oxidd_manager_index/node/
mod.rs

1use std::sync::atomic::Ordering;
2
3pub mod fixed_arity;
4
5/// Base traits to be satisfied by inner nodes for oxidd-manager. This does not
6/// include the [`InnerNode`][oxidd_core::InnerNode] trait.
7///
8/// # Safety
9///
10/// - The reference counter must be initialized to 2.
11/// - [`Self::retain()`] increments the counter by 1
12/// - [`Self::release()`] decrements the counter by 1 with (at least)
13///   [`Release`][std::sync::atomic::Ordering::Release] order.
14/// - [`Self::load_rc()`] loads the reference count with the specified load
15///   order.
16/// - An implementation must not modify the counter unless instructed externally
17///   via the `retain()` or `release()` methods.
18pub unsafe trait NodeBase: Eq + std::hash::Hash {
19    /// Atomically increment the reference counter (with
20    /// [`Relaxed`][std::sync::atomic::Ordering::Relaxed] order)
21    ///
22    /// This method is responsible for preventing an overflow of the reference
23    /// counter.
24    fn retain(&self);
25
26    /// Atomically decrement the reference counter (with
27    /// [`Release`][std::sync::atomic::Ordering::Release] order)
28    ///
29    /// Returns the previous reference count.
30    ///
31    /// A call to this function only modifies the counter value and never drops
32    /// `self`.
33    ///
34    /// # Safety
35    ///
36    /// The caller must give up ownership of one reference to `self`.
37    unsafe fn release(&self) -> usize;
38
39    /// Atomically load the current reference count with the given `order`
40    fn load_rc(&self, order: Ordering) -> usize;
41
42    /// Whether this node type contains additional data that needs to be dropped
43    /// to avoid memory leaks.
44    ///
45    /// If the node only consists of [`Edge`][crate::manager::Edge]s and types
46    /// that implement [`Copy`], an implementation may return `false`. This may
47    /// speed up dropping a diagram a lot.
48    #[inline(always)]
49    fn needs_drop() -> bool {
50        true
51    }
52}
oxidd_manager_index/node/mod.rs

oxidd_manager_index/node/
mod.rs
