From 79783084c4dc7484bb96c4d6238398f0ef84dfa4 Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Tue, 22 Dec 2020 16:28:10 +0900
Subject: [PATCH 01/13] Update crossbeam-channel to 0.5
---
Cargo.toml | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Cargo.toml b/Cargo.toml
index 573d27e..8674ff8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,7 +21,7 @@ maintenance = { status = "passively-maintained" }
atomic-option = "0.1"
num_cpus = "1.6.2"
parking_lot_core = "0.7"
-crossbeam-channel = "0.4"
+crossbeam-channel = "0.5"
[profile.release]
debug = true
From c54d6f0b39a907be5258b74a3566964711dbcf77 Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Tue, 22 Dec 2020 16:28:28 +0900
Subject: [PATCH 02/13] Update parking_lot_core to 0.8
---
Cargo.toml | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Cargo.toml b/Cargo.toml
index 8674ff8..939fe00 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -20,7 +20,7 @@ maintenance = { status = "passively-maintained" }
[dependencies]
atomic-option = "0.1"
num_cpus = "1.6.2"
-parking_lot_core = "0.7"
+parking_lot_core = "0.8"
crossbeam-channel = "0.5"
[profile.release]
From 5618b7bfaa7911251b7e2ca3bee06ba1416de9ea Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Sat, 26 Dec 2020 12:07:11 +0900
Subject: [PATCH 03/13] Fix miri test
---
azure-pipelines.yml | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 3a793dd..9975035 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -13,7 +13,7 @@ jobs:
components:
- miri
# ignore leaks due to https://github.com/crossbeam-rs/crossbeam/issues/464
- - bash: yes | cargo miri -Zmiri-ignore-leaks test
+ - bash: MIRIFLAGS="-Zmiri-ignore-leaks" cargo miri test
displayName: cargo miri test
- job: asan
displayName: "Run address sanitizer on test suite"
From 95aa5bf8b160ee245bcfd3d61c43cbda17663a72 Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Fri, 17 Jun 2022 11:40:31 +0900
Subject: [PATCH 04/13] Move drop(state) to fix UB
---
src/lib.rs | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/src/lib.rs b/src/lib.rs
index 3016c71..6471395 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -195,16 +195,18 @@ impl<T: Clone + Sync> Seat<T> {
// safely take a mutable reference, and just take the val instead of cloning it.
unsafe { &mut *self.state.get() }.val.take().unwrap()
} else {
- state
+ let v = state
.val
.clone()
- .expect("seat that should be occupied was empty")
+ .expect("seat that should be occupied was empty");
+
+ // let writer know that we no longer need this item.
+ // state is no longer safe to access.
+ #[allow(clippy::drop_ref)]
+ drop(state);
+ v
};
- // let writer know that we no longer need this item.
- // state is no longer safe to access.
- #[allow(clippy::drop_ref)]
- drop(state);
self.read.fetch_add(1, atomic::Ordering::AcqRel);
if let Some(t) = waiting {
From 732dc9f4f5e45856640a1aafafb7f22af3f5a9dd Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Fri, 17 Jun 2022 11:40:57 +0900
Subject: [PATCH 05/13] Disable Miri weak memory emulation and preemption
---
azure-pipelines.yml | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 9975035..58b63cd 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -13,7 +13,9 @@ jobs:
components:
- miri
# ignore leaks due to https://github.com/crossbeam-rs/crossbeam/issues/464
- - bash: MIRIFLAGS="-Zmiri-ignore-leaks" cargo miri test
+ # disable preemption due to https://github.com/rust-lang/rust/issues/55005
+ # disable weak memory emulation due to https://github.com/rust-lang/miri/issues/2223
+ - bash: MIRIFLAGS="-Zmiri-ignore-leaks -Zmiri-preemption-rate=0 -Zmiri-disable-weak-memory-emulation" cargo miri test
displayName: cargo miri test
- job: asan
displayName: "Run address sanitizer on test suite"
From 4384de5a493e06d7c2472bb5bd4e5aa77ff0903c Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Fri, 17 Jun 2022 11:41:27 +0900
Subject: [PATCH 06/13] Update parking_lot_core to 0.9
---
Cargo.toml | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Cargo.toml b/Cargo.toml
index 939fe00..907bcfe 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -20,7 +20,7 @@ maintenance = { status = "passively-maintained" }
[dependencies]
atomic-option = "0.1"
num_cpus = "1.6.2"
