From ceb829cc332a3903e81dd5d32f2c953f25210fc2 Mon Sep 17 00:00:00 2001 From: Liam Date: Thu, 10 Nov 2022 17:05:47 -0500 Subject: [PATCH] debugger: allow more than one connection attempt per session --- src/core/debugger/debugger.cpp | 173 +++++++++++++++++++-------------- 1 file changed, 99 insertions(+), 74 deletions(-) diff --git a/src/core/debugger/debugger.cpp b/src/core/debugger/debugger.cpp index 339f971e6f..1a8e02e6a4 100644 --- a/src/core/debugger/debugger.cpp +++ b/src/core/debugger/debugger.cpp @@ -27,12 +27,21 @@ static void AsyncReceiveInto(Readable& r, Buffer& buffer, Callback&& c) { const u8* buffer_start = reinterpret_cast(&buffer); std::span received_data{buffer_start, buffer_start + bytes_read}; c(received_data); + AsyncReceiveInto(r, buffer, c); } - - AsyncReceiveInto(r, buffer, c); }); } +template +static void AsyncAccept(boost::asio::ip::tcp::acceptor& acceptor, Callback&& c) { + acceptor.async_accept([&, c](const boost::system::error_code& error, auto&& peer_socket) { + if (!error.failed()) { + c(peer_socket); + AsyncAccept(acceptor, c); + } + }); +} + template static std::span ReceiveInto(Readable& r, Buffer& buffer) { static_assert(std::is_trivial_v); @@ -59,9 +68,7 @@ namespace Core { class DebuggerImpl : public DebuggerBackend { public: - explicit DebuggerImpl(Core::System& system_, u16 port) - : system{system_}, signal_pipe{io_context}, client_socket{io_context} { - frontend = std::make_unique(*this, system); + explicit DebuggerImpl(Core::System& system_, u16 port) : system{system_} { InitializeServer(port); } @@ -70,39 +77,42 @@ public: } bool SignalDebugger(SignalInfo signal_info) { - { - std::scoped_lock lk{connection_lock}; + std::scoped_lock lk{connection_lock}; - if (stopped) { - // Do not notify the debugger about another event. - // It should be ignored. - return false; - } - - // Set up the state. - stopped = true; - info = signal_info; + if (stopped || !state) { + // Do not notify the debugger about another event. + // It should be ignored. + return false; } + // Set up the state. + stopped = true; + state->info = signal_info; + // Write a single byte into the pipe to wake up the debug interface. - boost::asio::write(signal_pipe, boost::asio::buffer(&stopped, sizeof(stopped))); + boost::asio::write(state->signal_pipe, boost::asio::buffer(&stopped, sizeof(stopped))); + return true; } + // These functions are callbacks from the frontend, and the lock will be held. + // There is no need to relock it. + std::span ReadFromClient() override { - return ReceiveInto(client_socket, client_data); + return ReceiveInto(state->client_socket, state->client_data); } void WriteToClient(std::span data) override { - boost::asio::write(client_socket, boost::asio::buffer(data.data(), data.size_bytes())); + boost::asio::write(state->client_socket, + boost::asio::buffer(data.data(), data.size_bytes())); } void SetActiveThread(Kernel::KThread* thread) override { - active_thread = thread; + state->active_thread = thread; } Kernel::KThread* GetActiveThread() override { - return active_thread; + return state->active_thread; } private: @@ -113,65 +123,78 @@ private: // Run the connection thread. connection_thread = std::jthread([&, port](std::stop_token stop_token) { + Common::SetCurrentThreadName("Debugger"); + try { // Initialize the listening socket and accept a new client. tcp::endpoint endpoint{boost::asio::ip::address_v4::any(), port}; tcp::acceptor acceptor{io_context, endpoint}; - acceptor.async_accept(client_socket, [](const auto&) {}); - io_context.run_one(); - io_context.restart(); + AsyncAccept(acceptor, [&](auto&& peer) { AcceptConnection(std::move(peer)); }); - if (stop_token.stop_requested()) { - return; + while (!stop_token.stop_requested() && io_context.run()) { } - - ThreadLoop(stop_token); } catch (const std::exception& ex) { LOG_CRITICAL(Debug_GDBStub, "Stopping server: {}", ex.what()); } }); } + void AcceptConnection(boost::asio::ip::tcp::socket&& peer) { + LOG_INFO(Debug_GDBStub, "Accepting new peer connection"); + + std::scoped_lock lk{connection_lock}; + + // Ensure everything is stopped. + PauseEmulation(); + + // Set up the new frontend. + frontend = std::make_unique(*this, system); + + // Set the new state. This will tear down any existing state. + state = ConnectionState{ + .client_socket{std::move(peer)}, + .signal_pipe{io_context}, + .info{}, + .active_thread{}, + .client_data{}, + .pipe_data{}, + }; + + // Set