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implement RFCs 147 and 155, etc.

Browse source 
This commit:

- Implements RFC 147: "all functions must be safe"

- Implements RFC 155: "explicit Context parameter"

- Implements the pending breaking change #141: reject assign syntax in `init`
  (which was used to initialize late resources)

- Refactors code generation to make it more readable -- there are no more random
  identifiers in the output -- and align it with the book description of RTFM
  internals.

- Makes the framework hard depend on `core::mem::MaybeUninit` and thus will
  require nightly until that API is stabilized.

- Fixes a ceiling analysis bug where the priority of the system timer was not
  considered in the analysis.

- Shrinks the size of all the internal queues by turning `AtomicUsize` indices
  into `AtomicU8`s.

- Removes the integration with `owned_singleton`.
This commit is contained in:
Jorge Aparicio 2019-04-21 20:02:59 +02:00
parent e6fb2f216f
commit a452700628
11 changed files with 2491 additions and 2331 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

29
CHANGELOG.md
View file

@ -5,6 +5,35 @@ This project adheres to [Semantic Versioning](http://semver.org/).
## [Unreleased]
## v0.5.0 - 2019-??-?? (ALPHA pre-release)
### Changed
- [breaking-change][] [RFC 155] "explicit `Context` parameter" has been
implemented.
[RFC 155]: https://github.com/japaric/cortex-m-rtfm/issues/155
- [breaking-change][] [RFC 147] "all functions must be safe" has been
implemented.
[RFC 147]: https://github.com/japaric/cortex-m-rtfm/issues/147
- All the queues internally used by the framework now use `AtomicU8` indices
instead of `AtomicUsize`; this reduces the static memory used by the
framework.
### Removed
- [breaking-change] the integration with the `owned_singleton` crate has been
removed. You can use `heapless::Pool` instead of `alloc_singleton`.
- [breaking-change] late resources can no longer be initialized using the assign
syntax. `init::LateResources` is the only method to initialize late resources.
See [PR #140] for more details.
[PR #140]: https://github.com/japaric/cortex-m-rtfm/pull/140
## [v0.4.3] - 2019-04-21
### Changed

11
Cargo.toml
View file

@ -12,7 +12,7 @@ license = "MIT OR Apache-2.0"
name = "cortex-m-rtfm"
readme = "README.md"
repository = "https://github.com/japaric/cortex-m-rtfm"
version = "0.4.3"
version = "0.5.0-alpha.1"
[lib]
name = "rtfm"
@ -36,12 +36,13 @@ required-features = ["timer-queue"]
[dependencies]
cortex-m = "0.5.8"
cortex-m-rt = "0.6.7"
cortex-m-rtfm-macros = { path = "macros", version = "0.4.3" }
heapless = "0.4.1"
owned-singleton = "0.1.0"
cortex-m-rtfm-macros = { path = "macros", version = "0.5.0-alpha.1" }
[dependencies.heapless]
features = ["smaller-atomics"]
version = "0.4.1"
[dev-dependencies]
alloc-singleton = "0.1.0"
cortex-m-semihosting = "0.3.2"
lm3s6965 = "0.1.3"
panic-halt = "0.2.0"

6
macros/Cargo.toml
View file

@ -9,7 +9,7 @@ license = "MIT OR Apache-2.0"
name = "cortex-m-rtfm-macros"
readme = "../README.md"
repository = "https://github.com/japaric/cortex-m-rtfm"
version = "0.4.3"
version = "0.5.0-alpha.1"
[lib]
proc-macro = true
@ -22,10 +22,6 @@ proc-macro2 = "0.4.24"
features = ["extra-traits", "full"]
version = "0.15.23"
[dependencies.rand]
default-features = false
version = "0.5.5"
[features]
timer-queue = []
nightly = []

