- Boost-users - lists.boost.org

Re: [Boost-users] [Threads] Problem with starting a sub thread
by Nat Goodspeed 06 Nov '06

06 Nov '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of Goroll, Torsten > Sent: Monday, November 06, 2006 11:46 AM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [Threads] Problem with starting a sub thread > > I understood and experienced that the main thread blocks. But how can it > join > other threads, if it is blocked? That doesn't seem consistent to me. [Nat] Usually one wouldn't create a thread and then immediately join() it. The net effect of that would seem to be an expensive function call. Usually if you want a new thread to run in parallel with the thread that created it, you let both threads run for a while before one thread attempts to join() the other.

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Compiling error in windows VC8: unrecognized posix_time:: microsec_clock
by Cheng, Victor S 06 Nov '06

06 Nov '06

I'm testing the boost 1_33_1 date_time library, but run into a strange compilation problem. In the following code, second_clock::local_time() is fine, but microsec_clock::local_time() will not compile. I'm using XP and visual studio 2005 and VC8. Am I missing anything in my build? compiler messages: 1>.\t2.cpp(18) : error C2653: 'microsec_clock' : is not a class or namespace name 1>.\t2.cpp(18) : error C3861: 'local_time': identifier not found the code: #include "boost/date_time/posix_time/posix_time.hpp" #include <iostream> int main() { using namespace boost::posix_time; ptime now = microsec_clock::local_time(); std::cout << now << std::endl; return 0; } ------------------------------------------------------------------------------ This message is intended only for the personal and confidential use of the designated recipient(s) named above. If you are not the intended recipient of this message you are hereby notified that any review, dissemination, distribution or copying of this message is strictly prohibited. This communication is for information purposes only and should not be regarded as an offer to sell or as a solicitation of an offer to buy any financial product, an official confirmation of any transaction, or as an official statement of Lehman Brothers. Email transmission cannot be guaranteed to be secure or error-free. Therefore, we do not represent that this information is complete or accurate and it should not be relied upon as such. All information is subject to change without notice. -------- IRS Circular 230 Disclosure: Please be advised that any discussion of U.S. tax matters contained within this communication (including any attachments) is not intended or written to be used and cannot be used for the purpose of (i) avoiding U.S. tax related penalties or (ii) promoting, marketing or recommending to another party any transaction or matter addressed herein.

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Re: [Boost-users] [Threads] Problem with starting a sub thread
by Ovanes Markarian 06 Nov '06

06 Nov '06

Hi! join cause a calling thread to block until the second one is finished. This is also stated in the docs: 1.void join(); Requires: *this is joinable. !!!!!Effects: The current thread of execution blocks until the initial function of the thread of execution represented by *this finishes and all resources are reclaimed. Notes: If *this == thread() the result is implementation-defined. If the implementation doesn't detect this the result will be deadlock. There is a good article on boost threads at Dr.Dobbs site: http://www.ddj.com/dept/cpp/184401518 With Kind Regards, Ovanes Markarian On Mon, November 6, 2006 14:17, Torsten wrote: > Hi, > > im trying to initiate a sub thread for checking some variables during the main program is running: > > ...do sth... > > boost::thread checkT(&check); > checkT.join(); > > ...do sth... > > As I understand boost::threads the second "do sth" should be performed during the thread is running. Well, it doesn't seem so. After experimenting some time it came up that starting two threads like that: > > boost::thread checkT(&check); > boost::thread stopCheckT(&stopCheck); > checkT.join(); > scheckT.join(); > > does work, but that: > > boost::thread checkT(&check); > checkT.join(); > boost::thread stopCheckT(&stopCheck); > scheckT.join(); > > does not. I really don't understand why. Either .join() stops executing the code (so the scheckT.join() in the first example shouldn't be called) or it doesn't (than the second scheckT should be called too). > > Where am I wrong? Has anybody an idea? > > Torsten > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > With Kind Regards, Ovanes Markarian

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[Threads] Problem with starting a sub thread
by Torsten 06 Nov '06

06 Nov '06

Hi, im trying to initiate a sub thread for checking some variables during the main program is running: ...do sth... boost::thread checkT(&check); checkT.join(); ...do sth... As I understand boost::threads the second "do sth" should be performed during the thread is running. Well, it doesn't seem so. After experimenting some time it came up that starting two threads like that: boost::thread checkT(&check); boost::thread stopCheckT(&stopCheck); checkT.join(); scheckT.join(); does work, but that: boost::thread checkT(&check); checkT.join(); boost::thread stopCheckT(&stopCheck); scheckT.join(); does not. I really don't understand why. Either .join() stops executing the code (so the scheckT.join() in the first example shouldn't be called) or it doesn't (than the second scheckT should be called too). Where am I wrong? Has anybody an idea? Torsten

