Libevent is pretty cool, but it is not “fast” for all applications. For example, it retrieves the system clock frequently, which can be a performance. libtorque: Portable Multithreaded Continuations decade’s architectures and operating systems, as libevent , libev, Java NIO and others achieved ubiquity much room for improving non-blocking I/O solu- Network programming abounds with task idioms. .. this approach could be the fastest path to true zero- . I want to know how to use libevent l.4,especially the use of http. can anybody give me a Fast portable non-blocking network programming with Libevent.
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We do a lot of network programming, so it would be unthinkable for any performance intensive application to do blocking calls exclusively. When the buffer event is freed, close the underlying transport.
But it’s a tradeoff: Edit Report a Bug. But most apps don’t fall into those categories, and I’m not getting any of that vibe from this. For more information on what nwtwork error was, call EventUtil:: If you need to handle lots of concurrent connections and don’t need to be working in C, check it out.
It was used heavily in the 90’s when threaded multiplexing was still new and threads were expensiveand it works well enough.
Decide that we want to write some data to a connection; put that data in a buffer. On the other end, say you run a thread per socket – that’s not effective as the memory usage for reserving thread stack space will limit your maximum connection count. When we want to write data, for example, the usual pattern looks like: I know what you mean about an event loop complicating error handling from callbacks, though. Within a single thread they do serialize, but only by the length of your callbacks.
Programminb input buffer object EventBuffer. Note that gevent is a fork of Eventlet http: Hacker News new comments show ask jobs submit. It’s frombut is a good overview of well-understood techniques.
That can be extremely bad for latency. Also, I’m not convinced that the “nasty state bugs” from reorganizing around an event loop are necessarily worse than the ones that come from using threads with shared state.
Usually an application wants to perform some amount of data buffering in addition to just responding to events. See the other flags for which event it was.
Where I work, blovking one single library for concurrency, and every program or toolkit uses it. It uses greenlets to make code written sychronously run asynchronously behind the scenes.
Fast portable non-blocking network programming with Libevent wangafu. Also, the maintainer only updates sporadically, but I’ve never had real problems with it. JoachimSchipper on Jan 11, EOF Got an end-of-file indication on the buffer event. Also for python is pyevent, which works pretty well.
Constructing signal events
RoboTeddy on Jan 11, Libevent is rock solid — it handles the event loop for memcache, among other things. It’s not a standard part of Unix, of course, but poftable seems reasonably portable. Libevent is rock solid — it handles the event loop for memcache, among other things. Event programming is useful in that it effectively performs cooperative multitasking without the overhead of thread stack space.
This will close an underlying socket, free an underlying buffer event, etc.
PHP: EventBufferEvent – Manual
Witj you have any other links, please share. Equals to NULLif there is no file descriptor socket associated with the buffer event. Instead of regular events, which give callbacks when the underlying transport is ready to be read or written, a buffer event invokes its user-supplied callbacks when it has read or written enough data.
When we want to write data, for nerwork, the usual pattern looks like:. Event-based code obscures control flow, as you note; threaded code is subject to very subtle and hard-to-reproduce bugs. It splits sequential algorithms up into multiple callbacks with manually managed shared state.
It monkey-patches the python socket module with a version that automatically fzst with libevent’s loop. Thanks to you and ajross, this really helps. Numeric file descriptor associated with the buffer event. An event occured during a write operation on the bufferevent.
UNIX for Advanced & Expert Users
It feels sort of like writing in continuation-passing-style. It seems like a good fit for both the indexing hubs and the storage nodes, and it pairs well with Lua’s coroutines. But it’s difficult and error-prone. RoboTeddy on Jan 11, Once you set up a non-blocking event loop, it’s much simpler when you can go async all the way down.
There are plenty of services that won’t ever need to handle more than a couple simultaneous connections, and that way you don’t need to bother with asynchronous IO. An event occured during a read operation on the bufferevent. An error occurred during a bufferevent operation.