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Newbie query: no "deamon" thread?
by dick.bridges＠tais.com 07 Jun '03

07 Jun '03

I need to spawn worker threads that simply perform a task and exit. All the examples I can find seem to use join() to cleanup the thread resources from another thread. Isn't there some way to declare worker threads so that they "do the right thing" as they exit the thread function? TIA

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[BGL] bad edge iterator range returned by boost::out_edges(v,g)?
by Chris Russell 07 Jun '03

07 Jun '03

This is weird... I'm still using BGL from Boost 1_29_0 (which may be an issue?). Anyway, I've got a graph as so: typedef boost::property<vertex_forest_property_t, CProteinCircuitForestVertexProperty, boost::property<boost::vertex_index_t, long, boost::property<boost::vertex_color_t, boost::default_color_type> > > forest_vertex_property_maps_declaration_t; typedef boost::adjacency_list<boost::listS /*edges*/, boost::listS /*vertices*/, boost::bidirectionalS, forest_vertex_property_maps_declaration_t> forest_graph_t; I've done a lot with this class, including all kinds of edge traversal. Now suddenly I have a case where boost::out_edges seems to be returning an invalid iterator range. I'm absolutely certain the vertex descriptor is correct, boost::out_degree returns the expected number of out edges, however I fault inside my access loop because the iterator has gone out of range.... typedef boost::graph_traits<forest_graph_t>::vertex_descriptor forest_vertex_descriptor_t; typedef boost::graph_traits<forest_graph_t>::vertex_descriptor forest_vertex_descriptor_t; typedef boost::graph_traits<forest_graph_t>::edges_size_type forest_edges_size_t; typedef boost::graph_traits<forest_graph_t>::out_edge_iterator forest_edge_out_iterator_t; forest_edge_out_iterator_t edgeoutiterBegin, edgeoutiterEnd, edgeoutiterCurrent; boost::tie(edgeoutiterBegin, edgeoutiterEnd) = boost::out_edges(v/*forest_vertex_descriptor_t*/,g/*forest_graph_t); for (edgeoutiterCurrent = edgeoutiterBegin; edgeoutiterCurrent != edgeoutiterEnd ; ++edgeoutiterCurrent) { // works fine through the expected out edges - faults because the loop fails to terminate forest_vertex_descriptor_t vertexTarget = boost::target(*edgeoutiterCurrent, g); } // end for Any suggestions would be greatly appreciated. I'm really scratching my head because I've done this exact operation in several other places in the algorithm and it works just fine.... TIA - Chris

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Tree Object Needed!
by Hossein Haeri 07 Jun '03

07 Jun '03

Dear all, I need to have some template doing the jobs of an ordinary BST (Binary Search Tree). Nothing that fancy, but something at the level we all have been educated in CS1/FCS1, or similar courses. Does boosts repository contain such an object? Why don't I write it myself? Simply, because I want to optimise the time! Thank you, --Hossein __________________________________ Do you Yahoo!? Yahoo! Calendar - Free online calendar with sync to Outlook(TM). http://calendar.yahoo.com

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boost::filesystem help needed
by ericd 07 Jun '03

