Popular recipes by Glenn Eychaner

Queue for managing multiple SIGALRM alarms concurrently (Python)

2012-12-06T18:58:11-08:00

Python recipe 577600 by Glenn Eychaner (alarm, queue, signal). Revision 3.

In asynchronous code, signal.alarm() is extremely useful for setting and handling timeouts and other timed and periodic tasks. It has a major limitation, however, that only one alarm function and alarm time can be set at a time; setting a new alarm disables the previous alarm. This package uses a heapq to maintain a queue of alarm events, allowing multiple alarm functions and alarm times to be set concurrently.

Asynchronous subprocess using asyncore (Python)

2013-01-21T19:51:00-08:00

Python recipe 576957 by Glenn Eychaner (async, asynchronous, asyncore, coroutine, decorator, generator, ipc, subprocess). Revision 21.

A coroutine-based wrapper for subprocess.Popen that uses asyncore to communicate with child processes asynchronously. This allows subprocesses to be called from within socket servers or clients without needing a complicated event loop to check both. Uses recipe 576965 to provide the asynchronous coroutine framework, recipe 576967 to provide asynchronous pipes, and recipe 577600 to provide multiple alarms.

Asynchronous pipe communication using asyncore (Python)

2013-10-29T16:48:22-07:00

Python recipe 576967 by Glenn Eychaner (async, asyncore, i_o, pipe). Revision 9.

Extends file_dispatcher to provide extra functionality for reading from and writing to pipes. Uses the observer pattern (recipe 576962) to provide notification of new data and closed pipes.

Flexible observer pattern implementation (Python)

2012-12-06T19:23:11-08:00

Python recipe 576962 by Glenn Eychaner (event, observer, pattern, publish, subscribe, threadsafe). Revision 16.

A simple, flexible, general-purpose observer pattern.

Observers can be callable objects or objects with a particular named method (handle_notify() by default). Events can be any object, and observers can select which events they are interested in receiving. Support for a number of different types of lightweight event objects is included.

Multicontext (e.g. asynchronous) inline execution framework using coroutines (Python)

2012-12-06T19:32:20-08:00

Python recipe 576965 by Glenn Eychaner (asynchronous, coroutine, decorator, generator, inline, nonblocking, pattern, thread). Revision 14.

A framework for executing inline code, contained in a generator, across multiple execution contexts, by pairing it with an executor that handles the context switching at each yield. An example of a generator which executes some iterations synchronously and some asynchronously is provided. The framework is general enough to be applied to many different coroutine situations.