Re: [Boost-users] Way to Promise the io_service.run() Is Running

Subject: Re: [Boost-users] Way to Promise the io_service.run() Is Running
From: Edward Diener (eldiener_at_[hidden])
Date: 2016-03-16 12:31:24

On 3/16/2016 9:58 AM, Bo Zhou wrote:
> Hi !
>
> I have a program which has a following logic
>
>  1. Start the UDP listening in daemon thread
>  2. Send the UDP command from main thread, and wait the response, maybe
>     from the local
>
> So the program itself might also receive the message from second step.
>
> But the problem is, on Windows, the receiving thread will be executed
> before the main thread starts to send message, so the behaviour is correct.

Use a synchronization primitive so that the daemon thread does not do 
any UDP listening until the main thread has sent the UDP command.

>
> On Linux that's opposite, the main thread will be in deadlock because
> the 1st thread is not running and 2nd step it's trying to receive
> something after sending the command.
>
> My question, in the main thread of my application, what could I do to
> detect the io_service is running ? I tried to call
> m_io_services.stopped() seems the state is not correct, so I'd like to
> know how can I wait until the event loop in 1st step is running ?
>
> Thank you very much !