07 Jun '03

Hi all, I have compiled the boost::filesystem using bjam and that seemed to have gone well. The first question I have concerning this is if it is normal NOT to have a libfilesystem.so. I can only find the libfilesystem.a. The path where this lives is quite deep. /usr/local/boost_1_30_0/boost/libs/filesystem/build/bin/libboost_filesystem.a/gcc/release/runtime-link-dynamic and /usr/local/boost_1_30_0/boost/libs/filesystem/build/bin/libboost_filesystem.a/gcc/debug/runtime-link-dynamic My current setup is an Ultra 80 running Solaris 9. I use both gcc version 3.2.3 for compiling and linking. The version of Boost is 1.30.0. For my second question. Having this built, I have tried to use it but come up with undefined symbols The output follows: g++ -lboost_filesystem -o io main.o Undefined first referenced symbol in file boost::filesystem::path::native_directory_string() constmain.o boost::filesystem::path::native_file_string() constmain.o boost::filesystem::path::path[in-charge](char const*, boost::filesystem::path_fo rmat)main.o boost::filesystem::directory_iterator::directory_iterator[in-charge](boost::file system::path const&)main.o boost::filesystem::path::leaf() constmain.o boost::filesystem::initial_path() main.o boost::filesystem::system_complete(boost::filesystem::path const&)main.o boost::filesystem::directory_iterator::m_inc() main.o boost::filesystem::directory_iterator::directory_iterator[in-charge]()main.o boost::filesystem::is_directory(boost::filesystem::path const&)main.o boost::filesystem::directory_iterator::m_deref() constmain.o boost::filesystem::exists(boost::filesystem::path const&)main.o ld: fatal: Symbol referencing errors. No output written to io Now I am quite sure that the path to the filesystem library is correct and therefore, cannot figure out why this will not link properly. But then again, I might be mistaken. Here is a snip from my makefile. On second thought, here is the whole thing: SHELL = /bin/sh # PROJECTLOCATION = /home/ericd/Projects/FileSystemTest EXEDIR = $(PROJECTLOCATION)/bin # LIBPATH = -L/usr/local/lib # Sources, includes and the likes.. also output names SELFTESTSRC = main.cpp INCLUDE = -I/usr/local/boost_1_30_0/boost SELFTEST = io # ifeq (,$(filter _%,$(notdir $(CURDIR)))) include target.mk else VPATH = $(SRCDIR) # Compiler Linker Defines for test exe CXX = g++ LD = g++ DEBUG = -g CXXSELFTEST = $(DEBUG) $(INCLUDE) -c -O2 -W -Wall -Wno-unused -Wno-multichar -fexceptions LDSELFTESTFLAGS = -lboost_filesystem # Building options all: test test: CXXFLAGS = $(CXXSELFTEST) test: $(SELFTEST) # SELFTESTOBJ = $(SELFTESTSRC:.cpp=.o) # pull in dependency info for *existing* .o files -include $(SELFTESTOBJ:.o=.d) # Compile and generate dependency info %.o: %.cpp $(CXX) $(CXXFLAGS) -MMD $(SRCDIR)/$*.cpp -o $@ @mv -f $*.d $*.d.tmp @sed -e 's|.*:|$*.o:|' < $*.d.tmp > $*.d @sed -e 's/.*://' -e 's/\\$$//' < $*.d.tmp | fmt -1 | sed -e 's/^ *//' -e 's/$$/:/' >> $*.d @rm -f $*.d.tmp # Link all Object Files and copy them over to our bin $(SELFTEST): $(SELFTESTOBJ) $(LD) $(LDSELFTESTFLAGS) -o $(SELFTEST) $(SELFTESTOBJ) cp $(SELFTEST) $(EXEDIR)/$(SELFTEST) # endif I have added in my .cshrc at the LD_LIBRARY_PATH var the location of my filesystem library. Being relatively new to gcc my guess is that something has to be wrong with the flags I give it. I did do an nm -C libfilesystem.a and all missing symbols reported by the link are there. Does anyone have any clue as to why this aint working? Thanks in advance for your input, Eric

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Re: Can't find a clear example of disallowing parallel edges
by Arthur 06 Jun '03

06 Jun '03

The section pointed out says to use a set instead of list if you don't want parallel edges. I guess I was hoping to have parallel edge removal using a list (insertion/deletion consideration appear to make the list a better choice for me). A --- In Boost-Users(a)yahoogroups.com, "Arthur" <arthurc@t...> wrote: > Saw that... didn't help. Too many program fragments and not enough > complete code examples IMHO. I guess I'll just have to figure it out > the hard way. > > A > > --- In Boost-Users(a)yahoogroups.com, "Chris Russell" <cdr@e...> wrote: > > Arthur, > > > > see the following: > > > > http://www.boost.org/libs/graph/doc/using_adjacency_list.html > > ^- see specifically "Choosing the EdgeList type".. Sequence vs. > > AssociativeContainer vs. UniqueAssociativeContainer > > > > http://cvs.sourceforge.net/cgi- > bin/viewcvs.cgi/boost/boost/libs/graph/example/container_gen.cpp? > rev=1.1&content-type=text/vnd.viewcvs-markup > > ^- container_gen.cpp example > > > > HTH - Chris > > > > > > > > "Arthur" <arthurc@t...> wrote in message > > news:bbnl0i+k498@e... > > > I'm trying to use this graph class without detailed reading. I > can't > > > find a decent, clear example of doing this. I have a simple > graph: > > > > > > typedef adjacency_list<list, listS, bidirectionalS> Graph; > > > > > > What do I do to prevent parallel edges to be inserted? > > > > > > Thanks for any help offered, > > > Arthur

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How do I use Boost with the Visual Studio IDE?
by Ken Fogel 06 Jun '03

06 Jun '03

I can get the threads examples to compile and link with bjam but I am unable to get it to work from within the Visual Studio IDE (versions 6 or 7.1). Does anyone have a basic project structure that could be used in the IDE for threads? I am writing console applications rather than GUI apps.

