# asio run vs poll

asio run vs poll

discussions

Using io_service::poll instead of io_service::run is perfectly acceptable. The difference is explained in the documentation

The poll() function may also be used to dispatch ready handlers, but without blocking.

Note that io_service::run will block if there's any work left in the queue

The work class is used to inform the io_service when work starts and finishes. This ensures that the io_service object's run() function will not exit while work is underway, and that it does exit when there is no unfinished work remaining.

whereas io_service::poll does not exhibit this behavior, it just invokes ready handlers. Also note that you will need to invoke io_service::reset on any subsequent invocation to io_service:run or io_service::poll.

summary

  1. run: will block if there's any work left in the queue

  2. poll: dispatch ready handlers, but without blocking

  3. blocking vs non-blocking

    1. 所谓的blocking:除了invoke ready handlers,还会等待这些handler结束,以及继续执行ready queue里面的task
    2. 所谓的nonblocking:只是执行ready queue里面的task,但不会继续等待这些handler结束

如何集成到GraphApi中去

idea1: 一个graph配一个io_service. 用io_service的run()驱动graph执行

Pros:简单,容易debug。应用层是同步处理,用法简单

Cons:io_service创建的effort大不大?

idead2:所有graph使用同一个io_service。io_service在一个单独的线程执行。graph方面不提供同步的run函数。

Pros:

Cons:复杂,可能不好debug。由于应用层会是全异步,Mat生命周期管理会复杂一些

Ref

https://stackoverflow.com/questions/4705411/boostasio-io-service-run-vs-poll-or-how-do-i-integrate-boostasio-in-ma

posted on 2020-04-10 16:00  cutepig  阅读(163)  评论(0编辑  收藏  举报

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