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[wesite] Version history page
by Rene Rivera 15 Apr '05

15 Apr '05

I added the version history page that Daryle created, as a "Version History" link under the "Support" section. It has what would be a full version of the same style. With the footer having the license, etc info. http://redshift-software.com/~grafik/boost/index.htm Or you can look at the page directly.. http://redshift-software.com/~grafik/boost/more/version_history.html -- -- Grafik - Don't Assume Anything -- Redshift Software, Inc. - http://redshift-software.com -- rrivera/acm.org - grafik/redshift-software.com -- 102708583/icq - grafikrobot/aim - Grafik/jabber.org

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RE: [boost] Re: [website] Fluid layout.
by Matt Sutton 15 Apr '05

15 Apr '05

> > I like it at the right. I don't see any reason why it can't > be in the > > right. Could you give us a link to a W3C reference that says > > navigation bars should be in the left? > > While I don't know of any clear recommendation to put a > navigation bar not on the right side in my opinion it > violates Jakob Nielsen's rule "Do the same as everyone else" > (see #10 of "Ten Good Deeds in Web Design" at > http://www.useit.com/alertbox/991003.html) There have been > some links posted to websites that have the navigation on the > right side. However I would rather follow the mainstream. > Look at all the explorer-style windows in your operating > system: Navigation is always on the top and on the left. > If you really want to make an exception and put the > navigation bar on the right side you need a strong reason to > come up with something unusual. > Out of curiosity, have you experimented with the look of full justification for the text? At least for sentences that span multiple lines. I not a web designer, and like most other suggestions this is purely subjective, but I wonder if a subtly sharper edge on the right might further instruct one's eye to perform a carriage return/line feed? Kind of like a newspaper. Matt Sutton www.padtinc.com

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Debug Version of Project cannot be compiled with boost 1.32.0 and STLPort4.6.2..(boost\config\auto_link.hpp)
by Manish Mangal 15 Apr '05

15 Apr '05

Hi I am using boost 1.32.0 libraries along with STLPort4.6.2 on .Net2003 VC7.1. The release version of the Project compiles and runs successfully, but the Debug version gives the following error: warning: STLPort debug versions are built with /D_STLP_DEBUG=1 c:\SourceLibrary\Boost\boost_1_32_0\boost\config\auto_link.hpp(170) : fatal error C1189: #error : "Build options aren't compatible with pre-built libraries" I have included _STLP_DEBUG in the C++ Preprocessor settings for the Debug Version.. Can anyone help me?? Thanks in advance. Manish Mangal Stratagen Systems 1-425.821.8454 ext. 136

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FYI: old laptop
by Michael Glassford 15 Apr '05

15 Apr '05

I had the old laptop turned on for about an hour, not using it, when I got a black screen with this error: "Memory write/read failure at 0FFF0000, read FF10FF00 expecting FF10FF10 Memory address line failure at 0FF0000, read FF10FF10 expecting 00000000 Strike the F1 key to continue, F2 to run the setup utility" I hit F1 and it restarted and gave me a similar error. I'm trying it right now with the other DIMM. Maybe it doesn't like me anymore :) Mike

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Re: [network] An RFC posted to the sandbox
by Don G 15 Apr '05

