Public Member Functions | Static Public Member Functions | Static Public Attributes | Private Member Functions | Private Attributes | Static Private Attributes
tornado.ioloop.IOLoop Class Reference

List of all members.

Public Member Functions

def __init__
def add_callback
def add_handler
def add_timeout
def close
def handle_callback_exception
def install
def log_stack
def remove_handler
def remove_timeout
def running
def set_blocking_log_threshold
def set_blocking_signal_threshold
def start
def stop
def update_handler

Static Public Member Functions

def initialized
def instance

Static Public Attributes

 ERROR = _EPOLLERR|_EPOLLHUP
int NONE = 0
 READ = _EPOLLIN
 WRITE = _EPOLLOUT

Private Member Functions

def _run_callback

Private Attributes

 _blocking_signal_threshold
 _callback_lock
 _callbacks
 _events
 _handlers
 _impl
 _running
 _stopped
 _thread_ident
 _timeouts
 _waker

Static Private Attributes

int _EPOLLERR = 0x008
tuple _EPOLLET = (1 << 31)
int _EPOLLHUP = 0x010
int _EPOLLIN = 0x001
tuple _EPOLLONESHOT = (1 << 30)
int _EPOLLOUT = 0x004
int _EPOLLPRI = 0x002
int _EPOLLRDHUP = 0x2000
tuple _instance_lock = threading.Lock()

Detailed Description

A level-triggered I/O loop.

We use epoll (Linux) or kqueue (BSD and Mac OS X; requires python
2.6+) if they are available, or else we fall back on select(). If
you are implementing a system that needs to handle thousands of
simultaneous connections, you should use a system that supports either
epoll or queue.

Example usage for a simple TCP server::

    import errno
    import functools
    import ioloop
    import socket

    def connection_ready(sock, fd, events):
        while True:
            try:
                connection, address = sock.accept()
            except socket.error, e:
                if e.args[0] not in (errno.EWOULDBLOCK, errno.EAGAIN):
                    raise
                return
            connection.setblocking(0)
            handle_connection(connection, address)

    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    sock.setblocking(0)
    sock.bind(("", port))
    sock.listen(128)

    io_loop = ioloop.IOLoop.instance()
    callback = functools.partial(connection_ready, sock)
    io_loop.add_handler(sock.fileno(), callback, io_loop.READ)
    io_loop.start()

Definition at line 52 of file ioloop.py.


Constructor & Destructor Documentation

def tornado.ioloop.IOLoop.__init__ (   self,
  impl = None 
)

Definition at line 110 of file ioloop.py.


Member Function Documentation

def tornado.ioloop.IOLoop._run_callback (   self,
  callback 
) [private]

Definition at line 419 of file ioloop.py.

def tornado.ioloop.IOLoop.add_callback (   self,
  callback 
)
Calls the given callback on the next I/O loop iteration.

It is safe to call this method from any thread at any time.
Note that this is the *only* method in IOLoop that makes this
guarantee; all other interaction with the IOLoop must be done
from that IOLoop's thread.  add_callback() may be used to transfer
control from other threads to the IOLoop's thread.

Definition at line 398 of file ioloop.py.

def tornado.ioloop.IOLoop.add_handler (   self,
  fd,
  handler,
  events 
)
Registers the given handler to receive the given events for fd.

Definition at line 198 of file ioloop.py.

def tornado.ioloop.IOLoop.add_timeout (   self,
  deadline,
  callback 
)
Calls the given callback at the time deadline from the I/O loop.

Returns a handle that may be passed to remove_timeout to cancel.

``deadline`` may be a number denoting a unix timestamp (as returned
by ``time.time()`` or a ``datetime.timedelta`` object for a deadline
relative to the current time.

Note that it is not safe to call `add_timeout` from other threads.
Instead, you must use `add_callback` to transfer control to the
IOLoop's thread, and then call `add_timeout` from there.

Definition at line 369 of file ioloop.py.

def tornado.ioloop.IOLoop.close (   self,
  all_fds = False 
)
Closes the IOLoop, freeing any resources used.

If ``all_fds`` is true, all file descriptors registered on the
IOLoop will be closed (not just the ones created by the IOLoop itself).

Many applications will only use a single IOLoop that runs for the
entire lifetime of the process.  In that case closing the IOLoop
is not necessary since everything will be cleaned up when the
process exits.  `IOLoop.close` is provided mainly for scenarios
such as unit tests, which create and destroy a large number of
IOLoops.

An IOLoop must be completely stopped before it can be closed.  This
means that `IOLoop.stop()` must be called *and* `IOLoop.start()` must
be allowed to return before attempting to call `IOLoop.close()`.
Therefore the call to `close` will usually appear just after
the call to `start` rather than near the call to `stop`.

Definition at line 169 of file ioloop.py.

def tornado.ioloop.IOLoop.handle_callback_exception (   self,
  callback 
)
This method is called whenever a callback run by the IOLoop
throws an exception.

By default simply logs the exception as an error.  Subclasses
may override this method to customize reporting of exceptions.

The exception itself is not passed explicitly, but is available
in sys.exc_info.

Definition at line 425 of file ioloop.py.

Returns true if the singleton instance has been created.

Definition at line 155 of file ioloop.py.