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dynamic-bitset: reversing bits.
by chun ping wang 06 Nov '06

06 Nov '06

Hey i have a quick question regarding dynamic bits. Is there a quick and effective way to reverse bits. (if so how)... i try swapping.. but i get compile time error. so that i can calculate iterative-fft since it requires bit-reverse-copy for (i = 0; i<num_bits/2; ++i) swap(b[i], b[i+numbits/2]);

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Re: [Boost-users] [filesystem] unable to parse file path
by Nat Goodspeed 06 Nov '06

06 Nov '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of Küppers, Ben > Sent: Monday, November 06, 2006 2:59 AM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [filesystem] unable to parse file path > > Ongoing development now warrants that we interact with the Windows > apps from Linux and vice versa. In the midst of all this it becomes > inevitable to run into the occasional Windows file path on Linux (or Linux > path on Windows)(usually through file IO). I use portable paths wherever I > can but I don't have control over all the input. [Nat] I see. But it should work to convert to forward-slashes everywhere. Sorry for being terse earlier. When I said a character-substitution pass is "cheaper" than reimplementing any significant part of boost::filesystem, I was really thinking of coding/maintenance time. > I am disappointed that the library eliminates the code to treat > backslashes as directory separators at compile-time on non-Windows systems > and doesn't provide me with an option to explicitly enable this code for > the few file paths that I know will have a Windows syntax. [Nat] That could be a useful enhancement. If you're interested enough, you might submit a code and documentation patch. Until then, maybe you could introduce a path subclass for your own use that replaces all '\' with '/' before passing the input path string to the base class.

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[mpl::map] generating map for 150 types
by Ovanes Markarian 06 Nov '06

06 Nov '06

Hi! I need to define a map with int_<1...150>->Type1...150 pairs. Im source file I define: #define BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS #define BOOST_MPL_LIMIT_MAP_SIZE 150 #include <boost/mpl/map.hpp> When compiling I get an error in the file: ...\boost\include\boost-1_33_1\boost\mpl\map.hpp on line: 36 fatal error C1083: Cannot open include file: 'boost/mpl/map/map150.hpp': No such file or directory Development environment is Visual C++ 8 Express Edition The help states: BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS is an boolean configuration macro regulating library's internal use of preprocessed headers. When defined, it instructs the MPL to discard the pre-generated headers found in boost/mpl/aux_/preprocessed directory and use preprocessor metaprogramming techniques to generate the necessary versions of the library components on the fly. In this implementation of the library, the macro is not defined by default. To change the default configuration, define BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS before including any library header. I did what is written here and get this compiler error. Can someone suggest smth? With Kind Regards, Ovanes Markarian

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Re: [Boost-users] [filesystem] unable to parse file path
by Küppers, Ben 06 Nov '06

06 Nov '06

> [Nat] I guess I have a couple of comments. > > One is that a character substitution pass is still cheaper than the > directory parsing and other goodies that boost::filesystem gets you. Speed is not a concern. > The other is to ask why your *nix requirements include backslashes as > directory separators? Backslashes have other significance everywhere but > Windows, which is presumably why boost::filesystem::path wasn't written to > treat '\' and '/' interchangeably on all platforms. Backslashes (and > forward slashes) work on Windows, forward slashes work elsewhere, all per > convention. I work on a large application that runs on Windows and Linux and interacts with various 3rd party applications on either platform, all of them designed with only the dedicated platform in mind and thus using native syntax. Ongoing development now warrants that we interact with the Windows apps from Linux and vice versa. In the midst of all this it becomes inevitable to run into the occasional Windows file path on Linux (or Linux path on Windows)(usually through file IO). I use portable paths wherever I can but I don't have control over all the input. > You seem disappointed that boost::filesystem::path doesn't treat > backslashes as directory separators on non-Windows systems. Not quite, I am disappointed that the library eliminates the code to treat backslashes as directory separators at compile-time on non-Windows systems and doesn't provide me with an option to explicitly enable this code for the few file paths that I know will have a Windows syntax. Note that because Windows supports either directory separator it is possible to parse a Linux relative file path on Windows (with minimal limitations). This e-mail and any attachment is for authorised use by the intended recipient(s) only. It may contain proprietary material, confidential information and/or be subject to legal privilege. It should not be copied, disclosed to, retained or used by, any other party. If you are not an intended recipient then please promptly delete this e-mail and any attachment and all copies and inform the sender. Thank you.