28
macros/src/analyze.rs
View file

@ -190,19 +190,20 @@ pub fn app(app: &App) -> Analysis {
}
// Ceiling analysis of free queues (consumer end point) -- first pass
// Ceiling analysis of ready queues (producer end point)
// Ceiling analysis of ready queues (producer end point) -- first pass
// Also compute more Send-ness requirements
let mut free_queues: HashMap<_, _> = app.tasks.keys().map(|task| (task.clone(), 0)).collect();
let mut ready_queues: HashMap<_, _> = dispatchers.keys().map(|level| (*level, 0)).collect();
let mut free_queues = HashMap::new();
let mut ready_queues = HashMap::new();
for (priority, task) in app.spawn_calls() {
if let Some(priority) = priority {
// Users of `spawn` contend for the to-be-spawned task FREE_QUEUE
let c = free_queues.get_mut(task).expect("BUG: free_queue.get_mut");
// Users of `spawn` contend for the spawnee FREE_QUEUE
let c = free_queues.entry(task.clone()).or_default();
*c = cmp::max(*c, priority);
// Users of `spawn` contend for the spawnee's dispatcher READY_QUEUE
let c = ready_queues
.get_mut(&app.tasks[task].args.priority)
.expect("BUG: ready_queues.get_mut");
.entry(app.tasks[task].args.priority)
.or_default();
*c = cmp::max(*c, priority);
// Send is required when sending messages from a task whose priority doesn't match the
@ -215,16 +216,23 @@ pub fn app(app: &App) -> Analysis {
}
}
// Ceiling analysis of ready queues (producer end point) -- second pass
// Ceiling analysis of free queues (consumer end point) -- second pass
// Ceiling analysis of the timer queue
let mut tq_ceiling = tq_priority;
for (priority, task) in app.schedule_calls() {
// the system timer handler contends for the spawnee's dispatcher READY_QUEUE
let c = ready_queues
.entry(app.tasks[task].args.priority)
.or_default();
*c = cmp::max(*c, tq_priority);
if let Some(priority) = priority {
// Users of `schedule` contend for the to-be-spawned task FREE_QUEUE (consumer end point)
let c = free_queues.get_mut(task).expect("BUG: free_queue.get_mut");
// Users of `schedule` contend for the spawnee task FREE_QUEUE
let c = free_queues.entry(task.clone()).or_default();
*c = cmp::max(*c, priority);
// Users of `schedule` contend for the timer queu
// Users of `schedule` contend for the timer queue
tq_ceiling = cmp::max(tq_ceiling, priority);
} else {
// spawns from `init` are excluded from the ceiling analysis

17
macros/src/check.rs
View file

@ -35,22 +35,13 @@ pub fn app(app: &App) -> parse::Result<()> {
}
}
// Check that all late resources have been initialized in `#[init]` if `init` has signature
// `fn()`
if !app.init.returns_late_resources {
for res in
app.resources
.iter()
.filter_map(|(name, res)| if res.expr.is_none() { Some(name) } else { None })
{
if app.init.assigns.iter().all(|assign| assign.left != *res) {
// Check that `init` returns `LateResources` if there's any declared late resource
if !app.init.returns_late_resources && app.resources.iter().any(|(_, res)| res.expr.is_none()) {
return Err(parse::Error::new(
res.span(),
"late resources MUST be initialized at the end of `init`",
app.init.span,
"late resources have been specified so `init` must return `init::LateResources`",
));
}
}
}
// Check that all referenced tasks have been declared
for task in app

3898
macros/src/codegen.rs
View file

File diff suppressed because it is too large Load diff

6
macros/src/lib.rs
View file

@ -288,9 +288,9 @@ mod syntax;
pub fn app(args: TokenStream, input: TokenStream) -> TokenStream {
// Parse
let args = parse_macro_input!(args as syntax::AppArgs);
let items = parse_macro_input!(input as syntax::Input).items;
let input = parse_macro_input!(input as syntax::Input);
let app = match syntax::App::parse(items, args) {
let app = match syntax::App::parse(input.items, args) {
Err(e) => return e.to_compile_error().into(),
Ok(app) => app,
};
@ -304,5 +304,5 @@ pub fn app(args: TokenStream, input: TokenStream) -> TokenStream {
let analysis = analyze::app(&app);
// Code generation
codegen::app(&app, &analysis).into()
codegen::app(&input.ident, &app, &analysis).into()
}

