = new Conditional();
	comm = new ThreadData(name.c_str(), name.length(), NULL, mutex, cond);
}

Thread::~Thread()
{
	if (data)
		delete[] data;
	delete comm;
	module->unregister(name);
	delete mutex;
	delete cond;
	module->release();
}

void Thread::start()
{
	if (!handle && isThread)
	{
		handle = new ThreadThread(comm);
		handle->start();
	}
}

void Thread::kill()
{
	if (handle)
	{
		Lock lock((Mutex *) _gcmutex);
		handle->kill();
		delete handle;
		handle = 0;
	}
}

void Thread::wait()
{
	if (handle)
	{
		handle->wait();
		delete handle;
		handle = 0;
	}
}

void Thread::lock()
{
	mutex->lock();
}

void Thread::unlock()
{
	mutex->unlock();
}

std::string Thread::getName()
{
	return name;
}

Variant *Thread::get(const std::string &name)
{
	Variant *v = comm->getValue(name);
	if (v)
		v->retain();
	return v;
}

std::vector<std::string> Thread::getKeys()
{
	return comm->getKeys();
}

Variant *Thread::demand(const std::string &name)
{
	Variant *v = comm->getValue(name);
	while (!v)
	{
		if (comm->getValue("error"))
			return 0;
		cond->wait(mutex);
		v = comm->getValue(name);
	}
	v->retain();
	return v;
}

void Thread::clear(const std::string &name)
{
	comm->clearValue(name);
}

void Thread::set(const std::string &name, Variant *v)
{
	lock(); //this function explicitly locks
	comm->setValue(name, v); //because we need
	unlock(); //it to unlock here for the cond
	cond->broadcast();
}

ThreadModule::ThreadModule()
{
	threads["main"] = new Thread(this, "main");
}

ThreadModule::~ThreadModule()
{
	for (threadlist_t::iterator i = threads.begin(); i != threads.end(); i++)
	{
		i->second->kill();
		delete i->second;
	}
}

Thread *ThreadModule::newThread(const std::string &name, love::Data *data)
{
	if (threads.count(name) != 0)
		return 0;
	Thread *t = new Thread(this, name, data);
	threads[name] = t;
	return t;
}

Thread *ThreadModule::getThread(const std::string &name)
{
	if (threads.count(name) == 0)
		return 0;
	threadlist_t::iterator i = threads.find(name);
	return i->second;
}

void ThreadModule::getThreads(Thread **list)
{
	int c = 0;
	for (threadlist_t::iterator i = threads.begin(); i != threads.end(); i++, c++)
	{
		list[c] = i->second;
	}
}

unsigned ThreadModule::getThreadCount() const
{
	return threads.size();
}

void ThreadModule::unregister(const std::string &name)
{
	if (threads.count(name) == 0)
		return;
	threadlist_t::iterator i = threads.find(name);
	// FIXME: shouldn't the thread be deleted?
	threads.erase(i);
}

const char *ThreadModule::getName() const
{
	return "love.thread.sdl";
}

} // thread
} // love