编译使用 lua api 的 c 语言程序
gcc temp.c -o temp -llua -lm -ldl
生成动态链接库供 lua 程序调用
gcc temp.c -o temp.so -fPIV -shared
LUA_API
定义
/*
@@ LUA_API is a mark for all core API functions.
@@ LUALIB_API is a mark for all auxiliary library functions.
@@ LUAMOD_API is a mark for all standard library opening functions.
** CHANGE them if you need to define those functions in some special way.
** For instance, if you want to create one Windows DLL with the core and
** the libraries, you may want to use the following definition (define
** LUA_BUILD_AS_DLL to get it).
*/
#if defined(LUA_BUILD_AS_DLL) /* { */
#if defined(LUA_CORE) || defined(LUA_LIB) /* { */
#define LUA_API __declspec(dllexport)
#else /* }{ */
#define LUA_API __declspec(dllimport)
#endif /* } */
#else /* }{ */
#define LUA_API extern
#endif /* } */
/* more often than not the libs go together with the core */
#define LUALIB_API LUA_API
#define LUAMOD_API LUALIB_API
函数开头有 LUA_API:
- LUA_API : 标识核心 API 函数
- LUALIB_API : 标识辅助库函数
- LUAMOD_API : 标识标准库函数
- 有特殊需求可以自行修改。默认的，LUA_API、LUALIB_API、LUAMOD_API 是一样的
lua_lock 和 lua_unlock
定义
/*
** macros that are executed whenever program enters the Lua core
** ('lua_lock') and leaves the core ('lua_unlock')
*/
#if !defined(lua_lock)
#define lua_lock(L) ((void) 0)
#define lua_unlock(L) ((void) 0)
#endif
If you port Lua to another platform, you are "allowed" to overwrite lua_lock with your own definition; and this definition should essentially be a mutex, to disallow cross-thread operations on the same Lua objects. Essentially, when implemented, it should act similarly to Python's Global Interpreter Lock (GIL).
当需要将 Lua 移植到其他平台时，可以重写 lua_lock。必须注意的是，为了避免线程间对同一 Lua 对象的操作，lua_lock 的定义必须是互斥的，且其实现中其行为应该和 Python 的全局解释器锁（GIL）类似。
lua_lock 和 lua_unlock 主要用于线程间通信的情况，一般情况下我们不需要考虑，Lua 官方也对其做了保留，如果有需要涉及到多线程操作，则需开发者自行实现互斥行为。
参考链接
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