Add an AtomicCell abstraction

Author: Zoxc

Cargo.lock

@@ -240,7 +240,7 @@ dependencies = [
  "clap 2.32.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-foundation 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "crates-io 0.24.0",
- "crossbeam-utils 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "crypto-hash 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "curl 0.4.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "curl-sys 0.4.15 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -563,7 +563,7 @@ version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "crossbeam-epoch 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "crossbeam-utils 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -584,7 +584,7 @@ version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "crossbeam-epoch 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "crossbeam-utils 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -608,7 +608,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "arrayvec 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "crossbeam-utils 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "memoffset 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -624,10 +624,11 @@ dependencies = [
 
 [[package]]
 name = "crossbeam-utils"
-version = "0.6.2"
+version = "0.6.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2644,6 +2645,7 @@ name = "rustc_data_structures"
 version = "0.0.0"
 dependencies = [
  "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "ena 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "graphviz 0.0.0",
  "jobserver 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3553,7 +3555,7 @@ name = "tokio-executor"
 version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "crossbeam-utils 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -3597,7 +3599,7 @@ name = "tokio-reactor"
 version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "crossbeam-utils 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3645,7 +3647,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "crossbeam-channel 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-deque 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "crossbeam-utils 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 1.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3658,7 +3660,7 @@ name = "tokio-timer"
 version = "0.2.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "crossbeam-utils 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-executor 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4018,7 +4020,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum crossbeam-epoch 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "927121f5407de9956180ff5e936fe3cf4324279280001cd56b669d28ee7e9150"
 "checksum crossbeam-epoch 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f10a4f8f409aaac4b16a5474fb233624238fcdeefb9ba50d5ea059aab63ba31c"
 "checksum crossbeam-utils 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "2760899e32a1d58d5abb31129f8fae5de75220bc2176e77ff7c627ae45c918d9"
-"checksum crossbeam-utils 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e07fc155212827475223f0bcfae57e945e694fc90950ddf3f6695bbfd5555c72"
+"checksum crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)" = "f8306fcef4a7b563b76b7dd949ca48f52bc1141aa067d2ea09565f3e2652aa5c"
 "checksum crypto-hash 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "09de9ee0fc255ace04c7fa0763c9395a945c37c8292bb554f8d48361d1dcf1b4"
 "checksum curl 0.4.19 (registry+https://github.com/rust-lang/crates.io-index)" = "c7c9d851c825e0c033979d4516c9173bc19a78a96eb4d6ae51d4045440eafa16"
 "checksum curl-sys 0.4.15 (registry+https://github.com/rust-lang/crates.io-index)" = "721c204978be2143fab0a84b708c49d79d1f6100b8785610f456043a90708870"

src/librustc_data_structures/Cargo.toml

@@ -18,6 +18,7 @@ rustc_cratesio_shim = { path = "../librustc_cratesio_shim" }
 serialize = { path = "../libserialize" }
 graphviz = { path = "../libgraphviz" }
 cfg-if = "0.1.2"
+crossbeam-utils = { version = "0.6.5", features = ["nightly"] }
 stable_deref_trait = "1.0.0"
 rayon = { version = "0.1.2", package = "rustc-rayon" }
 rayon-core = { version = "0.1.2", package = "rustc-rayon-core" }

src/librustc_data_structures/sync.rs

@@ -67,6 +67,59 @@ cfg_if! {
         use std::ops::Add;
         use std::panic::{resume_unwind, catch_unwind, AssertUnwindSafe};
 
+        #[derive(Debug)]
+        pub struct AtomicCell<T: Copy>(Cell<T>);
+
+        impl<T: Copy> AtomicCell<T> {
+            #[inline]
+            pub fn new(v: T) -> Self {
+                AtomicCell(Cell::new(v))
+            }
+        }
+
+        impl<T: Copy> AtomicCell<T> {
+            pub fn into_inner(self) -> T {
+                self.0.into_inner()
+            }
+
+            #[inline]
+            pub fn load(&self) -> T {
+                self.0.get()
+            }
+
+            #[inline]
+            pub fn store(&self, val: T) {
+                self.0.set(val)
+            }
+
+            pub fn swap(&self, val: T) -> T {
+                self.0.replace(val)
+            }
+        }
+
+        impl<T: Copy + PartialEq> AtomicCell<T> {
+            pub fn compare_exchange(&self,
+                                    current: T,
+                                    new: T)
+                                    -> Result<T, T> {
+                let read = self.0.get();
+                if read == current {
+                    self.0.set(new);
+                    Ok(read)
+                } else {
+                    Err(read)
+                }
+            }
+        }
+
+        impl<T: Add<Output=T> + Copy> AtomicCell<T> {
+            pub fn fetch_add(&self, val: T) -> T {
+                let old = self.0.get();
+                self.0.set(old + val);
+                old
+            }
+        }
+
         #[derive(Debug)]
         pub struct Atomic<T: Copy>(Cell<T>);
 
@@ -77,7 +130,7 @@ cfg_if! {
             }
         }
 
-        impl<T: Copy + PartialEq> Atomic<T> {
+        impl<T: Copy> Atomic<T> {
             pub fn into_inner(self) -> T {
                 self.0.into_inner()
             }
@@ -95,7 +148,9 @@ cfg_if! {
             pub fn swap(&self, val: T, _: Ordering) -> T {
                 self.0.replace(val)
             }
+        }
 
+        impl<T: Copy + PartialEq> Atomic<T> {
             pub fn compare_exchange(&self,
                                     current: T,
                                     new: T,
@@ -271,6 +326,8 @@ cfg_if! {
 
         pub use std::sync::atomic::{AtomicBool, AtomicUsize, AtomicU32, AtomicU64};
 
+        pub use crossbeam_utils::atomic::AtomicCell;
+
         pub use std::sync::Arc as Lrc;
         pub use std::sync::Weak as Weak;