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[threads] two threads gain lock on the same mutex??
by David M. Cotter 02 Jan '10

02 Jan '10

i thought this was impossible. but i've caught it in the debugger *right now*! on thread 28, i've got this code: boost::mutex::scoped_lock lock(i_mutex); i_waitingB = true; if (i_semID) { if (!i_signaledB) { boost::xtime xt; if (wait_duration == kDurationForever) { xt = boost::xdelay(kEventDurationDay); } else { xt = boost::xdelay(0, 0, kNanoPerMicro * wait_duration); // wait_duration is in microseconds } PC --> if (!i_semID->timed_wait(lock, xt)) { err = kMPTimeoutErr; } } if (!err) { i_signaledB = false; } } else { err = kMPDeletedErr; } the PC is waiting (for 24 hours) in the timed_wait() call (wait_duration = kDurationForever) that thread it just hanging, which is correct. however on thread 30 i've got this: if (!err) { boost::mutex::scoped_lock lock(i_mutex); PC --> i_signaledB = true; < breakpoint set here, now hit CF_ASSERT(i_semID); IX(i_semID->notify_one()); } that should be impossible, right? the PC should in fact block on that scoped_lock, right?? yes: the mutex IS the same mutex on both threads the i_mutex is of type: boost::mutex i_mutex; it is not a shared mutex i realize that if the scoped_lock were actually functioning as expected, that the signal could never be sent to the semaphore to wake up. i'll fix the code design after i figure out WHY the lock is not actually locking. but the thread WAS waking up, my program is actually functioning as it should, but given the above code it should NOT be working. what's going on here?

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[graph] improvements on/documentation for transitive_reduction.hpp
by eric＠boese-wolf.eu 02 Jan '10

02 Jan '10

Hi there! I did improve on the transitive reduction and wrote some documentation. As there are multiple files now, I did not send them to the mailing list. Shall I send a tar.gz to the mailing list? How can I contribute these files to the graph library? As I wrote the code/documentation I noticed that it is possible to implement the transitive reduction by a few minor changes to the existing transitive_closure algorithm (and it would be better). I will follow that path someday in the future. Yours sincerely, Eric Böse-Wolf

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Proto Help
by David A. Greene 02 Jan '10

02 Jan '10

I am trying to use proto to generate an IR for a custom language. I've got basic expressions working and am moving on to generate the statements of the custom language I'm working on getting "if" statements generated. I've attached a compilable testcase. I can't seem to get the grammar+transforms to work for the IfRule. Am I on the right track? What am I missing? Thanks. -Dave

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bcp update #2: namespace renaming
by John Maddock 02 Jan '10

02 Jan '10

OK, since folks keep asking for it, bcp will now do namespace renaming, the two new options are: --namespace=newname Renames namespace boost to "newname" in all the source files copied. Also changes library names to start with the prefix "newname" or "libnewname" rather than "boost" or "libboost". --namespace-alias Makes namespace boost an alias for the new name. Using these two options you can get "strong versioning" with two different boost installs coexisting side by side (in the same application if necessary). What you can not do at present, is #include two different boost versions in the same translation unit. This update is in, and tested against, SVN Trunk only at present. Enjoy, John.

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Can any one help me with this fstream
by ch.asad＠gmail.com 02 Jan '10

