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Encapsulate accesses to IndexStore::streams and ::stream_aliases

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These two fields are able to hold `Stream` instances, which predicates like `close/1`
expect to be managed properly for their correctness. To ensure that this is the case,
I have removed direct accesses to those two fields, so that they can be properly managed
in one place.
This commit is contained in:
Emilie Burgun
2025-02-03 14:00:37 +01:00
parent 2fe7b55343
commit 0cf46d3ec4
5 changed files with 187 additions and 124 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
src/machine/loader.rs
View File

@@ -1808,7 +1808,7 @@ impl Machine {
pub(crate) fn push_load_context(&mut self) -> CallResult {
let stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("$push_load_context"),
2,
)?;

105
src/machine/machine_indices.rs
View File

@@ -7,8 +7,9 @@ use crate::atom_table::*;
use crate::forms::*;
use crate::machine::loader::*;
use crate::machine::machine_state::*;
use crate::machine::streams::Stream;
use crate::machine::streams::{Stream, StreamOptions};
use crate::machine::ClauseType;
use crate::machine::MachineStubGen;
use fxhash::FxBuildHasher;
use indexmap::{IndexMap, IndexSet};
@@ -261,8 +262,8 @@ pub struct IndexStore {
pub(super) meta_predicates: MetaPredicateDir,
pub(super) modules: ModuleDir,
pub(super) op_dir: OpDir,
pub(super) streams: StreamDir,
pub(super) stream_aliases: StreamAliasDir,
streams: StreamDir,
stream_aliases: StreamAliasDir,
}
impl IndexStore {
@@ -459,6 +460,94 @@ impl IndexStore {
}
}
pub(crate) fn add_stream(
&mut self,
stream: Stream,
stub_name: Atom,
stub_arity: usize,
) -> Result<(), MachineStubGen> {
if let Some(alias) = stream.options().get_alias() {
if self.stream_aliases.contains_key(&alias) {
return Err(Box::new(move |machine_st| {
machine_st.occupied_alias_permission_error(alias, stub_name, stub_arity)
}));
}
self.stream_aliases.insert(alias, stream);
}
self.streams.insert(stream);
Ok(())
}
pub(crate) fn remove_stream(&mut self, stream: Stream) {
if let Some(alias) = stream.options().get_alias() {
debug_assert_eq!(self.stream_aliases.get(&alias), Some(&stream));
self.stream_aliases.swap_remove(&alias);
}
self.streams.remove(&stream);
}
pub(crate) fn update_stream_options<F: Fn(&mut StreamOptions)>(
&mut self,
mut stream: Stream,
callback: F,
) {
if let Some(prev_alias) = stream.options().get_alias() {
debug_assert_eq!(self.stream_aliases.get(&prev_alias), Some(&stream));
}
let options = stream.options_mut();
let prev_alias = options.get_alias();
callback(options);
if options.get_alias() != prev_alias {
if let Some(prev_alias) = prev_alias {
self.stream_aliases.swap_remove(&prev_alias);
}
if let Some(new_alias) = options.get_alias() {
self.stream_aliases.insert(new_alias, stream);
}
}
}
pub(crate) fn has_stream(&self, alias: Atom) -> bool {
self.stream_aliases.contains_key(&alias)
}
pub(crate) fn get_stream(&self, alias: Atom) -> Option<Stream> {
self.stream_aliases.get(&alias).copied()
}
pub(crate) fn iter_streams<'a, R: std::ops::RangeBounds<Stream>>(
&'a self,
range: R,
) -> impl Iterator<Item = Stream> + 'a {
self.streams.range(range).into_iter().copied()
}
/// Forcibly sets `alias` to `stream`.
/// If there was a previous stream with that alias, it will lose that alias.
///
/// Consider using [`add_stream`](Self::add_stream) if you wish to instead
/// return an error when stream aliases conflict.
pub(crate) fn set_stream(&mut self, alias: Atom, mut stream: Stream) {
if let Some(mut prev_stream) = self.get_stream(alias) {
if prev_stream == stream {
// Nothing to do, as the stream is already present
return;
}
prev_stream.options_mut().set_alias_to_atom_opt(None);
}
stream.options_mut().set_alias_to_atom_opt(Some(alias));
self.stream_aliases.insert(alias, stream);
self.streams.insert(stream);
}
#[inline]
pub(super) fn new() -> Self {
index_store!(
@@ -468,3 +557,13 @@ impl IndexStore {
)
}
}
/// A stream is said to have a "protected" alias if modifying its
/// alias would cause breakage in other parts of the code.
///
/// A stream with a protected alias cannot be realiased through
/// [`IndexStore::update_stream_options`]. Instead, one has to use
/// [`IndexStore::set_stream`] to do so.
fn is_protected_alias(alias: Atom) -> bool {
alias == atom!("user_input") || alias == atom!("user_output") || alias == atom!("user_error")
}

