prevent memory leak when dropping ParallelSystemContainer (#2176)

`ParallelSystemContainer`'s `system` pointer was extracted from box, but it was never deallocated. This change adds missing drop implementation that cleans up that memory.
This commit is contained in:
Paweł Grabarz 2021-05-17 20:01:25 +00:00
parent 1d652941ea
commit 3cf10e2ef2

View File

@ -7,7 +7,7 @@ use crate::{
},
system::{ExclusiveSystem, System},
};
use std::{borrow::Cow, ptr::NonNull};
use std::{borrow::Cow, cell::UnsafeCell};
/// System metadata like its name, labels, order requirements and component access.
pub trait SystemContainer: GraphNode<Label = BoxedSystemLabel> {
@ -106,7 +106,7 @@ impl SystemContainer for ExclusiveSystemContainer {
}
pub struct ParallelSystemContainer {
system: NonNull<dyn System<In = (), Out = ()>>,
system: Box<UnsafeCell<dyn System<In = (), Out = ()>>>,
pub(crate) run_criteria_index: Option<usize>,
pub(crate) run_criteria_label: Option<BoxedRunCriteriaLabel>,
pub(crate) should_run: bool,
@ -123,7 +123,8 @@ unsafe impl Sync for ParallelSystemContainer {}
impl ParallelSystemContainer {
pub(crate) fn from_descriptor(descriptor: ParallelSystemDescriptor) -> Self {
ParallelSystemContainer {
system: unsafe { NonNull::new_unchecked(Box::into_raw(descriptor.system)) },
// SAFE: it is fine to wrap inner value with UnsafeCell, as it is repr(transparent)
system: unsafe { Box::from_raw(Box::into_raw(descriptor.system) as *mut _) },
should_run: false,
run_criteria_index: None,
run_criteria_label: None,
@ -140,20 +141,19 @@ impl ParallelSystemContainer {
}
pub fn system(&self) -> &dyn System<In = (), Out = ()> {
// SAFE: statically enforced shared access.
unsafe { self.system.as_ref() }
// SAFE: statically enforced shared access
unsafe { self.system.get().as_ref().unwrap() }
}
pub fn system_mut(&mut self) -> &mut dyn System<In = (), Out = ()> {
// SAFE: statically enforced exclusive access.
unsafe { self.system.as_mut() }
self.system.get_mut()
}
/// # Safety
/// Ensure no other borrows exist along with this one.
#[allow(clippy::mut_from_ref)]
pub unsafe fn system_mut_unsafe(&self) -> &mut dyn System<In = (), Out = ()> {
&mut *self.system.as_ptr()
self.system.get().as_mut().unwrap()
}
pub fn should_run(&self) -> bool {