I have a function called PreProcessSource, which allocates a boost::wave::context and does some preprocessing; nothing fancy at all.
std::string PreProcessSource(const std::string& instring, const std::string& defines)
{
typedef boost::wave::cpplexer::lex_token<> token_type;
typedef boost::wave::cpplexer::lex_iterator<token_type> lex_iterator_type;
typedef boost::wave::context<std::string::iterator, lex_iterator_type> context_type;
std::string source = instring;
context_type ctx(source.begin(), source.end()); // DEADLOCK here
ctx.set_language(boost::wave::enable_emit_line_directives(ctx.get_language(), true));
if(!defines.empty())
{
std::vector<std::string> tokens;
Split<std::string>(defines, tokens, ",");
std::vector<std::string>::const_iterator cit = tokens.begin();
for (;cit != tokens.end(); ++cit)
ctx.add_macro_definition(*cit);
}
context_type::iterator_type first = ctx.begin();
context_type::iterator_type last = ctx.end();
std::string outstring;
while (first != last)
{
const token_type::string_type& value = (*first).get_value();
std::copy(value.begin(), value.end(), std::back_inserter(outstring));
++first;
}
return outstring;
}
In the past (this project is being modernized so it was broken for a long time) it used to work fine in the same setup:
Library A is a DLL that hosts the PreProcess source function, executable B uses the DLL A and can call PreProcess source, and DLL A can also sometimes call the function itself.
But right now this is no longer the case: whenever DLL A calls the function itself, or DLL A calls another function, which in turn calls back into DLL A PreProcess source, it deadlocks.
Here’s an example that works just fine from my unit testing:
BOOST_AUTO_TEST_CASE(Preprocessor)
{
std::stringstream sstream;
sstream << "void main(inout float4 vtxInput : POSITION) { }" << std::endl << std::endl;
std::string source = sstream.str();
std::string defines = "";
try
{
std::string shaderCode = Nitro::PreProcessSource(source, defines);
} catch (boost::wave::preprocess_exception& pe)
{
std::cerr << pe.what() << std::endl;
}
}
And here is the weird bit, if DO_DEADLOCK is defined to 1 in the following piece of code, the deadlock will happen:
class Tutorial00 : public Game
{
public:
// ...
Tutorial00()
: Game()
{
#if !DO_DEADLOCK
std::stringstream sstream;
sstream << "void main(inout float4 vtxInput : POSITION) { }" << std::endl << std::endl;
std::string source = sstream.str();
std::string defines = "";
std::string shaderCode = Nitro::PreProcessSource(source, defines);
#endif
}
void LoadContent()
{
#if DO_DEADLOCK
std::stringstream sstream;
sstream << "void main(inout float4 vtxInput : POSITION) { }" << std::endl << std::endl;
std::string source = sstream.str();
std::string defines = "";
std::string shaderCode = Nitro::PreProcessSource(source, defines);
#endif
// Original code that deadlocks too.
// Calls in the DLL, which will call PreProcessSource.
// effect->Initialize(device, source, "DX11");
}
// ...
};
#if 1
int APIENTRY wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPWSTR lpCmdLine, int nCmdShow)
#else
int main(int argc, char* argv[])
#endif
{
Tutorial00 app;
app.Run();
return 0;
}
Note that the constructor is called directly from the executable, whereas LoadContent is called from the DLL:
// In the DLL
void Game::Run()
{
try
{
// ...
LoadContent();
// ...
} catch(/* ... */) { }
}
The code is compiled for x64 and in debug mode.
I compile boost myself into a DLL (using bcp to get the files for the libraries I use) with the following options:
Preprocessor:
- WIN32
- BOOST_ALL_NO_LIB
- BOOST_ALL_DYN_LINK
- BOOST_THREAD_BUILD_DLL
- _DLL
- _DEBUG
- _WINDOWS
- _USRDLL
Code Generation:
- C++ Exceptions (/EHsc)
- Multi-threaded Debug DLL (/MDd)
- Function-level linking (/Gy)
- Streaming SIMD Extensions 2 (/arch:SSE2) (/arch:SSE2)
- Fast floating point model (/fp:fast)
DLL A uses the same options except for BOOST_ALL_DYN_LINK, BOOST_THREAD_BUILD_DLL and the string pooling option.
The Boost unit test library is build separately as a static library.
Here is the stack trace of the working version:
Nitro.dll!boost::call_once<void (__cdecl*)(void)>(boost::once_flag & flag, void (void)* f) Line 200 C++
Nitro.dll!boost::call_once(void (void)* func, boost::once_flag & flag) Line 28 C++
Nitro.dll!boost::spirit::classic::static_<boost::thread_specific_ptr<boost::weak_ptr<boost::spirit::classic::impl::grammar_helper ... Line 72 + 0x13 bytes C++
Nitro.dll!boost::spirit::classic::impl::get_definition<boost::wave::util::time_conversion::time_conversion_grammar, ... Line 241 + 0x17 bytes C++
Nitro.dll!boost::spirit::classic::impl::grammar_parser_parse<0,boost::wave::util::time_conversion::time_conversion_grammar, ... Line 296 + 0xa bytes C++
Nitro.dll!boost::spirit::classic::grammar<boost::wave::util::time_conversion::time_conversion_grammar, ... Line 55 + 0x3c bytes C++
Nitro.dll!boost::spirit::classic::grammar<boost::wave::util::time_conversion::time_conversion_grammar, ... Line 65 + 0x75 bytes C++
Nitro.dll!boost::spirit::classic::impl::phrase_parser<boost::spirit::classic::space_parser>::parse<char const * __ptr64,boost::wave::util::time_conversion::time_conversion_grammar> ... Line 136 C++
Nitro.dll!boost::spirit::classic::parse<char const * __ptr64,boost::wave::util::time_conversion::time_conversion_grammar, ... Line 155 + 0x3a bytes C++
Nitro.dll!boost::spirit::classic::parse<char,boost::wave::util::time_conversion::time_conversion_grammar, ... Line 173 + 0x23 bytes C++
Nitro.dll!boost::wave::util::time_conversion::time_conversion_helper::time_conversion_helper(const char * act_time) Line 123 C++
Nitro.dll!boost::wave::util::predefined_macros::predefined_macros() Line 196 + 0x38 bytes C++
...
