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Merge pull request #139 from mkpankov/drop

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Drop closure environment
This commit is contained in:
tomaka 2017-04-15 18:16:21 +02:00 committed by GitHub
commit 05ab876b85
1 changed files with 78 additions and 0 deletions
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78
hlua/src/functions_write.rs
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@ -170,6 +170,16 @@ pub trait FunctionExt<P> {
fn call_mut(&mut self, params: P) -> Self::Output;
}
// Called when an object inside Lua is being dropped.
#[inline]
extern "C" fn closure_destructor_wrapper<T>(lua: *mut ffi::lua_State) -> libc::c_int {
unsafe {
let obj = ffi::lua_touserdata(lua, -1);
ptr::drop_in_place((obj as *mut u8) as *mut T);
0
}
}
macro_rules! impl_function_ext {
() => (
impl<Z, R> FunctionExt<()> for Function<Z, (), R> where Z: FnMut() -> R {
@ -198,6 +208,27 @@ macro_rules! impl_function_ext {
let lua_data: *mut Z = mem::transmute(lua_data);
ptr::write(lua_data, self.function);
let lua_raw = lua.as_mut_lua();
// Creating a metatable.
ffi::lua_newtable(lua.as_mut_lua().0);
// Index "__gc" in the metatable calls the object's destructor.
// TODO: Could use std::intrinsics::needs_drop to avoid that if not needed.
// After some discussion on IRC, it would be acceptable to add a reexport in libcore
// without going through the RFC process.
{
match "__gc".push_to_lua(&mut lua) {
Ok(p) => p.forget(),
Err(_) => unreachable!(),
};
ffi::lua_pushcfunction(lua.as_mut_lua().0, closure_destructor_wrapper::<Z>);
ffi::lua_settable(lua.as_mut_lua().0, -3);
}
ffi::lua_setmetatable(lua_raw.0, -2);
// pushing wrapper as a closure
let wrapper: extern fn(*mut ffi::lua_State) -> libc::c_int = wrapper::<Self, _, R>;
ffi::lua_pushcclosure(lua.as_mut_lua().0, wrapper, 1);
@ -244,6 +275,27 @@ macro_rules! impl_function_ext {
let lua_data: *mut Z = mem::transmute(lua_data);
ptr::write(lua_data, self.function);
let lua_raw = lua.as_mut_lua();
// Creating a metatable.
ffi::lua_newtable(lua.as_mut_lua().0);
// Index "__gc" in the metatable calls the object's destructor.
// TODO: Could use std::intrinsics::needs_drop to avoid that if not needed.
// After some discussion on IRC, it would be acceptable to add a reexport in libcore
// without going through the RFC process.
{
match "__gc".push_to_lua(&mut lua) {
Ok(p) => p.forget(),
Err(_) => unreachable!(),
};
ffi::lua_pushcfunction(lua.as_mut_lua().0, closure_destructor_wrapper::<Z>);
ffi::lua_settable(lua.as_mut_lua().0, -3);
}
ffi::lua_setmetatable(lua_raw.0, -2);
// pushing wrapper as a closure
let wrapper: extern fn(*mut ffi::lua_State) -> libc::c_int = wrapper::<Self, _, R>;
ffi::lua_pushcclosure(lua.as_mut_lua().0, wrapper, 1);
@ -376,6 +428,8 @@ mod tests {
use function1;
use function2;
use std::sync::Arc;
#[test]
fn simple_function() {
let mut lua = Lua::new();
@ -496,4 +550,28 @@ mod tests {
assert_eq!(a, 20)
}
#[test]
fn closures_drop_env() {
static mut DID_DESTRUCTOR_RUN: bool = false;
#[derive(Debug)]
struct Foo { };
impl Drop for Foo {
fn drop(&mut self) {
unsafe {
DID_DESTRUCTOR_RUN = true;
}
}
}
{
let foo = Arc::new(Foo { });
{
let mut lua = Lua::new();
lua.set("print_foo", function0(move || println!("{:?}", foo)));
}
}
assert_eq!(unsafe { DID_DESTRUCTOR_RUN }, true);
}
}