From ed055640119d7078d9b9ec1aea6ebc99dd1c6a43 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Tue, 14 Nov 2017 21:16:35 -0700
Subject: [PATCH] Remove SwitchResult, use out of band data to detect
interruption Update debugging code
---
src/context/mod.rs | 2 +-
src/context/switch.rs | 42 +++++++++++++-------------------------
src/lib.rs | 27 +++++++++---------------
src/scheme/pipe.rs | 9 +++-----
src/sync/wait_condition.rs | 37 +++++++++++++++++++++++++++++----
src/syscall/mod.rs | 13 ++++++------
6 files changed, 68 insertions(+), 62 deletions(-)
diff --git a/src/context/mod.rs b/src/context/mod.rs
index 62ef93a0..f0e428c1 100644
--- a/src/context/mod.rs
+++ b/src/context/mod.rs
@@ -7,7 +7,7 @@ use spin::{Once, RwLock, RwLockReadGuard, RwLockWriteGuard};
pub use self::context::{Context, ContextId, Status};
pub use self::list::ContextList;
-pub use self::switch::{switch, SwitchResult};
+pub use self::switch::switch;
#[path = "arch/x86_64.rs"]
mod arch;
diff --git a/src/context/switch.rs b/src/context/switch.rs
index 91ac6f2d..28b06965 100644
--- a/src/context/switch.rs
+++ b/src/context/switch.rs
@@ -10,22 +10,12 @@ use interrupt::irq::PIT_TICKS;
use syscall;
use time;
-#[must_use]
-pub enum SwitchResult {
- /// No context to switch to
- None,
- /// Received a signal
- Signal,
- /// Switched correctly
- Normal,
-}
-
/// Switch to the next context
///
/// # Safety
///
/// Do not call this while holding locks!
-pub unsafe fn switch() -> SwitchResult {
+pub unsafe fn switch() -> bool {
use core::ops::DerefMut;
//set PIT Interrupt counter to 0, giving each process same amount of PIT ticks
@@ -148,28 +138,24 @@ pub unsafe fn switch() -> SwitchResult {
if to_ptr as usize == 0 {
// No target was found, return
- SwitchResult::None
- } else if let Some(sig) = to_sig {
- // Signal was found, run signal handler
-
- //TODO: Allow nested signals
- assert!((&mut *to_ptr).ksig.is_none());
-
- let arch = (&mut *to_ptr).arch.clone();
- let kfx = (&mut *to_ptr).kfx.clone();
- let kstack = (&mut *to_ptr).kstack.clone();
- (&mut *to_ptr).ksig = Some((arch, kfx, kstack));
- (&mut *to_ptr).arch.signal_stack(signal_handler, sig);
+ false
+ } else {
+ if let Some(sig) = to_sig {
+ // Signal was found, run signal handler
- (&mut *from_ptr).arch.switch_to(&mut (&mut *to_ptr).arch);
+ //TODO: Allow nested signals
+ assert!((&mut *to_ptr).ksig.is_none());
- SwitchResult::Signal
- } else {
- // Found a target, had no signals
+ let arch = (&mut *to_ptr).arch.clone();
+ let kfx = (&mut *to_ptr).kfx.clone();
+ let kstack = (&mut *to_ptr).kstack.clone();
+ (&mut *to_ptr).ksig = Some((arch, kfx, kstack));
+ (&mut *to_ptr).arch.signal_stack(signal_handler, sig);
+ }
(&mut *from_ptr).arch.switch_to(&mut (&mut *to_ptr).arch);
- SwitchResult::Normal
+ true
}
}
diff --git a/src/lib.rs b/src/lib.rs
index 6a509ef8..c6f40ee7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -39,7 +39,6 @@ use alloc::arc::Arc;
use core::sync::atomic::{AtomicUsize, ATOMIC_USIZE_INIT, Ordering};
use spin::Mutex;
-use context::SwitchResult;
use scheme::{FileHandle, SchemeNamespace};
pub use consts::*;
@@ -170,14 +169,11 @@ pub fn kmain(cpus: usize, env: &[u8]) -> ! {
loop {
unsafe {
interrupt::disable();
- match context::switch() {
- SwitchResult::None => {
- // Enable interrupts, then halt CPU (to save power) until the next interrupt is actually fired.
- interrupt::enable_and_halt();
- }
- _ => {
- interrupt::enable_and_nop();
- }
+ if context::switch() {
+ interrupt::enable_and_nop();
+ } else {
+ // Enable interrupts, then halt CPU (to save power) until the next interrupt is actually fired.
+ interrupt::enable_and_halt();
}
}
}
@@ -197,14 +193,11 @@ pub fn kmain_ap(id: usize) -> ! {
loop {
unsafe {
interrupt::disable();
- match context::switch() {
- SwitchResult::None => {
- // Enable interrupts, then halt CPU (to save power) until the next interrupt is actually fired.
