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Merge branch 'pipe_list_const_fn' into 'master'

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Move more of `pipe:`'s initialization to compile time.

See merge request redox-os/kernel!182
This commit is contained in:
Jeremy Soller
2022-03-30 13:54:27 +00:00
parent cbc2902852 e92ff831b7
commit 37ebef2d35
2 changed files with 59 additions and 66 deletions
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57
src/scheme/pipe.rs
View File

@@ -4,7 +4,7 @@ use core::sync::atomic::{AtomicUsize, Ordering};
use spin::{Mutex, Once, RwLock, RwLockReadGuard, RwLockWriteGuard};
use crate::event;
use crate::scheme::{AtomicSchemeId, SchemeId};
use crate::scheme::SchemeId;
use crate::sync::WaitCondition;
use crate::syscall::error::{Error, Result, EAGAIN, EBADF, EINTR, EINVAL, EPIPE, ESPIPE};
use crate::syscall::flag::{EventFlags, EVENT_READ, EVENT_WRITE, F_GETFL, F_SETFL, O_ACCMODE, O_NONBLOCK, MODE_FIFO};
@@ -12,30 +12,21 @@ use crate::syscall::scheme::Scheme;
use crate::syscall::data::Stat;
/// Pipes list
pub static PIPE_SCHEME_ID: AtomicSchemeId = AtomicSchemeId::default();
// TODO: Preallocate a number of scheme IDs, since there can only be *one* root namespace, and
// therefore only *one* pipe scheme.
static PIPE_SCHEME_ID: Once<SchemeId> = Once::new();
static PIPE_NEXT_ID: AtomicUsize = AtomicUsize::new(0);
static PIPES: Once<RwLock<(BTreeMap<usize, Arc<PipeRead>>, BTreeMap<usize, Arc<PipeWrite>>)>> = Once::new();
static PIPES: RwLock<(BTreeMap<usize, Arc<PipeRead>>, BTreeMap<usize, Arc<PipeWrite>>)> = RwLock::new((BTreeMap::new(), BTreeMap::new()));
/// Initialize pipes, called if needed
fn init_pipes() -> RwLock<(BTreeMap<usize, Arc<PipeRead>>, BTreeMap<usize, Arc<PipeWrite>>)> {
RwLock::new((BTreeMap::new(), BTreeMap::new()))
}
/// Get the global pipes list, const
fn pipes() -> RwLockReadGuard<'static, (BTreeMap<usize, Arc<PipeRead>>, BTreeMap<usize, Arc<PipeWrite>>)> {
PIPES.call_once(init_pipes).read()
}
/// Get the global pipes list, mutable
fn pipes_mut() -> RwLockWriteGuard<'static, (BTreeMap<usize, Arc<PipeRead>>, BTreeMap<usize, Arc<PipeWrite>>)> {
PIPES.call_once(init_pipes).write()
pub fn pipe_scheme_id() -> Option<SchemeId> {
PIPE_SCHEME_ID.get().copied()
}
pub fn pipe(flags: usize) -> (usize, usize) {
let mut pipes = pipes_mut();
let scheme_id = PIPE_SCHEME_ID.load(Ordering::SeqCst);
let read_id = PIPE_NEXT_ID.fetch_add(1, Ordering::SeqCst);
let write_id = PIPE_NEXT_ID.fetch_add(1, Ordering::SeqCst);
let mut pipes = PIPES.write();
let scheme_id = *PIPE_SCHEME_ID.get().expect("pipe scheme not initialized when calling pipe()");
let read_id = PIPE_NEXT_ID.fetch_add(1, Ordering::Relaxed);
let write_id = PIPE_NEXT_ID.fetch_add(1, Ordering::Relaxed);
let read = PipeRead::new(scheme_id, write_id, flags);
let write = PipeWrite::new(&read, read_id, flags);
pipes.0.insert(read_id, Arc::new(read));
@@ -47,7 +38,12 @@ pub struct PipeScheme;
impl PipeScheme {
pub fn new(scheme_id: SchemeId) -> PipeScheme {
PIPE_SCHEME_ID.store(scheme_id, Ordering::SeqCst);
let mut called = false;
PIPE_SCHEME_ID.call_once(|| {
called = true;
scheme_id
});
assert!(called, "calling PipeScheme::new more than once");
PipeScheme
}
}
@@ -56,7 +52,7 @@ impl Scheme for PipeScheme {
fn read(&self, id: usize, buf: &mut [u8]) -> Result<usize> {
// Clone to prevent deadlocks
let pipe = {
let pipes = pipes();
let pipes = PIPES.read();
pipes.0.get(&id).map(|pipe| pipe.clone()).ok_or(Error::new(EBADF))?
};
@@ -66,7 +62,7 @@ impl Scheme for PipeScheme {
fn write(&self, id: usize, buf: &[u8]) -> Result<usize> {
// Clone to prevent deadlocks
let pipe = {
let pipes = pipes();
let pipes = PIPES.read();
pipes.1.get(&id).map(|pipe| pipe.clone()).ok_or(Error::new(EBADF))?
};
@@ -74,7 +70,7 @@ impl Scheme for PipeScheme {
}
fn fcntl(&self, id: usize, cmd: usize, arg: usize) -> Result<usize> {
let pipes = pipes();
let pipes = PIPES.read();
if let Some(pipe) = pipes.0.get(&id) {
return pipe.fcntl(cmd, arg);
@@ -88,7 +84,7 @@ impl Scheme for PipeScheme {
}
fn fevent(&self, id: usize, flags: EventFlags) -> Result<EventFlags> {
let pipes = pipes();
let pipes = PIPES.read();
if let Some(pipe) = pipes.0.get(&id) {
if flags == EVENT_READ {
@@ -111,13 +107,10 @@ impl Scheme for PipeScheme {
}
fn fpath(&self, _id: usize, buf: &mut [u8]) -> Result<usize> {
let mut i = 0;
let scheme_path = b"pipe:";
while i < buf.len() && i < scheme_path.len() {
buf[i] = scheme_path[i];
i += 1;
}
Ok(i)
let to_copy = core::cmp::min(buf.len(), scheme_path.len());
buf[..to_copy].copy_from_slice(&scheme_path[..to_copy]);
Ok(to_copy)
}
fn fstat(&self, _id: usize, stat: &mut Stat) -> Result<usize> {
@@ -134,7 +127,7 @@ impl Scheme for PipeScheme {
}
fn close(&self, id: usize) -> Result<usize> {
let mut pipes = pipes_mut();
let mut pipes = PIPES.write();
drop(pipes.0.remove(&id));
drop(pipes.1.remove(&id));

