从升压线程运行在主线程函数，参数传递到该功能 [英] Running a function on the main thread from a boost thread and passing parameters to that function

问题描述

我在修改的东西由不正常的主线程处理的线程提升一些code运行，这是有道理的。

I have some code running in a boost thread that modifies stuff handled by the main thread which is not working and it makes sense.

在Android上我将有处理程序这是将执行在主线程我的code消息队列，我可以通过我想这一切参数处理程序。

On android i would have the Handler which is a message queue that would execute my code on the main thread and i can pass whatever parameters i want to this handler.

我想要做同样的升压

等我的主线程我做到以下几点：

so on my main thread i do the following:

boost::thread workerThread(boost::bind(&SomeClass::pollService, this));

我pollService方式：

My pollService method:

SomeClass::pollService()
{
     //get some stuff from a web service
     //parse the json response
     //NEEDED part: call a function to be executed on the main thread and hand it some functions
}

P.S。我看过许多 io_service.post 的例子，我仍然不知道如何做到这一点的，也是我读答案说要用 ASIO 链但我也无法理解它。

P.S. I have looked at many io_service.post examples and i still have no clue how to do it, and also i read an answer that said to use asio strand but i am also unable to understand it.

有人能请哑下来我吗？
请不要写的东西非常抽象，我不会明白，我不是这个经验。
谢谢

Can some one please dumb it down for me ? Please don't write something so abstract that i won't understand, I am not experienced in this. Thank you

推荐答案

是 io_service对象::后（）是一个方便的工具来从一个线程张贴到仿函数另一个，但目标线程应该执行 io_service对象::运行（），这是阻止功能（这是一种 io_service对象的消息循环）。因此，假设你的主线程看起来是这样的：

Yes, io_service::post() is a convenient facility to post a functor from one thread to another, but the destination thread should execute io_service::run(), which is blocking function (it's kind of io_service "message loop"). So, assuming your main thread looks like this:

int main()
{
  // do some preparations, launch other threads...
  // ...
  io_service io;
  io.run();
}

...假设你有从 pollService 到 IO 对象的访问在另一个线程运行，你可以做到以下几点：

...and assuming you've got an access to io object from pollService running in another thread, you can do the following:

SomeClass::pollService()
{
  // do something...
  // ...
  io.post([=] { doStuffThatShoudRunInMainThread(); });
}

如果你的编译器不支持C ++ 11 lambda表达式，使用绑定 - 但是请注意，后预计无元仿函数，即函数对象，不接受参数。

If your compiler doesn't support c++11 lambdas, use bind -- but note that post expects nullary functor, i.e. a function-object that doesn't accept parameters.

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