-parking_lot_core = "0.8"
+parking_lot_core = "0.9"
crossbeam-channel = "0.5"
[profile.release]
From 183dc7260dfd08b2c4953fcfb6c7c46b907394b0 Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Fri, 17 Jun 2022 11:54:48 +0900
Subject: [PATCH 07/13] Use ubuntu-latest instead of ubuntu-16.04 in CI
---
azure-pipelines.yml | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 58b63cd..fac8820 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -5,7 +5,7 @@ jobs:
- job: miri
displayName: "Run miri on test suite"
pool:
- vmImage: ubuntu-16.04
+ vmImage: ubuntu-latest
steps:
- template: install-rust.yml@templates
parameters:
@@ -20,7 +20,7 @@ jobs:
- job: asan
displayName: "Run address sanitizer on test suite"
pool:
- vmImage: ubuntu-16.04
+ vmImage: ubuntu-latest
steps:
- template: install-rust.yml@templates
parameters:
@@ -35,7 +35,7 @@ jobs:
- job: lsan
displayName: "Run leak sanitizer on test suite"
pool:
- vmImage: ubuntu-16.04
+ vmImage: ubuntu-latest
steps:
- template: install-rust.yml@templates
parameters:
From a1177d4f84d96949b83c9b8aa63cb6e231f3070a Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Fri, 17 Jun 2022 12:04:37 +0900
Subject: [PATCH 08/13] Fix Miri installation
---
azure-pipelines.yml | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index fac8820..4908115 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -7,11 +7,8 @@ jobs:
pool:
vmImage: ubuntu-latest
steps:
- - template: install-rust.yml@templates
- parameters:
- rust: nightly
- components:
- - miri
+ - bash: rustup toolchain install nightly --component miri && rustup default nightly
+ displayName: install rust
# ignore leaks due to https://github.com/crossbeam-rs/crossbeam/issues/464
# disable preemption due to https://github.com/rust-lang/rust/issues/55005
# disable weak memory emulation due to https://github.com/rust-lang/miri/issues/2223
From a26092c77a76c670445e9f627a8e60b62f3e508c Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Fri, 17 Jun 2022 12:15:07 +0900
Subject: [PATCH 09/13] Pass -Zmiri-disable-isolation
---
azure-pipelines.yml | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 4908115..14f2ac1 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -12,7 +12,7 @@ jobs:
# ignore leaks due to https://github.com/crossbeam-rs/crossbeam/issues/464
# disable preemption due to https://github.com/rust-lang/rust/issues/55005
# disable weak memory emulation due to https://github.com/rust-lang/miri/issues/2223
- - bash: MIRIFLAGS="-Zmiri-ignore-leaks -Zmiri-preemption-rate=0 -Zmiri-disable-weak-memory-emulation" cargo miri test
+ - bash: MIRIFLAGS="-Zmiri-disable-isolation -Zmiri-ignore-leaks -Zmiri-preemption-rate=0 -Zmiri-disable-weak-memory-emulation" cargo miri test
displayName: cargo miri test
- job: asan
displayName: "Run address sanitizer on test suite"
From b70eee7a1e966e11c877fa54d4027bdbf07acfce Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Fri, 17 Jun 2022 12:58:55 +0900
Subject: [PATCH 10/13] Update azure pipelines templates
---
azure-pipelines.yml | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 14f2ac1..1b0c56d 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -57,5 +57,5 @@ resources:
- repository: templates
type: github
name: crate-ci/azure-pipelines
- ref: refs/heads/v0.3
+ ref: refs/heads/v0.4
endpoint: jonhoo
From eaed299388144156fe079d922c739af911c24a12 Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Fri, 17 Jun 2022 12:59:27 +0900
Subject: [PATCH 11/13] Bump MSRV to 1.49
---
azure-pipelines.yml | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 1b0c56d..f457f9c 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -1,7 +1,7 @@
jobs:
- template: default.yml@templates
parameters:
- minrust: 1.36.0 # MaybeUninit
+ minrust: 1.49.0 # parking_lot_core
- job: miri
displayName: "Run miri on test suite"
pool:
From a92614c7c1e415806e7ee49d557b11512477af34 Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Fri, 17 Jun 2022 14:05:02 +0900
Subject: [PATCH 12/13] Ignore a doc test with Miri
---
src/lib.rs | 1 +
1 file changed, 1 insertion(+)
diff --git a/src/lib.rs b/src/lib.rs
index 6471395..bd3247b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -35,6 +35,7 @@
//! Multi-send, multi-consumer example
//!
