Re: [boost] [ASIO] Having a hard time after upgrading my boost

Subject: Re: [boost] [ASIO] Having a hard time after upgrading my boost
From: Marat Abrarov (abrarov_at_[hidden])
Date: 2013-05-20 09:42:41

> My code is heavily multi-threaded. This problem doesn't show up in
> single threaded environment at all. My OS is SUSE 11 and g++-4.3.3 as the
> compiler. I may have to post some code eventually but on the top off your
> head - do you have any pointers for me?

Note that free functions like asio::async_read/aync_read_untill
(async_write/async_write_until, etc) are composed operations so "... The
program must ensure that the stream performs no other read operations (such
as async_read, async_read_until, the stream's async_read_some function, or
any other composed operations that perform reads) until this operation
completes"
(http://www.boost.org/doc/libs/1_53_0/doc/html/boost_asio/reference/async_re
ad_until.html).

Also note that most of Asio classes (sockets, timers, etc.) are not thread
safe. So in multi-threaded program you have to use some kind of
synchronization if there is no implicit strand
(http://www.boost.org/doc/libs/1_53_0/doc/html/boost_asio/overview/core/stra
nds.html). The simplest kind of synchronization is asio::io_service::strand.
If you use something else (for example, mutex) then notice intermediate
handlers created by composed operations
(http://www.boost.org/doc/libs/1_53_0/doc/html/boost_asio/overview/core/stra
nds.html, asio_handler_invoke) and use your synchronization in a right way
(for mutex see
https://github.com/boostcon/2011_presentations/raw/master/mon/thinking_async
hronously.pdf, struct mutex_wrapper at page 95-97).

There is a feature named "Handler Tracking"
(http://www.boost.org/doc/libs/1_53_0/doc/html/boost_asio/overview/core/hand
ler_tracking.html) that can help you to investigated the order of handler
invocation.

Regards, 
Marat Abrarov.