Function futures::task::current
[−]
[src]
pub fn current() -> Task
Returns a handle to the current task to call notify
at a later date.
The returned handle implements the Send
and 'static
bounds and may also
be cheaply cloned. This is useful for squirreling away the handle into a
location which is then later signaled that a future can make progress.
Implementations of the Future
trait typically use this function if they
would otherwise perform a blocking operation. When something isn't ready
yet, this current
function is called to acquire a handle to the current
task, and then the future arranges it such that when the blocking operation
otherwise finishes (perhaps in the background) it will notify
the
returned handle.
It's sometimes necessary to pass extra information to the task when
unparking it, so that the task knows something about why it was woken.
See the FutureQueue
documentation for details on how to do this.
Panics
This function will panic if a task is not currently being executed. That
is, this method can be dangerous to call outside of an implementation of
poll
.