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Revert "Move away from metatable hashmap cache to direct keys"

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This reverts commit adbc9ccc9b.
This commit is contained in:
Alex Orlenko 2021-07-08 18:40:14 +01:00
parent 8ff610529b
commit 60822d12d2
No known key found for this signature in database
GPG key ID: 4C150C250863B96D
3 changed files with 82 additions and 93 deletions
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68
src/lua.rs
View file

@ -27,10 +27,10 @@ use crate::userdata::{
};
use crate::util::{
self, assert_stack, callback_error, check_stack, get_destructed_userdata_metatable,
get_gc_metatable, get_gc_userdata, get_main_state, get_userdata, get_wrapped_error,
init_error_registry, init_gc_metatable, init_userdata_metatable, pop_error, push_gc_userdata,
push_string, push_table, push_userdata, push_wrapped_error, rawset_field, safe_pcall,
safe_xpcall, StackGuard, WrappedError, WrappedPanic, WRAPPED_ERROR_MT, WRAPPED_PANIC_MT,
get_gc_metatable_for, get_gc_userdata, get_main_state, get_userdata, get_wrapped_error,
init_error_registry, init_gc_metatable_for, init_userdata_metatable, pop_error,
push_gc_userdata, push_string, push_table, push_userdata, push_wrapped_error, rawset_field,
safe_pcall, safe_xpcall, StackGuard, WrappedError, WrappedPanic,
};
use crate::value::{FromLua, FromLuaMulti, MultiValue, Nil, ToLua, ToLuaMulti, Value};
@ -148,23 +148,11 @@ impl LuaOptions {
}
}
static CALLBACK_MT: u8 = 0;
static CALLBACK_UPVALUE_MT: u8 = 0;
pub(crate) static EXTRA_REGISTRY_KEY: u8 = 0;
#[cfg(feature = "async")]
static ASYNC_CALLBACK_MT: u8 = 0;
#[cfg(feature = "async")]
static ASYNC_CALLBACK_UPVALUE_MT: u8 = 0;
#[cfg(feature = "async")]
static ASYNC_POLL_UPVALUE_MT: u8 = 0;
#[cfg(feature = "async")]
pub(crate) static WAKER_MT: u8 = 0;
#[cfg(feature = "async")]
pub(crate) static WAKER_REGISTRY_KEY: u8 = 0;
#[cfg(feature = "async")]
pub(crate) static ASYNC_POLL_PENDING: u8 = 0;
#[cfg(feature = "async")]
pub(crate) static WAKER_REGISTRY_KEY: u8 = 0;
pub(crate) static EXTRA_REGISTRY_KEY: u8 = 0;
/// Requires `feature = "send"`
#[cfg(feature = "send")]
@ -409,18 +397,17 @@ impl Lua {
// Create the internal metatables and place them in the registry
// to prevent them from being garbage collected.
init_gc_metatable::<Callback>(state, &CALLBACK_MT, None)?;
init_gc_metatable::<CallbackUpvalue>(state, &CALLBACK_UPVALUE_MT, None)?;
init_gc_metatable_for::<Callback>(state, None)?;
init_gc_metatable_for::<CallbackUpvalue>(state, None)?;
#[cfg(feature = "async")]
{
init_gc_metatable::<AsyncCallback>(state, &ASYNC_CALLBACK_MT, None)?;
#[rustfmt::skip]
init_gc_metatable::<AsyncCallbackUpvalue>(state, &ASYNC_CALLBACK_UPVALUE_MT, None)?;
init_gc_metatable::<AsyncPollUpvalue>(state, &ASYNC_POLL_UPVALUE_MT, None)?;
init_gc_metatable::<Option<Waker>>(state, &WAKER_MT, None)?;
init_gc_metatable_for::<AsyncCallback>(state, None)?;
init_gc_metatable_for::<AsyncCallbackUpvalue>(state, None)?;
init_gc_metatable_for::<AsyncPollUpvalue>(state, None)?;
init_gc_metatable_for::<Option<Waker>>(state, None)?;
// Create empty Waker slot