15 Apr '05

Hi Caleb, On 4/12/05, Don G wrote: >> I've posted a zip with an HTML file and an HPP >> file that describes an abstract way to interact >> with the network. > > Overall it looks pretty nice. Thanks. :) And thanks for taking the time to look at the proposal. > A few observations: > * port_t should be unsigned short, not unsigned int That is, of course, true of TCP/IP :) > * timeout constructors are inconsistent. One takes > seconds + microseconds and one takes milliseconds, > at least according to the names of the arguments. Yeah, that was one of the adjustments I tried to make as I boost-ified the code. The Windows way is millisecs, but Unix is microsecs. To do microsecs, I think we would have to use uint64's. That would be fine by me, but I wasn't sure how widely supported it is. I know that for Solaris (SunPro), gcc, MSVC, CodeWarrior, uint64 is good. Of course, a timespec doesn't use uint64. La de da... :) > * I wouldn't call the type you pass to the > network::new_{local,broadcast,loopback,}_address > method a "url". It isn't one. But it is, at least from what the description in RFC 2396. You can pass this: http://user:pswd@www.boost.org:8080/foo?x=42 and it would create an address object given that description. The resolved (physical) address would be something like: http://user:pswd@66.35.250.210:8080/foo?x=42 > Perhaps "address_specifier" would be better? I can > imagine some sort of "stream factory" class with > pluggable protocols (e.g. http, https, ftp, etc) that > would take fully qualified URLs to create new > streams, but in this case you're dealing with at most > a hostname and port. Well, the semantics of such things quickly become non-streams. The intention of the scheme ("http") is to establish a port by means of name lookup. In the end, yes the URL is resolved to address/port. If an HTTP library was built on top, it would do no transformation before passing its URL to new_address(). Hence, the type "url". > I'd contend that in general, an operating system supplied > multiplexing facility will scale better than one that uses > a thread to handle each connection. Absolutely. The code I have in mind uses a thread pool and connections are managed by as few a number of threads as necessary. On Windows, each I/O thread can handle 64-ish connections. On Unix, it is much higher. By default, I create one I/O thread per processor and divvy up the connections. > Without some sort of multiplexing facility, how do > you know when a channel is ready for I/O? It seems that > your proposal is to use a pool of threads to handle > async/non-blocking operations, but I don't see any > interfaces defined to control or manage these > operations. Is that just TBD? I have contemplated just how a user would want to interact with the thread pool behind the scenes, but, it is ideally an issue of minimal concern. Of course, for advanced users it could be something that needs to be tweaked. In that sense, there is a TBD aspect. I just have yet to see a good abstraction/mechanism for doing this. > Clearly Windows select and WFMO are not as scalable > as UNIX select/poll/etc, In one sense WFMO could be better (it would not be constantly repopulating fd_sets), but select or IOCP (I/O Completion Ports) are it AFAIK. And IOCP is NT only (for those who care). > but I'd contend that if one is writing a serious > networking application for Windows, you are going to > make use of *both* of these approaches (>1 instance > of WFMO/select and thread pooling). > In some cases, you may want to do this on UNIX too. If one could do everything async, there should be no reason for another thread pool. That would become important only if some connection(s) had to do work that would prevent other connections from progressing fairly (for example, by making blocking calls). > I think the point I am trying to make is that there > isn't necessarily one right answer. Pools of threads > are good for some things, and I/O multiplexing > facilities are good for some things. And in some > cases, taken both together they are a good thing as > well. The threads in this pool are only doing I/O multiplexing, so I'm not sure I understand your concern. The kind of thread pool in my implementation is just to have roughly the minimum number of threads compared to connections based on multiplexing limits. Another kind of thread pool would be one/two per connection to handle blocking activity. The blocking methods in the proposal could be used when that was the right answer. Or did I miss your point here? For best possible performance, one would want everything to be async and handled directly in the I/O thread. That would eliminate undesirable context switches. Since a given connection has all its callbacks made from one thread (though that thread can change over time), it wouldn't even need a lock as long as side effects were confined. I guess what I should do is write lots more in the HTML file :) There are many areas left unclear that probably lead to confusion. Again, thanks for the very thoughtful response! Best regards, Don __________________________________ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/ __________________________________ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/

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Re: [boost] Re: Boost to the rescue
by Iain Hanson 15 Apr '05

15 Apr '05

On Fri, 2005-04-15 at 09:05 -0700, Robert Ramey wrote: > My experience in this regard is surprising to me. > > I'm amazed to discover that in only ONE single case have any of the > programmers, managers, etc ever even heard of boost. This group even > includes an ex head of the computer science department at a top tier > university !!! Sadly this is what I would expect. However, I have been surprised by the number of companies in London ( U.K. ) That have heard of boost. Mostly in the International banking sector. The most popular library by far has to be smart_ptrs. > When I first came upon boost, I was agog at the possibilities it opened up. > The utiliy and power of the whole was blindingly obvious to to me. As I get > older, I feel more and more disconnected from the rest of to programming > world. > I know what you mean. Many programmers are still stuck at the C++ is a better C stage and very few over here seem to understand or use design patterns :-(. /ikh

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Closure functions
by Tobias Schwinger 15 Apr '05

15 Apr '05

Hi Community, The Function Types library has just been updated to include an implementation of closure functions as an example: [ example (hpp): http://tinyurl.com/9ncso ] [ exmaple (cpp): http://tinyurl.com/9opx6 ] You need to have the Function Types library installed if you want to successfully compile it: [ archive (zip): http://tinyurl.com/4oe7q ] [ documentation: http://tinyurl.com/4fw9n ] A closure function (in object orientated context) is a member function bound to an object. Closure functions are well-suited to achieve orthogonal design because they capture member functions independent of their name and class an thus allow to operate on a per-function basis instead of requiring inheritance to e.g. implement classic design patterns such as "Observer". In contrast to Boost.Bind (and other Boost argument binding facilities) closures are intended to be stored and allow the captured target function to dynamically change at runtime. Out of curiosity I was wondering if there is a closure function implementation in Boost already (or components that make their implementation trivial - IIRC I have seen something labeled 'closure' in the vault, but I can't find it anymore), whether there is any interest in brushing it up to give it a right to exist somewhere outside an 'example' folder and what requirements you would like it to meet in this case. I know there are "closures" in Boost.Phoenix, but these are about capturing fields, which is not quite the same and why I used the term "closure function" instead of "closure" here. What I describe here is close to the BCC compiler extension '__closure', which is used by C++Builder IDE to easily map GUI (and other) events to member functions. Regards, Tobias

