Overhead of luaJIT_setmode(L, -1, LUAJIT_MODE_WRAPCFUNC|LUAJIT_MODE_ON)
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- Subject: Overhead of luaJIT_setmode(L, -1, LUAJIT_MODE_WRAPCFUNC|LUAJIT_MODE_ON)
- From: Konstantin Osipov <kostja.osipov@...>
- Date: 2011年12月16日 15:49:13 +0400
Hello,
what is the overhead of luaJIT_setmode(LUAJIT_MODE_WRAPFUNC)?
Can I call it on every invocation of a certain C function?
My story: I call C++ code from Lua, and it throws C++ exceptions.
Moreover, I set lua_atpanic(L, box_lua_panic) to throw C++
exception as well.
This works very well in my scenario, since my C++ code can call
back Lua code, and vice versa. But in a way, I broke 'pcall' Lua
built-in.
Whenever I use it now, and there is an error I get:
false,
"C++ exception"
pair back.
Since I need something more informative than "C++ exception",
I decided the best solution is to re-implement 'pcall' built-in.
One way to re-implement is to turn on WRAPFUNC every time
pcall() is called. Is this a good solution?
An alternative solution would look like:
int my_pcall(lua_State *L)
{
try {
lua_call(L, lua_gettop(L), LUA_MULTRET);
lua_pushboolean(L, true); /* push completion status */
lua_insert(L, 1); /* move 'true' to stack start */
} catch (ClientError *e) {
lua_settop(L, 0); /* pop any possible garbage */
lua_pushboolean(L, 0); /* completion status */
lua_pushstring(L, e->errmsg); /* error message */
}
return lua_gettop(L);
}
Any comments on the matter are greatly appreciated,
--
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http://tarantool.org
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