Re: report on the Lua in the Gaming Industry Roundtable at GDC 2004

[Mark Hamburg <mhamburg@...>]

on 4/16/04 6:22 AM, Edgar Toernig at froese@gmx.de wrote:

> The C<->Lua transition is normally cheap.  Not very different from a
> function call within Lua.  But what *could* be expensive is lua_pcall.
> The problem with lua_pcall is that it uses setjmp/longjmp which
> performs a system call on some systems (those which preserve signal
> masks).  You could either try _setjmp/_longjmp instead or use lua_call
> and catch errors elsewhere (may become difficult with C++).
> Additionally, lua_call instead of lua_pcall would remove stack frames
> 5, 6, and 7 from the above trace.

You could also revise luaD_rawrunprotected and luaD_throw to use C++
exceptions. (Covered previously on this list.) Then Lunar wouldn't need to
use pcall to catch any errors since they would be reported just like other
C++ errors.

Mark

P.S. lua_lock and lua_unlock for multithreaded execution become a noticeable
issue in Lua/C and C/Lua transitions.