[zeromq-dev] context as global/static variable

[Daniel Krikun]

Just out of curiousity, nobody ever encountered such problem or nobody
tried to define zmq::context_t as global variable (in c++)?

On Wed, May 9, 2012 at 3:23 PM, Daniel Krikun <krikun.daniel at gmail.com>wrote:

> Further, I suspected there maybe a problem due to the singleton not being
> thread-safe. Thus, I modified the code to something like this:
>
> boost::mutex mutex_;
> zmq::context_t* p_ = 0;
>
> zmq::context_t& get_global_context()
> {
>        boost::mutex::scoped_lock(mutex_);
>        if(p_ == 0)
>             p_ = new zmq::context_t(1);
>
>        return *p_;
> }
>
> Well, that worked fine, but apparently, context_t destructor is never
> invoked (am I correct?). If, for example, I change p_ to some smart
> pointer, like boost::shared_ptr, which will invoke ~context_t at program
> shutdown, then the same problem appears.
> I guess, there is some problem in calling ~context_t at program exit.
> Ideas?
>
>
> On Wed, May 9, 2012 at 12:39 PM, Daniel Krikun <krikun.daniel at gmail.com>wrote:
>
>> Hello,
>>
>> I have some c++ code, that uses zeromq. In the code, I have a singleton
>> wrapping zmq::context_t, like this:
>>
>> struct ctx_singleton
>> {
>>            zmq::context_t& instance()
>>            {
>>                  static zmq::context_t _ctx;
>>                  return _ctx;
>>            }
>> };
>>
>> At application shutdown, I get an assertion failure:
>>   Successful WSASTARTUP not yet perfromed (..\..\..\src\signaler.cpp:124)
>>
>> I suspected there was a problem w/ zmq::context_t having global storage,
>> so I just take some zeromq sample and moved context definition from main
>> into global scope, and yes, I yields the same failure. I looked at the
>> stack trace, it seems that some socket/synch. mechanism is already disposed
>> when zmq_term is invoked and thus the failure.
>>
>> I really would like to put zmq::context_t instance, just to make things
>> easier, and not to pass the instance to all threads. Is there a possibility
>> to do so?
>>
>> I'm using zeromq-2.1.11, visual studio 2008 on Windows XP sp3, 32-bit.
>>
>> Thanks,
>>
>> --
>> Daniel Krikun
>>
>>
>
>
> --
> Daniel Krikun
>
>


-- 
Daniel Krikun
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