Task execution related traits and utilities.
In the Tokio execution model, futures are lazy. When a future is created, no work is performed. In order for the work defined by the future to happen, the future must be submitted to an executor. A future that is submitted to an executor is called a "task".
The executor is responsible for ensuring that
Future::poll is called
whenever the task is notified. Notification happens when the internal
state of a task transitions from not ready to ready. For example, a
socket might have received data and a call to
read will now be able to
This crate provides traits and utilities that are necessary for building an executor, including:
Executortrait spawns future object onto an executor.
TypedExecutortrait spawns futures of a specific type onto an executor. This is used to be generic over executors that spawn futures that are either
!Sendor implement executors that apply to specific futures.
entermarks that the current thread is entering an execution context. This prevents a second executor from accidentally starting from within the context of one that is already running.
DefaultExecutorspawns tasks onto the default executor for the current context.
Parkabstracts over blocking and unblocking the current thread.
Implementing an executor
Executors should always implement
TypedExecutor. This usually is the bound
that applications and libraries will use when generic over an executor. See
the trait documentation for more details.
If the executor is able to spawn all futures that are
Send, then the
executor should also implement the
Executor trait. This trait is rarely
used directly by applications and libraries. Instead,
configured to dispatch to type that implements
Abstraction over blocking and unblocking the current thread.
Executes futures on the default executor for the current execution context.
Ensures that the executor is removed from the thread-local context when leaving the scope. This handles cases that involve panicking.
Represents an executor context.
An error returned by
Errors returned by
A value that executes futures.
A value that spawns futures of a specific type.
Marks the current thread as being within the dynamic extent of an executor.
Submits a future for execution on the default executor -- usually a threadpool.
Set the default executor for the duration of the closure