350
macros/src/syntax.rs
View file

@ -11,8 +11,8 @@ use syn::{
spanned::Spanned,
token::Brace,
ArgCaptured, AttrStyle, Attribute, Expr, FnArg, ForeignItem, Ident, IntSuffix, Item, ItemFn,
ItemForeignMod, ItemStatic, LitInt, Path, PathArguments, PathSegment, ReturnType, Stmt, Token,
Type, TypeTuple, Visibility,
ItemForeignMod, ItemStatic, LitInt, Pat, Path, PathArguments, ReturnType, Stmt, Token, Type,
TypeTuple, Visibility,
};
pub struct AppArgs {
@ -70,7 +70,7 @@ impl Parse for AppArgs {
pub struct Input {
_const_token: Token![const],
_ident: Ident,
pub ident: Ident,
_colon_token: Token![:],
_ty: TypeTuple,
_eq_token: Token![=],
@ -94,7 +94,7 @@ impl Parse for Input {
let content;
Ok(Input {
_const_token: input.parse()?,
_ident: input.parse()?,
ident: input.parse()?,
_colon_token: input.parse()?,
_ty: input.parse()?,
_eq_token: input.parse()?,
@ -435,7 +435,7 @@ pub type FreeInterrupts = BTreeMap<Ident, FreeInterrupt>;
pub struct Idle {
pub args: IdleArgs,
pub attrs: Vec<Attribute>,
pub unsafety: Option<Token![unsafe]>,
pub context: Pat,
pub statics: BTreeMap<Ident, Static>,
pub stmts: Vec<Stmt>,
}
@ -444,34 +444,29 @@ pub type IdleArgs = InitArgs;
impl Idle {
fn check(args: IdleArgs, item: ItemFn) -> parse::Result<Self> {
let valid_signature = item.vis == Visibility::Inherited
&& item.constness.is_none()
&& item.asyncness.is_none()
&& item.abi.is_none()
&& item.decl.generics.params.is_empty()
&& item.decl.generics.where_clause.is_none()
&& item.decl.inputs.is_empty()
&& item.decl.variadic.is_none()
&& is_bottom(&item.decl.output);
let valid_signature =
check_signature(&item) && item.decl.inputs.len() == 1 && is_bottom(&item.decl.output);
let span = item.span();
if !valid_signature {
return Err(parse::Error::new(
span,
"`idle` must have type signature `[unsafe] fn() -> !`",
));
}
if valid_signature {
if let Some((context, _)) = check_inputs(item.decl.inputs, "idle") {
let (statics, stmts) = extract_statics(item.block.stmts);
Ok(Idle {
return Ok(Idle {
args,
attrs: item.attrs,
unsafety: item.unsafety,
context,
statics: Static::parse(statics)?,
stmts,
})
});
}
}
Err(parse::Error::new(
span,
"`idle` must have type signature `fn(idle::Context) -> !`",
))
}
}
@ -596,34 +591,21 @@ impl Parse for InitArgs {
}
}
// TODO remove in v0.5.x
pub struct Assign {
pub attrs: Vec<Attribute>,
pub left: Ident,
pub right: Box<Expr>,
}
pub struct Init {
pub args: InitArgs,
pub attrs: Vec<Attribute>,
pub unsafety: Option<Token![unsafe]>,
pub statics: BTreeMap<Ident, Static>,
pub context: Pat,
pub stmts: Vec<Stmt>,
// TODO remove in v0.5.x
pub assigns: Vec<Assign>,
pub returns_late_resources: bool,
pub span: Span,
}
impl Init {
fn check(args: InitArgs, item: ItemFn) -> parse::Result<Self> {
let mut valid_signature = item.vis == Visibility::Inherited
&& item.constness.is_none()
&& item.asyncness.is_none()
&& item.abi.is_none()
&& item.decl.generics.params.is_empty()
&& item.decl.generics.where_clause.is_none()
&& item.decl.inputs.is_empty()
&& item.decl.variadic.is_none();
let mut valid_signature = check_signature(&item) && item.decl.inputs.len() == 1;
const DONT_CARE: bool = false;
let returns_late_resources = match &item.decl.output {
ReturnType::Default => false,