28
src/machine/mod.rs
View File

@@ -483,32 +483,16 @@ impl Machine {
}
}
/// Ensures that [`Machine::indices`] properly reflects
/// the streams stored in [`Machine::user_input`], [`Machine::user_output`]
/// and [`Machine::user_error`].
pub(crate) fn configure_streams(&mut self) {
self.user_input
.options_mut()
.set_alias_to_atom_opt(Some(atom!("user_input")));
self.indices
.stream_aliases
.insert(atom!("user_input"), self.user_input);
self.indices.streams.insert(self.user_input);
self.user_output
.options_mut()
.set_alias_to_atom_opt(Some(atom!("user_output")));
.set_stream(atom!("user_input"), self.user_input);
self.indices
.stream_aliases
.insert(atom!("user_output"), self.user_output);
self.indices.streams.insert(self.user_output);
.set_stream(atom!("user_output"), self.user_output);
self.indices
.stream_aliases
.insert(atom!("user_error"), self.user_error);
self.indices.streams.insert(self.user_error);
.set_stream(atom!("user_error"), self.user_error);
}
#[inline(always)]

12
src/machine/streams.rs
View File

@@ -1594,7 +1594,7 @@ impl MachineState {
pub(crate) fn get_stream_or_alias(
&mut self,
addr: HeapCellValue,
stream_aliases: &StreamAliasDir,
indices: &IndexStore,
caller: Atom,
arity: usize,
) -> Result<Stream, MachineStub> {
@@ -1604,8 +1604,8 @@ impl MachineState {
(HeapCellValueTag::Atom, (name, arity)) => {
debug_assert_eq!(arity, 0);
return match stream_aliases.get(&name) {
Some(stream) if !stream.is_null_stream() => Ok(*stream),
return match indices.get_stream(name) {
Some(stream) if !stream.is_null_stream() => Ok(stream),
_ => {
let stub = functor_stub(caller, arity);
let addr = atom_as_cell!(name);
@@ -1622,8 +1622,8 @@ impl MachineState {
debug_assert_eq!(arity, 0);
return match stream_aliases.get(&name) {
Some(stream) if !stream.is_null_stream() => Ok(*stream),
return match indices.get_stream(name) {
Some(stream) if !stream.is_null_stream() => Ok(stream),
_ => {
let stub = functor_stub(caller, arity);
let addr = atom_as_cell!(name);
@@ -1813,7 +1813,7 @@ impl MachineState {
// 8.11.5.3l)
if let Some(alias) = options.get_alias() {
if indices.stream_aliases.contains_key(&alias) {
if indices.has_stream(alias) {
return Err(self.occupied_alias_permission_error(alias, atom!("open"), 4));
}
}

