Public Member Functions | Private Member Functions | Private Attributes
tornado.concurrent.Future Class Reference

List of all members.

Public Member Functions

def __init__
def add_done_callback
def cancel
def cancelled
def done
def exc_info
def exception
def result
def running
def set_exc_info
def set_exception
def set_result

Private Member Functions

def _check_done
def _set_done

Private Attributes

 _callbacks
 _done
 _exc_info
 _exception
 _result

Detailed Description

Placeholder for an asynchronous result.

A ``Future`` encapsulates the result of an asynchronous
operation.  In synchronous applications ``Futures`` are used
to wait for the result from a thread or process pool; in
Tornado they are normally used with `.IOLoop.add_future` or by
yielding them in a `.gen.coroutine`.

`tornado.concurrent.Future` is similar to
`concurrent.futures.Future`, but not thread-safe (and therefore
faster for use with single-threaded event loops).

In addition to ``exception`` and ``set_exception``, methods ``exc_info``
and ``set_exc_info`` are supported to capture tracebacks in Python 2.
The traceback is automatically available in Python 3, but in the
Python 2 futures backport this information is discarded.
This functionality was previously available in a separate class
``TracebackFuture``, which is now a deprecated alias for this class.

.. versionchanged:: 4.0
   `tornado.concurrent.Future` is always a thread-unsafe ``Future``
   with support for the ``exc_info`` methods.  Previously it would
   be an alias for the thread-safe `concurrent.futures.Future`
   if that package was available and fall back to the thread-unsafe
   implementation if it was not.

Definition at line 43 of file concurrent.py.


Constructor & Destructor Documentation

Definition at line 71 of file concurrent.py.


Member Function Documentation

def tornado.concurrent.Future._check_done (   self) [private]

Definition at line 169 of file concurrent.py.

def tornado.concurrent.Future._set_done (   self) [private]

Definition at line 173 of file concurrent.py.

Attaches the given callback to the `Future`.

It will be invoked with the `Future` as its argument when the Future
has finished running and its result is available.  In Tornado
consider using `.IOLoop.add_future` instead of calling
`add_done_callback` directly.

Definition at line 125 of file concurrent.py.

Cancel the operation, if possible.

Tornado ``Futures`` do not support cancellation, so this method always
returns False.

Definition at line 78 of file concurrent.py.

Returns True if the operation has been cancelled.

Tornado ``Futures`` do not support cancellation, so this method
always returns False.

Definition at line 86 of file concurrent.py.

Returns True if the future has finished running.

Definition at line 98 of file concurrent.py.

Returns a tuple in the same format as `sys.exc_info` or None.

.. versionadded:: 4.0

Definition at line 152 of file concurrent.py.

def tornado.concurrent.Future.exception (   self,
  timeout = None 
)
If the operation raised an exception, return the `Exception`
object.  Otherwise returns None.

Definition at line 115 of file concurrent.py.

def tornado.concurrent.Future.result (   self,
  timeout = None 
)
If the operation succeeded, return its result.  If it failed,
re-raise its exception.

Definition at line 102 of file concurrent.py.

Returns True if this operation is currently running.

Definition at line 94 of file concurrent.py.

def tornado.concurrent.Future.set_exc_info (   self,
  exc_info 
)
Sets the exception information of a ``Future.``

Preserves tracebacks on Python 2.

.. versionadded:: 4.0

Definition at line 159 of file concurrent.py.

def tornado.concurrent.Future.set_exception (   self,
  exception 
)
Sets the exception of a ``Future.``

Definition at line 147 of file concurrent.py.

def tornado.concurrent.Future.set_result (   self,
  result 
)
Sets the result of a ``Future``.

It is undefined to call any of the ``set`` methods more than once
on the same object.

Definition at line 138 of file concurrent.py.


Member Data Documentation

Definition at line 71 of file concurrent.py.

Definition at line 71 of file concurrent.py.

Definition at line 71 of file concurrent.py.

Definition at line 71 of file concurrent.py.

Definition at line 71 of file concurrent.py.


The documentation for this class was generated from the following file:


rosbridge_server
Author(s): Jonathan Mace
autogenerated on Wed Sep 13 2017 03:18:20