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[variant] trouble using recursive_variant with MSVC ...
by Andy Wu 06 Nov '06

06 Nov '06

Hi all, I'm trying to use the recursive variant as following: typedef boost::make_recursive_variant< int, std::vector<boost::recursive_variant_>, std::map<std::string, boost::recursive_variant_> >::type var_t; ... var_t var(34); ... VC 8.0 can not compile with error C2079: 'std::pair<_Ty1,_Ty2>::second' uses undefined struct 'boost::recursive_variant_' Struct recursive_variant_ is declared but not implement at all. But GCC works well. I'm confused how to solve the problem. Here is the whole program: #include "boost/variant.hpp" #include <iostream> #include <sstream> #include <vector> #include <map> struct vector_printer : boost::static_visitor<std::string> { template <typename T> std::string *operator*()(const std::vector<T>& vec) const { std::ostringstream ost; ost << "( "; typename std::vector<T>::const_iterator it = vec.begin(); *for* (; it != vec.end(); ++it) ost << boost::apply_visitor( vector_printer(), *it ); ost << ") "; *return* ost.str(); } template <typename T> std::string *operator*()(const std::map<std::string, T>& m) const { std::ostringstream ost; ost << "( "; typename std::map<std::string, T>::const_iterator it = m.begin(); *for* (; it != m.end(); ++it) ost << it->first << '\t' << boost::apply_visitor( vector_printer(), it->second ); ost << ") "; *return* ost.str(); } template <typename T> std::string *operator*()(const T& operand) const { std::ostringstream ost; ost << operand << ' '; *return* ost.str(); } }; int main(int , char* []) { typedef boost::make_recursive_variant< int, std::vector<boost::recursive_variant_>, std::map<std::string, boost::recursive_variant_> >::type var_t; std::vector<var_t> vec; vec.push_back(3); vec.push_back(5); vec.push_back(vec); vec.push_back(7); var_t var(vec); std::string result( boost::apply_visitor( vector_printer(), var ) ); std::cout << "result: " << result << '\n'; *return* 0; } And the compile error from VC8 is : test_map_variant.cpp D:\Program\boost\boost_1_33_1\boost/type_traits/is_base_and_derived.hpp : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss D:\Program\boost\boost_1_33_1\boost/utility/enable_if.hpp : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss D:\Program\boost\boost_1_33_1\boost/type_traits/is_base_and_derived.hpp : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss D:\Program\boost\boost_1_33_1\boost/utility/enable_if.hpp : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss D:\Program\boost\boost_1_33_1\boost/utility/enable_if.hpp : warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss D:\Program\vs8\VC\INCLUDE\utility(54) : error C2079: 'std::pair<_Ty1,_Ty2>::second' uses undefined struct 'boost::recursive_variant_' with [ _Ty1=const std::string, _Ty2=boost::recursive_variant_ ] D:\Program\vs8\VC\INCLUDE\vector(1083) : see reference to class template instantiation 'std::pair<_Ty1,_Ty2>' being compiled with [ _Ty1=const std::string, _Ty2=boost::recursive_variant_ ] D:\Program\vs8\VC\INCLUDE\vector(1082) : while compiling class template member function 'void std::vector<_Ty>::_Destroy(boost::variant<T0_,T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12,T13,T14,T15,T16,T17,T18,T19> *,boost::variant<T0_,T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12,T13,T14,T15,T16,T17,T18,T19> *)' with [ _Ty=var_t, T0_=boost::detail::variant::recursive_flag<int>, T1=std::vector<boost::recursive_variant_>, T2=std::map<std::string,boost::recursive_variant_>, T3=boost::detail::variant::void_, T4=boost::detail::variant::void_, T5=boost::detail::variant::void_, T6=boost::detail::variant::void_, T7=boost::detail::variant::void_, T8=boost::detail::variant::void_, T9=boost::detail::variant::void_, T10=boost::detail::variant::void_, T11=boost::detail::variant::void_, T12=boost::detail::variant::void_, T13=boost::detail::variant::void_, T14=boost::detail::variant::void_, T15=boost::detail::variant::void_, T16=boost::detail::variant::void_, T17=boost::detail::variant::void_, T18=boost::detail::variant::void_, T19=boost::detail::variant::void_ ] test_map_variant.cpp(63) : see reference to class template instantiation 'std::vector<_Ty>' being compiled with [ _Ty=var_t ] -- B. R. Andy

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[asio] doc directory not present in cvs?
by Andrew Schweitzer 05 Nov '06

05 Nov '06

I assume this is on purpose? Because doc isn't updated to latest changes? Doc is included if I download 0.3.7

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