164
src/machine/system_calls.rs
View File

@@ -41,7 +41,6 @@ use indexmap::IndexSet;
use std::cell::Cell;
use std::cmp::Ordering;
use std::collections::BTreeSet;
use std::convert::TryFrom;
use std::env;
#[cfg(feature = "ffi")]
@@ -55,7 +54,6 @@ use std::mem;
use std::net::{SocketAddr, ToSocketAddrs};
use std::net::{TcpListener, TcpStream};
use std::num::NonZeroU32;
use std::ops::Sub;
use std::process;
#[cfg(feature = "http")]
use std::str::FromStr;
@@ -2543,7 +2541,7 @@ impl Machine {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("peek_byte"),
2,
)?;
@@ -2634,7 +2632,7 @@ impl Machine {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("peek_char"),
2,
)?;
@@ -2726,7 +2724,7 @@ impl Machine {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("peek_code"),
2,
)?;
@@ -3147,7 +3145,7 @@ impl Machine {
pub(crate) fn put_code(&mut self) -> CallResult {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("put_code"),
2,
)?;
@@ -3199,7 +3197,7 @@ impl Machine {
pub(crate) fn put_char(&mut self) -> CallResult {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("put_char"),
2,
)?;
@@ -3243,7 +3241,7 @@ impl Machine {
pub(crate) fn put_chars(&mut self) -> CallResult {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("$put_chars"),
2,
)?;
@@ -3292,7 +3290,7 @@ impl Machine {
pub(crate) fn put_byte(&mut self) -> CallResult {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("put_byte"),
2,
)?;
@@ -3359,7 +3357,7 @@ impl Machine {
pub(crate) fn get_byte(&mut self) -> CallResult {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("get_byte"),
2,
)?;
@@ -3444,7 +3442,7 @@ impl Machine {
pub(crate) fn get_char(&mut self) -> CallResult {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("get_char"),
2,
)?;
@@ -3539,7 +3537,7 @@ impl Machine {
pub(crate) fn get_n_chars(&mut self) -> CallResult {
let stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("get_n_chars"),
3,
)?;
@@ -3608,7 +3606,7 @@ impl Machine {
pub(crate) fn get_code(&mut self) -> CallResult {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("get_code"),
2,
)?;
@@ -3715,19 +3713,11 @@ impl Machine {
#[inline(always)]
pub(crate) fn first_stream(&mut self) {
let mut first_stream = None;
let mut null_streams = BTreeSet::new();
for stream in self.indices.streams.iter().cloned() {
if !stream.is_null_stream() {
first_stream = Some(stream);
break;
} else {
null_streams.insert(stream);
}
}
self.indices.streams = self.indices.streams.sub(&null_streams);
let first_stream = self
.indices
.iter_streams(..)
.filter(|s| !s.is_null_stream())
.next();
if let Some(first_stream) = first_stream {
let stream = stream_as_cell!(first_stream);
@@ -3743,20 +3733,12 @@ impl Machine {
#[inline(always)]
pub(crate) fn next_stream(&mut self) {
let prev_stream = cell_as_stream!(self.deref_register(1));
let mut next_stream = None;
let mut null_streams = BTreeSet::new();
for stream in self.indices.streams.range(prev_stream..).skip(1).cloned() {
if !stream.is_null_stream() {
next_stream = Some(stream);
break;
} else {
null_streams.insert(stream);
}
}
self.indices.streams = self.indices.streams.sub(&null_streams);
let next_stream = self
.indices
.iter_streams(prev_stream..)
.filter(|s| !s.is_null_stream())
.skip(1)
.next();
if let Some(next_stream) = next_stream {
let var = self.deref_register(2).as_var().unwrap();
@@ -3772,7 +3754,7 @@ impl Machine {
