From 68d9e9e23b521f6a00c66354191320eaf797fe40 Mon Sep 17 00:00:00 2001
From: Per Lindgren <per.lindgren@ltu.se>
Date: Sat, 3 Apr 2021 15:27:51 +0200
Subject: [PATCH] pool trait
---
examples/usage.rs | 9 +--
src/lib.rs | 153 +++++++++++++++++++++++++++++++++++-----------
2 files changed, 122 insertions(+), 40 deletions(-)
diff --git a/examples/usage.rs b/examples/usage.rs
index a7268d0..f9c8d06 100644
--- a/examples/usage.rs
+++ b/examples/usage.rs
@@ -3,6 +3,7 @@ use poolman::PoolMan;
#[derive(Debug)]
struct IDrop(u32);
+unsafe impl Sync for IDrop(u32) {}
impl core::ops::Drop for IDrop {
fn drop(&mut self) {
@@ -15,17 +16,17 @@ static P: PoolMan<IDrop, 2> = PoolMan::new([IDrop(10), IDrop(11)]);
fn main() {
P.init();
{
- let e = P.alloc().unwrap();
+ let e = P.allocb().unwrap();
println!("e {:?}", *e);
mem::drop(e);
- let mut e1 = P.alloc().unwrap();
+ let mut e1 = P.allocb().unwrap();
println!("e1 {:?}", *e1);
*e1 = IDrop(2);
println!("e1 {:?}", *e1);
- let e2 = P.alloc().unwrap();
+ let e2 = P.allocb().unwrap();
println!("e2 {:?}", *e2);
}
- let e = P.alloc().unwrap();
+ let e = P.allocb().unwrap();
println!("e {:?}", *e);
}
diff --git a/src/lib.rs b/src/lib.rs
index 9b7a039..5f324ca 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,5 +1,6 @@
#![no_std]
use core::cell::UnsafeCell;
+// use core::marker::PhantomData;
use core::ops::{Deref, DerefMut, Drop};
use cortex_m::interrupt;
@@ -42,40 +43,73 @@ pub enum Error {
AlreadyInitialized,
}
-pub struct Box<T: 'static + Sized, const S: usize> {
+trait Pool<T>
+where
+ T: Send + Sync,
+{
+ fn dealloc(&'static self, index: usize);
+ fn index_deref(&'static self, index: usize) -> &T;
+ fn index_deref_mut(&'static self, index: usize) -> &mut T;
+}
+
+pub struct B<T: 'static + Sized + Send + Sync> {
index: usize,
- allocator: &'static PoolMan<T, S>,
+ allocator: &'static dyn Pool<T>,
}
-impl<T: 'static, const S: usize> Drop for Box<T, S> {
+impl<T: 'static + Sized + Send + Sync> Drop for B<T> {
fn drop(&mut self) {
self.allocator.dealloc(self.index)
}
}
-impl<T: 'static, const S: usize> Deref for Box<T, S> {
+impl<T: 'static + Sized + Send + Sync> Deref for B<T> {
type Target = T;
fn deref(&self) -> &T {
- unsafe {
- self.allocator
- .data /* RacyCell */
- .get_mut_unchecked() /* Array */
- .get_unchecked(self.index)
- }
+ self.allocator.index_deref(self.index)
}
}
-impl<T: 'static, const S: usize> DerefMut for Box<T, S> {
+impl<T: 'static + Sized + Send + Sync> DerefMut for B<T> {
fn deref_mut(&mut self) -> &mut T {
- unsafe {
- self.allocator
- .data /* RacyCell */
- .get_mut_unchecked() /* Array */
- .get_unchecked_mut(self.index)
- }
+ self.allocator.index_deref_mut(self.index)
}
}
+// pub struct Box<T: 'static + Sized, const S: usize> {
+// index: usize,
+// allocator: &'static PoolMan<T, S>,
+// }
+
+// impl<T: 'static, const S: usize> Drop for Box<T, S> {
+// fn drop(&mut self) {
+// self.allocator.dealloc(self.index)
+// }
+// }
+
+// impl<T: 'static, const S: usize> Deref for Box<T, S> {
+// type Target = T;
+// fn deref(&self) -> &T {
+// unsafe {
+// self.allocator
+// .data /* RacyCell */
+// .get_mut_unchecked() /* Array */
+// .get_unchecked(self.index)
+// }
+// }
+// }
+
+// impl<T: 'static, const S: usize> DerefMut for Box<T, S> {
+// fn deref_mut(&mut self) -> &mut T {
