This project aims to provide a support for debugging stackfull coroutines
from boost.Coroutine2.
An lldb plugin for boost.Coroutine2, hence the name llc2.
The plugin is very limited in functionality and is focused exclusively
on uServer,
and although it may work for other use cases this isn't a priority for now.
Start an LLDB session, load the plugin, configure it and backtrace sleeping coroutines.
(lldb) plugin load /home/itrofimow/work/llc2/build/libllc2.so
(lldb) llc2 init -s 262144 -c fcontext
LLC2 plugin initialized. Settings:
stack_size: 262144
context implementation: fcontext
with magic: false
filter by: (null)
truncate at: (null)
(lldb) llc2 bt
----------------------------------------------------------------------------------------- FOUND SLEEPING COROUTINE -----------------------------------------------------------------------------------------
coro stack address: 0x7fffecf2e000
----------------------------------
Current span (name, span_id, trace_id): http/handler-hello-sample | 75e2fb6fe8dff5c1 | 66acd8c970ec4923879c17396bba7a5c
-----------------------------------------------------------------------------------------------------------------------
frame #0: 0x00000000003025f9 userver-samples-hello_service`boost::coroutines2::detail::pull_coroutine<userver::engine::impl::TaskContext*>::control_block::resume() [inlined] std::enable_if<__and_<std::__not_<std::__is_tuple_like<void*> >, std::is_move_constructible<void*>, std::is_move_assignable<void*> >::value, void>::type std::swap<void*>(__a=0x00007fffffffd210, __b=<unavailable>) at move.h:204:19
frame #1: 0x00000000003025f9 userver-samples-hello_service`boost::coroutines2::detail::pull_coroutine<userver::engine::impl::TaskContext*>::control_block::resume() [inlined] boost::context::fiber::swap(this=0x00007fffffffd210, other=<unavailable>) at fiber_fcontext.hpp:335
frame #2: 0x00000000003025f9 userver-samples-hello_service`boost::coroutines2::detail::pull_coroutine<userver::engine::impl::TaskContext*>::control_block::resume() at fiber_fcontext.hpp:269
frame #3: 0x00000000003025f9 userver-samples-hello_service`boost::coroutines2::detail::pull_coroutine<userver::engine::impl::TaskContext*>::control_block::resume(this=0x00007fffffffd210) at pull_control_block_cc.ipp:147
frame #4: 0x00000000002fea45 userver-samples-hello_service`userver::engine::impl::TaskContext::Sleep(userver::engine::impl::WaitStrategy&) [inlined] boost::coroutines2::detail::pull_coroutine<userver::engine::impl::TaskContext*>::operator(this=<unavailable>)() at pull_coroutine.ipp:77:10
frame #5: 0x00000000002fea3d userver-samples-hello_service`userver::engine::impl::TaskContext::Sleep(this=0x00007fffde2dd800, wait_strategy=0x00007fffffffd2f0) at task_context.cpp:331
frame #6: 0x000000000029963d userver-samples-hello_service`samples::hello::Hello::HandleRequestThrow[abi:cxx11](userver::server::http::HttpRequest const&, userver::server::request::RequestContext&) const [inlined] userver::engine::InterruptibleSleepUntil(deadline=<unavailable>) at sleep.cpp:28:11
frame #7: 0x000000000029960c userver-samples-hello_service`samples::hello::Hello::HandleRequestThrow[abi:cxx11](userver::server::http::HttpRequest const&, userver::server::request::RequestContext&) const [inlined] userver::engine::SleepUntil(deadline=<unavailable>) at sleep.cpp:33
frame #8: 0x0000000000299604 userver-samples-hello_service`samples::hello::Hello::HandleRequestThrow[abi:cxx11](userver::server::http::HttpRequest const&, userver::server::request::RequestContext&) const [inlined] void userver::engine::SleepFor<long, std::ratio<1l, 1l> >(duration=<unavailable>) at sleep.hpp:44
frame #9: 0x00000000002995eb userver-samples-hello_service`samples::hello::Hello::HandleRequestThrow[abi:cxx11](this=<unavailable>, (null)=<unavailable>, (null)=<unavailable>) const at hello_service.cpp:22
frame #10: 0x000000000034a906 userver-samples-hello_service`userver::server::handlers::HttpHandlerBase::HandleRequest(userver::server::request::RequestBase&, userver::server::request::RequestContext&) const [inlined] userver::server::handlers::HttpHandlerBase::HandleRequest(this=<unavailable>) const::$_19::operator()() const at http_handler_base.cpp:574:30
frame #11: 0x000000000034a7c3 userver-samples-hello_service`userver::server::handlers::HttpHandlerBase::HandleRequest(userver::server::request::RequestBase&, userver::server::request::RequestContext&) const [inlined] bool userver::server::handlers::(anonymous namespace)::RequestProcessor::DoProcessRequestStep<userver::server::handlers::HttpHandlerBase::HandleRequest(this=0x00007fffecf6ca98, step_name=<unavailable>, process_step_func=<unavailable>) const::$_19>(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, userver::server::handlers::HttpHandlerBase::HandleRequest(userver::server::request::RequestBase&, userver::server::request::RequestContext&) const::$_19 const&) at http_handler_base.cpp:171
frame #12: 0x000000000034a6e1 userver-samples-hello_service`userver::server::handlers::HttpHandlerBase::HandleRequest(userver::server::request::RequestBase&, userver::server::request::RequestContext&) const [inlined] bool userver::server::handlers::(anonymous namespace)::RequestProcessor::ProcessRequestStep<userver::server::handlers::HttpHandlerBase::HandleRequest(this=0x00007fffecf6ca98, step_name=<unavailable>, process_step_func=<unavailable>) const::$_19>(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, userver::server::handlers::HttpHandlerBase::HandleRequest(userver::server::request::RequestBase&, userver::server::request::RequestContext&) const::$_19 const&) at http_handler_base.cpp:159
frame #13: 0x000000000034a6cb userver-samples-hello_service`userver::server::handlers::HttpHandlerBase::HandleRequest(this=0x00007fffdcc27080, request=0x00007fffdc88e410, context=0x00007fffecf6dcf0) const at http_handler_base.cpp:568
----------------------------------------------------------------------------------------- FOUND SLEEPING COROUTINE -----------------------------------------------------------------------------------------
coro stack address: 0x7fffed37f000
... coro frames follow ...
Install lldb development headers (liblldb-XX-dev) of matching lldb version,
next, clone this code and run
mkdir build && cd build && cmake -DCMAKE_BUILD_TYPE=Release .. && make
Now you have a libllc2.so and should be able to plugin load it into lldb.
Install llvm package using brew brew install llvm,
next, clone this code and run
mkdir build && cd build && cmake -DLLVM_DIR=/usr/local/opt/llvm/lib/cmake/llvm -DCMAKE_BUILD_TYPE=Release .. && make
Now you have a libllc2.dylib and should be able to plugin load at into lldb.
- x86_64 linux and macos
- Only works with protected_fixedsize
- Some of
llc2 initoptions are completely ignored:-f,-t. They are hardcoded to uServer-specific values for now. - Might not work with different versions of boost.Coroutine2
- Might accidentally not work at all
Supported options:
-s- stack size of a coroutine. ForuServerit should be either default value of 256Kb or that specified instatic_config.yaml-c- context implementation, eitherucontextorfcontext. ForuServerit should befcontext, until the binary is built with sanitizers, thenucontext.