pub(crate) fn flush_output(&mut self) -> CallResult {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("flush_output"),
1,
)?;
@@ -3859,7 +3841,7 @@ impl Machine {
pub(crate) fn close(&mut self) -> CallResult {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("close"),
2,
)?;
@@ -3873,11 +3855,7 @@ impl Machine {
return Ok(());
}
self.indices.streams.remove(&stream);
if let Some(alias) = stream.options().get_alias() {
self.indices.stream_aliases.swap_remove(&alias);
}
self.indices.remove_stream(stream);
stream.close().map_err(|_| {
let stub = functor_stub(atom!("close"), 1);
@@ -4445,11 +4423,10 @@ impl Machine {
&mut self.machine_st.arena,
);
*stream.options_mut() = StreamOptions::default();
if let Some(alias) = stream.options().get_alias() {
self.indices.stream_aliases.insert(alias, stream);
}
self.indices.streams.insert(stream);
self.indices
.add_stream(stream, atom!("http_open"), 3)
.map_err(|stub_gen| stub_gen(&mut self.machine_st))?;
let stream = stream_as_cell!(stream);
@@ -4667,7 +4644,10 @@ impl Machine {
);
*stream.options_mut() = StreamOptions::default();
stream.options_mut().set_stream_type(StreamType::Binary);
self.indices.streams.insert(stream);
self.indices.add_stream(stream, atom!("http_accept"), 7)
.map_err(|stub_gen| stub_gen(&mut self.machine_st))?;
let stream = stream_as_cell!(stream);
let handle: TypedArenaPtr<HttpResponse> = arena_alloc!(request.response, &mut self.machine_st.arena);
@@ -4781,7 +4761,11 @@ impl Machine {
);
*stream.options_mut() = StreamOptions::default();
stream.options_mut().set_stream_type(StreamType::Binary);
self.indices.streams.insert(stream);
self.indices.add_stream(stream, atom!("http_answer"), 4)
.map_err(|stub_gen| stub_gen(&mut self.machine_st))?;
let stream = stream_as_cell!(stream);
self.machine_st.bind(stream_addr.as_var().unwrap(), stream);
}
@@ -5096,11 +5080,10 @@ impl Machine {
.stream_from_file_spec(file_spec, &mut self.indices, &options)?;
*stream.options_mut() = options;
self.indices.streams.insert(stream);
if let Some(alias) = stream.options().get_alias() {
self.indices.stream_aliases.insert(alias, stream);
}
self.indices
.add_stream(stream, atom!("open"), 4)
.map_err(|stub_gen| stub_gen(&mut self.machine_st))?;
let stream_var = self.deref_register(3);
self.machine_st
@@ -5181,7 +5164,7 @@ impl Machine {
pub(crate) fn set_stream_options(&mut self) -> CallResult {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("open"),
4,
)?;
@@ -5937,12 +5920,9 @@ impl Machine {
pub(crate) fn set_input(&mut self) -> CallResult {
let addr = self.deref_register(1);
let stream = self.machine_st.get_stream_or_alias(
addr,
&self.indices.stream_aliases,
atom!("set_input"),
1,
)?;
let stream =
self.machine_st
.get_stream_or_alias(addr, &self.indices, atom!("set_input"), 1)?;
if !stream.is_input_stream() {
let stub = functor_stub(atom!("set_input"), 1);
@@ -5964,12 +5944,9 @@ impl Machine {
#[inline(always)]
pub(crate) fn set_output(&mut self) -> CallResult {
let addr = self.deref_register(1);
let stream = self.machine_st.get_stream_or_alias(
addr,
&self.indices.stream_aliases,
atom!("set_output"),
1,
)?;
let stream =
self.machine_st
.get_stream_or_alias(addr, &self.indices, atom!("set_output"), 1)?;
if !stream.is_output_stream() {
let stub = functor_stub(atom!("set_output"), 1);
@@ -6275,7 +6252,7 @@ impl Machine {
let stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("read_term"),
3,
)?;
@@ -6516,7 +6493,7 @@ impl Machine {