02 Jan '10

Hi i am new to boost. i have written a code. can any one guide me whats the issue with this code. It gives an error when I assign the File pointer to a Global poiter. " h_file = file; h_str = str; " Can any one guide me whats the issue with this and how cna i solve this issue. thanks, Asad // Accelor-test.cpp : Defines the entry point for the console application. // #include <iostream> #include <string> #include <fstream> #include <string> #include <vector> #include <iostream> #include <iterator> #include <functional> #include <boost/asio.hpp> #include <boost/algorithm/string/classification.hpp> #include <boost/algorithm/string/split.hpp> #include <boost/algorithm/string/find_iterator.hpp> #include <boost/thread/thread.hpp> using boost::asio::ip::tcp; using namespace std; using namespace boost; std::fstream h_file; int hb; int cnt; tcp::iostream h_str; //boost::mutex mutex; void Accelor_test() { std::cout<<"\nAPP started ...\n"; char ver[100]; char s1[100]; vector<std::string> strng,st,u_p; //int ef; h_str.read(ver,sizeof(ver)); std::cout<<" INBOUND : Version read : " <<ver<<std::endl; h_file.getline(s1,sizeof(s1)); std::cout<<s1<<std::endl; } void send_HB() { std::cout<<"\nHeart Beat Started..."; // boost::mutex::scoped_lock lock(mutex); char h_b[] = "HB\n"; for(;;) { boost::xtime xt; boost::xtime_get(&xt, boost::TIME_UTC); xt.sec += 1; h_str.write(h_b,sizeof(h_b)); boost::thread::sleep(xt); std::cout <<"OUTBOUND : HB ,"<< ++cnt << std::endl; } } int main(int argc, char* argv[]) { std::fstream file = std::fstream("inttest_sample.csv",std::fstream::in); if(h_file == NULL) { std::cout<<"File not found"; } char s1[100]; vector<std::string> conf,connection,u_p; int ef; h_file.getline(s1,sizeof(s1)); std::cout<<"s1 = "<<s1<<endl; std::cout<<"Split Conf"; split(conf, s1, is_any_of(","), token_compress_on); split(connection, conf[0], is_any_of(":"), token_compress_on); tcp::iostream str(connection[0],connection[1]); h_file = file; h_str = str; boost::thread thrd_hb(&send_HB); boost::thread thrd_acc(&Accelor_test); thrd_hb.join(); thrd_acc.join(); file.close(); str.close(); //std::cout<<"kjdshkjf"; } -- View this message in context: http://old.nabble.com/Can-any-one-help-me-with-this-fstream-tp26986763p2698… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[any] New feature idea for boost.any
by Andres B. 01 Jan '10

01 Jan '10

Hello, i am Andrés, i am new in the boost world and i have an idea to boost.any. With the actual boost::any i can't do this: boost::any any_var; int i; any_var = 10; i = 1 + any_var; double d; // d = 1.0 + any_var; // throw: bad_any_cast, because any_var is int any_var = 10.0; d = 1.0 + any_var - 3.0; // now any_var is double because are incompatible types. To solve this problem, we need add the casting operator and add overload the global operators. I wrote the code and actually have the global operators overloaded +, -, *, /, %. I don't know how write code to Boost, for this reason maybe has errors. namespase boost { class any { //.... public: // casting operators template <class ValueType> operator ValueType () const { return boost::any_cast<ValueType>(*this); } template <class ValueType> operator ValueType () { return boost::any_cast<ValueType>(*this); } // arithmetic operators template <typename ValueType> ValueType operator+ (const ValueType& t1) const { return (ValueType)(*this) + t1; } template <typename ValueType> ValueType operator- (const ValueType& t1) const { return (ValueType)(*this) - t1; } template <typename ValueType> ValueType operator* (const ValueType& t1) const { return (ValueType)(*this) * t1; } template <typename ValueType> ValueType operator/ (const ValueType& t1) const { return (ValueType)(*this) / t1; } template <typename ValueType> ValueType operator% (const ValueType& t1) const { return (ValueType)(*this) % t1; } //... } // End any //... // Global operators template <class ValueType> ValueType operator+ (ValueType t1, boost::any t2) { return t1 + (ValueType)(t2); } template <class ValueType> ValueType operator- (ValueType t1, boost::any t2) { return t1 - (ValueType)(t2); } template <class ValueType> ValueType operator* (ValueType t1, boost::any t2) { return t1 * (ValueType)(t2); } template <class ValueType> ValueType operator/ (ValueType t1, boost::any t2) { return t1 - (ValueType)(t2); } template <class ValueType> ValueType operator% (ValueType t1, boost::any t2) { return t1 % (ValueType)(t2); } } If you like it or not, please tell me. Excuse my English

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linear algebra (and matrix) library (again)
by DE 31 Dec '09

31 Dec '09

hi again i worked on a linear algebra library there are almost fully working prototype and its documentation in the vault (BIBLAL) http://www.boostpro.com/vault/index.php?direction=0&order=&directory=linalg& i would appreciate your interest and feedback -- Pavel ps happy new year!

