src/vendor/magenta/src/timer.rs

   1 // Copyright 2016 The Fuchsia Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 //! Type-safe bindings for Magenta timer objects.
   6
   7 use {ClockId, Duration, HandleBase, Handle, HandleRef, Status, Time};
   8 use {sys, into_result};
   9
  10 /// An object representing a Magenta
  11 /// [event pair](https://fuchsia.googlesource.com/magenta/+/master/docs/concepts.md#Other-IPC_Events_Event-Pairs_and-User-Signals).
  12 ///
  13 /// As essentially a subtype of `Handle`, it can be freely interconverted.
  14 #[derive(Debug, Eq, PartialEq)]
  15 pub struct Timer(Handle);
  16
  17 impl HandleBase for Timer {
  18     fn get_ref(&self) -> HandleRef {
  19         self.0.get_ref()
  20     }
  21
  22     fn from_handle(handle: Handle) -> Self {
  23         Timer(handle)
  24     }
  25 }
  26
  27 impl Timer {
  28     /// Create a timer, an object that can signal when a specified point in time has been reached.
  29     /// Wraps the
  30     /// [mx_timer_create](https://fuchsia.googlesource.com/magenta/+/master/docs/syscalls/timer_create.md)
  31     /// syscall.
  32     pub fn create(options: TimerOpts, clock_id: ClockId) -> Result<Timer, Status> {
  33         let mut out = 0;
  34         let status = unsafe { sys::mx_timer_create(options as u32, clock_id as u32, &mut out) };
  35         into_result(status, || Self::from_handle(Handle(out)))
  36     }
  37
  38     /// Starts a timer which will fire when `deadline` passes. Wraps the
  39     /// [mx_timer_start](https://fuchsia.googlesource.com/magenta/+/master/docs/syscalls/timer_start.md)
  40     /// syscall.
  41     pub fn start(&self, deadline: Time, period: Duration, slack: Duration) -> Result<(), Status> {
  42         let status = unsafe { sys::mx_timer_start(self.raw_handle(), deadline, period, slack) };
  43         into_result(status, || ())
  44     }
  45
  46     /// Cancels a pending timer that was started with start(). Wraps the
  47     /// [mx_timer_cancel](https://fuchsia.googlesource.com/magenta/+/master/docs/syscalls/timer_cancel.md)
  48     /// syscall.
  49     pub fn cancel(&self) -> Result<(), Status> {
  50         let status = unsafe { sys::mx_timer_cancel(self.raw_handle()) };
  51         into_result(status, || ())
  52     }
  53 }
  54
  55 /// Options for creating a timer.
  56 #[repr(u32)]
  57 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
  58 pub enum TimerOpts {
  59     /// Default options.
  60     Default = 0,
  61 }
  62
  63 impl Default for TimerOpts {
  64     fn default() -> Self {
  65         TimerOpts::Default
  66     }
  67 }
  68
  69 #[cfg(test)]
  70 mod tests {
  71     use super::*;
  72     use {Duration, MX_SIGNAL_LAST_HANDLE, MX_TIMER_SIGNALED};
  73     use deadline_after;
  74
  75     #[test]
  76     fn create_timer_invalid_clock() {
  77         assert_eq!(Timer::create(TimerOpts::Default, ClockId::UTC).unwrap_err(), Status::ErrInvalidArgs);
  78         assert_eq!(Timer::create(TimerOpts::Default, ClockId::Thread), Err(Status::ErrInvalidArgs));
  79     }
  80
  81     #[test]
  82     fn timer_basic() {
  83         let ten_ms: Duration = 10_000_000;
  84         let twenty_ms: Duration = 20_000_000;
  85
  86         // Create a timer
  87         let timer = Timer::create(TimerOpts::Default, ClockId::Monotonic).unwrap();
  88
  89         // Should not signal yet.
  90         assert_eq!(timer.wait(MX_TIMER_SIGNALED, deadline_after(ten_ms)), Err(Status::ErrTimedOut));
  91
  92         // Start it, and soon it should signal.
  93         assert_eq!(timer.start(ten_ms, 0, 0), Ok(()));
  94         assert_eq!(timer.wait(MX_TIMER_SIGNALED, deadline_after(twenty_ms)).unwrap(),
  95             MX_TIMER_SIGNALED | MX_SIGNAL_LAST_HANDLE);
  96
  97         // Cancel it, and it should stop signalling.
  98         assert_eq!(timer.cancel(), Ok(()));
  99         assert_eq!(timer.wait(MX_TIMER_SIGNALED, deadline_after(ten_ms)), Err(Status::ErrTimedOut));
 100     }
 101 }