}
if let Some(alias) = options.get_alias() {
if self.indices.stream_aliases.contains_key(&alias) {
if self.indices.has_stream(alias) {
return Err(self.machine_st.occupied_alias_permission_error(
alias,
atom!("socket_client_open"),
@@ -6532,11 +6509,9 @@ impl Machine {
*stream.options_mut() = options;
if let Some(alias) = stream.options().get_alias() {
self.indices.stream_aliases.insert(alias, stream);
}
self.indices.streams.insert(stream);
self.indices
.add_stream(stream, atom!("socket_client_open"), 7)
.map_err(|stub_gen| stub_gen(&mut self.machine_st))?;
stream_as_cell!(stream)
}
@@ -6544,7 +6519,7 @@ impl Machine {
return Err(self.machine_st.open_permission_error(
addr,
atom!("socket_client_open"),
3,
7,
));
}
Err(ErrorKind::NotFound) => {
@@ -6661,7 +6636,7 @@ impl Machine {
}
if let Some(alias) = options.get_alias() {
if self.indices.stream_aliases.contains_key(&alias) {
if self.indices.has_stream(alias) {
return Err(self.machine_st.occupied_alias_permission_error(
alias,
atom!("socket_server_accept"),
@@ -6688,11 +6663,10 @@ impl Machine {
*tcp_stream.options_mut() = options;
if let Some(alias) = &tcp_stream.options().get_alias() {
self.indices.stream_aliases.insert(*alias, tcp_stream);
}
self.indices.streams.insert(tcp_stream);
self.indices.add_stream(tcp_stream, atom!("socket_server_accept"), 4)
.map_err(|stub_gen| {
stub_gen(&mut self.machine_st)
})?;
let tcp_stream = stream_as_cell!(tcp_stream);
let client = atom_as_cell!(client);
@@ -6728,7 +6702,7 @@ impl Machine {
{
let stream0 = self.machine_st.get_stream_or_alias(
self.machine_st.registers[2],
&self.indices.stream_aliases,
&self.indices,
atom!("tls_client_negotiate"),
3,
)?;
@@ -6747,7 +6721,10 @@ impl Machine {
let addr = atom!("TLS");
let stream = Stream::from_tls_stream(addr, stream, &mut self.machine_st.arena);
self.indices.streams.insert(stream);
self.indices
.add_stream(stream, atom!("tls_client_negotiate"), 3)
.map_err(|stub_gen| stub_gen(&mut self.machine_st))?;
self.machine_st.heap.push(stream_as_cell!(stream));
let stream_addr = self.deref_register(3);
@@ -6782,7 +6759,7 @@ impl Machine {
let stream0 = self.machine_st.get_stream_or_alias(
self.machine_st.registers[3],
&self.indices.stream_aliases,
&self.indices,
atom!("tls_server_negotiate"),
3,
)?;
@@ -6801,7 +6778,10 @@ impl Machine {
};
let stream = Stream::from_tls_stream(atom!("TLS"), stream, &mut self.machine_st.arena);
self.indices.streams.insert(stream);
self.indices
.add_stream(stream, atom!("tls_server_negotiate"), 3)
.map_err(|stub_gen| stub_gen(&mut self.machine_st))?;
let stream_addr = self.deref_register(4);
self.machine_st
@@ -6843,7 +6823,7 @@ impl Machine {
pub(crate) fn set_stream_position(&mut self) -> CallResult {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("set_stream_position"),
2,
)?;
@@ -6886,7 +6866,7 @@ impl Machine {
pub(crate) fn stream_property(&mut self) -> CallResult {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("stream_property"),
2,
)?;
@@ -7237,7 +7217,7 @@ impl Machine {
pub(crate) fn write_term(&mut self) -> CallResult {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("write_term"),
3,
)?;
@@ -8113,7 +8093,7 @@ impl Machine {
pub(crate) fn devour_whitespace(&mut self) -> CallResult {
let mut stream = self.machine_st.get_stream_or_alias(
self.machine_st.registers[1],
&self.indices.stream_aliases,
&self.indices,
atom!("$devour_whitespace"),
1,
)?;