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Re: [Boost-Users] Re: Newbie query: no "deamon" thread?
by dick.bridges＠tais.com 06 Jun '03

06 Jun '03

I was asking this question for someone else. Except for trivial programs, I always use one form of pool or another. Spend a lot of time reading "pattern" books. To tell the truth, I have no idea what the "real" cost of creating & killing threads is for the various OSs. I just treat it like small object memory allocation: if you don't have a custom allocator, try to avoid doing it. ;) Mark Sizer <yg-boost-users@m To: boost-users(a)yahoogroups.com .gmane.org> cc: Sent by: news Subject: [Boost-Users] Re: Newbie query: no "deamon" thread? <news(a)main.gmane. org> 06/05/2003 05:23 PM Please respond to Boost-Users BTW: Is there enough of a penalty to creating threads that a thread pool should be used rather than creating them on-demand? I'm curious because I'm using a pool pulling from a work queue. - Mark P.S. I realize "enough" is a bit vague. Mark Sizer wrote: > What is "the right thing"? > > You don't HAVE to join(). The creating thread will just keep going if > you don't. If you join, it waits. > > If you're passing ownership (e.g. delete responsibility) across thread > boundaries, you have to be careful, but that doesn't have much to do > with join(). > > After starting the thread, you can use a condtional in the creator to > wait for the thread to "get going" and accept ownership, sort of a > "started()" rather than an "ended()", like join(). Or you can flip it > around and have the started thread wait on the conditional whilst the > creator thread continues to use what will eventually be given to the thread. > > Is that at all helpful? > > - Mark > > dick.bridges(a)tais.com wrote: > > >>I need to spawn worker threads that simply perform a task and exit. All >>the examples I can find seem to use join() to cleanup the thread resources >>from another thread. Isn't there some way to declare worker threads so >>that they "do the right thing" as they exit the thread function? >> >>TIA >> >> >> >>Info: <http://www.boost.org> >>Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> >>Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> >> >> >>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ >> >> >> >> >> > > > > > > Info: <http://www.boost.org> > Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> > Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > > > Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

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[BGL] vistor works w/DFS, won't compile w/DFV - appearent concept check violation - but why?
by Chris Russell 06 Jun '03

06 Jun '03

I initially posted this to the devel list. Apologies for reposting it to the user list but this is really a library _user_ question - not a devel question. I've now screwed around with this for the better part of a day and haven't figured it out. I'm off re-reading BGL book 2.5 concept checking explanation but I'll still baffled. I will post the compiler errors if anyone is willing to give me hand understanding why I can't get what I believe should be quite a simple case working. Here's the problem statement: --- I've got a struct derived from boost::default_dfs_visitor that I've been using w/out any problems in an invocation of boost::depth_first_search. The call that works looks like: boost::depth_first_search(g, boost::visitor(MyDfsVisitor)); ^- NP. compiles and executes fine. Now I'm trying to use the exact same visitor in the context of a boost::depth_first_visit call (so I can set the starting vertex). But I'm having big troubles. I tried this: boost::depth_first_visit(g, s, boost::vistor(MyDfsVisitor), boost::get(boost::vertex_color, g)) // note I'm using an internal, default color map ^- this won't compile. It seems to be balking duing Jeremy's visitor concept checking? The compiler errors are extensive and it looks like none of the visitor methods are being correctly identified. (e.g. missing vis.InitializeVertex ... etc. etc..) p.172 of the BGL book on DFS notes: IN: visitor(DFSVisitor vis) whereas p.175 on DFV notes: IN: DFSVisitor visitor. So I guessed and tried this syntax: boost:depth_first_visit(g, s, MyDfsVisitor, boost::get(boost::vertex_color, g)) ^- this compiles. But I'm getting an exception fault during visitor invocation somewhere deep inside the the RTL. Can anyone enlighten me about what's going on here? What exactly does boost::vistor(X) do? And why is it needed on the DFS call, and apparently rejected in the DFV call? Any help would be sincerely appreciated. - Regards Chris

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uBLAS file io
by cerenoc 06 Jun '03

06 Jun '03

Hi, I'm new to BOOST/uBLAS. I would like to use uBLAS on a matrix that I read in from a file. How does file io work with uBLAS? What are the specific formats? If someone could provide a small example it would be much appreciated. Thank you, Julian

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Warning - Format library adds 48 KB
by Tom 06 Jun '03

06 Jun '03

Boost::Format adds 36KB (VC7.1) or 48 KB (VC6) to my release executable! Details: Take one C++ Win32 application which uses both MFC and the VC STL, but not std::string. Optimizations are set for minimum size. In VC7.1 the release exe is 552 KB. Add std::string, adds 4 KB. Add boost::format, adds another 36 KB. (For each I just added one statement.) For VC6 SP5 the release exe is also 552 KB. Add just the '#include's for string & format libraries, adds 20 KB (VC7.1 didn't do this). Add std::string and boost::format, adds another 32 KB. Total added by format is (20 + 32 - 4) = 48. This is not acceptable for my application. Is there a better way to use C-style printf statements with std::string? Tom. (Thanks to Gmane for making this list usenet accessible!)

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