November 2009 - Boost - lists.boost.org

[thread] #2361 thread_specific_ptr: nature of the key, complexity and rationale
by Vicente Botet Escriba 25 Nov '09

25 Nov '09

Hi Anthony, As you have made some modifications on the thread-specific_ptr, maybe you could now complete the documentation to answer the questions of the ticket. Best, Vicente -- View this message in context: http://old.nabble.com/-thread---2361--%09-thread_specific_ptr%3A-nature-of-… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[thread] #2742 Why the at_thread_exit cleanup function is const?
by Vicente Botet Escriba 25 Nov '09

25 Nov '09

Hi Anthony, thanks for fixing this ticket. Best, Vicente -- View this message in context: http://old.nabble.com/-thread---2742-Why-the-at_thread_exit-cleanup-functio… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[thread] #2742 Why the at_thread_exit cleanup function is const?
by vicente.botet 25 Nov '09

25 Nov '09

Hi, Anthony, could you verify the patch and test I have attached to the ticket works for other platforms that cygwin? Thanks, _____________________ Vicente Juan Botet Escribá

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Boost sprint: #3407 boost::call_once not re-entrant (at least in win32)
by Vicente Botet Escriba 25 Nov '09

25 Nov '09

Hi, I have changed the ticket from threads to thread As this works as expected, Anthony could just add on the documentation why reentrant call_once functions are not a good idea. The explanation of Steven could be a good starting point: "I'll also point out that there is no good behavior for a recursive call to call_once. If it calls the function again, then f will be called twice. If it does not, then whatever initialization that call_once is doing may be incomplete. In either case, you have to know whether a call can be recursive and carefully design for it. If it happens accidentally, you're probably toast regardless of how it behaves. In the face of recursive calls it is impossible to maintain the post-condition that the function has run exactly once." After this modification IMO the ticket can be closed. Best, Vicente -- View this message in context: http://old.nabble.com/Boost-sprint%3A--3407-boost%3A%3Acall_once-not-re-ent… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[test] New ticket #3664 (SIGCHLD always considered fatal error)
by Johan Nilsson 25 Nov '09

25 Nov '09

New ticket: https://svn.boost.org/trac/boost/ticket/3664 Regards / Johan

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Boost Server Downtime Wednesday Morning
by Doug Gregor 25 Nov '09

25 Nov '09

The main Boost server will be down for a short time Wednesday, November 25th (tomorrow!) from 8:00AM Eastern time to 8:30AM Eastern time to replace some memory. This outage will affect most of Boost's services, including the mailing lists, boost.org web server, and Boost Subversion repository (including the sandbox). Sorry for the inconvenience! - Doug

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Re: [boost] Re view Queue Needs Attention
by Tom Brinkman 25 Nov '09

25 Nov '09

>> What's the difference between a non-stable branch as you're suggesting and >> the existing sandbox? The only difference I could see is to establish some >> kind of pre-review process. But that would just move the problem to a >> different spot, no? The "non-stable" branch would be for libraries that have requested reviews or for "approved" libraries that have not yet stabilized. The "sand-box" branch would be for all other libraries that either have not requested reviews or don't plan to. The "review-wizards" John or Ronald or any of the "boost-moderators" could monitor the "non-stable" branch. This would clear the review queue. The only important review would be to establish when a particular library has achieved sufficient maturity to be moved from the "non-stable" branch to the "stable" branch. Once a library is in the "non-stable" branch, the library could be reviewed by anyone anytime. There would be no need for scheduled reviews, like we've had, although they could still be done, if the review manager wants to schedule it. The reviews would be ongoing and done in a blog format, not limited to a ten day block of time. After a library has been in the "non-stable" branch for say six months, the review manager could posts its progress to the mailing list and pose questions to elicit more feedback. The "non-stable" branch would be included as part of the boost installation, but only an optional part, not required. If a library is distributed as "non-stable", it should get lots and lots of attention. Nothing focuses an authors mind more than if they know that their library is going to get some exposure. The libraries in the review queue are not getting the exposure that they need, and are just sitting there for 6-18 months. Very few people are actually aware of these libraries. A better job needs to done to elicit feedback from domain experts. Having only a 10 day review period is way to short. It needs to be like 6-12 months, where the domain experts can contribute at their leisure. This could best be done if a "non-stable" branch is created, which is distributed along with the "stable" branch.

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[serialization] how to serialize map of non-default-constructible?
by ivo.t＠moss-soft.de 25 Nov '09

25 Nov '09

Hi to everybody, I'm new to the list, work for some time with Boost and C++ and have a fair knowledge but am not an expert yet. I try to serialize a map whose type ist not default-constructible, and I'm seriously stuck there. I thought the load_construct_data and save_construct_data overrides would help me there, but that seems not to be the case. I tried to create a private default constructor hoping that the map (respectively pair) constructor could access it, due to the boost::serialization::access friend declaration, but that didn't work as well. I really do _not_ want to make a public default constructor. What could I do as a workaround?? Any help would be greatly appreciated!! Btw, I work with Boost 1.39 and Visual Studio 2005. Thank you very much in advance Ivo

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[filesystem]: infinite-recursion with symlink
by variadic.template 24 Nov '09

24 Nov '09

While playing around with boost::filesystem and the recursive_directory_iterator, I'm running into a infinite-recursion caused by symlinks. Not following symlinks would be, a solution, of course, but... So, is there a way to ascertain the path where the symlink is aiming at? And a second question: I didn't find anything about permission-handling - are there any plans? In my eyes, this is something essential for a filesystem-library. Thanks in advance

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Proposal for library addition: faster signals/slots, reactor, atomics
by Helge Bahmann 24 Nov '09

24 Nov '09

Hello everyone I have written a small library providing: - a (thread-safe) signal/slot implementation - poll/timer/reactor implementation - atomic operations modelled after the proposed C++0x standard (x86 32/64 bit, ppc, alpha, more if someone donates hardware; fallback implementation using locks) Currently I am reworking the library to be more closely tied to and better reuse services provided by Boost. Obviously, there is considerable functional overlap with Boost.Signal/Boost.Signals2 and Boost.Asio, however what sets my implementation apart is that it is considerably faster, measurable in both synthetic tests and real-world applications (the main way this is achieved is through extensive use of atomic operations and carefully designed accessor protocols instead of locking, there is a small documentation section explaining the technique). The signal/slot implementation is thread-safe, with the same guarantees as Boost.Signals2, but about 3 times as fast as (thread-unsafe) Boost.Signal (!) and about 6 times as fast as (thread-safe) Boost.Signals2. The reactor implementation is obviously only suitable for Unix-like systems, while the proactor interface provided by Boost.Asio is a nice and portable abstraction. However, my reactor implementation is about 2-3 times as fast on Unix-like systems for typical network-server-style apps. Moreover I have always found Boost.Asio to be difficult to integrate with third party libraries (think ALSA or ldap) and frameworks (think Qt, Glib), so other developers not interested in portability may also prefer a bare reactor implementation. If you are interested, I invite you to have a look at: http://www.chaoticmind.net/~hcb/projects/libtscb Maybe parts of the library might be interesting for Boost? In particular the atomic operations could be salvaged and provide a "transitional" implementation internal to boost as an interim solution until compiler vendors catch up with C++0x, and I would also like to propose the reactor as a higher-performance alternative to Boost.Asio (my signal/slot implementation lacks combiners and other features provided by Boost.Signals2). Best regards Helge Bahmann

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