From 888f499188cb869dc8f8f1597c46add65c005324 Mon Sep 17 00:00:00 2001
From: Liam <byteslice@airmail.cc>
Date: Mon, 13 Jun 2022 18:36:30 -0400
Subject: kernel: implement KProcess suspension
---
src/core/debugger/debugger.cpp | 94 +++++++++++++++++++-----------------------
1 file changed, 43 insertions(+), 51 deletions(-)
(limited to 'src/core/debugger/debugger.cpp')
diff --git a/src/core/debugger/debugger.cpp b/src/core/debugger/debugger.cpp
index edf991d71c..ab39409223 100644
--- a/src/core/debugger/debugger.cpp
+++ b/src/core/debugger/debugger.cpp
@@ -67,17 +67,19 @@ 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;
- }
+ 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;
+ // Set up the state.
+ stopped = true;
+ 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)));
@@ -141,9 +143,6 @@ private:
AsyncReceiveInto(signal_pipe, pipe_data, [&](auto d) { PipeData(d); });
AsyncReceiveInto(client_socket, client_data, [&](auto d) { ClientData(d); });
- // Stop the emulated CPU.
- AllCoreStop();
-
// Set the active thread.
UpdateActiveThread();
@@ -159,7 +158,7 @@ private:
switch (info.type) {
case SignalType::Stopped:
// Stop emulation.
- AllCoreStop();
+ PauseEmulation();
// Notify the client.
active_thread = info.thread;
@@ -171,7 +170,6 @@ private:
frontend->ShuttingDown();
// Wait for emulation to shut down gracefully now.
- suspend.reset();
signal_pipe.close();
client_socket.shutdown(boost::asio::socket_base::shutdown_both);
LOG_INFO(Debug_GDBStub, "Shut down server");
@@ -189,32 +187,29 @@ private:
std::scoped_lock lk{connection_lock};
stopped = true;
}
- AllCoreStop();
+ PauseEmulation();
UpdateActiveThread();
frontend->Stopped(active_thread);
break;
}
case DebuggerAction::Continue:
- active_thread->SetStepState(Kernel::StepState::NotStepping);
- ResumeInactiveThreads();
- AllCoreResume();
+ MarkResumed([&] { ResumeEmulation(); });
break;
case DebuggerAction::StepThreadUnlocked:
- active_thread->SetStepState(Kernel::StepState::StepPending);
- ResumeInactiveThreads();
- AllCoreResume();
+ MarkResumed([&] {
+ active_thread->SetStepState(Kernel::StepState::StepPending);
+ active_thread->Resume(Kernel::SuspendType::Debug);
+ ResumeEmulation(active_thread);
+ });
break;
- case DebuggerAction::StepThreadLocked:
- active_thread->SetStepState(Kernel::StepState::StepPending);
- SuspendInactiveThreads();
- AllCoreResume();
+ case DebuggerAction::StepThreadLocked: {
+ MarkResumed([&] {
+ active_thread->SetStepState(Kernel::StepState::StepPending);
+ active_thread->Resume(Kernel::SuspendType::Debug);
+ });
break;
+ }
case DebuggerAction::ShutdownEmulation: {
- // Suspend all threads and release any locks held
- active_thread->RequestSuspend(Kernel::SuspendType::Debug);
- SuspendInactiveThreads();
- AllCoreResume();
-
// Spawn another thread that will exit after shutdown,
// to avoid a deadlock
Core::System* system_ref{&system};
@@ -226,33 +221,33 @@ private:
}
}
- void AllCoreStop() {
- if (!suspend) {
- suspend = system.StallCPU();
+ void PauseEmulation() {
+ // Put all threads to sleep on next scheduler round.
+ for (auto* thread : ThreadList()) {
+ thread->RequestSuspend(Kernel::SuspendType::Debug);
}
- }
- void AllCoreResume() {
- stopped = false;
- system.UnstallCPU();
- suspend.reset();
+ // Signal an interrupt so that scheduler will fire.
+ system.Kernel().InterruptAllPhysicalCores();
}
- void SuspendInactiveThreads() {
+ void ResumeEmulation(Kernel::KThread* except = nullptr) {
+ // Wake up all threads.
for (auto* thread : ThreadList()) {
- if (thread != active_thread) {
- thread->RequestSuspend(Kernel::SuspendType::Debug);
+ if (thread == except) {
+ continue;
}
+
+ thread->SetStepState(Kernel::StepState::NotStepping);
+ thread->Resume(Kernel::SuspendType::Debug);
}
}
- void ResumeInactiveThreads() {
- for (auto* thread : ThreadList()) {
- if (thread != active_thread) {
- thread->Resume(Kernel::SuspendType::Debug);
- thread->SetStepState(Kernel::StepState::NotStepping);
- }
- }
+ template <typename Callback>
+ void MarkResumed(Callback&& cb) {
+ std::scoped_lock lk{connection_lock};
+ stopped = false;
+ cb();
}
void UpdateActiveThread() {
@@ -260,8 +255,6 @@ private:
if (std::find(threads.begin(), threads.end(), active_thread) == threads.end()) {
active_thread = threads[0];
}
- active_thread->Resume(Kernel::SuspendType::Debug);
- active_thread->SetStepState(Kernel::StepState::NotStepping);
}
const std::vector<Kernel::KThread*>& ThreadList() {
@@ -277,7 +270,6 @@ private:
boost::asio::io_context io_context;
boost::process::async_pipe signal_pipe;
boost::asio::ip::tcp::socket client_socket;
- std::optional<std::unique_lock<std::mutex>> suspend;
SignalInfo info;
Kernel::KThread* active_thread;
--
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