@ -636,36 +618,25 @@ impl Init {
} else {
valid_signature = false;
false // don't care
DONT_CARE
}
}
Type::Path(p) => {
let mut segments = p.path.segments.iter();
if p.qself.is_none()
&& p.path.leading_colon.is_none()
&& p.path.segments.len() == 2
&& segments.next().map(|s| {
s.arguments == PathArguments::None && s.ident.to_string() == "init"
}) == Some(true)
&& segments.next().map(|s| {
s.arguments == PathArguments::None
&& s.ident.to_string() == "LateResources"
}) == Some(true)
{
Type::Path(_) => {
if is_path(ty, &["init", "LateResources"]) {
// -> init::LateResources
true
} else {
valid_signature = false;
false // don't care
DONT_CARE
}
}
_ => {
valid_signature = false;
false // don't care
DONT_CARE
}
}
}
@ -673,29 +644,26 @@ impl Init {
let span = item.span();
if !valid_signature {
return Err(parse::Error::new(
span,
"`init` must have type signature `[unsafe] fn() [-> init::LateResources]`",
));
}
if valid_signature {
if let Some((context, _)) = check_inputs(item.decl.inputs, "init") {
let (statics, stmts) = extract_statics(item.block.stmts);
let (stmts, assigns) = if returns_late_resources {
(stmts, vec![])
} else {
extract_assignments(stmts)
};
Ok(Init {
return Ok(Init {
args,
attrs: item.attrs,
unsafety: item.unsafety,
statics: Static::parse(statics)?,
context,
stmts,
assigns,
returns_late_resources,
})
span,
});
}
}
Err(parse::Error::new(
span,
"`init` must have type signature `fn(init::Context) [-> init::LateResources]`",
))
}
}
@ -725,8 +693,8 @@ impl Default for Args {
pub struct Exception {
pub args: ExceptionArgs,
pub attrs: Vec<Attribute>,
pub unsafety: Option<Token![unsafe]>,
pub statics: BTreeMap<Ident, Static>,
pub context: Pat,
pub stmts: Vec<Stmt>,
}
@ -770,25 +738,21 @@ impl Parse for ExceptionArgs {
impl Exception {
fn check(args: ExceptionArgs, item: ItemFn) -> parse::Result<Self> {
let valid_signature = item.vis == Visibility::Inherited
&& item.constness.is_none()
&& item.asyncness.is_none()
&& item.abi.is_none()
&& item.decl.generics.params.is_empty()
&& item.decl.generics.where_clause.is_none()
&& item.decl.inputs.is_empty()
&& item.decl.variadic.is_none()
&& is_unit(&item.decl.output);
let valid_signature =
check_signature(&item) && item.decl.inputs.len() == 1 && is_unit(&item.decl.output);
if !valid_signature {
return Err(parse::Error::new(
item.span(),
"`exception` handlers must have type signature `[unsafe] fn()`",
));
}
let span = item.span();
let name = item.ident.to_string();
if valid_signature {
if let Some((context, _)) = check_inputs(item.decl.inputs, &name) {
let span = item.ident.span();
match &*args.binds.as_ref().unwrap_or(&item.ident).to_string() {
match &*args
.binds
.as_ref()
.map(|ident| ident.to_string())
.unwrap_or(name)
{
"MemoryManagement" | "BusFault" | "UsageFault" | "SecureFault" | "SVCall"
| "DebugMonitor" | "PendSV" => {} // OK
"SysTick" => {
@ -810,21 +774,31 @@ impl Exception {
let (statics, stmts) = extract_statics(item.block.stmts);
Ok(Exception {
return Ok(Exception {
args,
attrs: item.attrs,
unsafety: item.unsafety,
statics: Static::parse(statics)?,
context,
stmts,
})
});
}
}
Err(parse::Error::new(
span,
&format!(
"this `exception` handler must have type signature `fn({}::Context)`",