push_gc_userdata::<Option<Waker>>(state, &WAKER_MT, None)?;
push_gc_userdata::<Option<Waker>>(state, None)?;
protect_lua!(state, 1, 0, state => {
let waker_key = &WAKER_REGISTRY_KEY as *const u8 as *const c_void;
ffi::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, waker_key);
@ -1622,9 +1609,7 @@ impl Lua {
let err = err.clone();
ffi::lua_pop(state, 1);
Value::Error(err)
} else if let Some(panic) =
get_gc_userdata::<WrappedPanic>(state, -1, &WRAPPED_PANIC_MT).as_mut()
{
} else if let Some(panic) = get_gc_userdata::<WrappedPanic>(state, -1).as_mut() {
if let Some(panic) = (*panic).0.take() {
ffi::lua_pop(state, 1);
resume_unwind(panic);
@ -1883,12 +1868,8 @@ impl Lua {
check_stack(self.state, 4)?;
let lua = self.clone();
push_gc_userdata(
self.state,
&CALLBACK_UPVALUE_MT,
CallbackUpvalue { lua, func },
)?;
let func = mem::transmute(func);
push_gc_userdata(self.state, CallbackUpvalue { lua, func })?;
protect_lua!(self.state, 1, 1, state => {
ffi::lua_pushcclosure(state, call_callback, 1);
})?;
@ -1939,7 +1920,7 @@ impl Lua {
let fut = ((*upvalue).func)(lua, args);
let lua = lua.clone();
push_gc_userdata(state, &ASYNC_POLL_UPVALUE_MT, AsyncPollUpvalue { lua, fut })?;
push_gc_userdata(state, AsyncPollUpvalue { lua, fut })?;
protect_lua!(state, 1, 1, state => {
ffi::lua_pushcclosure(state, poll_future, 1);
})?;
@ -1970,7 +1951,7 @@ impl Lua {
// Try to get an outer poll waker
let waker_key = &WAKER_REGISTRY_KEY as *const u8 as *const c_void;
ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, waker_key);
let waker = match get_gc_userdata::<Option<Waker>>(state, -1, &WAKER_MT).as_ref() {
let waker = match get_gc_userdata::<Option<Waker>>(state, -1).as_ref() {
Some(Some(waker)) => waker.clone(),
_ => noop_waker(),
};
@ -2004,11 +1985,8 @@ impl Lua {
check_stack(self.state, 4)?;
let lua = self.clone();
push_gc_userdata(
self.state,
&ASYNC_CALLBACK_UPVALUE_MT,
AsyncCallbackUpvalue { lua, func },
)?;
let func = mem::transmute(func);
push_gc_userdata(self.state, AsyncCallbackUpvalue { lua, func })?;
protect_lua!(self.state, 1, 1, state => {
ffi::lua_pushcclosure(state, call_callback, 1);
})?;
@ -2438,7 +2416,7 @@ where
Ok(Err(err)) => {
let wrapped_error = get_prealloc_err() as *mut WrappedError;
ptr::write(wrapped_error, WrappedError(err));
get_gc_metatable(state, &WRAPPED_ERROR_MT);
get_gc_metatable_for::<WrappedError>(state);
ffi::lua_setmetatable(state, -2);
// Convert to CallbackError and attach traceback
@ -2458,7 +2436,7 @@ where
Err(p) => {
let wrapped_panic = get_prealloc_err() as *mut WrappedPanic;
ptr::write(wrapped_panic, WrappedPanic(Some(p)));
get_gc_metatable(state, &WRAPPED_PANIC_MT);
get_gc_metatable_for::<WrappedPanic>(state);
ffi::lua_setmetatable(state, -2);
ffi::lua_error(state)
}

6
src/thread.rs
View file

@ -13,7 +13,7 @@ use crate::function::Function;
#[cfg(feature = "async")]
use {
crate::{
lua::{ASYNC_POLL_PENDING, WAKER_MT, WAKER_REGISTRY_KEY},
lua::{ASYNC_POLL_PENDING, WAKER_REGISTRY_KEY},
util::get_gc_userdata,
value::Value,
},
@ -362,7 +362,7 @@ impl WakerGuard {
let waker_key = &WAKER_REGISTRY_KEY as *const u8 as *const c_void;
ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, waker_key);
