Re: [Boost-users] multi_index: thread safety

Subject: Re: [Boost-users] multi_index: thread safety
From: Matwey V. Kornilov (matwey.kornilov_at_[hidden])
Date: 2015-03-08 12:51:46

08.03.2015 18:06, Joaquin M Lopez Munoz пишет:
> Matwey V. Kornilov <matwey.kornilov <at> gmail.com> writes:
> 
>>
>> Hi,
>>
>> I have a multi_index container and would like to make concurrent READs.
>> Is it thread-safe? I mean that there could be mutable members inside the
>> object, so calling formally const functions leaded to concurrent writes.
> 
> Adding to Ernest's answer: if your formally const function changes the
> value of some mutable data member, then concurrent access is NOT safe.
> For instance:
> 
> struct X
> {
>   int x;
>   mutable std::size_t count;
> 
>   int get_x()const
>   {
>     ++count;
>     return x;
>   }
> };
> 
> Concurrent execution of X::get_x is not safe. This has nothing to do
> with Boost.MultiIndex, by the way; if your problem is different please
> answer back.

Yes, It is clear to me. This is why I asked if there any mutable inside
MultiIndex.