Classes | Functions | Variables
tornado::concurrent Namespace Reference

Classes

class  DummyExecutor
class  Future
class  ReturnValueIgnoredError

Functions

def chain_future
def is_future
def return_future
def run_on_executor

Variables

tuple _NO_RESULT = object()
tuple dummy_executor = DummyExecutor()
 futures = None
 FUTURES = Future
 TracebackFuture = Future

Function Documentation

def tornado.concurrent.chain_future (   a,
  b 
)
Chain two futures together so that when one completes, so does the other.

The result (success or failure) of ``a`` will be copied to ``b``, unless
``b`` has already been completed or cancelled by the time ``a`` finishes.

Definition at line 312 of file concurrent.py.

Definition at line 188 of file concurrent.py.

Decorator to make a function that returns via callback return a
`Future`.

The wrapped function should take a ``callback`` keyword argument
and invoke it with one argument when it has finished.  To signal failure,
the function can simply raise an exception (which will be
captured by the `.StackContext` and passed along to the ``Future``).

From the caller's perspective, the callback argument is optional.
If one is given, it will be invoked when the function is complete
with `Future.result()` as an argument.  If the function fails, the
callback will not be run and an exception will be raised into the
surrounding `.StackContext`.

If no callback is given, the caller should use the ``Future`` to
wait for the function to complete (perhaps by yielding it in a
`.gen.engine` function, or passing it to `.IOLoop.add_future`).

Usage::

    @return_future
    def future_func(arg1, arg2, callback):
        # Do stuff (possibly asynchronous)
        callback(result)

    @gen.engine
    def caller(callback):
        yield future_func(arg1, arg2)
        callback()

Note that ``@return_future`` and ``@gen.engine`` can be applied to the
same function, provided ``@return_future`` appears first.  However,
consider using ``@gen.coroutine`` instead of this combination.

Definition at line 230 of file concurrent.py.

Decorator to run a synchronous method asynchronously on an executor.

The decorated method may be called with a ``callback`` keyword
argument and returns a future.

This decorator should be used only on methods of objects with attributes
``executor`` and ``io_loop``.

Definition at line 207 of file concurrent.py.


Variable Documentation

Definition at line 227 of file concurrent.py.

Definition at line 204 of file concurrent.py.

Definition at line 36 of file concurrent.py.

Definition at line 183 of file concurrent.py.

Definition at line 180 of file concurrent.py.



rosbridge_server
Author(s): Jonathan Mace
autogenerated on Thu Jun 6 2019 21:51:51