name
),
))
}
}
pub struct Interrupt {
pub args: InterruptArgs,
pub attrs: Vec<Attribute>,
pub unsafety: Option<Token![unsafe]>,
pub statics: BTreeMap<Ident, Static>,
pub context: Pat,
pub stmts: Vec<Stmt>,
}
@ -832,26 +806,15 @@ pub type InterruptArgs = ExceptionArgs;
impl Interrupt {
fn check(args: InterruptArgs, item: ItemFn) -> parse::Result<Self> {
let valid_signature = item.vis == Visibility::Inherited
&& item.constness.is_none()
&& item.asyncness.is_none()
&& item.abi.is_none()
&& item.decl.generics.params.is_empty()
&& item.decl.generics.where_clause.is_none()
&& item.decl.inputs.is_empty()
&& item.decl.variadic.is_none()
&& is_unit(&item.decl.output);
let valid_signature =
check_signature(&item) && item.decl.inputs.len() == 1 && is_unit(&item.decl.output);
let span = item.span();
if !valid_signature {
return Err(parse::Error::new(
span,
"`interrupt` handlers must have type signature `[unsafe] fn()`",
));
}
match &*item.ident.to_string() {
let name = item.ident.to_string();
if valid_signature {
if let Some((context, _)) = check_inputs(item.decl.inputs, &name) {
match &*name {
"init" | "idle" | "resources" => {
return Err(parse::Error::new(
span,
@ -863,18 +826,27 @@ impl Interrupt {
let (statics, stmts) = extract_statics(item.block.stmts);
Ok(Interrupt {
return Ok(Interrupt {
args,
attrs: item.attrs,
unsafety: item.unsafety,
statics: Static::parse(statics)?,
context,
stmts,
})
});
}
}
Err(parse::Error::new(
span,
format!(
"this `interrupt` handler must have type signature `fn({}::Context)`",
name
),
))
}
}
pub struct Resource {
pub singleton: bool,
pub cfgs: Vec<Attribute>,
pub attrs: Vec<Attribute>,
pub mutability: Option<Token![mut]>,
@ -883,7 +855,7 @@ pub struct Resource {
}
impl Resource {
fn check(mut item: ItemStatic) -> parse::Result<Resource> {
fn check(item: ItemStatic) -> parse::Result<Resource> {
if item.vis != Visibility::Inherited {
return Err(parse::Error::new(
item.span(),
@ -896,19 +868,9 @@ impl Resource {
_ => false,
};
let pos = item.attrs.iter().position(|attr| eq(attr, "Singleton"));
if let Some(pos) = pos {
item.attrs[pos].path.segments.insert(
0,
PathSegment::from(Ident::new("owned_singleton", Span::call_site())),
);
}
let (cfgs, attrs) = extract_cfgs(item.attrs);
Ok(Resource {
singleton: pos.is_some(),
cfgs,
attrs,
mutability: item.mutability,
@ -1177,47 +1139,32 @@ pub struct Task {
pub args: TaskArgs,
pub cfgs: Vec<Attribute>,
pub attrs: Vec<Attribute>,
pub unsafety: Option<Token![unsafe]>,
pub inputs: Vec<ArgCaptured>,
pub context: Pat,
pub statics: BTreeMap<Ident, Static>,
pub stmts: Vec<Stmt>,
}
impl Task {
fn check(args: TaskArgs, item: ItemFn) -> parse::Result<Self> {
let valid_signature = item.vis == Visibility::Inherited
&& item.constness.is_none()
&& item.asyncness.is_none()
&& item.abi.is_none()
&& item.decl.generics.params.is_empty()
&& item.decl.generics.where_clause.is_none()
&& item.decl.variadic.is_none()
&& is_unit(&item.decl.output);
let valid_signature =
check_signature(&item) && !item.decl.inputs.is_empty() && is_unit(&item.decl.output);
let span = item.span();
if !valid_signature {
return Err(parse::Error::new(
span,
"`task` handlers must have type signature `[unsafe] fn(..)`",