let waker_slot = get_gc_userdata::<Option<Waker>>(state, -1, &WAKER_MT).as_mut();
let waker_slot = get_gc_userdata::<Option<Waker>>(state, -1).as_mut();
let old = mlua_expect!(waker_slot, "Waker is destroyed").replace(waker);
Ok(WakerGuard(state, old))
@ -380,7 +380,7 @@ impl Drop for WakerGuard {
let waker_key = &WAKER_REGISTRY_KEY as *const u8 as *const c_void;
ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, waker_key);
let waker_slot = get_gc_userdata::<Option<Waker>>(state, -1, &WAKER_MT).as_mut();
let waker_slot = get_gc_userdata::<Option<Waker>>(state, -1).as_mut();
mem::swap(mlua_expect!(waker_slot, "Waker is destroyed"), &mut self.1);
}
}

101
src/util.rs
View file

@ -1,18 +1,21 @@
use std::any::Any;
use std::any::{Any, TypeId};
use std::collections::HashMap;
use std::error::Error as StdError;
use std::fmt::Write;
use std::os::raw::{c_char, c_int, c_void};
use std::panic::{catch_unwind, resume_unwind, AssertUnwindSafe};
use std::sync::Arc;
use std::sync::{Arc, Mutex};
use std::{mem, ptr, slice};
use once_cell::sync::Lazy;
use crate::error::{Error, Result};
use crate::ffi;
pub(crate) static WRAPPED_ERROR_MT: u8 = 0;
pub(crate) static WRAPPED_PANIC_MT: u8 = 0;
static DESTRUCTED_USERDATA_MT: u8 = 0;
static ERROR_PRINT_BUFFER_KEY: u8 = 0;
static METATABLE_CACHE: Lazy<Mutex<HashMap<TypeId, u8>>> = Lazy::new(|| {
// The capacity must(!) be greater than number of stored keys
Mutex::new(HashMap::with_capacity(32))
});
// Checks that Lua has enough free stack space for future stack operations. On failure, this will
// panic with an internal error message.
@ -196,9 +199,7 @@ pub unsafe fn pop_error(state: *mut ffi::lua_State, err_code: c_int) -> Error {
if let Some(err) = get_wrapped_error(state, -1).as_ref() {
ffi::lua_pop(state, 1);
err.clone()
} else if let Some(panic) =
get_gc_userdata::<WrappedPanic>(state, -1, &WRAPPED_PANIC_MT).as_mut()
{
} else if let Some(panic) = get_gc_userdata::<WrappedPanic>(state, -1).as_mut() {
if let Some(p) = (*panic).0.take() {
resume_unwind(p);
} else {
@ -297,24 +298,20 @@ pub unsafe fn take_userdata<T>(state: *mut ffi::lua_State) -> T {
// Pushes the userdata and attaches a metatable with __gc method.
// Internally uses 3 stack spaces, does not call checkstack.
pub unsafe fn push_gc_userdata<T>(state: *mut ffi::lua_State, key: *const u8, t: T) -> Result<()> {
pub unsafe fn push_gc_userdata<T: Any>(state: *mut ffi::lua_State, t: T) -> Result<()> {
push_userdata(state, t)?;
get_gc_metatable(state, key);
get_gc_metatable_for::<T>(state);
ffi::lua_setmetatable(state, -2);
Ok(())
}
// Uses 2 stack spaces, does not call checkstack
pub unsafe fn get_gc_userdata<T>(
state: *mut ffi::lua_State,
index: c_int,
key: *const u8,
) -> *mut T {
pub unsafe fn get_gc_userdata<T: Any>(state: *mut ffi::lua_State, index: c_int) -> *mut T {
let ud = ffi::lua_touserdata(state, index) as *mut T;
if ud.is_null() || ffi::lua_getmetatable(state, index) == 0 {
return ptr::null_mut();
}
get_gc_metatable(state, key);
get_gc_metatable_for::<T>(state);
let res = ffi::lua_rawequal(state, -1, -2);
ffi::lua_pop(state, 2);
if res == 0 {
@ -528,7 +525,7 @@ where
let wrapped_error = ud as *mut WrappedError;
