Tasks used to drive a future computation
It's intended over time a particular operation (such as servicing an HTTP request) will involve many futures. This entire operation, however, can be thought of as one unit, as the entire result is essentially just moving through one large state machine.
A "task" is the unit of abstraction for what is driving this state machine
and tree of futures forward. A task is used to poll futures and schedule
futures with, and has utilities for sharing data between tasks and handles
for notifying when a future is ready. Each task also has its own set of
task-local data generated by
Note that libraries typically should not manage tasks themselves, but rather
leave that to event loops and other "executors" (see the
or by using the
wait method to create and execute a task directly on the
More information about the task model can be found online at tokio.rs.
There is an important bare function in this module:
current function returns a handle to the currently running task, panicking
if one isn't present. This handle is then used to later notify the task that
it's ready to make progress through the
A synchronization primitive for task notification.
A key for task-local data stored in a future's task.
A handle to a "task", which represents a single lightweight "thread" of execution driving a future to completion.
A set insertion to trigger upon
A concurrent set which allows for the insertion of
Returns a handle to the current task to call
Return whether the caller is running in a task (and so can use task_local!).
For the duration of the given callback, add an "unpark event" to be triggered when the task handle is used to unpark the task.