));
}
let name = item.ident.to_string();
if valid_signature {
if let Some((context, rest)) = check_inputs(item.decl.inputs, &name) {
let (statics, stmts) = extract_statics(item.block.stmts);
let mut inputs = vec![];
for input in item.decl.inputs {
if let FnArg::Captured(capture) = input {
inputs.push(capture);
} else {
return Err(parse::Error::new(
span,
let inputs = rest.map_err(|arg| {
parse::Error::new(
arg.span(),
"inputs must be named arguments (e.f. `foo: u32`) and not include `self`",
));
}
}
)
})?;
match &*item.ident.to_string() {
match &*name {
"init" | "idle" | "resources" => {
return Err(parse::Error::new(
span,
@ -1228,15 +1175,25 @@ impl Task {
}
let (cfgs, attrs) = extract_cfgs(item.attrs);
Ok(Task {
return Ok(Task {
args,
cfgs,
attrs,
unsafety: item.unsafety,
inputs,
context,
statics: Static::parse(statics)?,
stmts,
})
});
}
}
Err(parse::Error::new(
span,
&format!(
"this `task` handler must have type signature `fn({}::Context, ..)`",
name
),
))
}
}
@ -1335,38 +1292,69 @@ fn extract_statics(stmts: Vec<Stmt>) -> (Statics, Vec<Stmt>) {
(statics, stmts)
}
// TODO remove in v0.5.x
fn extract_assignments(stmts: Vec<Stmt>) -> (Vec<Stmt>, Vec<Assign>) {
let mut istmts = stmts.into_iter().rev();
// checks that the list of arguments has the form `#pat: #name::Context, (..)`
//
// if the check succeeds it returns `#pat` plus the remaining arguments
fn check_inputs(
inputs: Punctuated<FnArg, Token![,]>,
name: &str,
) -> Option<(Pat, Result<Vec<ArgCaptured>, FnArg>)> {
let mut inputs = inputs.into_iter();
let mut assigns = vec![];
let mut stmts = vec![];
while let Some(stmt) = istmts.next() {
match stmt {
Stmt::Semi(Expr::Assign(assign), semi) => {
if let Expr::Path(ref expr) = *assign.left {
if expr.path.segments.len() == 1 {
assigns.push(Assign {
attrs: assign.attrs,
left: expr.path.segments[0].ident.clone(),
right: assign.right,
});
continue;
match inputs.next() {
Some(FnArg::Captured(first)) => {
if is_path(&first.ty, &[name, "Context"]) {
let rest = inputs
.map(|arg| match arg {
FnArg::Captured(arg) => Ok(arg),
_ => Err(arg),
})
.collect::<Result<Vec<_>, _>>();
Some((first.pat, rest))
} else {
None
}
}
stmts.push(Stmt::Semi(Expr::Assign(assign), semi));
}
_ => {
stmts.push(stmt);
break;
}
_ => None,
}
}
stmts.extend(istmts);
/// checks that a function signature
///
/// - has no bounds (like where clauses)
/// - is not `async`
/// - is not `const`
/// - is not `unsafe`
/// - is not generic (has no type parametrs)
/// - is not variadic
/// - uses the Rust ABI (and not e.g. "C")
fn check_signature(item: &ItemFn) -> bool {
item.vis == Visibility::Inherited
&& item.constness.is_none()
&& item.asyncness.is_none()
&& item.abi.is_none()
&& item.unsafety.is_none()
&& item.decl.generics.params.is_empty()
&& item.decl.generics.where_clause.is_none()
&& item.decl.variadic.is_none()
}
(stmts.into_iter().rev().collect(), assigns)
fn is_path(ty: &Type, segments: &[&str]) -> bool {
match ty {
Type::Path(tpath) if tpath.qself.is_none() => {
tpath.path.segments.len() == segments.len()
&& tpath
.path
.segments
.iter()
.zip(segments)
.all(|(lhs, rhs)| lhs.ident == **rhs)
}
_ => false,
}
}
fn is_bottom(ty: &ReturnType) -> bool {