ptr::write(wrapped_error, WrappedError(err));
get_gc_metatable(state, &WRAPPED_ERROR_MT);
get_gc_metatable_for::<WrappedError>(state);
ffi::lua_setmetatable(state, -2);
// Convert to CallbackError and attach traceback
@ -548,7 +545,7 @@ where
Err(p) => {
ffi::lua_settop(state, 1);
ptr::write(ud as *mut WrappedPanic, WrappedPanic(Some(p)));
get_gc_metatable(state, &WRAPPED_PANIC_MT);
get_gc_metatable_for::<WrappedPanic>(state);
ffi::lua_setmetatable(state, -2);
ffi::lua_error(state)
}
@ -562,8 +559,8 @@ pub unsafe extern "C" fn error_traceback(state: *mut ffi::lua_State) -> c_int {
return 1;
}
if get_gc_userdata::<WrappedError>(state, -1, &WRAPPED_ERROR_MT).is_null()
&& get_gc_userdata::<WrappedPanic>(state, -1, &WRAPPED_PANIC_MT).is_null()
if get_gc_userdata::<WrappedError>(state, -1).is_null()
&& get_gc_userdata::<WrappedPanic>(state, -1).is_null()
{
let s = ffi::luaL_tolstring(state, -1, ptr::null_mut());
if ffi::lua_checkstack(state, ffi::LUA_TRACEBACK_STACK) != 0 {
@ -590,7 +587,7 @@ pub unsafe extern "C" fn safe_pcall(state: *mut ffi::lua_State) -> c_int {
ffi::lua_insert(state, 1);
ffi::lua_gettop(state)
} else {
if !get_gc_userdata::<WrappedPanic>(state, -1, &WRAPPED_PANIC_MT).is_null() {
if !get_gc_userdata::<WrappedPanic>(state, -1).is_null() {
ffi::lua_error(state);
}
ffi::lua_pushboolean(state, 0);
@ -604,7 +601,7 @@ pub unsafe extern "C" fn safe_xpcall(state: *mut ffi::lua_State) -> c_int {
unsafe extern "C" fn xpcall_msgh(state: *mut ffi::lua_State) -> c_int {
ffi::luaL_checkstack(state, 2, ptr::null());
if !get_gc_userdata::<WrappedPanic>(state, -1, &WRAPPED_PANIC_MT).is_null() {
if !get_gc_userdata::<WrappedPanic>(state, -1).is_null() {
1
} else {
ffi::lua_pushvalue(state, ffi::lua_upvalueindex(1));
@ -632,7 +629,7 @@ pub unsafe extern "C" fn safe_xpcall(state: *mut ffi::lua_State) -> c_int {
ffi::lua_insert(state, 2);
ffi::lua_gettop(state) - 1
} else {
if !get_gc_userdata::<WrappedPanic>(state, -1, &WRAPPED_PANIC_MT).is_null() {
if !get_gc_userdata::<WrappedPanic>(state, -1).is_null() {
ffi::lua_error(state);
}
ffi::lua_pushboolean(state, 0);
@ -667,14 +664,14 @@ pub unsafe fn get_main_state(state: *mut ffi::lua_State) -> Option<*mut ffi::lua
// Pushes a WrappedError to the top of the stack.
// Uses 3 stack spaces and does not call checkstack.
pub unsafe fn push_wrapped_error(state: *mut ffi::lua_State, err: Error) -> Result<()> {
push_gc_userdata::<WrappedError>(state, &WRAPPED_ERROR_MT, WrappedError(err))
push_gc_userdata::<WrappedError>(state, WrappedError(err))
}
// Checks if the value at the given index is a WrappedError, and if it is returns a pointer to it,
// otherwise returns null.
// Uses 2 stack spaces and does not call checkstack.
pub unsafe fn get_wrapped_error(state: *mut ffi::lua_State, index: c_int) -> *const Error {
let ud = get_gc_userdata::<WrappedError>(state, index, &WRAPPED_ERROR_MT);
let ud = get_gc_userdata::<WrappedError>(state, index);
if ud.is_null() {
return ptr::null();
}
@ -683,13 +680,23 @@ pub unsafe fn get_wrapped_error(state: *mut ffi::lua_State, index: c_int) -> *co
// Initialize the internal (with __gc method) metatable for a type T.