//! ```rust
+//! # if cfg!(miri) { return } // Miri is too slow
//! use bus::Bus;
//! use std::thread;
//!
From 5d85f31845e03916a3b8746e086883bd72c1bf25 Mon Sep 17 00:00:00 2001
From: Taiki Endo <te316e89@gmail.com>
Date: Fri, 17 Jun 2022 14:05:09 +0900
Subject: [PATCH 13/13] Remove dependency on unsound atomic-option crate
---
Cargo.toml | 1 -
src/lib.rs | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++----
2 files changed, 50 insertions(+), 5 deletions(-)
diff --git a/Cargo.toml b/Cargo.toml
index 907bcfe..a1b647a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -18,7 +18,6 @@ codecov = { repository = "jonhoo/bus", branch = "master", service = "github" }
maintenance = { status = "passively-maintained" }
[dependencies]
-atomic-option = "0.1"
num_cpus = "1.6.2"
parking_lot_core = "0.9"
crossbeam-channel = "0.5"
diff --git a/src/lib.rs b/src/lib.rs
index bd3247b..bf5618d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -100,12 +100,13 @@
#![deny(missing_docs)]
#![warn(rust_2018_idioms)]
-use atomic_option::AtomicOption;
use crossbeam_channel as mpsc;
use parking_lot_core::SpinWait;
use std::cell::UnsafeCell;
+use std::marker::PhantomData;
use std::ops::Deref;
+use std::ptr;
use std::sync::atomic;
use std::sync::mpsc as std_mpsc;
use std::sync::Arc;
@@ -190,7 +191,7 @@ impl<T: Clone + Sync> Seat<T> {
// we're the last reader, so we may need to notify the writer there's space in the buf.
// can be relaxed, since the acquire at the top already guarantees that we'll see
// updates.
- waiting = self.waiting.take(atomic::Ordering::Relaxed);
+ waiting = self.waiting.take();
// since we're the last reader, no-one else will be cloning this value, so we can
// safely take a mutable reference, and just take the val instead of cloning it.
@@ -381,7 +382,7 @@ impl<T> Bus<T> {
// no, so block by parking and telling readers to notify on last read
self.state.ring[fence]
.waiting
- .replace(Some(Box::new(thread::current())), atomic::Ordering::Relaxed);
+ .swap(Some(Box::new(thread::current())));
// need the atomic fetch_add to ensure reader threads will see the new .waiting
self.state.ring[fence]
@@ -419,7 +420,7 @@ impl<T> Bus<T> {
let state = unsafe { &mut *next.state.get() };
state.max = readers;
state.val = Some(val);
- next.waiting.replace(None, atomic::Ordering::Relaxed);
+ next.waiting.take();
next.read.store(0, atomic::Ordering::Release);
}
self.rleft[tail] = 0;
@@ -820,3 +821,48 @@ impl<T: Clone + Sync> Iterator for BusIntoIter<T> {
self.0.recv().ok()
}
}
+
+struct AtomicOption<T> {
+ ptr: atomic::AtomicPtr<T>,
+ _marker: PhantomData<Option<Box<T>>>,
+}
+
+unsafe impl<T: Send> Send for AtomicOption<T> {}
+unsafe impl<T: Send> Sync for AtomicOption<T> {}
+
+impl<T> AtomicOption<T> {
+ fn empty() -> Self {
+ Self {
+ ptr: atomic::AtomicPtr::new(ptr::null_mut()),
+ _marker: PhantomData,
+ }
+ }
+
+ fn swap(&self, val: Option<Box<T>>) -> Option<Box<T>> {
+ let old = match val {
+ Some(val) => self.ptr.swap(Box::into_raw(val), atomic::Ordering::AcqRel),
+ // Acquire is needed to synchronize with the store of a non-null ptr, but since a null ptr
+ // will never be dereferenced, there is no need to synchronize the store of a null ptr.
+ None => self.ptr.swap(ptr::null_mut(), atomic::Ordering::Acquire),
+ };
+ if old.is_null() {
+ None
+ } else {
+ // SAFETY:
+ // - AcqRel/Acquire ensures that it does not read a pointer to potentially invalid memory.
+ // - We've checked that old is not null.
+ // - We do not store invalid pointers other than null in self.ptr.
+ Some(unsafe { Box::from_raw(old) })
+ }
+ }
+
+ fn take(&self) -> Option<Box<T>> {
+ self.swap(None)
+ }
+}
+
+impl<T> Drop for AtomicOption<T> {
+ fn drop(&mut self) {
+ drop(self.take());
+ }
+}