Could you guys help me decypher unknown exception that is thrown by boost::iostreams::mapped_file_sink
?
My configuration
Here is the code I have
try
{
boost::iostreams::mapped_file_params params_;
boost::iostreams::mapped_file_sink sink_;
params_.length = 0;
params_.new_file_size = 1024;
params_.path = "./test.bin";
sink_.open(params_);
sink_.close();
}
catch (std::ios::failure& ex)
{
std::cout << "\t" << "what: " << ex.what() << "\n";
}
catch (std::system_error& ex)
{
std::cout << "\t" << "code: " << ex.code() << " what: " << ex.what() << "\n";
}
catch (std::runtime_error& ex)
{
std::cout << "\t" << ex.what() << "\n";
}
catch (boost::archive::archive_exception& ex)
{
std::cout << "\t" << ex.what() << "\n";
}
catch (boost::exception& ex)
{
std::cout << "blah\n";
}
catch (std::exception& ex)
{
std::cout << "\t" << ex.what() << " --- " << typeid(ex).name() << "\n";
}
It always works in Windows.
In Ubuntu it creates empty file of given size but throws exception on open()
. Subsequent execution of the code if exists doesn't cause exception.
The worst part is that I can't see the reason of the exception. I can only catch std::exception
whose what()
returns meaningless "std::exception".
In desperate attempt to find out what's wrong I output typeid(ex).name()
which shows
N5boost16exception_detail10clone_implINS0_19error_info_injectorISt9exception
which according to Google means: boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<std::exception> >
Any ideas what's wrong?
You could run the code in a debugger and set a breakpoint in the function which actually throws an exceptions, eg, __cxa_throw
. The name of the function may be different on your system: use nm -po program | less
nm -po program | less
and search for a function containing throw
. Set a breakpoint in the one(s) which look most likely as if they are created by the system. If there are only few exceptions being thrown, you can also set a breakpoint into std::exception::exception()
.
After 50 mins of guessing I found out that problem was in length
field. The documentation doesn't say that but its default value has to be -1 as stated in source code
BOOST_STATIC_CONSTANT(size_type, max_length = static_cast<size_type>(-1));
I intuitively assumed that if I set new_file_size
to be more than zero it would ignore length
.
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.