// Uses 6 stack spaces and calls checkstack.
pub unsafe fn init_gc_metatable<T>(
pub unsafe fn init_gc_metatable_for<T: Any>(
state: *mut ffi::lua_State,
key: *const u8,
customize_fn: Option<fn(*mut ffi::lua_State) -> Result<()>>,
) -> Result<()> {
check_stack(state, 6)?;
let type_id = TypeId::of::<T>();
let ref_addr = {
let mut mt_cache = mlua_expect!(METATABLE_CACHE.lock(), "cannot lock metatable cache");
mlua_assert!(
mt_cache.capacity() - mt_cache.len() > 0,
"out of metatable cache capacity"
);
mt_cache.insert(type_id, 0);
&mt_cache[&type_id] as *const u8
};
push_table(state, 0, 3)?;
ffi::lua_pushcfunction(state, userdata_destructor::<T>);
@ -703,14 +710,19 @@ pub unsafe fn init_gc_metatable<T>(
}
protect_lua!(state, 1, 0, |state| {
ffi::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, key as *const c_void)
ffi::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, ref_addr as *mut c_void)
})?;
Ok(())
}
pub unsafe fn get_gc_metatable(state: *mut ffi::lua_State, key: *const u8) {
ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, key as *const c_void);
pub unsafe fn get_gc_metatable_for<T: Any>(state: *mut ffi::lua_State) {
let type_id = TypeId::of::<T>();
let ref_addr = {
let mt_cache = mlua_expect!(METATABLE_CACHE.lock(), "cannot lock metatable cache");
mlua_expect!(mt_cache.get(&type_id), "gc metatable does not exist") as *const u8
};
ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, ref_addr as *const c_void);
}
// Initialize the error, panic, and destructed userdata metatables.
@ -759,9 +771,7 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
_ => {}
}
Ok(err_buf)
} else if let Some(panic) =
get_gc_userdata::<WrappedPanic>(state, -1, &WRAPPED_PANIC_MT).as_ref()
{
} else if let Some(panic) = get_gc_userdata::<WrappedPanic>(state, -1).as_ref() {
if let Some(ref p) = (*panic).0 {
let err_buf_key = &ERROR_PRINT_BUFFER_KEY as *const u8 as *const c_void;
ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, err_buf_key);
@ -792,18 +802,16 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
})
}
init_gc_metatable::<WrappedError>(
init_gc_metatable_for::<WrappedError>(
state,
&WRAPPED_ERROR_MT,
Some(|state| {
ffi::lua_pushcfunction(state, error_tostring);
rawset_field(state, -2, "__tostring")
}),
)?;
init_gc_metatable::<WrappedPanic>(
init_gc_metatable_for::<WrappedPanic>(
state,
&WRAPPED_PANIC_MT,
Some(|state| {
ffi::lua_pushcfunction(state, error_tostring);
rawset_field(state, -2, "__tostring")
@ -862,16 +870,16 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
ffi::lua_pop(state, 1);
protect_lua!(state, 1, 0, state => {
let key = &DESTRUCTED_USERDATA_MT as *const u8 as *const c_void;
ffi::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, key)
let destructed_metatable_key = &DESTRUCTED_USERDATA_METATABLE as *const u8 as *const c_void;
ffi::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, destructed_metatable_key)
})?;
// Create error print buffer
init_gc_metatable::<String>(state, &ERROR_PRINT_BUFFER_KEY, None)?;
push_gc_userdata(state, &ERROR_PRINT_BUFFER_KEY, String::new())?;
init_gc_metatable_for::<String>(state, None)?;
push_gc_userdata(state, String::new())?;
protect_lua!(state, 1, 0, state => {
let key = &ERROR_PRINT_BUFFER_KEY as *const u8 as *const c_void;
ffi::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, key)
let err_buf_key = &ERROR_PRINT_BUFFER_KEY as *const u8 as *const c_void;
ffi::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, err_buf_key)
})?;
Ok(())
@ -915,6 +923,9 @@ pub(crate) unsafe fn to_string(state: *mut ffi::lua_State, index: c_int) -> Stri
}
pub(crate) unsafe fn get_destructed_userdata_metatable(state: *mut ffi::lua_State) {
let key = &DESTRUCTED_USERDATA_MT as *const u8 as *const c_void;
let key = &DESTRUCTED_USERDATA_METATABLE as *const u8 as *const c_void;
ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, key);
}
static DESTRUCTED_USERDATA_METATABLE: u8 = 0;
static ERROR_PRINT_BUFFER_KEY: u8 = 0;