diff options
Diffstat (limited to 'library/std/src/sys/itron')
| -rw-r--r-- | library/std/src/sys/itron/abi.rs | 155 | ||||
| -rw-r--r-- | library/std/src/sys/itron/condvar.rs | 294 | ||||
| -rw-r--r-- | library/std/src/sys/itron/error.rs | 159 | ||||
| -rw-r--r-- | library/std/src/sys/itron/mutex.rs | 183 | ||||
| -rw-r--r-- | library/std/src/sys/itron/spin.rs | 164 | ||||
| -rw-r--r-- | library/std/src/sys/itron/task.rs | 44 | ||||
| -rw-r--r-- | library/std/src/sys/itron/thread.rs | 352 | ||||
| -rw-r--r-- | library/std/src/sys/itron/time.rs | 123 | ||||
| -rw-r--r-- | library/std/src/sys/itron/time/tests.rs | 33 |
9 files changed, 1507 insertions, 0 deletions
diff --git a/library/std/src/sys/itron/abi.rs b/library/std/src/sys/itron/abi.rs new file mode 100644 index 00000000000..f99ee4fa897 --- /dev/null +++ b/library/std/src/sys/itron/abi.rs @@ -0,0 +1,155 @@ +//! ABI for μITRON derivatives +pub type int_t = crate::os::raw::c_int; +pub type uint_t = crate::os::raw::c_uint; +pub type bool_t = int_t; + +/// Kernel object ID +pub type ID = int_t; + +/// The current task. +pub const TSK_SELF: ID = 0; + +/// Relative time +pub type RELTIM = u32; + +/// Timeout (a valid `RELTIM` value or `TMO_FEVR`) +pub type TMO = u32; + +/// The infinite timeout value +pub const TMO_FEVR: TMO = TMO::MAX; + +/// The maximum valid value of `RELTIM` +pub const TMAX_RELTIM: RELTIM = 4_000_000_000; + +/// System time +pub type SYSTIM = u64; + +/// Error code type +pub type ER = int_t; + +/// Error code type, `ID` on success +pub type ER_ID = int_t; + +/// Task or interrupt priority +pub type PRI = int_t; + +/// The special value of `PRI` representing the current task's priority. +pub const TPRI_SELF: PRI = 0; + +/// Object attributes +pub type ATR = uint_t; + +/// Use the priority inheritance protocol +#[cfg(target_os = "solid_asp3")] +pub const TA_INHERIT: ATR = 0x02; + +/// Activate the task on creation +pub const TA_ACT: ATR = 0x01; + +/// The maximum count of a semaphore +pub const TMAX_MAXSEM: uint_t = uint_t::MAX; + +/// Callback parameter +pub type EXINF = isize; + +/// Task entrypoint +pub type TASK = Option<unsafe extern "C" fn(EXINF)>; + +// Error codes +pub const E_OK: ER = 0; +pub const E_SYS: ER = -5; +pub const E_NOSPT: ER = -9; +pub const E_RSFN: ER = -10; +pub const E_RSATR: ER = -11; +pub const E_PAR: ER = -17; +pub const E_ID: ER = -18; +pub const E_CTX: ER = -25; +pub const E_MACV: ER = -26; +pub const E_OACV: ER = -27; +pub const E_ILUSE: ER = -28; +pub const E_NOMEM: ER = -33; +pub const E_NOID: ER = -34; +pub const E_NORES: ER = -35; +pub const E_OBJ: ER = -41; +pub const E_NOEXS: ER = -42; +pub const E_QOVR: ER = -43; +pub const E_RLWAI: ER = -49; +pub const E_TMOUT: ER = -50; +pub const E_DLT: ER = -51; +pub const E_CLS: ER = -52; +pub const E_RASTER: ER = -53; +pub const E_WBLK: ER = -57; +pub const E_BOVR: ER = -58; +pub const E_COMM: ER = -65; + +#[derive(Clone, Copy)] +#[repr(C)] +pub struct T_CSEM { + pub sematr: ATR, + pub isemcnt: uint_t, + pub maxsem: uint_t, +} + +#[derive(Clone, Copy)] +#[repr(C)] +pub struct T_CMTX { + pub mtxatr: ATR, + pub ceilpri: PRI, +} + +#[derive(Clone, Copy)] +#[repr(C)] +pub struct T_CTSK { + pub tskatr: ATR, + pub exinf: EXINF, + pub task: TASK, + pub itskpri: PRI, + pub stksz: usize, + pub stk: *mut u8, +} + +extern "C" { + #[link_name = "__asp3_acre_tsk"] + pub fn acre_tsk(pk_ctsk: *const T_CTSK) -> ER_ID; + #[link_name = "__asp3_get_tid"] + pub fn get_tid(p_tskid: *mut ID) -> ER; + #[link_name = "__asp3_dly_tsk"] + pub fn dly_tsk(dlytim: RELTIM) -> ER; + #[link_name = "__asp3_ter_tsk"] + pub fn ter_tsk(tskid: ID) -> ER; + #[link_name = "__asp3_del_tsk"] + pub fn del_tsk(tskid: ID) -> ER; + #[link_name = "__asp3_get_pri"] + pub fn get_pri(tskid: ID, p_tskpri: *mut PRI) -> ER; + #[link_name = "__asp3_rot_rdq"] + pub fn rot_rdq(tskpri: PRI) -> ER; + #[link_name = "__asp3_slp_tsk"] + pub fn slp_tsk() -> ER; + #[link_name = "__asp3_tslp_tsk"] + pub fn tslp_tsk(tmout: TMO) -> ER; + #[link_name = "__asp3_wup_tsk"] + pub fn wup_tsk(tskid: ID) -> ER; + #[link_name = "__asp3_unl_cpu"] + pub fn unl_cpu() -> ER; + #[link_name = "__asp3_dis_dsp"] + pub fn dis_dsp() -> ER; + #[link_name = "__asp3_ena_dsp"] + pub fn ena_dsp() -> ER; + #[link_name = "__asp3_sns_dsp"] + pub fn sns_dsp() -> bool_t; + #[link_name = "__asp3_get_tim"] + pub fn get_tim(p_systim: *mut SYSTIM) -> ER; + #[link_name = "__asp3_acre_mtx"] + pub fn acre_mtx(pk_cmtx: *const T_CMTX) -> ER_ID; + #[link_name = "__asp3_del_mtx"] + pub fn del_mtx(tskid: ID) -> ER; + #[link_name = "__asp3_loc_mtx"] + pub fn loc_mtx(mtxid: ID) -> ER; + #[link_name = "__asp3_ploc_mtx"] + pub fn ploc_mtx(mtxid: ID) -> ER; + #[link_name = "__asp3_tloc_mtx"] + pub fn tloc_mtx(mtxid: ID, tmout: TMO) -> ER; + #[link_name = "__asp3_unl_mtx"] + pub fn unl_mtx(mtxid: ID) -> ER; + pub fn exd_tsk() -> ER; +} diff --git a/library/std/src/sys/itron/condvar.rs b/library/std/src/sys/itron/condvar.rs new file mode 100644 index 00000000000..dac4b8abfc4 --- /dev/null +++ b/library/std/src/sys/itron/condvar.rs @@ -0,0 +1,294 @@ +//! POSIX conditional variable implementation based on user-space wait queues. +use super::{abi, error::expect_success_aborting, spin::SpinMutex, task, time::with_tmos_strong}; +use crate::{mem::replace, ptr::NonNull, sys::mutex::Mutex, time::Duration}; + +// The implementation is inspired by the queue-based implementation shown in +// Andrew D. Birrell's paper "Implementing Condition Variables with