Installs this IOloop object as the singleton instance.

This is normally not necessary as `instance()` will create
an IOLoop on demand, but you may want to call `install` to use
a custom subclass of IOLoop.

Definition at line 159 of file ioloop.py.

Returns a global IOLoop instance.

Most single-threaded applications have a single, global IOLoop.
Use this method instead of passing around IOLoop instances
throughout your code.

A common pattern for classes that depend on IOLoops is to use
a default argument to enable programs with multiple IOLoops
but not require the argument for simpler applications::

    class MyClass(object):
def __init__(self, io_loop=None):
    self.io_loop = io_loop or IOLoop.instance()

Definition at line 132 of file ioloop.py.

def tornado.ioloop.IOLoop.log_stack (   self,
  signal,
  frame 
)
Signal handler to log the stack trace of the current thread.

For use with set_blocking_signal_threshold.

Definition at line 242 of file ioloop.py.

def tornado.ioloop.IOLoop.remove_handler (   self,
  fd 
)
Stop listening for events on fd.

Definition at line 207 of file ioloop.py.

def tornado.ioloop.IOLoop.remove_timeout (   self,
  timeout 
)
Cancels a pending timeout.

The argument is a handle as returned by add_timeout.

Definition at line 386 of file ioloop.py.

Returns true if this IOLoop is currently running.

Definition at line 365 of file ioloop.py.

def tornado.ioloop.IOLoop.set_blocking_log_threshold (   self,
  seconds 
)
Logs a stack trace if the ioloop is blocked for more than s seconds.
Equivalent to set_blocking_signal_threshold(seconds, self.log_stack)

Definition at line 236 of file ioloop.py.

def tornado.ioloop.IOLoop.set_blocking_signal_threshold (   self,
  seconds,
  action 
)
Sends a signal if the ioloop is blocked for more than s seconds.

Pass seconds=None to disable.  Requires python 2.6 on a unixy
platform.

The action parameter is a python signal handler.  Read the
documentation for the python 'signal' module for more information.
If action is None, the process will be killed if it is blocked for
too long.

Definition at line 216 of file ioloop.py.

Starts the I/O loop.

The loop will run until one of the I/O handlers calls stop(), which
will make the loop stop after the current event iteration completes.

Definition at line 251 of file ioloop.py.

Stop the loop after the current event loop iteration is complete.
If the event loop is not currently running, the next call to start()
will return immediately.

To use asynchronous methods from otherwise-synchronous code (such as
unit tests), you can start and stop the event loop like this::

  ioloop = IOLoop()
  async_method(ioloop=ioloop, callback=ioloop.stop)
  ioloop.start()

ioloop.start() will return after async_method has run its callback,
whether that callback was invoked before or after ioloop.start.

Note that even after `stop` has been called, the IOLoop is not
completely stopped until `IOLoop.start` has also returned.

Definition at line 343 of file ioloop.py.

def tornado.ioloop.IOLoop.update_handler (   self,
  fd,
  events 
)
Changes the events we listen for fd.

Definition at line 203 of file ioloop.py.


Member Data Documentation

Definition at line 110 of file ioloop.py.

Definition at line 110 of file ioloop.py.

Definition at line 110 of file ioloop.py.

int tornado::ioloop.IOLoop::_EPOLLERR = 0x008 [static, private]

Definition at line 95 of file ioloop.py.

tuple tornado::ioloop.IOLoop::_EPOLLET = (1 << 31) [static, private]

Definition at line 99 of file ioloop.py.

int tornado::ioloop.IOLoop::_EPOLLHUP = 0x010 [static, private]

Definition at line 96 of file ioloop.py.

int tornado::ioloop.IOLoop::_EPOLLIN = 0x001 [static, private]

Definition at line 92 of file ioloop.py.

tuple tornado::ioloop.IOLoop::_EPOLLONESHOT = (1 << 30) [static, private]

Definition at line 98 of file ioloop.py.

int tornado::ioloop.IOLoop::_EPOLLOUT = 0x004 [static, private]

Definition at line 94 of file ioloop.py.

int tornado::ioloop.IOLoop::_EPOLLPRI = 0x002 [static, private]

Definition at line 93 of file ioloop.py.

int tornado::ioloop.IOLoop::_EPOLLRDHUP = 0x2000 [static, private]

Definition at line 97 of file ioloop.py.

Definition at line 110 of file ioloop.py.

Definition at line 110 of file ioloop.py.

Definition at line 110 of file ioloop.py.

tuple tornado::ioloop.IOLoop::_instance_lock = threading.Lock() [static, private]

Definition at line 108 of file ioloop.py.

Definition at line 110 of file ioloop.py.

Definition at line 110 of file ioloop.py.

Definition at line 110 of file ioloop.py.

Definition at line 110 of file ioloop.py.

Definition at line 110 of file ioloop.py.

Definition at line 105 of file ioloop.py.

int tornado::ioloop.IOLoop::NONE = 0 [static]

Definition at line 102 of file ioloop.py.

Definition at line 103 of file ioloop.py.

Definition at line 104 of file ioloop.py.


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


roswww
Author(s): Jonathan Mace
autogenerated on Thu Jan 2 2014 11:53:30