107
src/export.rs
View file

@ -1,7 +1,5 @@
//! IMPLEMENTATION DETAILS. DO NOT USE ANYTHING IN THIS MODULE
#[cfg(not(feature = "nightly"))]
use core::ptr;
use core::{cell::Cell, u8};
#[cfg(armv7m)]
@ -14,25 +12,31 @@ pub use heapless::consts;
use heapless::spsc::{Queue, SingleCore};
#[cfg(feature = "timer-queue")]
pub use crate::tq::{isr as sys_tick, NotReady, TimerQueue};
pub use crate::tq::{NotReady, TimerQueue};
pub type FreeQueue<N> = Queue<u8, N, usize, SingleCore>;
pub type ReadyQueue<T, N> = Queue<(T, u8), N, usize, SingleCore>;
pub type FreeQueue<N> = Queue<u8, N, u8, SingleCore>;
pub type ReadyQueue<T, N> = Queue<(T, u8), N, u8, SingleCore>;
#[cfg(armv7m)]
#[inline(always)]
pub fn run<F>(f: F)
pub fn run<F>(priority: u8, f: F)
where
F: FnOnce(),
{
if priority == 1 {
// if the priority of this interrupt is `1` then BASEPRI can only be `0`
f();
unsafe { basepri::write(0) }
} else {
let initial = basepri::read();
f();
unsafe { basepri::write(initial) }
}
}
#[cfg(not(armv7m))]
#[inline(always)]
pub fn run<F>(f: F)
pub fn run<F>(_priority: u8, f: F)
where
F: FnOnce(),
{
@ -52,7 +56,7 @@ impl Priority {
}
}
// these two methods are used by claim (see below) but can't be used from the RTFM application
// these two methods are used by `lock` (see below) but can't be used from the RTFM application
#[inline(always)]
fn set(&self, value: u8) {
self.inner.set(value)
@ -64,13 +68,12 @@ impl Priority {
}
}
#[cfg(feature = "nightly")]
// We newtype `core::mem::MaybeUninit` so the end-user doesn't need `#![feature(maybe_uninit)]` in
// their code
pub struct MaybeUninit<T> {
// we newtype so the end-user doesn't need `#![feature(maybe_uninit)]` in their code
inner: core::mem::MaybeUninit<T>,
}
#[cfg(feature = "nightly")]
impl<T> MaybeUninit<T> {
pub const fn uninit() -> Self {
MaybeUninit {
@ -86,64 +89,15 @@ impl<T> MaybeUninit<T> {
self.inner.as_mut_ptr()
}
pub unsafe fn read(&self) -> T {
self.inner.read()
}
pub fn write(&mut self, value: T) -> &mut T {
self.inner.write(value)
}
}
#[cfg(not(feature = "nightly"))]
pub struct MaybeUninit<T> {
value: Option<T>,
}
#[cfg(not(feature = "nightly"))]
const MSG: &str =
"you have hit a bug (UB) in RTFM implementation; try enabling this crate 'nightly' feature";
#[cfg(not(feature = "nightly"))]
impl<T> MaybeUninit<T> {
pub const fn uninit() -> Self {
MaybeUninit { value: None }
}
pub fn as_ptr(&self) -> *const T {
if let Some(x) = self.value.as_ref() {
x
} else {
unreachable!(MSG)
}
}
pub fn as_mut_ptr(&mut self) -> *mut T {
if let Some(x) = self.value.as_mut() {
x
} else {
unreachable!(MSG)
}
}
pub unsafe fn get_ref(&self) -> &T {
if let Some(x) = self.value.as_ref() {
x
} else {
unreachable!(MSG)
}
}
pub unsafe fn get_mut(&mut self) -> &mut T {
if let Some(x) = self.value.as_mut() {
x
} else {
unreachable!(MSG)
}
}
pub fn write(&mut self, val: T) {
// NOTE(volatile) we have observed UB when this uses a plain `ptr::write`
unsafe { ptr::write_volatile(&mut self.value, Some(val)) }
}
}
#[inline(always)]
pub fn assert_send<T>()
where
@ -160,19 +114,16 @@ where
#[cfg(armv7m)]
#[inline(always)]
pub unsafe fn claim<T, R, F>(
pub unsafe fn lock<T, R>(
ptr: *mut T,
priority: &Priority,
ceiling: u8,
nvic_prio_bits: u8,
f: F,
) -> R
where
F: FnOnce(&mut T) -> R,
{
f: impl FnOnce(&mut T) -> R,
) -> R {
let current = priority.get();
if priority.get() < ceiling {
if current < ceiling {
if ceiling == (1 << nvic_prio_bits) {
priority.set(u8::MAX);
let r = interrupt::free(|_| f(&mut *ptr));
@ -193,19 +144,16 @@ where
#[cfg(not(armv7m))]
#[inline(always)]
pub unsafe fn claim<T, R, F>(
pub unsafe fn lock<T, R>(
ptr: *mut T,
priority: &Priority,
ceiling: u8,
_nvic_prio_bits: u8,
f: F,
) -> R
where
F: FnOnce(&mut T) -> R,
{
f: impl FnOnce(&mut T) -> R,
) -> R {
let current = priority.get();
if priority.get() < ceiling {
if current < ceiling {
priority.set(u8::MAX);
let r = interrupt::free(|_| f(&mut *ptr));
priority.set(current);
@ -215,8 +163,7 @@ where
}
}
#[cfg(armv7m)]
#[inline]
fn logical2hw(logical: u8, nvic_prio_bits: u8) -> u8 {
pub fn logical2hw(logical: u8, nvic_prio_bits: u8) -> u8 {
((1 << nvic_prio_bits) - logical) << (8 - nvic_prio_bits)
}

