flush MessageBox

[John Colvin via Digitalmars-d-learn]

On Friday, 21 August 2015 at 10:43:22 UTC, Chris wrote:
> On Thursday, 20 August 2015 at 15:57:47 UTC, John Colvin wrote:
>> On Thursday, 20 August 2015 at 15:25:57 UTC, Chris wrote:
>>> Is there a way to flush a thread's message box other than 
>>> aborting the thread? MailBox is private:
>>>
>>> https://github.com/D-Programming-Language/phobos/blob/master/std/concurrency.d#L1778
>>
>> flush from inside the thread? You could call receiveTimeout 
>> with a 0 timer in a loop until it returns false.
>
> Yes, from inside the thread. I have a worker thread (with 
> receiveTimeout) that is started when the program starts and 
> sits there waiting for input. I naively thought this was a 
> great idea, until I noticed that when input comes fast the 
> mailbox grows and the bloody thread won't stop until all the 
> items in the mailbox are processed. I was looking for something 
> like `if (abort) { mailbox.flush(); }`

void flushMailbox()
{
     bool r;
     do
     {
         r = receiveTimeout(Duration.zero, (Variant _){});
     } while(r);
}

You could optimise that to more efficiently deal with the actual 
types you're receiving, instead of making a Variant every time, 
but it's probably not worth it. The compiler might even optimise 
it away anyway.