Semaphores" + +pub struct Condvar { + waiters: SpinMutex<waiter_queue::WaiterQueue>, +} + +unsafe impl Send for Condvar {} +unsafe impl Sync for Condvar {} + +pub type MovableCondvar = Condvar; + +impl Condvar { + pub const fn new() -> Condvar { + Condvar { waiters: SpinMutex::new(waiter_queue::WaiterQueue::new()) } + } + + pub unsafe fn init(&mut self) {} + + pub unsafe fn notify_one(&self) { + self.waiters.with_locked(|waiters| { + if let Some(task) = waiters.pop_front() { + // Unpark the task + match unsafe { abi::wup_tsk(task) } { + // The task already has a token. + abi::E_QOVR => {} + // Can't undo the effect; abort the program on failure + er => { + expect_success_aborting(er, &"wup_tsk"); + } + } + } + }); + } + + pub unsafe fn notify_all(&self) { + self.waiters.with_locked(|waiters| { + while let Some(task) = waiters.pop_front() { + // Unpark the task + match unsafe { abi::wup_tsk(task) } { + // The task already has a token. + abi::E_QOVR => {} + // Can't undo the effect; abort the program on failure + er => { + expect_success_aborting(er, &"wup_tsk"); + } + } + } + }); + } + + pub unsafe fn wait(&self, mutex: &Mutex) { + // Construct `Waiter`. + let mut waiter = waiter_queue::Waiter::new(); + let waiter = NonNull::from(&mut waiter); + + self.waiters.with_locked(|waiters| unsafe { + waiters.insert(waiter); + }); + + unsafe { mutex.unlock() }; + + // Wait until `waiter` is removed from the queue + loop { + // Park the current task + expect_success_aborting(unsafe { abi::slp_tsk() }, &"slp_tsk"); + + if !self.waiters.with_locked(|waiters| unsafe { waiters.is_queued(waiter) }) { + break; + } + } + + unsafe { mutex.lock() }; + } + + pub unsafe fn wait_timeout(&self, mutex: &Mutex, dur: Duration) -> bool { + // Construct and pin `Waiter` + let mut waiter = waiter_queue::Waiter::new(); + let waiter = NonNull::from(&mut waiter); + + self.waiters.with_locked(|waiters| unsafe { + waiters.insert(waiter); + }); + + unsafe { mutex.unlock() }; + + // Park the current task and do not wake up until the timeout elapses + // or the task gets woken up by `notify_*` + match with_tmos_strong(dur, |tmo| { + let er = unsafe { abi::tslp_tsk(tmo) }; + if er == 0 { + // We were unparked. Are we really dequeued? + if self.waiters.with_locked(|waiters| unsafe { waiters.is_queued(waiter) }) { + // No we are not. Continue waiting. + return abi::E_TMOUT; + } + } + er + }) { + abi::E_TMOUT => {} + er => { + expect_success_aborting(er, &"tslp_tsk"); + } + } + + // Remove `waiter` from `self.waiters`. If `waiter` is still in + // `waiters`, it means we woke up because of a timeout. Otherwise, + // we woke up because of `notify_*`. + let success = self.waiters.with_locked(|waiters| unsafe { !waiters.remove(waiter) }); + + unsafe { mutex.lock() }; + success + } + + pub unsafe fn destroy(&self) {} +} + +mod waiter_queue { + use super::*; + + pub struct WaiterQueue { + head: Option<ListHead>, + } + + #[derive(Copy, Clone)] + struct ListHead { + first: NonNull<Waiter>, + last: NonNull<Waiter>, + } + + unsafe impl Send for ListHead {} + unsafe impl Sync for ListHead {} + + pub struct Waiter { + // These fields are only accessed through `&[mut] WaiterQueue`. + /// The waiting task's ID. Will be zeroed when the task is woken up + /// and removed from a queue. + task: abi::ID, + priority: abi::PRI, + prev: Option<NonNull<Waiter>>, + next: Option<NonNull<Waiter>>, + } + + unsafe impl Send for Waiter {} + unsafe impl Sync for Waiter {} + + impl Waiter { + #[inline] + pub fn new() -> Self { + let task = task::current_task_id(); + let priority = task::task_priority(abi::TSK_SELF); + + // Zeroness of `Waiter::task` indicates whether the `Waiter` is + // linked to a queue or not. This invariant is important for + // the correctness. + debug_assert_ne!(task, 0); + + Self { task, priority, prev: None, next: None } + } + } + + impl WaiterQueue { + #[inline] + pub const fn new() -> Self { + Self { head: None } + } + + /// # Safety + /// + /// - The caller must own `*waiter_ptr`. The caller will lose the + /// ownership until `*waiter_ptr` is removed from `self`. + /// + /// - `*waiter_ptr` must be valid until it's removed from the queue. + /// + /// - `*waiter_ptr` must not have been previously inserted to a `WaiterQueue`. + /// + pub unsafe fn insert(&mut self, mut waiter_ptr: NonNull<Waiter>) { + unsafe { + let waiter = waiter_ptr.as_mut(); + + debug_assert!(waiter.prev.is_none()); + debug_assert!(waiter.next.is_none()); + + if let Some(head) = &mut self.head { + // Find the insertion position and insert `waiter` + let insert_after = { + let mut cursor = head.last; + loop { + if waiter.priority <= cursor.as_ref().priority { + // `cursor` and all previous waiters have the same or higher + // priority than `current_task_priority`. Insert the new + // waiter right after `cursor`. + break Some(cursor); + } + cursor = if let Some(prev) = cursor.as_ref().prev { + prev + } else { + break None; + }; + } + }; + + if let Some(mut insert_after) = insert_after { + // Insert `waiter` after `insert_after` + let insert_before = insert_after.as_ref().prev; + + waiter.prev = Some(insert_after); + insert_after.as_mut().next = Some(waiter_ptr); + + waiter.next = insert_before; + if let Some(mut insert_before) = insert_before { + insert_before.as_mut().prev = Some(waiter_ptr); + } + } else { + // Insert `waiter` to the front + waiter.next = Some(head.first); + head.first.as_mut().prev = Some(waiter_ptr); + head.first = waiter_ptr; + } + } else { + // `waiter` is the only element + self.head = Some(ListHead { first: waiter_ptr, last: waiter_ptr }); + } + } + } + + /// Given a `Waiter` that was previously inserted to `self`, remove + /// it from `self` if it's still there. + #[inline] + pub unsafe fn remove(&mut self, mut waiter_ptr: NonNull<Waiter>) -> bool { + unsafe { + let waiter = waiter_ptr.as_mut(); + if waiter.task != 0 { + let head = self.head.as_mut().unwrap(); + + match (waiter.prev, waiter.next) { + (Some(mut prev), Some(mut next)) => { + prev.as_mut().next = Some(next); + next.as_mut().next = Some(prev); + } + (None, Some(mut next)) => { + head.first = next; + next.as_mut().next = None; + } + (Some(mut prev), None) => { + prev.as_mut().next = None; + head.last = prev; + } + (None, None) => { + self.head = None; + } + } + + waiter.task = 0; + + true + } else { + false + } + } + } + + /// Given a `Waiter` that was previously inserted to `self`, return a + /// flag indicating whether it's still in `self`. + #[inline] + pub unsafe fn is_queued(&self, waiter: NonNull<Waiter>) -> bool { + unsafe { waiter.as_ref().task != 0 } + } + + pub fn pop_front(&mut self) -> Option<abi::ID> { + unsafe { + let head = self.head.as_mut()?; + let waiter = head.first.as_mut(); + + // Get the ID + let id = replace(&mut waiter.task, 0); + + // Unlink the waiter + if let Some(mut next) = waiter.next { + head.first = next; + next.as_mut().prev = None; + } else { + self.head = None; + } + + Some(id) + } + } + } +} diff --git a/library/std/src/sys/itron/error.rs b/library/std/src/sys/itron/error.rs new file mode 100644 index 00000000000..830c60d329e --- /dev/null +++ b/library/std/src/sys/itron/error.rs @@ -0,0 +1,159 @@ +use crate::{fmt, io::ErrorKind}; + +use super::abi; + +/// Wraps a μITRON error code. +#[derive(Debug, Copy, Clone)] +pub struct ItronError { + er: abi::ER, +} + +impl ItronError { + /// Construct `ItronError` from the specified error code. Returns `None` if the + /// error code does not represent a failure or warning. + #[inline] + pub fn new(er: abi::ER) -> Option<Self> { + if er < 0 { Some(Self { er }) } else { None } + } + + /// Returns `Ok(er)` if `er` represents a success or `Err(_)` otherwise. + #[inline] + pub fn err_if_negative(er: abi::ER) -> Result<abi::ER, Self> { + if let Some(error) = Self::new(er) { Err(error) } else { Ok(er) } + } + + /// Get the raw error code. + #[inline] + pub fn as_raw(&self) -> abi::ER { + self.er + } +} + +impl fmt::Display for ItronError { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + // Allow the platforms to extend `error_name` + if let Some(name) = crate::sys::error::error_name(self.er) { + write!(f, "{} ({})", name, self.er) + } else { + write!(f, "{}", self.er) + } + } +} + +/// Describe the specified μITRON error code. Returns `None` if it's an +/// undefined error code. +pub fn error_name(er: abi::ER) -> Option<&'static str> { + match er { + // Success + er if er >= 0 => None, + + // μITRON 4.0 + abi::E_SYS => Some("system error"), + abi::E_NOSPT => Some("unsupported function"), + abi::E_RSFN => Some("reserved function code"), + abi::E_RSATR => Some("reserved attribute"), + abi::E_PAR => Some("parameter error"), + abi::E_ID => Some("invalid ID number"), + abi::E_CTX => Some("context error"), + abi::E_MACV => Some("memory access violation"), + abi::E_OACV => Some("object access violation"), + abi::E_ILUSE => Some("illegal service call use"), + abi::E_NOMEM => Some("insufficient memory"), + abi::E_NOID => Some("no ID number available"), + abi::E_OBJ => Some("object state error"), + abi::E_NOEXS => Some("non-existent object"), + abi::E_QOVR => Some("queue overflow"), + abi::E_RLWAI => Some("forced release from waiting"), + abi::E_TMOUT => Some("polling failure or timeout"), + abi::E_DLT => Some("waiting object deleted"), + abi::E_CLS => Some("waiting object state changed"), + abi::E_WBLK => Some("non-blocking code accepted"), + abi::E_BOVR => Some("buffer overflow"), + + // The TOPPERS third generation kernels + abi::E_NORES => Some("insufficient system resources"), + abi::E_RASTER => Some("termination request raised"), + abi::E_COMM => Some("communication failure"), + + _ => None, + } +} + +pub fn decode_error_kind(er: abi::ER) -> ErrorKind { + match er { + // Success + er if er >= 0 => ErrorKind::Uncategorized, + + // μITRON 4.0 + // abi::E_SYS + abi::E_NOSPT => ErrorKind::Unsupported, // Some("unsupported function"), + abi::E_RSFN => ErrorKind::InvalidInput, // Some("reserved function code"), + abi::E_RSATR => ErrorKind::InvalidInput, // Some("reserved attribute"), + abi::E_PAR => ErrorKind::InvalidInput, // Some("parameter error"), + abi::E_ID => ErrorKind::NotFound, // Some("invalid ID number"), + // abi::E_CTX + abi::E_MACV => ErrorKind::PermissionDenied, // Some("memory access violation"), + abi::E_OACV => ErrorKind::PermissionDenied, // Some("object access violation"), + // abi::E_ILUSE + abi::E_NOMEM => ErrorKind::OutOfMemory, // Some("insufficient memory"), + abi::E_NOID => ErrorKind::OutOfMemory, // Some("no ID number available"), + // abi::E_OBJ + abi::E_NOEXS => ErrorKind::NotFound, // Some("non-existent object"), + // abi::E_QOVR + abi::E_RLWAI => ErrorKind::Interrupted, // Some("forced release from waiting"), + abi::E_TMOUT => ErrorKind::TimedOut, // Some("polling failure or timeout"), + // abi::E_DLT + // abi::E_CLS + // abi::E_WBLK + // abi::E_BOVR + + // The TOPPERS third generation kernels + abi::E_NORES => ErrorKind::OutOfMemory, // Some("insufficient system