Re: [boost] [thread] thread_specific_ptr performance (was: Re:Boostlibrary submission (poll for interest))

Subject: Re: [boost] [thread] thread_specific_ptr performance (was: Re:Boostlibrary submission (poll for interest))
From: vicente.botet (vicente.botet_at_[hidden])
Date: 2010-01-08 19:22:25

----- Original Message ----- 
From: "Stefan Strasser" <strasser_at_[hidden]>
To: <boost_at_[hidden]>
Sent: Saturday, January 09, 2010 1:19 AM
Subject: Re: [boost] [thread] thread_specific_ptr performance (was: Re:Boostlibrary submission (poll for interest))

> 
> Am Friday 08 January 2010 20:36:46 schrieb vicente.botet:
>> > is there any chance for a thread_specific_ptr implementation based on GCC
>> > __thread and MSVC __declspec(thread)?
>> >
>> > __thread results in a simple read access using a thread-specific memory
>> > segment.
>>
>> Hi,
>> As Anthony has already state on other threads this seems to be not posible
>> (the semantic is different). 
> 
> could you point me towards that thread? the one about dynamically loaded 
> libraries?

http://old.nabble.com/-thread--TSS-cleanup-tt19590361.html#a19617150
 
>> What about defining a macro BOOST_LOCAL_THREAD 
>> that do the needed portable issues? Have you make some measures with
>> __thread and/or MSVC __declspec(thread)?
> 
> I'm not sure if you can bring together all the different semantics of those 
> extensions using a macro.
> the proposal of C++0x thread local storage is about 10 pages:
> http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2659.htm

Well the proposal may have 10 pages but the syntactical addition is quite simple, the problem is that each compiler has each own syntax. 
 
>> BTW, Anthony has made some improvements to which thread_specific_ptr in
>> 1.41. Which version are you using?
> 
> 1.41

Have you made some mesurements comparing thread_specific_ptr and __thread for example?
If there is a big difference maybe you could make a ticket then.

Best,
Vicente