�Ʒ�� BLOG: Lua ��д C ��չ��ʱ�õ��һЩ��

��췽��ͬ��ʵ��һЩ lua ��⣬��Ҫ�ǹ�� C ��չ��ġ��Ҿ��Щ��ԵĶ��ֵͦ�ø��ҷ��һ�£��ô��дƪ blog �ɡ�

ͨ��C ��չ�� C ��һЩ��Ҫ�� lua ״̬��С�Lua �ṩ�ķ��Ƿ�� ע�� С��ĵ��ԣ��Ϊ Lua ��ע��ȫ�ֹ��ģ�ѡ�� key ��ʱ��Ҫǧ��С��ˡ�� key �Ѿ�� reference ϵͳ�õ��ˣ�һ��ǻ��ַ�� key ��

�� C ��ѹ��ַ��Ч�ʲ��ߣ��Ϊ�ⲿ�ַ��״̬��ʱ��Ҫ�� hash ��Ψһ��¡��ڱ��ֱ��ѹ��ַ��⣬��ǰд��һƪ blog ̸��( btw, ��ǰ�Ǹ��Ҳ��õĽ��ǿ��Ϊһ��ο�� :)

��뵽����ܱ�֤Ψһ�Ե� key ��һ�� light userdata ��һ�㣬�ڲο��ֲ��Լ� Programming in Lua �ж��ᵽ��

��ǿ��һ�� static ��ĵ�ַ��Ϊ key ��ע��Ҫ��ֵ��´��룺

static const void *key = 0; lua_pushlightuserdata(L, (void *)&key); lua_pushnumber(L, myNumber); lua_settable(L, LUA_REGISTRYINDEX);

��Ͱ�һ�� C �е�� myNumber ��ע��ˡ��Ժ�Ҫ��Ȼ��Ĵ��룺

lua_pushlightuserdata(L, (void *)&key); lua_gettable(L, LUA_REGISTRYINDEX); myNumber = lua_tonumber(L, -1);

��õ��һ�� static ��ĵ�ַ�� key ��Ծ��Բ��ͱ��չ��ͻ��һ��ȱ�㣬�� key ��һ��ȫ�ֱ��ʽ��֣��̫��ۡ��ң��õ�� key ��ʱ�򣬲��ô��õ��Ҫô�� extern �� key ��Ҫô��Ҫ��һ��ʽ��¶һ��õ�� key ��Ч��ϻ��ִ��һЩ�ۿ��ˡ�

��ھ͸��һ��еķ��þ��⣺ �Ǿ��ǣ��һ�� light userdata �� key �� key ��ٺ�һ��Ψһ�ַ��ÿ��Ҫ�õ� key ָ��ĺ��Щд��

static const void *key = 0; if (key==0) { lua_getfield (L, LUA_REGISTRYINDEX, "MyExtensionLibrary"); key=lua_touserdata(L,-1); lua_pop(L,1); if (key==0) { key=(void*)&key; lua_pushlightuserdata(L,key); lua_setfield(L, LUA_REGISTRYINDEX, "MyExtensionLibrary"); } }

��ǾͿ��Զ� key ��һ�ζ��Գ�ʼ��ˡ��ֻ��ʾ��ʼ��ֿ��һ��ͺ귽��ظ��á�

˳��һ��ױ��Ե�С��ɣ� ��ͨ�� full userdata ��ʵ�ָ��ӵ� C �ṹ�� C++ �еĶ��󣬰�� Lua �С��Ҫ�� Lua �е�һ��ݹ�� userdata �ϡ�Ϊ�� Lua �� gc ��̿��ȷ�Ĺ��Ҫ��һЩ��Ĺ��

��²ߵĽ��ǣ�� userdata �б��һ��ص� Lua �� reference ��Ȼ�� userdata ��һ��Ԫ��ʵ��һ�� gc ��Ԫ�� gc �¼��ʱ��unref �� Lua ��ĵط��ڣ�ʵ�ֹ��ڷ��Ҹ� gc ��̴��ִ�п��

�в��ע��б��һ��ӳ��Ϊ weak table ��ÿ�� userdata �� userdata Ϊ key ��Ӱ��б�� Lua ��ݡ��ô��յĹ��̾Ϳ�� Lua ��ά��ˡ��䲻��֮��ڣ�ÿ�� C �� userdata ��ص� Lua ��ʱ��Ҫ��õ�ע��е��ӳ��õĵ��ƪ blog ǰ�벿��ᵽ�Ķ��

��ʵ��һ��ϲߣ�Lua ��Ƶ�ʱ��Ϳ��ǵ��ˡ��Ǿ�� full userdata ��ӵ��һ��Ļ�� Lua ��塣��ȴ�� gc ��ֻ��Ҫ�� lua_getfenv �� lua_setfenv ��д��͹�� :D

Comments

��Ҫע��һ��ɱ��C/C++��lua Ӧ��Ҫ��ôʵ�ְ�

Posted by: ׿С�� | (11) November 21, 2017 02:56 PM

I just wanted to comment your blog and say that I really enjoyed reading your blog post here. It was very informative and I also digg the way you write! Keep it up and I'll be back to read more soon mate

Posted by: microsoft office 2007 | (10) November 20, 2010 11:05 AM

��õİ취һ�㶼�ǰ�c++��ĵ�ַ��lightuserdata��õ�ʱ��ֱ��ȡ��ָ��Ϊ��һ�㶼��ĳ�Ա��ⲿ��ʱ��ڲ�˳��û��ע��lua�

Posted by: cloud | (9) September 23, 2010 03:40 AM

���Ҫ�� windows api��֧�֡� ��û��ֳɵ� ��dll�ӿڣ� ��һ��ң��ǳ��ĸ�л��

Posted by: struct | (8) November 24, 2006 04:12 PM

��һ��lua��⣬ ��lua��Ӧ�ó��һ�𣬳��е�ʱ��lua�ű�� lua�ű��Լ�д��Ϣ? ��Ϣ��

Posted by: struct | (7) November 24, 2006 04:09 PM

��ǰûע��`lua_getfenv`�� `lua_setfenv`��ֿ��ʵ��pascal��with object do�Ĺ��

Posted by: N/A | (6) November 22, 2006 07:20 PM

лл�ṩ��

Posted by: 11ff | (5) November 22, 2006 01:38 PM

lua��