Struct signal_hook::low_level::channel::Channel [−][src]
channel
only.A restricted async-signal-safe channel
This is a bit like the usual channel used for inter-thread communication, but with several restrictions:
- There's a limited number of slots (currently 5).
- There's no way to wait for a place in it or for a value. If value is not available,
None
is returned. If there's no space for a value, the value is silently dropped.
In exchange for that, all the operations on that channel are async-signal-safe. That means it is possible to use it to communicate between a signal handler and the rest of the world with it (specifically, it's designed to send information from the handler to the rest of the application). The throwing out of values when full is in line with collating of the same type in kernel (you should not use the same channel for multiple different signals).
Technically, this is a MPMC queue which preserves order, but it is expected to be used in MPSC mode mostly (in theory, multiple threads can be executing a signal handler for the same signal at the same time). The channel is not responsible for wakeups.
While the channel is async-signal-safe, you still need to make sure creating of the values is
too (it should not contain anything that allocates, for example ‒ so no String
s inside, etc).
The code was not tuned for performance (signals are not expected to happen often).
Implementations
impl<T> Channel<T>
[src]
pub fn new() -> Self
[src]
Creates a new channel with nothing in it.
pub fn send(&self, val: T)
[src]
Inserts a value into the channel.
If the value doesn't fit, it is silently dropped. Never blocks.
pub fn recv(&self) -> Option<T>
[src]
Takes a value from the channel.
Or returns None
if the channel is empty. Never blocks.
Trait Implementations
impl<T> Default for Channel<T>
[src]
impl<T: Send> Send for Channel<T>
[src]
impl<T: Send> Sync for Channel<T>
[src]
Auto Trait Implementations
impl<T> !RefUnwindSafe for Channel<T>
[src]
impl<T> Unpin for Channel<T> where
T: Unpin,
[src]
T: Unpin,
impl<T> UnwindSafe for Channel<T> where
T: UnwindSafe,
[src]
T: UnwindSafe,
Blanket Implementations
impl<T> Any for T where
T: 'static + ?Sized,
[src]
T: 'static + ?Sized,
impl<T> Borrow<T> for T where
T: ?Sized,
[src]
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
[src]
T: ?Sized,
pub fn borrow_mut(&mut self) -> &mut T
[src]
impl<T> From<T> for T
[src]
impl<T, U> Into<U> for T where
U: From<T>,
[src]
U: From<T>,
impl<T, U> TryFrom<U> for T where
U: Into<T>,
[src]
U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
[src]
impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
[src]
U: TryFrom<T>,