Skip to content

Fix miri errors and tests #5

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: main
Choose a base branch
from
Open

Fix miri errors and tests #5

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion Cargo.toml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@ concurrent_map_minimum = ["concurrent-map"]
debug = true

[dependencies]
concurrent-map = { version = "5.0", features = ["serde"], path = "../concurrent-map", optional = true }
concurrent-map = { version = "5.0", features = ["serde"], optional = true }
serde = { version = "1.0", optional = true }

[dev-dependencies]
Expand Down
96 changes: 66 additions & 30 deletions src/lib.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -26,8 +26,7 @@
//!
//! # Features
//!
//! * `serde` implements `serde::Serialize` and `serde::Deserialize` for `InlineArray` (disabled by
//! default)
//! * `serde` implements `serde::Serialize` and `serde::Deserialize` for `InlineArray` (disabled by default)
//!
//! # Examples
//!
Expand All @@ -48,6 +47,7 @@ use std::{
mem::size_of,
num::NonZeroU64,
ops::Deref,
ptr::{with_exposed_provenance, with_exposed_provenance_mut},
sync::atomic::{AtomicU16, AtomicU8, Ordering},
};

Expand Down Expand Up @@ -176,13 +176,15 @@ impl Drop for InlineArray {

let layout = Layout::from_size_align(
small_trailer.len() + size_of::<SmallRemoteTrailer>(),
8,
SZ,
)
.unwrap();

unsafe {
let ptr = self.remote_ptr().sub(small_trailer.len());
dealloc(ptr as *mut u8, layout);
let ptr = self.remote_ptr().map_addr(|a| a - small_trailer.len());
let ptr_addr = ptr.expose_provenance();

dealloc(with_exposed_provenance_mut(ptr_addr), layout);
}
}
} else if kind == Kind::BigRemote {
Expand All @@ -193,11 +195,14 @@ impl Drop for InlineArray {
std::sync::atomic::fence(Ordering::Acquire);

let layout =
Layout::from_size_align(big_header.len() + size_of::<BigRemoteHeader>(), 8)
Layout::from_size_align(big_header.len() + size_of::<BigRemoteHeader>(), SZ)
.unwrap();
let remote = self.remote_ptr();
let remote_addr = remote.expose_provenance();
let ptr = with_exposed_provenance_mut::<u8>(remote_addr);

unsafe {
dealloc(self.remote_ptr() as *mut u8, layout);
dealloc(ptr, layout);
}
}
}
Expand Down Expand Up @@ -257,13 +262,18 @@ impl Deref for InlineArray {
Kind::Inline => &self.0[..self.inline_len()],
Kind::SmallRemote => unsafe {
let len = self.deref_small_trailer().len();
let data_ptr = self.remote_ptr().sub(len);
std::slice::from_raw_parts(data_ptr, len)
let data_ptr = self.remote_ptr().map_addr(|a| a - len);
let data_addr = data_ptr.expose_provenance();

std::slice::from_raw_parts(with_exposed_provenance(data_addr), len)
},
Kind::BigRemote => unsafe {
let data_ptr = self.remote_ptr().add(size_of::<BigRemoteHeader>());
let len = self.deref_big_header().len();
std::slice::from_raw_parts(data_ptr, len)
let remote_ptr = self.remote_ptr();
let data_ptr = remote_ptr.map_addr(|a| a + size_of::<BigRemoteHeader>());
let data_addr = data_ptr.expose_provenance();

std::slice::from_raw_parts(with_exposed_provenance(data_addr), len)
},
}
}
Expand Down Expand Up @@ -297,7 +307,7 @@ impl InlineArray {
data[SZ - 1] |= INLINE_TRAILER_TAG;
} else if slice.len() <= SMALL_REMOTE_CUTOFF {
let layout =
Layout::from_size_align(slice.len() + size_of::<SmallRemoteTrailer>(), 8).unwrap();
Layout::from_size_align(slice.len() + size_of::<SmallRemoteTrailer>(), SZ).unwrap();

let trailer = SmallRemoteTrailer {
rc: 1.into(),
Expand All @@ -307,11 +317,14 @@ impl InlineArray {
unsafe {
let data_ptr = alloc(layout);
assert!(!data_ptr.is_null());
let trailer_ptr = data_ptr.add(slice.len());
let trailer_ptr = data_ptr.map_addr(|o| o + slice.len());

std::ptr::write(trailer_ptr as *mut SmallRemoteTrailer, trailer);
std::ptr::copy_nonoverlapping(slice.as_ptr(), data_ptr, slice.len());
std::ptr::write_unaligned(data.as_mut_ptr() as _, trailer_ptr);
std::ptr::write_unaligned(
data.as_mut_ptr() as _,
trailer_ptr.expose_provenance().to_le_bytes(),
);
}

// assert that the bottom 3 bits are empty, as we expect
Expand All @@ -322,7 +335,7 @@ impl InlineArray {
data[SZ - 1] |= SMALL_REMOTE_TRAILER_TAG;
} else {
let layout =
Layout::from_size_align(slice.len() + size_of::<BigRemoteHeader>(), 8).unwrap();
Layout::from_size_align(slice.len() + size_of::<BigRemoteHeader>(), SZ).unwrap();

let slice_len_buf: [u8; 8] = (slice.len() as u64).to_le_bytes();