+// unsafe {
+// self.allocator
+// .data /* RacyCell */
+// .get_mut_unchecked() /* Array */
+// .get_unchecked_mut(self.index)
+// }
+// }
+// }
+
pub struct PoolMan<T: 'static, const S: usize> {
data: RacyCell<[T; S]>,
free: RacyCell<[usize; S]>,
@@ -83,13 +117,15 @@ pub struct PoolMan<T: 'static, const S: usize> {
init: RacyCell<bool>,
}
+
+
impl<T, const S: usize> PoolMan<T, S>
where
- T: Sized,
+ T: Sized + Send + Sync,
{
pub const fn new(v: [T; S]) -> Self
where
- T: Sized,
+ T: Sized + Send + Sync,
{
Self {
data: RacyCell::new(v),
@@ -115,23 +151,45 @@ where
})
}
- // Safety:
- // dealloc can only be called by dropping Box
- // which can happen only if already initialized
- // thus it is safe to assume init == true
- //
- // not accissible from user code
- #[inline]
- fn dealloc(&self, index: usize) {
- interrupt_free(|| unsafe {
- *self.free.get_mut_unchecked().get_unchecked_mut(index) =
- *self.head.get_mut_unchecked();
- *self.head.get_mut_unchecked() = index;
- });
- }
+ // // Safety:
+ // // dealloc can only be called by dropping Box
+ // // which can happen only if already initialized
+ // // thus it is safe to assume init == true
+ // //
+ // // not accessible from user code
+ // #[inline]
+ // fn dealloc(&self, index: usize) {
+ // interrupt_free(|| unsafe {
+ // *self.free.get_mut_unchecked().get_unchecked_mut(index) =
+ // *self.head.get_mut_unchecked();
+ // *self.head.get_mut_unchecked() = index;
+ // });
+ // }
- #[inline]
- pub fn alloc(&'static self) -> Result<Box<T, S>, Error> {
+ // #[inline]
+ // pub fn alloc(&'static self) -> Result<Box<T, S>, Error> {
+ // // this check does not need to be inside of critical section
+ // // as initialization is monotonic, cannot be undone
+ // if !unsafe { *self.init.get_mut_unchecked() } {
+ // Err(Error::Uninitialized)
+ // } else {
+ // interrupt_free(|| unsafe {
+ // let index = *self.head.get_mut_unchecked();
+ // *self.head.get_mut_unchecked() =
+ // *self.free.get_mut_unchecked().get_unchecked(index);
+ // if *self.head.get_mut_unchecked() > S {
+ // Err(Error::OutOfMemory)
+ // } else {
+ // Ok(Box {
+ // index,
+ // allocator: self,
+ // })
+ // }
+ // })
+ // }
+ // }
+
+ pub fn allocb(&'static self) -> Result<B<T>, Error> {
// this check does not need to be inside of critical section
// as initialization is monotonic, cannot be undone
if !unsafe { *self.init.get_mut_unchecked() } {
@@ -144,7 +202,7 @@ where
if *self.head.get_mut_unchecked() > S {
Err(Error::OutOfMemory)
} else {
- Ok(Box {
+ Ok(B {
index,
allocator: self,
})
@@ -153,3 +211,26 @@ where
}
}
}
+
+// sealed, should only be externally accessible
+impl<T, const S: usize> Pool<T> for PoolMan<T, S>
+where
+ T: Sized + Send + Sync,
+{
+ #[inline]
+ fn dealloc(&'static self, index: usize) {
+ interrupt_free(|| unsafe {
+ *self.free.get_mut_unchecked().get_unchecked_mut(index) =
+ *self.head.get_mut_unchecked();
+ *self.head.get_mut_unchecked() = index;
+ });
+ }
+
+ fn index_deref(&'static self, index: usize) -> &'static T {
+ unsafe { self.data.get_mut_unchecked().get_unchecked(index) }
+ }
+
+ fn index_deref_mut(&'static self, index: usize) -> &'static mut T {
+ unsafe { self.data.get_mut_unchecked().get_unchecked_mut(index) }
+ }
+}
--
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