From e5d307401e65a08507fbf23b3124265c21fd9d38 Mon Sep 17 00:00:00 2001
From: Michael Aaron Murphy <mmstickman@gmail.com>
Date: Thu, 26 Oct 2017 10:57:02 -0400
Subject: [PATCH] Use integer_atomics feature Rather than using AtomicUsize and
AtomicBool fields within our ForegroundSignals structure, I'm switching this
over to using AtomicU32 and AtomicU8 values instead.
---
src/lib.rs | 1 +
src/main.rs | 1 +
src/shell/pipe_exec/foreground.rs | 49 +++++++++++++------------------
3 files changed, 23 insertions(+), 28 deletions(-)
diff --git a/src/lib.rs b/src/lib.rs
index c28a059a..b758479a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,6 +1,7 @@
#![allow(unknown_lints)]
#![allow(while_let_on_iterator)]
#![feature(conservative_impl_trait)]
+#![feature(integer_atomics)]
extern crate app_dirs;
#[macro_use]
diff --git a/src/main.rs b/src/main.rs
index d575fb63..36928eb3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,6 +1,7 @@
#![allow(unknown_lints)]
#![allow(while_let_on_iterator)]
#![feature(conservative_impl_trait)]
+#![feature(integer_atomics)]
// For a performance boost on Linux
// #![feature(alloc_system)]
diff --git a/src/shell/pipe_exec/foreground.rs b/src/shell/pipe_exec/foreground.rs
index 30c9caeb..31972532 100644
--- a/src/shell/pipe_exec/foreground.rs
+++ b/src/shell/pipe_exec/foreground.rs
@@ -1,64 +1,57 @@
//! Contains the logic for enabling foreground management.
-
-use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
+use std::sync::atomic::{AtomicU32, AtomicU8, Ordering};
pub(crate) enum BackgroundResult {
Errored,
Status(u8),
}
+const REPLIED: u8 = 1;
+const ERRORED: u8 = 2;
+
/// An atomic structure that can safely be shared across threads, which serves to provide
/// communication between the shell and background threads. The `fg` command uses this
/// structure to notify a background thread that it needs to wait for and return
/// the exit status back to the `fg` function.
pub(crate) struct ForegroundSignals {
- grab: AtomicUsize, // TODO: Use AtomicU32 when stable
- status: AtomicUsize, // TODO: Use AtomicU8 when stable
- reply: AtomicBool,
- errored: AtomicBool, // TODO: Combine with reply when U8 is stable
+ grab: AtomicU32,
+ status: AtomicU8,
+ reply: AtomicU8,
}
impl ForegroundSignals {
pub(crate) fn new() -> ForegroundSignals {
ForegroundSignals {
- grab: AtomicUsize::new(0),
- status: AtomicUsize::new(0),
- reply: AtomicBool::new(false),
- errored: AtomicBool::new(false),
+ grab: AtomicU32::new(0),
+ status: AtomicU8::new(0),
+ reply: AtomicU8::new(0),
}
}
- pub(crate) fn signal_to_grab(&self, pid: u32) {
- self.grab.store(pid as usize, Ordering::Relaxed);
- }
+ pub(crate) fn signal_to_grab(&self, pid: u32) { self.grab.store(pid, Ordering::Relaxed); }
pub(crate) fn reply_with(&self, status: i8) {
self.grab.store(0, Ordering::Relaxed);
- self.status.store(status as usize, Ordering::Relaxed);
- self.reply.store(true, Ordering::Relaxed);
+ self.status.store(status as u8, Ordering::Relaxed);
+ self.reply.store(REPLIED, Ordering::Relaxed);
}
pub(crate) fn errored(&self) {
self.grab.store(0, Ordering::Relaxed);
- self.errored.store(true, Ordering::Relaxed);
- self.reply.store(true, Ordering::Relaxed);
+ self.reply.store(ERRORED, Ordering::Relaxed);
}
pub(crate) fn was_processed(&self) -> Option<BackgroundResult> {
- if self.reply.load(Ordering::Relaxed) {
- self.reply.store(false, Ordering::Relaxed);
- if self.errored.load(Ordering::Relaxed) {
- self.errored.store(false, Ordering::Relaxed);
- Some(BackgroundResult::Errored)
- } else {
- Some(BackgroundResult::Status(self.status.load(Ordering::Relaxed) as u8))
- }
+ let reply = self.reply.load(Ordering::Relaxed);
+ self.reply.store(0, Ordering::Relaxed);
+ if reply & ERRORED != 0 {
+ Some(BackgroundResult::Errored)
+ } else if reply & REPLIED != 0 {
+ Some(BackgroundResult::Status(self.status.load(Ordering::Relaxed) as u8))
} else {
None
}
}
- pub(crate) fn was_grabbed(&self, pid: u32) -> bool {
- self.grab.load(Ordering::Relaxed) == pid as usize
- }
+ pub(crate) fn was_grabbed(&self, pid: u32) -> bool { self.grab.load(Ordering::Relaxed) == pid }
}
--
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