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[iostreams] Yet another utf8 code copy?
by Vladimir Prus 15 Apr '05

15 Apr '05

I note that there's libs/iostreams/test/detail/utf8_codecvt_facet.cpp file. Is there any chance that instead of duplicating code, the boost/detail/utf8_codecvt_facet.hpp and libs/detail/utf8_codecvt_facet.cpp will be used, just like program_options and serialization do now? - Volodya

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Re: [boost] Re: Network library: What we have until now
by Iain Hanson 15 Apr '05

15 Apr '05

On Fri, 2005-04-15 at 06:32 -0700, Don G wrote: > Hi Maxim, [snip] > > One of my previous project was a soft realtime VoIP > > softswitch. It has only one thread of execution and is > > capable of handling 1000+ simultaneous calls (2000- > > 4000 sockets). It scales up by just starting additional > > processes on the same box, no recompilation needed, no > > locking, simple and immensely powerful. > > I knew we had a definition problem: handling 1000+ simultaneous > connections would not be something I would label as "simple"! ;) With all due respect I think that you are confusing size/scalability with complexity. They are not the same thing. An application gateway is often a very simple piece of software irrespective of the number of connections it handles. > > I have multiple thoughts here. First, I think the only difference our > two approaches would yield is that with my approach, one might need > locks. I did say "might". No lock is needed if the object managing a > connection is basically autonomous, changing only its state is > response to I/O completion or requesting further I/O, and/or creating > new connections. While the internals of the network implementation > are threaded, on a per-connection basis, callbacks are single > threaded. > Secondly, I don't think a queue of boost::function<> would be found > by the profiler as a performance bottle-neck (though I haven't looked > inside it at all). This is the approach I have taken to handle lots > of async calls from one thread. Not 1000+, but I'm not sure the > hardware and OS you used. Rather than 'guess' what a boost::function costs why not look it up here http://www.boost.org/doc/html/function/misc.html#id538868 > > >>> I hope this won't happen. There are several I/O > >>> patterns in use out there. > >> > >> But, honestly, how many do we need? *All* of the ones provided by the 'C' socket API i.e. single threaded reactive ( blocking), Single threaded reactive ( non-blocking ), signal driven, multi-threaded async, and multi-threaded reactive. And before you say again that signals are not portable, they have been part of the libc library on DOS and windows from MSDOS 3.0 on Lattice C, Borland Turbo C 2.0 and MS C compilers and it is still supported under Windows XP. see http://msdn.microsoft.com/library/default.asp? url=/library/en-us/vclib/html/_crt_signal.asp > > > > This is the main questions. I doubt we can ever > > answer this. So, I see no reason in dictating a > > style. > > There are some reasons for picking a small number of styles: > > 1. Simpler for a user to understand > 2. Simpler to document > 3. Simpler to test > 4. Simpler to write higher level libs (they should have > have symmetric styles for their users) > 5. Not all styles are portable (w/o undue complexity) > 6. Simpler to implement :) > > I can only think of one advantage of multiple styles: familiarity > with existing practice. Then I'm afraid your education has been some what lacking. Threading is greate for certain kinds of high performance servers but can introduce a lot of complexity. ( potential for deadlocks, races, priority inversion, starvation etc) Single threaded fork/exec reactive servers eliminate the complexity of threads but add complexity if they need to share data ( IPC ) and use heavy weight context switches. Both of the above, because of context switching behave non- deterministically with regard to time. Which is why you have signal driven I/O. We do not chose our architecture based on familiarity but rather on the requirements and these models each satisfy different forces. /ikh

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Review Request: Function Types
by Tobias Schwinger 15 Apr '05

15 Apr '05

The Function Types library provides a metaprogramming facility to classify, decompose and synthesize function-, function pointer-, function reference- and member function pointer types. It supports variadic functions (e.g. printf) and can be configured to work with several different calling conventions. [ archive (zip): http://tinyurl.com/4oe7q ] [ documentation: http://tinyurl.com/4fw9n ] The features provided by this library are definitely missing in boost, as there currently is no "function_traits for member function pointers", no way to create and modify function types (for e.g. overload selection) and no way to get a function parameter type by integral constant in template code. Every once in a while, someone asks for one or the other [ see http://tinyurl.com/dxgap , for example ]. Although the audience for such a library is fairly small, due its low-level nature, I got both competent and positive feedback. Writing the closure function example [ I announced in this thread: http://tinyurl.com/cceec ] only took me a few hours -- it would have been days, if not weeks, to achieve the same functionality without library support regarding function types. These indications lead me to the conclusion that the time is right to hereby request formal review. I sent out an evaluation request to determine whether this library qualifies for Fast Track Review to the Wizard, several weeks ago (and just reposted it in case the mail got lost). Thanks, Tobias

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