up the client signals for new data. + AsyncReceiveInto(state->signal_pipe, state->pipe_data, [&](auto d) { PipeData(d); }); + AsyncReceiveInto(state->client_socket, state->client_data, [&](auto d) { ClientData(d); }); + + // Set the active thread. + UpdateActiveThread(); + + // Set up the frontend. + frontend->Connected(); + } + void ShutdownServer() { connection_thread.request_stop(); io_context.stop(); connection_thread.join(); } - void ThreadLoop(std::stop_token stop_token) { - Common::SetCurrentThreadName("Debugger"); - - // Set up the client signals for new data. - AsyncReceiveInto(signal_pipe, pipe_data, [&](auto d) { PipeData(d); }); - AsyncReceiveInto(client_socket, client_data, [&](auto d) { ClientData(d); }); - - // Set the active thread. - UpdateActiveThread(); - - // Set up the frontend. - frontend->Connected(); - - // Main event loop. - while (!stop_token.stop_requested() && io_context.run()) { - } - } - void PipeData(std::span data) { - switch (info.type) { + std::scoped_lock lk{connection_lock}; + + switch (state->info.type) { case SignalType::Stopped: case SignalType::Watchpoint: // Stop emulation. PauseEmulation(); // Notify the client. - active_thread = info.thread; + state->active_thread = state->info.thread; UpdateActiveThread(); - if (info.type == SignalType::Watchpoint) { - frontend->Watchpoint(active_thread, *info.watchpoint); + if (state->info.type == SignalType::Watchpoint) { + frontend->Watchpoint(state->active_thread, *state->info.watchpoint); } else { - frontend->Stopped(active_thread); + frontend->Stopped(state->active_thread); } break; @@ -179,8 +202,8 @@ private: frontend->ShuttingDown(); // Wait for emulation to shut down gracefully now. - signal_pipe.close(); - client_socket.shutdown(boost::asio::socket_base::shutdown_both); + state->signal_pipe.close(); + state->client_socket.shutdown(boost::asio::socket_base::shutdown_both); LOG_INFO(Debug_GDBStub, "Shut down server"); break; @@ -188,17 +211,16 @@ private: } void ClientData(std::span data) { + std::scoped_lock lk{connection_lock}; + const auto actions{frontend->ClientData(data)}; for (const auto action : actions) { switch (action) { case DebuggerAction::Interrupt: { - { - std::scoped_lock lk{connection_lock}; - stopped = true; - } + stopped = true; PauseEmulation(); UpdateActiveThread(); - frontend->Stopped(active_thread); + frontend->Stopped(state->active_thread); break; } case DebuggerAction::Continue: @@ -206,15 +228,15 @@ private: break; case DebuggerAction::StepThreadUnlocked: MarkResumed([&] { - active_thread->SetStepState(Kernel::StepState::StepPending); - active_thread->Resume(Kernel::SuspendType::Debug); - ResumeEmulation(active_thread); + state->active_thread->SetStepState(Kernel::StepState::StepPending); + state->active_thread->Resume(Kernel::SuspendType::Debug); + ResumeEmulation(state->active_thread); }); break; case DebuggerAction::StepThreadLocked: { MarkResumed([&] { - active_thread->SetStepState(Kernel::StepState::StepPending); - active_thread->Resume(Kernel::SuspendType::Debug); + state->active_thread->SetStepState(Kernel::StepState::StepPending); + state->active_thread->Resume(Kernel::SuspendType::Debug); }); break; } @@ -254,15 +276,14 @@ private: template void MarkResumed(Callback&& cb) { Kernel::KScopedSchedulerLock sl{system.Kernel()}; - std::scoped_lock cl{connection_lock}; stopped = false; cb(); } void UpdateActiveThread() { const auto& threads{ThreadList()}; - if (std::find(threads.begin(), threads.end(), active_thread) == threads.end()) { - active_thread = threads[0]; + if (std::find(threads.begin(), threads.end(), state->active_thread) == threads.end()) { + state->active_thread = threads[0]; } } @@ -274,18 +295,22 @@ private: System& system; std::unique_ptr frontend; + boost::asio::io_context io_context; std::jthread connection_thread; std::mutex connection_lock; - boost::asio::io_context io_context; - boost::process::async_pipe signal_pipe; - boost::asio::ip::tcp::socket client_socket; - SignalInfo info; - Kernel::KThread* active_thread; - bool pipe_data; - bool stopped; + struct ConnectionState { + boost::asio::ip::tcp::socket client_socket; + boost::process::async_pipe signal_pipe; - std::array client_data; + SignalInfo info; + Kernel::KThread* active_thread; + std::array client_data; + bool pipe_data; + }; + + std::optional state{}; + bool stopped{}; }; Debugger::Debugger(Core::System& system, u16 port) {