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Re: [boost] [date_time] quarters as new durations?
by pete＠pcbartlett.com 31 Dec '09

31 Dec '09

On Tue 22/12/09 13:54 , "Stewart, Robert" <Robert.Stewart(a)sig.com> wrote: > wrote: > > On Tue 22/12/09 13:27 , "Stewart, Robert" wrote: > > > Jeff Garland wrote: > > > > > > > > Month durations play some games to handle this problem (see > > > > docs for details) which quarters could adopt. But if you > > > > adopt the month rules then I don't thing you buy much more > > > > than simply writing > > > > > > > > const months quarters = months(3); > > > > > That's an excellent point. I don't think the fuzzy math > approach is > > > appropriate for quarters because they have a precise definition: > 1/4 > > > of a year. Months are less precise, though 365 / 4 is not a > whole > > > number, of course. > > > > Possibly opening a can of worms here, but a quarter in my > > line of work is invariably three months. If your mileage > > varies, then there could be a problem in providing a fully > > meaningful quarter duration type if people think it means > > different things. > Jeff's idea of months(3) is all you need, right? Yup, and in fact I use exactly that approach at the moment. A new duration type with quarter in the name that meant something other than three months could serve to confuse as much as it helps though, IMO.

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GPL and boost
by Stefan Strasser 31 Dec '09

31 Dec '09

Hi, is there a precedent of optional(!) external library dependencies to GPLed libraries in boost? IIUC the implementation of the interface to the library in boost would constitute a derivative work of the GPLed library and therefore be "infected" by it. do the terms of the GPL then only apply if a boost user is actually using this optional code and linking to the external library or does this inhibit the distribution of such code with boost releases in general? and if so, is external distribution, e.g. in the vault, but documentation in the main library acceptable? I'm asking because of a possible interface to Oracle's Berkeley DB, but I guess this will come up again with Boost.Rdb and GPLed SQL databases.

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Linking Errors in Boost Logging
by nsk＠umd.edu 31 Dec '09

31 Dec '09

Hi, I am a beginner in using the Boost Libraries. I came across them when I was trying to implement the Boost Logging Framework version2 from John Torjo's website. I tried implementing the starter project(http://torjo.com/log2/doc/html/starter_project.html) from Boost Log documentation using Visual Studios 2005 IDE. I got the following 2 errors: error C2440: '<function-style-cast>' : cannot convert from 'const char [13]' to 'boost::logging::formatter::tag::time' and error C2780: 'void boost::logging::writer::format_write<formatter_base,destinatio n_base,lock_resource,apply_format_and_write,router_type,format ter_array,destination_array>::add_formatter(formatter,const boost::logging::char_type *)' : expects 2 arguments - 1 provided So, I commented the formatter::tag::time line assuming that I don't need time to be displayed for the time being. The program complied properly but it gave me link errors: error LNK2019: unresolved external symbol "struct boost::logging::filter::use_tss_with_cache<10> * __cdecl g_l_filter(void)" (?g_l_filter@@YAPAU? $use_tss_with_cache@$09@filter@logging@boost@@XZ) referenced in function "void __cdecl `anonymous namespace'::`dynamic initializer for 'ensure_log_is_created_before_maing_l_filter''(void)" (?? __Eensure_log_is_created_before_maing_l_filter@? A0x6e6fd73c@@YAXXZ) my_app_log.obj and error LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup MSVCRTD.lib Please let me know whether I am missing some linker dependencies. Please help! -Nik Kale

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