resources"), + // abi::E_RASTER + // abi::E_COMM + _ => ErrorKind::Uncategorized, + } +} + +/// Similar to `ItronError::err_if_negative(er).expect()` except that, while +/// panicking, it prints the message to `panic_output` and aborts the program +/// instead. This ensures the error message is not obscured by double +/// panicking. +/// +/// This is useful for diagnosing creation failures of synchronization +/// primitives that are used by `std`'s internal mechanisms. Such failures +/// are common when the system is mis-configured to provide a too-small pool for +/// kernel objects. +#[inline] +pub fn expect_success(er: abi::ER, msg: &&str) -> abi::ER { + match ItronError::err_if_negative(er) { + Ok(x) => x, + Err(e) => fail(e, msg), + } +} + +/// Similar to `ItronError::err_if_negative(er).expect()` but aborts instead. +/// +/// Use this where panicking is not allowed or the effect of the failure +/// would be persistent. +#[inline] +pub fn expect_success_aborting(er: abi::ER, msg: &&str) -> abi::ER { + match ItronError::err_if_negative(er) { + Ok(x) => x, + Err(e) => fail_aborting(e, msg), + } +} + +#[cold] +pub fn fail(e: impl fmt::Display, msg: &&str) -> ! { + if crate::thread::panicking() { + fail_aborting(e, msg) + } else { + panic!("{} failed: {}", *msg, e) + } +} + +#[cold] +pub fn fail_aborting(e: impl fmt::Display, msg: &&str) -> ! { + rtabort!("{} failed: {}", *msg, e) +} diff --git a/library/std/src/sys/itron/mutex.rs b/library/std/src/sys/itron/mutex.rs new file mode 100644 index 00000000000..e01f595ac54 --- /dev/null +++ b/library/std/src/sys/itron/mutex.rs @@ -0,0 +1,183 @@ +//! Mutex implementation backed by μITRON mutexes. Assumes `acre_mtx` and +//! `TA_INHERIT` are available. +use super::{ + abi, + error::{expect_success, expect_success_aborting, fail, ItronError}, + spin::SpinIdOnceCell, +}; +use crate::cell::UnsafeCell; + +pub struct Mutex { + /// The ID of the underlying mutex object + mtx: SpinIdOnceCell<()>, +} + +pub type MovableMutex = Mutex; + +/// Create a mutex object. This function never panics. +fn new_mtx() -> Result<abi::ID, ItronError> { + ItronError::err_if_negative(unsafe { + abi::acre_mtx(&abi::T_CMTX { + // Priority inheritance mutex + mtxatr: abi::TA_INHERIT, + // Unused + ceilpri: 0, + }) + }) +} + +impl Mutex { + pub const fn new() -> Mutex { + Mutex { mtx: SpinIdOnceCell::new() } + } + + pub unsafe fn init(&mut self) { + // Initialize `self.mtx` eagerly + let id = new_mtx().unwrap_or_else(|e| fail(e, &"acre_mtx")); + unsafe { self.mtx.set_unchecked((id, ())) }; + } + + /// Get the inner mutex's ID, which is lazily created. + fn raw(&self) -> abi::ID { + match self.mtx.get_or_try_init(|| new_mtx().map(|id| (id, ()))) { + Ok((id, ())) => id, + Err(e) => fail(e, &"acre_mtx"), + } + } + + pub unsafe fn lock(&self) { + let mtx = self.raw(); + expect_success(unsafe { abi::loc_mtx(mtx) }, &"loc_mtx"); + } + + pub unsafe fn unlock(&self) { + let mtx = unsafe { self.mtx.get_unchecked().0 }; + expect_success_aborting(unsafe { abi::unl_mtx(mtx) }, &"unl_mtx"); + } + + pub unsafe fn try_lock(&self) -> bool { + let mtx = self.raw(); + match unsafe { abi::ploc_mtx(mtx) } { + abi::E_TMOUT => false, + er => { + expect_success(er, &"ploc_mtx"); + true + } + } + } + + pub unsafe fn destroy(&self) { + if let Some(mtx) = self.mtx.get().map(|x| x.0) { + expect_success_aborting(unsafe { abi::del_mtx(mtx) }, &"del_mtx"); + } + } +} + +pub(super) struct MutexGuard<'a>(&'a Mutex); + +impl<'a> MutexGuard<'a> { + #[inline] + pub(super) fn lock(x: &'a Mutex) -> Self { + unsafe { x.lock() }; + Self(x) + } +} + +impl Drop for MutexGuard<'_> { + #[inline] + fn drop(&mut self) { + unsafe { self.0.unlock() }; + } +} + +// All empty stubs because this platform does not yet support threads, so lock +// acquisition always succeeds. +pub struct ReentrantMutex { + /// The ID of the underlying mutex object + mtx: abi::ID, + /// The lock count. + count: UnsafeCell<usize>, +} + +unsafe impl Send for ReentrantMutex {} +unsafe impl Sync for ReentrantMutex {} + +impl ReentrantMutex { + pub const unsafe fn uninitialized() -> ReentrantMutex { + ReentrantMutex { mtx: 0, count: UnsafeCell::new(0) } + } + + pub unsafe fn init(&mut self) { + self.mtx = expect_success( + unsafe { + abi::acre_mtx(&abi::T_CMTX { + // Priority inheritance mutex + mtxatr: abi::TA_INHERIT, + // Unused + ceilpri: 0, + }) + }, + &"acre_mtx", + ); + } + + pub unsafe fn lock(&self) { + match unsafe { abi::loc_mtx(self.mtx) } { + abi::E_OBJ => { + // Recursive lock + unsafe { + let count = &mut *self.count.get(); + if let Some(new_count) = count.checked_add(1) { + *count = new_count; + } else { + // counter overflow + rtabort!("lock count overflow"); + } + } + } + er => { + expect_success(er, &"loc_mtx"); + } + } + } + + pub unsafe fn unlock(&self) { + unsafe { + let count = &mut *self.count.get(); + if *count > 0 { + *count -= 1; + return; + } + } + + expect_success_aborting(unsafe { abi::unl_mtx(self.mtx) }, &"unl_mtx"); + } + + pub unsafe fn try_lock(&self) -> bool { + let er = unsafe { abi::ploc_mtx(self.mtx) }; + if er == abi::E_OBJ { + // Recursive lock + unsafe { + let count = &mut *self.count.get(); + if let Some(new_count) = count.checked_add(1) { + *count = new_count; + } else { + // counter overflow + rtabort!