Re: [asio-users] Resource deadlock exception

[Dev G. <dev...@gm...>]

Hi Alex, thanks that was it, how I didn't notice that myself :)

On Fri, Dec 25, 2015 at 3:37 PM, Alex Biv <bob...@gm...> wrote:
> Hi again!
>
>
>
> I tried to study your code (
> https://github.com/ryadav/simple_async_server/blob/master/src/main.cpp )
>
>
>
> It seems i understand what is going on.
>
>
>
> Look at pthread_join man page:
>
> http://linux.die.net/man/3/pthread_join
>
>
>
> EDEADLK
>
> A deadlock was detected (e.g., two threads tried to join with each other);
> or thread specifies the calling thread.
>
>
>
> After connection is accepted by your server, run (0) called in accept
> callback. It starts waiting for another connection to accept.
>
> Input parameter 'threads' is 0, so no threads are added to _workers, but
> this code:
>
> for( auto & t : _workers)
>
>       {
>
>          t.join();
>
>       }
>
>
>
> is executing,
>
>
>
> and it is executing from inside one of threads in _workers vector (probably
> it is thread at the beginning of vector _workers). And it calls join for
> himself.
>
>
> P.S. Sorry for my english
>
>
> 2015-12-25 22:02 GMT+03:00 Dev Guy <dev...@gm...>:
>>
>> Hi Scott,
>>
>> you can find the code I am using to learn about ASIO here:
>>
>> https://github.com/ryadav/simple_async_server
>>
>> There is a if / def you can play with to see what I mean.
>>
>> Thanks,
>> Rajinder Yadav
>>
>> On Fri, Dec 25, 2015 at 12:59 AM, Scott Mueller <smu...@os...>
>> wrote:
>> > std::vector<>::push_back has an overload which takes an rvalue
>> > reference,
>> > which is what std::thread() will generate. If you’re trying to
>> > copy-construct a thread, it will fail at compile-time. There’s something
>> > else going on here. Is there a work object that you’re releasing after
>> > you’ve detected that the socket has expired? Do you need several threads
>> > to
>> > handle traffic on one socket? I think I need to see more code to find
>> > out
>> > what it is tha tyou’re trying to do.
>> >
>> >
>> >
>> > Best regards,
>> >
>> >
>> >
>> > M. Scott Mueller
>> >
>> >
>> >
>> > From: Alex Biv [mailto:bob...@gm...]
>> > Sent: Thursday, December 24, 2015 9:38 PM
>> > To: asi...@li...
>> > Subject: Re: [asio-users] Resource deadlock exception
>> >
>> >
>> >
>> > Hi!
>> >
>> >
>> >
>> > std::thread is not copy-constructible.
>> >
>> >
>> >
>> > You should use emplace_back.
>> >
>> >
>> >
>> >
>> >
>> > 2015-12-25 8:22 GMT+03:00 Dev Guy <dev...@gm...>:
>> >
>> > Hello can  some help clear up what I am doing wrong with trying to use
>> > threads with vector? I am coding up a simple async echo, here is a
>> > snippet of the problem area,
>> >
>> >
>> >       for( int i=0; i < threads; ++i )
>> >       {
>> >          _workers.push_back( std::thread( [this]() {
>> >                                    _sock.get_io_service().run();
>> >                                 } ) );
>> >       }
>> >
>> >       for( auto & t : _workers)
>> >       {
>> >          t.join();
>> >       }
>> >
>> > When I run my server and as soon as I connect to it using netcat I get
>> > an exception?
>> >
>> > $ ./simple_async_server 5050
>> > terminate called after throwing an instance of 'std::system_error'
>> >   what():  Resource deadlock avoided
>> > Aborted (core dumped)
>> >
>> >
>> > However the following works no matter how many threads.
>> >
>> > std::thread t( [this]() { _sock.get_io_service().run(); } );
>> > t.join();
>> >
>> > So not clean why it doesn't work when I save the threads in a vector?
>> >
>> >
>> > ------------------------------------------------------------------------------
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>> > asi...@li...
>> > https://lists.sourceforge.net/lists/listinfo/asio-users
>> > _______________________________________________
>> > Using Asio? List your project at
>> > http://think-async.com/Asio/WhoIsUsingAsio
>> >
>> >
>> >
>> >
>> >
>> > ------------------------------------------------------------------------------
>> >
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>> > _______________________________________________
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>> >
>>
>>
>>
>> --
>> Kind Regards,
>> Rajinder Yadav
>>
>> SafetyNet Test Driven Development
>> http://safetynet.devmentor.org
>>
>>
>> ------------------------------------------------------------------------------
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>
>
>
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>
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>



-- 
Kind Regards,
Rajinder Yadav

SafetyNet Test Driven Development
http://safetynet.devmentor.org