Expand All @@ -342,11 +355,15 @@ impl InlineArray {
unsafe {
let header_ptr = alloc(layout);
assert!(!header_ptr.is_null());
let data_ptr = header_ptr.add(size_of::<BigRemoteHeader>());

let data_ptr = header_ptr.map_addr(|o| o + size_of::<BigRemoteHeader>());

std::ptr::write(header_ptr as *mut BigRemoteHeader, header);
std::ptr::copy_nonoverlapping(slice.as_ptr(), data_ptr, slice.len());
std::ptr::write_unaligned(data.as_mut_ptr() as _, header_ptr);
std::ptr::write_unaligned(
data.as_mut_ptr() as _,
header_ptr.expose_provenance().to_le_bytes(),
);
}

// assert that the bottom 3 bits are empty, as we expect
Expand All @@ -361,35 +378,47 @@ impl InlineArray {

fn remote_ptr(&self) -> *const u8 {
assert_ne!(self.kind(), Kind::Inline);

let mut copied = self.0;
copied[SZ - 1] &= TRAILER_PTR_MASK;

unsafe { std::ptr::read((&copied).as_ptr() as *const *const u8) }
unsafe { std::ptr::read_unaligned(copied.as_ptr() as *const *const u8) }
}

fn deref_small_trailer(&self) -> &SmallRemoteTrailer {
assert_eq!(self.kind(), Kind::SmallRemote);
unsafe { &*(self.remote_ptr() as *mut SmallRemoteTrailer) }
let remote = self.remote_ptr();
let ptr = with_exposed_provenance_mut(remote.expose_provenance());

unsafe { &*(ptr) }
}

fn deref_big_header(&self) -> &BigRemoteHeader {
assert_eq!(self.kind(), Kind::BigRemote);
unsafe { &*(self.remote_ptr() as *mut BigRemoteHeader) }
let remote = self.remote_ptr();
let ptr = with_exposed_provenance_mut(remote.expose_provenance());

unsafe { &*(ptr) }
}

#[cfg(miri)]
fn inline_len(&self) -> usize {
(self.trailer() >> 2) as usize
(self.inline_trailer() >> 2) as usize
}

#[cfg(miri)]
fn kind(&self) -> Kind {
self.trailer() & TRAILER_TAG_MASK == INLINE_TRAILER_TAG
match self.inline_trailer() & TRAILER_TAG_MASK {
INLINE_TRAILER_TAG => Kind::Inline,
SMALL_REMOTE_TRAILER_TAG => Kind::SmallRemote,
BIG_REMOTE_TRAILER_TAG => Kind::BigRemote,
_other => unsafe { std::hint::unreachable_unchecked() },
}
}

#[cfg(miri)]
fn inline_trailer(&self) -> u8 {
self.deref()[SZ - 1]
self.0[SZ - 1]
}

#[cfg(not(miri))]
Expand Down Expand Up @@ -429,18 +458,24 @@ impl InlineArray {
}
unsafe {
let len = self.deref_small_trailer().len();
let data_ptr = self.remote_ptr().sub(len);
std::slice::from_raw_parts_mut(data_ptr as *mut u8, len)
let data_ptr = self.remote_ptr().map_addr(|a| a - len);
let data_addr = data_ptr.expose_provenance();
std::slice::from_raw_parts_mut(with_exposed_provenance_mut(data_addr), len)
}
}
Kind::BigRemote => {
if self.deref_big_header().rc.load(Ordering::Acquire) != 1 {
*self = InlineArray::from(self.deref())
}
unsafe {
let data_ptr = self.remote_ptr().add(size_of::<BigRemoteHeader>());
let data_ptr = self
.remote_ptr()
.map_addr(|a| a + size_of::<BigRemoteHeader>());
let len = self.deref_big_header().len();
std::slice::from_raw_parts_mut(data_ptr as *mut u8, len)
std::slice::from_raw_parts_mut(
with_exposed_provenance_mut(data_ptr.expose_provenance()),
len,
)
}
}
}
Expand Down Expand Up @@ -478,7 +513,7 @@ impl InlineArray {

/// Similar in spirit to [`std::boxed::Box::from_raw`].
///
/// # Unsafe contract
/// # Safety
///
/// * Must only be used with a `NonZeroU64` that was produced from [`InlineArray::into_raw`]
/// * When an [`InlineArray`] drops, it decrements a reference count (if its size is over the inline threshold)
Expand Down Expand Up @@ -624,6 +659,7 @@ impl fmt::Debug for InlineArray {

#[cfg(test)]
mod tests {

use super::InlineArray;

#[test]
Expand Down Expand Up @@ -671,11 +707,11 @@ mod tests {
}

if *inline_array != *iv2 {
println!("expected AsMut to equal original");
println!("expected to equal original");
return false;
}

if &*inline_array != iv2.make_mut() {
if inline_array != iv2.make_mut() {
println!("expected AsMut to equal original");
return false;
}
Expand Down