32
src/lib.rs
View file

@ -1,5 +1,8 @@
//! Real Time For the Masses (RTFM) framework for ARM Cortex-M microcontrollers
//!
//! **HEADS UP** This is an **alpha** pre-release; there may be breaking changes in the API and
//! semantics before a proper release is made.
//!
//! **IMPORTANT**: This crate is published as [`cortex-m-rtfm`] on crates.io but the name of the
//! library is `rtfm`.
//!
@ -7,7 +10,7 @@
//!
//! The user level documentation can be found [here].
//!
//! [here]: https://japaric.github.io/cortex-m-rtfm/book/en/
//! [here]: https://japaric.github.io/rtfm5/book/en/
//!
//! Don't forget to check the documentation of the [`#[app]`] attribute, which is the main component
//! of the framework.
@ -16,7 +19,7 @@
//!
//! # Minimum Supported Rust Version (MSRV)
//!
//! This crate is guaranteed to compile on stable Rust 1.31 (2018 edition) and up. It *might*
//! This crate is guaranteed to compile on stable Rust 1.36 (2018 edition) and up. It *might*
//! compile on older versions but that may change in any new patch release.
//!
//! # Semantic Versioning
@ -36,12 +39,11 @@
//! [`Instant`]: struct.Instant.html
//! [`Duration`]: struct.Duration.html
//!
//! - `nightly`. Enabling this opt-in feature makes RTFM internally use the unstable
//! `core::mem::MaybeUninit` API and unstable `const_fn` language feature to reduce static memory
//! usage, runtime overhead and initialization overhead. This feature requires a nightly compiler
//! and may stop working at any time!
//! - `nightly`. Enabling this opt-in feature makes RTFM internally use the unstable `const_fn`
//! language feature to reduce static memory usage, runtime overhead and initialization overhead.
//! This feature requires a nightly compiler and may stop working at any time!
#![cfg_attr(feature = "nightly", feature(maybe_uninit))]
#![feature(maybe_uninit)]
#![deny(missing_docs)]
#![deny(warnings)]
#![no_std]
@ -132,7 +134,7 @@ pub struct Instant(i32);
impl Instant {
/// IMPLEMENTATION DETAIL. DO NOT USE
#[doc(hidden)]
pub fn artificial(timestamp: i32) -> Self {
pub unsafe fn artificial(timestamp: i32) -> Self {
Instant(timestamp)
}
@ -290,9 +292,7 @@ pub trait Mutex {
type T;
/// Creates a critical section and grants temporary access to the protected data
fn lock<R, F>(&mut self, f: F) -> R
where
F: FnOnce(&mut Self::T) -> R;
fn lock<R>(&mut self, f: impl FnOnce(&mut Self::T) -> R) -> R;
}
impl<'a, M> Mutex for &'a mut M
@ -301,10 +301,7 @@ where
{
type T = M::T;
fn lock<R, F>(&mut self, f: F) -> R
where
F: FnOnce(&mut Self::T) -> R,
{
fn lock<R>(&mut self, f: impl FnOnce(&mut M::T) -> R) -> R {
(**self).lock(f)
}
}
@ -317,10 +314,7 @@ pub struct Exclusive<'a, T>(pub &'a mut T);
impl<'a, T> Mutex for Exclusive<'a, T> {
type T = T;
fn lock<R, F>(&mut self, f: F) -> R
where
F: FnOnce(&mut Self::T) -> R,
{
fn lock<R>(&mut self, f: impl FnOnce(&mut T) -> R) -> R {
f(self.0)
}
}

78
src/tq.rs
View file

@ -3,7 +3,7 @@ use core::cmp::{self, Ordering};
use cortex_m::peripheral::{SCB, SYST};
use heapless::{binary_heap::Min, ArrayLength, BinaryHeap};
use crate::{Instant, Mutex};
use crate::Instant;
pub struct TimerQueue<T, N>
where
@ -43,11 +43,39 @@ where
}
// set SysTick pending
(*SCB::ptr()).icsr.write(1 << 26);
SCB::set_pendst();
}
self.queue.push_unchecked(nr);
}
#[inline]
pub fn dequeue(&mut self) -> Option<(T, u8)> {
if let Some(instant) = self.queue.peek().map(|p| p.instant) {
let diff = instant.0.wrapping_sub(Instant::now().0);
if diff < 0 {
// task became ready
let nr = unsafe { self.queue.pop_unchecked() };
Some((nr.task, nr.index))
} else {
// set a new timeout
const MAX: u32 = 0x00ffffff;
self.syst.set_reload(cmp::min(MAX, diff as u32));
// start counting down from the new reload
self.syst.clear_current();
None
}
} else {
// the queue is empty
self.syst.disable_interrupt();
None
}
}
}
pub struct NotReady<T>
@ -87,49 +115,3 @@ where
Some(self.cmp(&other))
}
}
#[inline(always)]
pub fn isr<TQ, T, N, F>(mut tq: TQ, mut f: F)
where
TQ: Mutex<T = TimerQueue<T, N>>,
T: Copy + Send,
N: ArrayLength<NotReady<T>>,
F: FnMut(T, u8),
{
loop {
// XXX does `#[inline(always)]` improve performance or not?
let next = tq.lock(#[inline(always)]
|tq| {
if let Some(instant) = tq.queue.peek().map(|p| p.instant) {
let diff = instant.0.wrapping_sub(Instant::now().0);
if diff < 0 {
// task became ready
let m = unsafe { tq.queue.pop_unchecked() };
Some((m.task, m.index))
} else {
// set a new timeout
const MAX: u32 = 0x00ffffff;
tq.syst.set_reload(cmp::min(MAX, diff as u32));
// start counting down from the new reload
tq.syst.clear_current();
None
}
} else {
// the queue is empty
tq.syst.disable_interrupt();
None
}
});
if let Some((task, index)) = next {
f(task, index)
} else {
return;
}
}
}