- interrupt::enable_and_halt();
- }
- _ => {
- interrupt::enable_and_nop();
- }
+ if context::switch() {
+ interrupt::enable_and_nop();
+ } else {
+ // Enable interrupts, then halt CPU (to save power) until the next interrupt is actually fired.
+ interrupt::enable_and_halt();
}
}
}
diff --git a/src/scheme/pipe.rs b/src/scheme/pipe.rs
index cf677601..fbbbb9eb 100644
--- a/src/scheme/pipe.rs
+++ b/src/scheme/pipe.rs
@@ -3,7 +3,7 @@ use alloc::{BTreeMap, VecDeque};
use core::sync::atomic::{AtomicUsize, ATOMIC_USIZE_INIT, Ordering};
use spin::{Mutex, Once, RwLock, RwLockReadGuard, RwLockWriteGuard};
-use context::{self, SwitchResult};
+use context;
use scheme::{AtomicSchemeId, ATOMIC_SCHEMEID_INIT, SchemeId};
use sync::WaitCondition;
use syscall::error::{Error, Result, EAGAIN, EBADF, EINTR, EINVAL, EPIPE, ESPIPE};
@@ -236,11 +236,8 @@ impl PipeRead {
} else if self.flags.load(Ordering::SeqCst) & O_NONBLOCK == O_NONBLOCK {
return Err(Error::new(EAGAIN));
} else {
- match self.condition.wait() {
- SwitchResult::Signal => {
- return Err(Error::new(EINTR));
- },
- _ => ()
+ if ! self.condition.wait() {
+ return Err(Error::new(EINTR));
}
}
}
diff --git a/src/sync/wait_condition.rs b/src/sync/wait_condition.rs
index 8c9a6a7c..500e8cd3 100644
--- a/src/sync/wait_condition.rs
+++ b/src/sync/wait_condition.rs
@@ -2,7 +2,7 @@ use alloc::arc::Arc;
use alloc::Vec;
use spin::{Mutex, RwLock};
-use context::{self, Context, SwitchResult};
+use context::{self, Context};
#[derive(Debug)]
pub struct WaitCondition {
@@ -25,7 +25,8 @@ impl WaitCondition {
len
}
- pub fn wait(&self) -> SwitchResult {
+ pub fn wait(&self) -> bool {
+ let id;
{
let context_lock = {
let contexts = context::contexts();
@@ -33,12 +34,40 @@ impl WaitCondition {
context_lock.clone()
};
- context_lock.write().block();
+ {
+ let mut context = context_lock.write();
+ id = context.id;
+ context.block();
+ }
self.contexts.lock().push(context_lock);
}
- unsafe { context::switch() }
+ unsafe { context::switch(); }
+
+ let mut waited = true;
+
+ {
+ let mut contexts = self.contexts.lock();
+
+ let mut i = 0;
+ while i < contexts.len() {
+ let remove = {
+ let context = contexts[i].read();
+ context.id == id
+ };
+
+ if remove {
+ contexts.remove(i);
+ waited = false;
+ break;
+ } else {
+ i += 1;
+ }
+ }
+ }
+
+ waited
}
}
diff --git a/src/syscall/mod.rs b/src/syscall/mod.rs
index 22e62b1c..793f23b2 100644
--- a/src/syscall/mod.rs
+++ b/src/syscall/mod.rs
@@ -142,7 +142,9 @@ pub extern fn syscall(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize
let contexts = ::context::contexts();
if let Some(context_lock) = contexts.current() {
let context = context_lock.read();
- if unsafe { ::core::str::from_utf8_unchecked(&context.name.lock()) } == "file:/bin/acid" {
+ let name_raw = context.name.lock();
+ let name = unsafe { ::core::str::from_utf8_unchecked(&name_raw) };
+ if name == "file:/bin/cargo" || name == "file:/bin/rustc" {
if (a == SYS_WRITE || a == SYS_FSYNC) && (b == 1 || b == 2) {
false
} else {
@@ -163,8 +165,7 @@ pub extern fn syscall(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize
print!("{} ({}): ", unsafe { ::core::str::from_utf8_unchecked(&context.name.lock()) }, context.id.into());
}
- let _ = debug::print_call(a, b, c, d, e, f);
- println!("");
+ println!("{}", debug::format_call(a, b, c, d, e, f));
}
*/
@@ -194,14 +195,14 @@ pub extern fn syscall(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize
print!("{} ({}): ", unsafe { ::core::str::from_utf8_unchecked(&context.name.lock()) }, context.id.into());
}
- let _ = debug::print_call(a, b, c, d, e, f);
+ print!("{} = ", debug::format_call(a, b, c, d, e, f));
match result {
Ok(ref ok) => {
- println!(" = Ok({} ({:#X}))", ok, ok);
+ println!("Ok({} ({:#X}))", ok, ok);
},
Err(ref err) => {
- println!(" = Err({} ({:#X}))", err, err.errno);
+ println!("Err({} ({:#X}))", err, err.errno);
}
}
}
--
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