delta/mlua
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Wiki Activity

Even better optimization after 14d5c2c887

Browse source
This commit is contained in:
Alex Orlenko 2021-06-20 19:48:33 +01:00
parent 42b396d0d1
commit 9e3b0ecc1e
No known key found for this signature in database
GPG key ID: 4C150C250863B96D
1 changed files with 57 additions and 31 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

88
src/lua.rs
View file

@ -2289,7 +2289,7 @@ impl<'lua, T: AsRef<[u8]> + ?Sized> AsChunk<'lua> for T {
}
// An optimized version of `callback_error` that does not allocate `WrappedError+Panic` userdata
// and instead reuses first unsed and cached value from previous calls (or allocates new).
// and instead reuses unsed and cached values from previous calls (or allocates new).
// It assumes that ephemeral `Lua` struct is passed as a 2nd upvalue.
pub unsafe fn callback_error2<F, R>(state: *mut ffi::lua_State, f: F) -> R
where
@ -2310,47 +2310,73 @@ where
cstr!("not enough stack space for callback error handling"),
);
enum PreallocatedError {
New(*mut c_void),
Cached(i32),
}
// We cannot shadow Rust errors with Lua ones, so we need to obtain pre-allocated memory
// to store a wrapped error or panic *before* we proceed.
let lua = get_userdata::<Lua>(state, upvalue_idx2);
let ud = {
let prealloc_err = {
let mut extra = mlua_expect!((*lua).extra.lock(), "extra is poisoned");
if let Some(index) = extra.prealloc_wrapped_errors.pop() {
// Move pre-allocatd WrappedError+Panic from the ref thread to the current thread
ffi::lua_pushvalue(extra.ref_thread, index);
ffi::lua_xmove(extra.ref_thread, state, 1);
ffi::lua_pushnil(extra.ref_thread);
ffi::lua_replace(extra.ref_thread, index);
extra.ref_free.push(index);
ffi::lua_touserdata(state, -1)
} else {
ffi::lua_newuserdata(
state,
mem::size_of::<WrappedError>().max(mem::size_of::<WrappedPanic>()),
)
match extra.prealloc_wrapped_errors.pop() {
Some(index) => PreallocatedError::Cached(index),
None => {
let size = mem::size_of::<WrappedError>().max(mem::size_of::<WrappedPanic>());
let ud = ffi::lua_newuserdata(state, size);
ffi::lua_rotate(state, 1, 1);
PreallocatedError::New(ud)
}
}
};
let get_prealloc_err = || {
let mut extra = mlua_expect!((*lua).extra.lock(), "extra is poisoned");
match prealloc_err {
PreallocatedError::New(ud) => {
ffi::lua_settop(state, 1);
ud
}
PreallocatedError::Cached(index) => {
ffi::lua_settop(state, 0);
ffi::lua_pushvalue(extra.ref_thread, index);
ffi::lua_xmove(extra.ref_thread, state, 1);
ffi::lua_pushnil(extra.ref_thread);
ffi::lua_replace(extra.ref_thread, index);
extra.ref_free.push(index);
ffi::lua_touserdata(state, -1)
}
}
};
ffi::lua_rotate(state, 1, 1);
match catch_unwind(AssertUnwindSafe(|| f(nargs))) {
Ok(Ok(r)) => {
let extra = mlua_expect!((*lua).extra.lock(), "extra is poisoned");
if extra.prealloc_wrapped_errors.len() < 10 {
// Return unused WrappedError+Panic to the cache
ffi::lua_rotate(state, 1, -1);
ffi::lua_xmove(state, extra.ref_thread, 1);
let (index, mut extra) = ref_stack_pop(extra);
extra.prealloc_wrapped_errors.push(index);
} else {
ffi::lua_remove(state, 1);
// Return unused WrappedError+Panic to the cache
let mut extra = mlua_expect!((*lua).extra.lock(), "extra is poisoned");
match prealloc_err {
PreallocatedError::New(_) if extra.prealloc_wrapped_errors.len() < 16 => {
ffi::lua_rotate(state, 1, -1);
ffi::lua_xmove(state, extra.ref_thread, 1);
let (index, mut extra) = ref_stack_pop(extra);
extra.prealloc_wrapped_errors.push(index);
}
PreallocatedError::New(_) => {
ffi::lua_remove(state, 1);
}
PreallocatedError::Cached(index) if extra.prealloc_wrapped_errors.len() < 16 => {
extra.prealloc_wrapped_errors.push(index);
}
PreallocatedError::Cached(index) => {
ffi::lua_pushnil(extra.ref_thread);
ffi::lua_replace(extra.ref_thread, index);
extra.ref_free.push(index);
}
}
r
}
Ok(Err(err)) => {
ffi::lua_settop(state, 1);
let wrapped_error = ud as *mut WrappedError;
let wrapped_error = get_prealloc_err() as *mut WrappedError;
ptr::write(wrapped_error, WrappedError(err));
get_gc_metatable_for::<WrappedError>(state);
ffi::lua_setmetatable(state, -2);
@ -2370,8 +2396,8 @@ where
ffi::lua_error(state)
}
Err(p) => {
ffi::lua_settop(state, 1);
ptr::write(ud as *mut WrappedPanic, WrappedPanic(Some(p)));
let wrapped_panic = get_prealloc_err() as *mut WrappedPanic;
ptr::write(wrapped_panic, WrappedPanic(Some(p)));
get_gc_metatable_for::<WrappedPanic>(state);
ffi::lua_setmetatable(state, -2);
ffi::lua_error(state)