eqemu-server/libs/luabind/src/weak_ref.cpp
2019-10-12 21:07:06 -07:00

158 lines
3.7 KiB
C++

// Copyright (c) 2004 Daniel Wallin and Arvid Norberg
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
// ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
// TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
// PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
// SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
// ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
// ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
// OR OTHER DEALINGS IN THE SOFTWARE.
#define LUABIND_BUILDING
#include <algorithm>
#include <luabind/lua_include.hpp>
#include <luabind/config.hpp>
#include <luabind/weak_ref.hpp>
#include <cassert>
namespace luabind {
namespace
{
int weak_table_tag;
} // namespace unnamed
LUABIND_API void get_weak_table(lua_State* L)
{
lua_pushlightuserdata(L, &weak_table_tag);
lua_rawget(L, LUA_REGISTRYINDEX);
if (lua_isnil(L, -1))
{
lua_pop(L, 1);
lua_newtable(L);
// metatable
lua_newtable(L);
lua_pushliteral(L, "__mode");
lua_pushliteral(L, "v");
lua_rawset(L, -3);
// set metatable
lua_setmetatable(L, -2);
lua_pushlightuserdata(L, &weak_table_tag);
lua_pushvalue(L, -2);
lua_rawset(L, LUA_REGISTRYINDEX);
}
}
} // namespace luabind
namespace luabind
{
struct weak_ref::impl
{
impl(lua_State* main, lua_State* s, int index)
: count(0)
, state(main)
, ref(0)
{
get_weak_table(s);
lua_pushvalue(s, index);
ref = luaL_ref(s, -2);
lua_pop(s, 1);
}
~impl()
{
get_weak_table(state);
luaL_unref(state, -1, ref);
lua_pop(state, 1);
}
int count;
lua_State* state;
int ref;
};
weak_ref::weak_ref()
: m_impl(0)
{
}
weak_ref::weak_ref(lua_State* main, lua_State* L, int index)
: m_impl(new impl(main, L, index))
{
m_impl->count = 1;
}
weak_ref::weak_ref(weak_ref const& other)
: m_impl(other.m_impl)
{
if (m_impl) ++m_impl->count;
}
weak_ref::~weak_ref()
{
if (m_impl && --m_impl->count == 0)
{
delete m_impl;
}
}
weak_ref& weak_ref::operator=(weak_ref const& other)
{
weak_ref(other).swap(*this);
return *this;
}
void weak_ref::swap(weak_ref& other)
{
std::swap(m_impl, other.m_impl);
}
int weak_ref::id() const
{
assert(m_impl);
return m_impl->ref;
}
// L may not be the same pointer as
// was used when creating this reference
// since it may be a thread that shares
// the same globals table.
void weak_ref::get(lua_State* L) const
{
assert(m_impl);
assert(L);
get_weak_table(L);
lua_rawgeti(L, -1, m_impl->ref);
lua_remove(L, -2);
}
lua_State* weak_ref::state() const
{
assert(m_impl);
return m_impl->state;
}
} // namespace luabind