mirror of
https://github.com/love2d/love.git
synced 2026-08-12 08:30:56 +02:00
Alex Szpakowski
84 lines
2.1 KiB
C++
84 lines
2.1 KiB
C++
/**
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* Copyright (c) 2006-2021 LOVE Development Team
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*
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* This software is provided 'as-is', without any express or implied
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* warranty. In no event will the authors be held liable for any damages
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* arising from the use of this software.
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*
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* Permission is granted to anyone to use this software for any purpose,
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* including commercial applications, and to alter it and redistribute it
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* freely, subject to the following restrictions:
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*
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* 1. The origin of this software must not be misrepresented; you must not
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* claim that you wrote the original software. If you use this software
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* in a product, an acknowledgment in the product documentation would be
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* appreciated but is not required.
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* 2. Altered source versions must be plainly marked as such, and must not be
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* misrepresented as being the original software.
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* 3. This notice may not be removed or altered from any source distribution.
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**/
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#include "Reference.h"
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#include "runtime.h"
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namespace love
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{
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const char REFERENCE_TABLE_NAME[] = "love-references";
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Reference::Reference()
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: pinnedL(nullptr)
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, idx(LUA_REFNIL)
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{
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}
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Reference::Reference(lua_State *L)
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: pinnedL(nullptr)
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, idx(LUA_REFNIL)
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{
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ref(L);
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}
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Reference::~Reference()
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{
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unref();
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}
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void Reference::ref(lua_State *L)
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{
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unref(); // Previously created reference needs to be cleared
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pinnedL = luax_getpinnedthread(L);
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luax_insist(L, LUA_REGISTRYINDEX, REFERENCE_TABLE_NAME);
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lua_insert(L, -2); // Move reference table behind value.
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idx = luaL_ref(L, -2);
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lua_pop(L, 1);
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}
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void Reference::unref()
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{
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if (idx != LUA_REFNIL)
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{
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// We use a pinned thread/coroutine for the Lua state because we know it
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// hasn't been garbage collected and is valid, as long as the whole lua
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// state is still open.
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luax_insist(pinnedL, LUA_REGISTRYINDEX, REFERENCE_TABLE_NAME);
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luaL_unref(pinnedL, -1, idx);
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lua_pop(pinnedL, 1);
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idx = LUA_REFNIL;
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}
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}
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void Reference::push(lua_State *L)
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{
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if (idx != LUA_REFNIL)
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{
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luax_insist(L, LUA_REGISTRYINDEX, REFERENCE_TABLE_NAME);
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lua_rawgeti(L, -1, idx);
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lua_remove(L, -2);
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}
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else
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lua_pushnil(L);
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}
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} // love
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