From 83dea72a5068eb0f3f984f5df07584c3f590fa38 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jeremy@system76.com>
Date: Sat, 13 Feb 2021 12:57:53 -0700
Subject: [PATCH] Switch Context::files to RwLock
---
src/context/context.rs | 14 +++++++-------
src/event.rs | 2 +-
src/scheme/sys/iostat.rs | 2 +-
src/scheme/user.rs | 4 ++--
src/syscall/fs.rs | 2 +-
src/syscall/process.rs | 10 +++++-----
6 files changed, 17 insertions(+), 17 deletions(-)
diff --git a/src/context/context.rs b/src/context/context.rs
index 2068d399..fccd6b0e 100644
--- a/src/context/context.rs
+++ b/src/context/context.rs
@@ -127,7 +127,7 @@ impl ContextSnapshot {
pub fn new(context: &Context) -> Self {
let name = context.name.read().clone();
let mut files = Vec::new();
- for descriptor_opt in context.files.lock().iter() {
+ for descriptor_opt in context.files.read().iter() {
let description = if let Some(descriptor) = descriptor_opt {
let description = descriptor.description.read();
Some(FileDescription {
@@ -239,7 +239,7 @@ pub struct Context {
/// The current working directory
pub cwd: Arc<RwLock<Vec<u8>>>,
/// The open files in the scheme
- pub files: Arc<Mutex<Vec<Option<FileDescriptor>>>>,
+ pub files: Arc<RwLock<Vec<Option<FileDescriptor>>>>,
/// Signal actions
pub actions: Arc<Mutex<Vec<(SigAction, usize)>>>,
/// The pointer to the user-space registers, saved after certain
@@ -294,7 +294,7 @@ impl Context {
grants: Arc::new(Mutex::new(UserGrants::default())),
name: Arc::new(RwLock::new(String::new().into_boxed_str())),
cwd: Arc::new(RwLock::new(Vec::new())),
- files: Arc::new(Mutex::new(Vec::new())),
+ files: Arc::new(RwLock::new(Vec::new())),
actions: Arc::new(Mutex::new(vec![(
SigAction {
sa_handler: unsafe { mem::transmute(SIG_DFL) },
@@ -416,7 +416,7 @@ impl Context {
/// Add a file to the lowest available slot greater than or equal to min.
/// Return the file descriptor number or None if no slot was found
pub fn add_file_min(&self, file: FileDescriptor, min: usize) -> Option<FileHandle> {
- let mut files = self.files.lock();
+ let mut files = self.files.write();
for (i, file_option) in files.iter_mut().enumerate() {
if file_option.is_none() && i >= min {
*file_option = Some(file);
@@ -439,7 +439,7 @@ impl Context {
/// Get a file
pub fn get_file(&self, i: FileHandle) -> Option<FileDescriptor> {
- let files = self.files.lock();
+ let files = self.files.read();
if i.into() < files.len() {
files[i.into()].clone()
} else {
@@ -450,7 +450,7 @@ impl Context {
/// Insert a file with a specific handle number. This is used by dup2
/// Return the file descriptor number or None if the slot was not empty, or i was invalid
pub fn insert_file(&self, i: FileHandle, file: FileDescriptor) -> Option<FileHandle> {
- let mut files = self.files.lock();
+ let mut files = self.files.write();
if i.into() < super::CONTEXT_MAX_FILES {
while i.into() >= files.len() {
files.push(None);
@@ -469,7 +469,7 @@ impl Context {
/// Remove a file
// TODO: adjust files vector to smaller size if possible
pub fn remove_file(&self, i: FileHandle) -> Option<FileDescriptor> {
- let mut files = self.files.lock();
+ let mut files = self.files.write();
if i.into() < files.len() {
files[i.into()].take()
} else {
diff --git a/src/event.rs b/src/event.rs
index f221bc20..73e2de1f 100644
--- a/src/event.rs
+++ b/src/event.rs
@@ -35,7 +35,7 @@ impl EventQueue {
let contexts = context::contexts();
let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
let context = context_lock.read();
- let files = context.files.lock();
+ let files = context.files.read();
match files.get(event.id).ok_or(Error::new(EBADF))? {
Some(file) => file.clone(),
None => return Err(Error::new(EBADF))
diff --git a/src/scheme/sys/iostat.rs b/src/scheme/sys/iostat.rs