("lock count overflow"); + } + } + true + } else if er == abi::E_TMOUT { + // Locked by another thread + false + } else { + expect_success(er, &"ploc_mtx"); + // Top-level lock by the current thread + true + } + } + + pub unsafe fn destroy(&self) { + expect_success_aborting(unsafe { abi::del_mtx(self.mtx) }, &"del_mtx"); + } +} diff --git a/library/std/src/sys/itron/spin.rs b/library/std/src/sys/itron/spin.rs new file mode 100644 index 00000000000..d0149d1f037 --- /dev/null +++ b/library/std/src/sys/itron/spin.rs @@ -0,0 +1,164 @@ +use super::abi; +use crate::{ + cell::UnsafeCell, + convert::TryFrom, + mem::MaybeUninit, + sync::atomic::{AtomicBool, AtomicUsize, Ordering}, +}; + +/// A mutex implemented by `dis_dsp` (for intra-core synchronization) and a +/// spinlock (for inter-core synchronization). +pub struct SpinMutex<T = ()> { + locked: AtomicBool, + data: UnsafeCell<T>, +} + +impl<T> SpinMutex<T> { + #[inline] + pub const fn new(x: T) -> Self { + Self { locked: AtomicBool::new(false), data: UnsafeCell::new(x) } + } + + /// Acquire a lock. + #[inline] + pub fn with_locked<R>(&self, f: impl FnOnce(&mut T) -> R) -> R { + struct SpinMutexGuard<'a>(&'a AtomicBool); + + impl Drop for SpinMutexGuard<'_> { + #[inline] + fn drop(&mut self) { + self.0.store(false, Ordering::Release); + unsafe { abi::ena_dsp() }; + } + } + + let _guard; + if unsafe { abi::sns_dsp() } == 0 { + let er = unsafe { abi::dis_dsp() }; + debug_assert!(er >= 0); + + // Wait until the current processor acquires a lock. + while self.locked.swap(true, Ordering::Acquire) {} + + _guard = SpinMutexGuard(&self.locked); + } + + f(unsafe { &mut *self.data.get() }) + } +} + +/// `OnceCell<(abi::ID, T)>` implemented by `dis_dsp` (for intra-core +/// synchronization) and a spinlock (for inter-core synchronization). +/// +/// It's assumed that `0` is not a valid ID, and all kernel +/// object IDs fall into range `1..=usize::MAX`. +pub struct SpinIdOnceCell<T = ()> { + id: AtomicUsize, + spin: SpinMutex<()>, + extra: UnsafeCell<MaybeUninit<T>>, +} + +const ID_UNINIT: usize = 0; + +impl<T> SpinIdOnceCell<T> { + #[inline] + pub const fn new() -> Self { + Self { + id: AtomicUsize::new(ID_UNINIT), + extra: UnsafeCell::new(MaybeUninit::uninit()), + spin: SpinMutex::new(()), + } + } + + #[inline] + pub fn get(&self) -> Option<(abi::ID, &T)> { + match self.id.load(Ordering::Acquire) { + ID_UNINIT => None, + id => Some((id as abi::ID, unsafe { (&*self.extra.get()).assume_init_ref() })), + } + } + + #[inline] + pub fn get_mut(&mut self) -> Option<(abi::ID, &mut T)> { + match *self.id.get_mut() { + ID_UNINIT => None, + id => Some((id as abi::ID, unsafe { (&mut *self.extra.get()).assume_init_mut() })), + } + } + + #[inline] + pub unsafe fn get_unchecked(&self) -> (abi::ID, &T) { + (self.id.load(Ordering::Acquire) as abi::ID, unsafe { + (&*self.extra.get()).assume_init_ref() + }) + } + + /// Assign the content without checking if it's already initialized or + /// being initialized. + pub unsafe fn set_unchecked(&self, (id, extra): (abi::ID, T)) { + debug_assert!(self.get().is_none()); + + // Assumption: A positive `abi::ID` fits in `usize`. + debug_assert!(id >= 0); + debug_assert!(usize::try_from(id).is_ok()); + let id = id as usize; + + unsafe { *self.extra.get() = MaybeUninit::new(extra) }; + self.id.store(id, Ordering::Release); + } + + /// Gets the contents of the cell, initializing it with `f` if + /// the cell was empty. If the cell was empty and `f` failed, an + /// error is returned. + /// + /// Warning: `f` must not perform a blocking operation, which + /// includes panicking. + #[inline] + pub fn get_or_try_init<F, E>(&self, f: F) -> Result<(abi::ID, &T), E> + where + F: FnOnce() -> Result<(abi::ID, T), E>, + { + // Fast path + if let Some(x) = self.get() { + return Ok(x); + } + + self.initialize(f)?; + + debug_assert!(self.get().is_some()); + + // Safety: The inner value has been initialized + Ok(unsafe { self.get_unchecked() }) + } + + fn initialize<F, E>(&self, f: F) -> Result<(), E> + where + F: FnOnce() -> Result<(abi::ID, T), E>, + { + self.spin.with_locked(|_| { + if self.id.load(Ordering::Relaxed) == ID_UNINIT { + let (initialized_id, initialized_extra) = f()?; + + // Assumption: A positive `abi::ID` fits in `usize`. + debug_assert!(initialized_id >= 0); + debug_assert!(usize::try_from(initialized_id).is_ok()); + let initialized_id = initialized_id as usize; + + // Store the initialized contents. Use the release ordering to + // make sure the write is visible to the callers of `get`. + unsafe { *self.extra.get() = MaybeUninit::new(initialized_extra) }; + self.id.store(initialized_id, Ordering::Release); + } + Ok(()) + }) + } +} + +impl<T> Drop for SpinIdOnceCell<T> { + #[inline] + fn drop(&mut self) { + if self.get_mut().is_some() { + unsafe { (&mut *self.extra.get()).assume_init_drop() }; + } + } +} diff --git a/library/std/src/sys/itron/task.rs b/library/std/src/sys/itron/task.rs new file mode 100644 index 00000000000..94beb50a254 --- /dev/null +++ b/library/std/src/sys/itron/task.rs @@ -0,0 +1,44 @@ +use super::{ + abi, + error::{fail, fail_aborting, ItronError}, +}; + +use crate::mem::MaybeUninit; + +/// Get the ID of the task in Running state. Panics on failure. +#[inline] +pub fn current_task_id() -> abi::ID { + try_current_task_id().unwrap_or_else(|e| fail(e, &"get_tid")) +} + +/// Get the ID of the task in Running state. Aborts on failure. +#[inline] +pub fn current_task_id_aborting() -> abi::ID { + try_current_task_id().unwrap_or_else(|e| fail_aborting(e, &"get_tid")) +} + +/// Get the ID of the task in Running state. +#[inline] +pub fn try_current_task_id() -> Result<abi::ID, ItronError> { + unsafe { + let mut out = MaybeUninit::uninit(); + ItronError::err_if_negative(abi::get_tid(out.as_mut_ptr()))?; + Ok(out.assume_init()) + } +} + +/// Get the specified task's priority. Panics on failure. +#[inline] +pub fn task_priority(task: abi::ID) -> abi::PRI { + try_task_priority(task).unwrap_or_else(|e| fail(e, &"get_pri")) +} + +/// Get the specified task's priority. +#[inline] +pub fn try_task_priority(task: abi::ID) -> Result<abi::PRI, ItronError> { + unsafe { + let mut out = MaybeUninit::uninit(); + ItronError::err_if_negative(abi::get_pri(task, out.as_mut_ptr()))?; + Ok(out.assume_init()) + } +} diff --git a/library/std/src/sys/itron/thread.rs b/library/std/src/sys/itron/thread.rs new file mode 100644 index 00000000000..4feb9c5a6d7 --- /dev/null +++ b/library/std/src/sys/itron/thread.rs @@ -0,0 +1,352 @@ +//! Thread implementation backed by μITRON tasks. Assumes `acre_tsk` and +//! `exd_tsk` are available. +use super::{ + abi, + error::{expect_success, expect_success_aborting, ItronError}, + task, + time::dur2reltims, +}; +use crate::{ + cell::UnsafeCell, + convert::TryFrom, + ffi::CStr, + hint, io, + mem::ManuallyDrop, + sync::atomic::{AtomicUsize, Ordering}, + sys::thread_local_dtor::run_dtors, + time::Duration, +}; + +pub struct Thread { + inner: ManuallyDrop<Box<ThreadInner>>, + + /// The ID of the underlying task. + task: abi::ID, +} + +/// State data shared between a parent thread and child thread. It's dropped on +/// a transition to one of the final states. +struct ThreadInner { + /// This field is used on thread creation to pass a closure from + /// `Thread::new` to the created task. + start: UnsafeCell<ManuallyDrop<Box<dyn FnOnce()>>>, + + /// A state machine. Each transition is annotated with `[...]` in the + /// source code. + /// + /// ```text + /// + /// <P>: parent, <C>: child, (?): don't-care + /// + /// DETACHED (-1) --------------------> EXITED (?) + /// <C>finish/exd_tsk + /// ^ + /// | + /// | <P>detach + /// | + /// + /// INIT (0) -----------------------> FINISHED (-1) + /// <C>finish + /// | | + /// | <P>join/slp_tsk | <P>join/del_tsk + /// | | <P>detach/del_tsk + /// v v + /// + /// JOINING JOINED (?) + /// (parent_tid) + /// ^ + /// \ / + /// \ <C>finish/wup_tsk / <P>slp_tsk-complete/ter_tsk + /// \ / & del_tsk + /// \ / + /// '--> JOIN_FINALIZE ---' + /// (-1) + /// + lifecycle: AtomicUsize, +} + +// Safety: The only `!Sync` field, `ThreadInner::start`, is only touched by +// the task represented by `ThreadInner`. +unsafe impl Sync for ThreadInner {} + +const LIFECYCLE_INIT: usize = 0; +const LIFECYCLE_FINISHED: usize = usize::MAX; +const LIFECYCLE_DETACHED: usize = usize::MAX; +const LIFECYCLE_JOIN_FINALIZE: usize = usize::MAX; +const LIFECYCLE_DETACHED_OR_JOINED: usize = usize::MAX; +const LIFECYCLE_EXITED_OR_FINISHED_OR_JOIN_FINALIZE: usize = usize::MAX; +// there's no single value for `JOINING` + +pub const DEFAULT_MIN_STACK_SIZE: usize = 1024 * crate::mem::size_of::<usize>(); + +impl Thread { + /// # Safety + /// + /// See `thread::Builder::spawn_unchecked` for safety requirements. + pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> { + // Inherit the current task's priority + let current_task = task::try_current_task_id().map_err(|e| e.as_io_error())?; + let priority = task::try_task_priority(current_task).map_err(|e| e.as_io_error())?; + + let inner = Box::new(ThreadInner { + start: UnsafeCell::new(ManuallyDrop::new(p)), + lifecycle: AtomicUsize::new(LIFECYCLE_INIT), + }); + + unsafe extern "C" fn trampoline(exinf: isize) { + // Safety: `ThreadInner` is alive at this point + let inner = unsafe { &*(exinf as *const ThreadInner) }; + + // Safety: Since `trampoline` is called only once for each + // `ThreadInner` and only `trampoline` touches `start`, + // `start` contains contents and is safe to mutably borrow. + let p = unsafe { ManuallyDrop::take(&mut *inner.start.get()) }; + p(); + + // Fix the current thread's state just in case, so that the + // destructors won't abort + // Safety: Not really unsafe + let _ = unsafe { abi::unl_cpu() }; + let _ = unsafe { abi::ena_dsp() }; + + // Run TLS destructors now because they are not + // called automatically for terminated tasks. + unsafe { run_dtors() }; + + let old_lifecycle = inner + .lifecycle + .swap(LIFECYCLE_EXITED_OR_FINISHED_OR_JOIN_FINALIZE, Ordering::Release); + + match old_lifecycle { + LIFECYCLE_DETACHED => { + // [DETACHED → EXITED] + // No one will ever join, so we'll ask the collector task to + // delete the task. + + // In this case, `inner`'s ownership has been moved to us, + // And we are responsible for dropping it. The acquire + // ordering is not necessary because the parent thread made + // no memory acccess needing synchronization since the call + // to `acre_tsk`. + // Safety: See above. + let _ = unsafe { Box::from_raw(inner as *const _ as *mut ThreadInner) }; + + // Safety: There are no pinned references to the stack + unsafe { terminate_and_delete_current_task() }; + } + LIFECYCLE_INIT => { + // [INIT → FINISHED] + // The parent hasn't decided whether to join or detach this + // thread yet. Whichever option the parent chooses, + // it'll have to delete this task. + // Since the parent might drop `*inner` as soon as it sees + // `FINISHED`, the release ordering must be used in the + // above `swap` call. + } + parent_tid => { + // Since the parent might drop `*inner` and terminate us as + // soon as it sees `JOIN_FINALIZE`, the release ordering + // must be used in the above `swap` call. + + // [JOINING → JOIN_FINALIZE] + // Wake up the parent task. + expect_success( + unsafe { + let mut er = abi::wup_tsk(parent_tid as _); + if er == abi::E_QOVR { + // `E_QOVR` indicates there's already + // a parking token + er = abi::E_OK; + } + er + }, + &"wup_tsk", + ); + } + } + } + + let inner_ptr = (&*inner) as *const ThreadInner; + + let new_task = ItronError::err_if_negative(unsafe { + abi::acre_tsk(&abi::T_CTSK { + // Activate this task immediately + tskatr: abi::TA_ACT, + exinf: inner_ptr as abi::EXINF, + // The entry point + task: Some(trampoline), + itskpri: priority, + stksz: stack, + // Let the kernel allocate the stack, + stk: crate::ptr::null_mut(), + }) + }) + .map_err(|e| e.as_io_error())?; + + Ok(Self { inner: ManuallyDrop::new(inner), task: new_task }) + } + + pub fn yield_now() { + expect_success(unsafe { abi::rot_rdq(abi::TPRI_SELF) }, &"rot_rdq"); + } + + pub fn set_name(_name: &CStr) { + // nope + } + + pub fn sleep(dur: Duration) { + for timeout in dur2reltims(dur) { + expect_success(unsafe { abi::dly_tsk(timeout) }, &"dly_tsk"); + } + } + + pub fn join(mut self) { + let inner = &*self.inner; + // Get the current task ID. Panicking here would cause a resource leak, + // so just abort on failure. + let current_task = task::current_task_id_aborting(); + debug_assert!(usize::try_from(current_task).is_ok()); + debug_assert_ne!(current_task as usize, LIFECYCLE_INIT); + debug_assert_ne!(current_task as usize, LIFECYCLE_DETACHED); + + let current_task = current_task as usize; + + match inner.lifecycle.swap(current_task, Ordering::Acquire) { + LIFECYCLE_INIT => { + // [INIT → JOINING] + // The child task will transition the state to `JOIN_FINALIZE` + // and wake us up. + loop { + expect_success_aborting(unsafe { abi::slp_tsk() }, &"slp_tsk"); + // To synchronize with the child task's memory accesses to + // `inner` up to the point of the assignment of + // `JOIN_FINALIZE`, `Ordering::Acquire` must be used for the + // `load`. + if inner.lifecycle.load(Ordering::Acquire) == LIFECYCLE_JOIN_FINALIZE { + break; + } + } + + // [JOIN_FINALIZE → JOINED] + } + LIFECYCLE_FINISHED => { + // [FINISHED → JOINED] + // To synchronize with the child task's memory accesses to + // `inner` up to the point of the assignment of `FINISHED`, + // `Ordering::Acquire` must be used for the above `swap` call`. + } + _ => unsafe { hint::unreachable_unchecked() }, + } + + // Terminate and delete the task + // Safety: `self.task` still represents a task we own (because this + // method or `detach_inner` is called only once for each + // `Thread`). The task indicated that it's safe to delete by + // entering the `FINISHED` or `JOIN_FINALIZE` state. + unsafe { terminate_and_delete_task(self.task) }; + + // In either case, we are responsible for dropping `inner`. + // Safety: The contents of `self.inner` will not be accessed hereafter + let _inner = unsafe { ManuallyDrop::take(&mut self.inner) }; + + // Skip the destructor (because it would attempt to detach the thread) + crate::mem::forget(self); + } +} + +impl Drop for Thread { + fn drop(&mut self) { + // Detach the thread. + match self.inner.lifecycle.swap(LIFECYCLE_DETACHED_OR_JOINED, Ordering::Acquire) { + LIFECYCLE_INIT => { + // [INIT → DETACHED] + // When the time comes, the child will figure out that no + // one will ever join it. + // The ownership of `self.inner` is moved to the child thread. + // However, the release ordering is not necessary because we + // made no memory acccess needing synchronization since the call + // to `acre_tsk`. + } + LIFECYCLE_FINISHED => { + // [FINISHED → JOINED] + // The task has already decided that we should delete the task. + // To synchronize with the child task's memory accesses to + // `inner` up to the point of the assignment of `FINISHED`, + // the acquire ordering is required for the above `swap` call. + + // Terminate and delete the task + // Safety: `self.task` still represents a task we own (because + // this method or `join_inner` is called only once for + // each `Thread`). The task indicated that it's safe to + // delete by entering the `FINISHED` state. + unsafe { terminate_and_delete_task(self.task) }; + + // Wwe are responsible for dropping `inner`. + // Safety: The contents of `self.inner` will not be accessed + // hereafter + unsafe { ManuallyDrop::drop(&mut self.inner) }; + } + _ => unsafe { hint::unreachable_unchecked() }, + } + } +} + +pub mod guard { + pub type Guard = !; + pub unsafe fn current() -> Option<Guard> { + None + } + pub unsafe fn init() -> Option<Guard> { + None + } +} + +/// Terminate and delete the specified task. +/// +/// This function will abort if `deleted_task` refers to the calling task. +/// +/// It is assumed that the specified task is solely managed by the caller - +/// i.e., other threads must not "resuscitate" the specified task or delete it +/// prematurely while this function is still in progress. It is allowed for the +/// specified task to exit by its own. +/// +/// # Safety +/// +/// The task must be safe to terminate. This is in general not true +/// because there might be pinned references to the task's stack. +unsafe fn terminate_and_delete_task(deleted_task: abi::ID) { + // Terminate the task + // Safety: Upheld by the caller + match unsafe { abi::ter_tsk(deleted_task) } { + // Indicates the task is already dormant, ignore it + abi::E_OBJ => {} + er => { + expect_success_aborting(er, &"ter_tsk"); + } + } + + // Delete the task + // Safety: Upheld by the