68
src/syscall/fs.rs
View File

@@ -162,41 +162,41 @@ pub fn open(path: &str, flags: usize) -> Result<FileHandle> {
}
pub fn pipe2(fds: &mut [usize], flags: usize) -> Result<usize> {
if fds.len() >= 2 {
let scheme_id = crate::scheme::pipe::PIPE_SCHEME_ID.load(Ordering::SeqCst);
let (read_id, write_id) = crate::scheme::pipe::pipe(flags);
let contexts = context::contexts();
let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
let context = context_lock.read();
let read_fd = context.add_file(FileDescriptor {
description: Arc::new(RwLock::new(FileDescription {
namespace: context.ens,
scheme: scheme_id,
number: read_id,
flags: O_RDONLY | flags & !O_ACCMODE & !O_CLOEXEC,
})),
cloexec: flags & O_CLOEXEC == O_CLOEXEC,
}).ok_or(Error::new(EMFILE))?;
let write_fd = context.add_file(FileDescriptor {
description: Arc::new(RwLock::new(FileDescription {
namespace: context.ens,
scheme: scheme_id,
number: write_id,
flags: O_WRONLY | flags & !O_ACCMODE & !O_CLOEXEC,
})),
cloexec: flags & O_CLOEXEC == O_CLOEXEC,
}).ok_or(Error::new(EMFILE))?;
fds[0] = read_fd.into();
fds[1] = write_fd.into();
Ok(0)
} else {
Err(Error::new(EFAULT))
if fds.len() < 2 {
return Err(Error::new(EFAULT));
}
let scheme_id = crate::scheme::pipe::pipe_scheme_id().ok_or(Error::new(ENODEV))?;
let (read_id, write_id) = crate::scheme::pipe::pipe(flags);
let contexts = context::contexts();
let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
let context = context_lock.read();
let read_fd = context.add_file(FileDescriptor {
description: Arc::new(RwLock::new(FileDescription {
namespace: context.ens,
scheme: scheme_id,
number: read_id,
flags: O_RDONLY | flags & !O_ACCMODE & !O_CLOEXEC,
})),
cloexec: flags & O_CLOEXEC == O_CLOEXEC,
}).ok_or(Error::new(EMFILE))?;
let write_fd = context.add_file(FileDescriptor {
description: Arc::new(RwLock::new(FileDescription {
namespace: context.ens,
scheme: scheme_id,
number: write_id,
flags: O_WRONLY | flags & !O_ACCMODE & !O_CLOEXEC,
})),
cloexec: flags & O_CLOEXEC == O_CLOEXEC,
}).ok_or(Error::new(EMFILE))?;
fds[0] = read_fd.into();
fds[1] = write_fd.into();
Ok(0)
}
/// chmod syscall