Nitro.dll!Nitro::PreProcessSource(const std::basic_string<char,std::char_traits<char>,std::allocator<char> > & instring, const std::basic_string<char,std::char_traits<char>,std::allocator<char> > & defines) Line 51 + 0xa0 bytes C++
NitroCoreUnitTests.exe!Preprocessor::test_method() Line 16 C++
NitroCoreUnitTests.exe!Preprocessor_invoker() Line 7 + 0x1f bytes C++
...
NitroCoreUnitTests.exe!boost::unit_test::unit_test_main(boost::unit_test::test_suite * (int, char * *)* init_func, int argc, char * * argv) Line 187 C++
NitroCoreUnitTests.exe!main(int argc, char * * argv) Line 238 C++
NitroCoreUnitTests.exe!__tmainCRTStartup() Line 555 + 0x19 bytes C
NitroCoreUnitTests.exe!mainCRTStartup() Line 371 C
kernel32.dll!00000000766a652d()
[Frames below may be incorrect and/or missing, no symbols loaded for kernel32.dll]
ntdll.dll!0000000076d9c521()
And here is the stack trace of the deadlock:
ntdll.dll!0000000076dc135a()
[Frames below may be incorrect and/or missing, no symbols loaded for ntdll.dll]
KernelBase.dll!000007fefd4f10dc()
Nitro.dll!boost::call_once<void (__cdecl*)(void)>(boost::once_flag & flag, void (void)* f) Line 197 + 0x18 bytes C++
Nitro.dll!boost::call_once(void (void)* func, boost::once_flag & flag) Line 28 C++
Nitro.dll!boost::spirit::classic::static_<boost::thread_specific_ptr<boost::weak_ptr<boost::spirit::classic::impl::grammar_helper ... Line 72 + 0x13 bytes C++
Nitro.dll!boost::spirit::classic::impl::get_definition<boost::wave::util::time_conversion::time_conversion_grammar, ... Line 241 + 0x17 bytes C++
Nitro.dll!boost::spirit::classic::impl::grammar_parser_parse<0,boost::wave::util::time_conversion::time_conversion_grammar, ... Line 296 + 0xa bytes C++
Nitro.dll!boost::spirit::classic::grammar<boost::wave::util::time_conversion::time_conversion_grammar, ... Line 55 + 0x3c bytes C++
Nitro.dll!boost::spirit::classic::grammar<boost::wave::util::time_conversion::time_conversion_grammar, ... Line 65 + 0x75 bytes C++
Nitro.dll!boost::spirit::classic::impl::phrase_parser<boost::spirit::classic::space_parser>::parse<char const * __ptr64,boost::wave::util::time_conversion::time_conversion_grammar> ... Line 136 C++
Nitro.dll!boost::spirit::classic::parse<char const * __ptr64,boost::wave::util::time_conversion::time_conversion_grammar, ... Line 155 + 0x3a bytes C++
Nitro.dll!boost::spirit::classic::parse<char,boost::wave::util::time_conversion::time_conversion_grammar, ... Line 173 + 0x23 bytes C++
Nitro.dll!boost::wave::util::time_conversion::time_conversion_helper::time_conversion_helper(const char * act_time) Line 123 C++
Nitro.dll!boost::wave::util::predefined_macros::predefined_macros() Line 196 + 0x38 bytes C++
...
Nitro.dll!Nitro::PreProcessSource(const std::basic_string<char,std::char_traits<char>,std::allocator<char> > & instring, const std::basic_string<char,std::char_traits<char>,std::allocator<char> > & defines) Line 51 + 0xa0 bytes C++
Tutorial01.exe!Tutorial01::LoadContent() Line 70 + 0x33 bytes C++
Nitro.dll!Nitro::Game::Run() Line 40 C++
Tutorial01.exe!wWinMain(HINSTANCE__ * hInstance, HINSTANCE__ * hPrevInstance, wchar_t * lpCmdLine, int nCmdShow) Line 149 C++
Tutorial01.exe!__tmainCRTStartup() Line 547 + 0x42 bytes C
Tutorial01.exe!wWinMainCRTStartup() Line 371 C
kernel32.dll!00000000766a652d()
ntdll.dll!0000000076d9c521()
It seems boost::wave is trying to parse some time stamp, and by doing so instantiates a grammar and that’s when things seem to go South.
Thanks in advance for any help 🙂
I found the following ticket opened on boost’s trac: boost::call_once not re-entrant (at least in win32)
It says that call_once is not re-entrant, and shouldn’t be called recursively. Thus the code that I am employing is undefined behavior; the ticket was marked as “will not fix”.
The solution I’ve taken was to create a separate DLL that only contains the PreProcessSource function.