caller + expect_success_aborting(unsafe { abi::del_tsk(deleted_task) }, &"del_tsk"); +} + +/// Terminate and delete the calling task. +/// +/// Atomicity is not required - i.e., it can be assumed that other threads won't +/// `ter_tsk` the calling task while this function is still in progress. (This +/// property makes it easy to implement this operation on μITRON-derived kernels +/// that don't support `exd_tsk`.) +/// +/// # Safety +/// +/// The task must be safe to terminate. This is in general not true +/// because there might be pinned references to the task's stack. +unsafe fn terminate_and_delete_current_task() -> ! { + expect_success_aborting(unsafe { abi::exd_tsk() }, &"exd_tsk"); + // Safety: `exd_tsk` never returns on success + unsafe { crate::hint::unreachable_unchecked() }; +} + +pub fn available_concurrency() -> io::Result<crate::num::NonZeroUsize> { + super::unsupported() +} diff --git a/library/std/src/sys/itron/time.rs b/library/std/src/sys/itron/time.rs new file mode 100644 index 00000000000..6a992ad1d3c --- /dev/null +++ b/library/std/src/sys/itron/time.rs @@ -0,0 +1,123 @@ +use super::{abi, error::expect_success}; +use crate::{convert::TryInto, mem::MaybeUninit, time::Duration}; + +#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)] +pub struct Instant(abi::SYSTIM); + +impl Instant { + pub fn now() -> Instant { + // Safety: The provided pointer is valid + unsafe { + let mut out = MaybeUninit::uninit(); + expect_success(abi::get_tim(out.as_mut_ptr()), &"get_tim"); + Instant(out.assume_init()) + } + } + + pub const fn zero() -> Instant { + Instant(0) + } + + pub fn actually_monotonic() -> bool { + // There are ways to change the system time + false + } + + pub fn checked_sub_instant(&self, other: &Instant) -> Option<Duration> { + self.0.checked_sub(other.0).map(|ticks| { + // `SYSTIM` is measured in microseconds + Duration::from_micros(ticks) + }) + } + + pub fn checked_add_duration(&self, other: &Duration) -> Option<Instant> { + // `SYSTIM` is measured in microseconds + let ticks = other.as_micros(); + + Some(Instant(self.0.checked_add(ticks.try_into().ok()?)?)) + } + + pub fn checked_sub_duration(&self, other: &Duration) -> Option<Instant> { + // `SYSTIM` is measured in microseconds + let ticks = other.as_micros(); + + Some(Instant(self.0.checked_sub(ticks.try_into().ok()?)?)) + } +} + +/// Split `Duration` into zero or more `RELTIM`s. +#[inline] +pub fn dur2reltims(dur: Duration) -> impl Iterator<Item = abi::RELTIM> { + // `RELTIM` is microseconds + let mut ticks = dur.as_micros(); + + crate::iter::from_fn(move || { + if ticks == 0 { + None + } else if ticks <= abi::TMAX_RELTIM as u128 { + Some(crate::mem::replace(&mut ticks, 0) as abi::RELTIM) + } else { + ticks -= abi::TMAX_RELTIM as u128; + Some(abi::TMAX_RELTIM) + } + }) +} + +/// Split `Duration` into one or more `TMO`s. +#[inline] +fn dur2tmos(dur: Duration) -> impl Iterator<Item = abi::TMO> { + // `TMO` is microseconds + let mut ticks = dur.as_micros(); + let mut end = false; + + crate::iter::from_fn(move || { + if end { + None + } else if ticks <= abi::TMAX_RELTIM as u128 { + end = true; + Some(crate::mem::replace(&mut ticks, 0) as abi::TMO) + } else { + ticks -= abi::TMAX_RELTIM as u128; + Some(abi::TMAX_RELTIM) + } + }) +} + +/// Split `Duration` into one or more API calls with timeout. +#[inline] +pub fn with_tmos(dur: Duration, mut f: impl FnMut(abi::TMO) -> abi::ER) -> abi::ER { + let mut er = abi::E_TMOUT; + for tmo in dur2tmos(dur) { + er = f(tmo); + if er != abi::E_TMOUT { + break; + } + } + er +} + +/// Split `Duration` into one or more API calls with timeout. This function can +/// handle spurious wakeups. +#[inline] +pub fn with_tmos_strong(dur: Duration, mut f: impl FnMut(abi::TMO) -> abi::ER) -> abi::ER { + // `TMO` and `SYSTIM` are microseconds. + // Clamp at `SYSTIM::MAX` for performance reasons. This shouldn't cause + // a problem in practice. (`u64::MAX` μs ≈ 584942 years) + let ticks = dur.as_micros().min(abi::SYSTIM::MAX as u128) as abi::SYSTIM; + + let start = Instant::now().0; + let mut elapsed = 0; + let mut er = abi::E_TMOUT; + while elapsed <= ticks { + er = f(elapsed.min(abi::TMAX_RELTIM as abi::SYSTIM) as abi::TMO); + if er != abi::E_TMOUT { + break; + } + elapsed = Instant::now().0.wrapping_sub(start); + } + + er +} + +#[cfg(test)] +mod tests; diff --git a/library/std/src/sys/itron/time/tests.rs b/library/std/src/sys/itron/time/tests.rs new file mode 100644 index 00000000000..d14035d9da4 --- /dev/null +++ b/library/std/src/sys/itron/time/tests.rs @@ -0,0 +1,33 @@ +use super::*; + +fn reltim2dur(t: u64) -> Duration { + Duration::from_micros(t) +} + +#[test] +fn test_dur2reltims() { + assert_eq!(dur2reltims(reltim2dur(0)).collect::<Vec<_>>(), vec![]); + assert_eq!(dur2reltims(reltim2dur(42)).collect::<Vec<_>>(), vec![42]); + assert_eq!( + dur2reltims(reltim2dur(abi::TMAX_RELTIM as u64)).collect::<Vec<_>>(), + vec![abi::TMAX_RELTIM] + ); + assert_eq!( + dur2reltims(reltim2dur(abi::TMAX_RELTIM as u64 + 10000)).collect::<Vec<_>>(), + vec![abi::TMAX_RELTIM, 10000] + ); +} + +#[test] +fn test_dur2tmos() { + assert_eq!(dur2tmos(reltim2dur(0)).collect::<Vec<_>>(), vec![0]); + assert_eq!(dur2tmos(reltim2dur(42)).collect::<Vec<_>>(), vec![42]); + assert_eq!( + dur2tmos(reltim2dur(abi::TMAX_RELTIM as u64)).collect::<Vec<_>>(), + vec![abi::TMAX_RELTIM] + ); + assert_eq!( + dur2tmos(reltim2dur(abi::TMAX_RELTIM as u64 + 10000)).collect::<Vec<_>>(), + vec![abi::TMAX_RELTIM, 10000] + ); +} |