index 6a732279..fe0d65fa 100644
--- a/src/scheme/sys/iostat.rs
+++ b/src/scheme/sys/iostat.rs
@@ -16,7 +16,7 @@ pub fn resource() -> Result<Vec<u8>> {
let contexts = context::contexts();
for (id, context_lock) in contexts.iter() {
let context = context_lock.read();
- rows.push((*id, context.name.read().clone(), context.files.lock().clone()));
+ rows.push((*id, context.name.read().clone(), context.files.read().clone()));
}
}
diff --git a/src/scheme/user.rs b/src/scheme/user.rs
index 8ba07864..c28b8a4f 100644
--- a/src/scheme/user.rs
+++ b/src/scheme/user.rs
@@ -349,7 +349,7 @@ impl Scheme for UserScheme {
// TODO: Faster, cleaner mechanism to get descriptor
let scheme = inner.scheme_id.load(Ordering::SeqCst);
let mut desc_res = Err(Error::new(EBADF));
- for context_file_opt in context.files.lock().iter() {
+ for context_file_opt in context.files.read().iter() {
if let Some(context_file) = context_file_opt {
let (context_scheme, context_number) = {
let desc = context_file.description.read();
@@ -402,7 +402,7 @@ impl Scheme for UserScheme {
// TODO: Faster, cleaner mechanism to get descriptor
let scheme = inner.scheme_id.load(Ordering::SeqCst);
let mut desc_res = Err(Error::new(EBADF));
- for context_file_opt in context.files.lock().iter() {
+ for context_file_opt in context.files.read().iter() {
if let Some(context_file) = context_file_opt {
let (context_scheme, context_number) = {
let desc = context_file.description.read();
diff --git a/src/syscall/fs.rs b/src/syscall/fs.rs
index 780f869c..dd19ea42 100644
--- a/src/syscall/fs.rs
+++ b/src/syscall/fs.rs
@@ -377,7 +377,7 @@ pub fn fcntl(fd: FileHandle, cmd: usize, arg: usize) -> Result<usize> {
let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
let context = context_lock.read();
- let mut files = context.files.lock();
+ let mut files = context.files.write();
match *files.get_mut(fd.into()).ok_or(Error::new(EBADF))? {
Some(ref mut file) => match cmd {
F_GETFD => {
diff --git a/src/syscall/process.rs b/src/syscall/process.rs
index 4f0cbacf..262ffff9 100644
--- a/src/syscall/process.rs
+++ b/src/syscall/process.rs
@@ -259,7 +259,7 @@ pub fn clone(flags: CloneFlags, stack_base: usize) -> Result<ContextId> {
if flags.contains(CLONE_FILES) {
files = Arc::clone(&context.files);
} else {
- files = Arc::new(Mutex::new(context.files.lock().clone()));
+ files = Arc::new(RwLock::new(context.files.read().clone()));
}
if flags.contains(CLONE_SIGHAND) {
@@ -272,7 +272,7 @@ pub fn clone(flags: CloneFlags, stack_base: usize) -> Result<ContextId> {
// If not cloning files, dup to get a new number from scheme
// This has to be done outside the context lock to prevent deadlocks
if !flags.contains(CLONE_FILES) {
- for (_fd, file_opt) in files.lock().iter_mut().enumerate() {
+ for (_fd, file_opt) in files.write().iter_mut().enumerate() {
let new_file_opt = if let Some(ref file) = *file_opt {
Some(FileDescriptor {
description: Arc::clone(&file.description),
@@ -866,7 +866,7 @@ fn fexec_noreturn(
(vfork, context.ppid, files)
};
- for (_fd, file_opt) in files.lock().iter_mut().enumerate() {
+ for (_fd, file_opt) in files.write().iter_mut().enumerate() {
let mut cloexec = false;
if let Some(ref file) = *file_opt {
if file.cloexec {
@@ -1108,12 +1108,12 @@ pub fn exit(status: usize) -> ! {
let pid = {
let mut context = context_lock.write();
{
- let mut lock = context.files.lock();
+ let mut lock = context.files.write();
if Arc::strong_count(&context.files) == 1 {
mem::swap(lock.deref_mut(), &mut close_files);
}
}
- context.files = Arc::new(Mutex::new(Vec::new()));
+ context.files = Arc::new(RwLock::new(Vec::new()));
context.id
};
--
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