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// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2
// Refer to the license.txt file included.
#pragma once
#include <array>
#include <condition_variable>
#include <list>
#include <memory>
#include <mutex>
namespace Tegra {
class DebugContext {
public:
enum class Event {
FirstEvent = 0,
MaxwellCommandLoaded = FirstEvent,
MaxwellCommandProcessed,
IncomingPrimitiveBatch,
FinishedPrimitiveBatch,
NumEvents
};
/**
* Inherit from this class to be notified of events registered to some debug context.
* Most importantly this is used for our debugger GUI.
*
* To implement event handling, override the OnMaxwellBreakPointHit and OnMaxwellResume methods.
* @warning All BreakPointObservers need to be on the same thread to guarantee thread-safe state
* access
* @todo Evaluate an alternative interface, in which there is only one managing observer and
* multiple child observers running (by design) on the same thread.
*/
class BreakPointObserver {
public:
/// Constructs the object such that it observes events of the given DebugContext.
explicit BreakPointObserver(std::shared_ptr<DebugContext> debug_context)
: context_weak(debug_context) {
std::unique_lock lock{debug_context->breakpoint_mutex};
debug_context->breakpoint_observers.push_back(this);
}
virtual ~BreakPointObserver() {
auto context = context_weak.lock();
if (context) {
{
std::unique_lock lock{context->breakpoint_mutex};
context->breakpoint_observers.remove(this);
}
// If we are the last observer to be destroyed, tell the debugger context that
// it is free to continue. In particular, this is required for a proper yuzu
// shutdown, when the emulation thread is waiting at a breakpoint.
if (context->breakpoint_observers.empty())
context->Resume();
}
}
/**
* Action to perform when a breakpoint was reached.
* @param event Type of event which triggered the breakpoint
* @param data Optional data pointer (if unused, this is a nullptr)
* @note This function will perform nothing unless it is overridden in the child class.
*/
virtual void OnMaxwellBreakPointHit(Event event, void* data) {}
/**
* Action to perform when emulation is resumed from a breakpoint.
* @note This function will perform nothing unless it is overridden in the child class.
*/
virtual void OnMaxwellResume() {}
protected:
/**
* Weak context pointer. This need not be valid, so when requesting a shared_ptr via
* context_weak.lock(), always compare the result against nullptr.
*/
std::weak_ptr<DebugContext> context_weak;
};
/**
* Simple structure defining a breakpoint state
*/
struct BreakPoint {
bool enabled = false;
};
/**
* Static constructor used to create a shared_ptr of a DebugContext.
*/
static std::shared_ptr<DebugContext> Construct() {
return std::shared_ptr<DebugContext>(new DebugContext);
}
/**
* Used by the emulation core when a given event has happened. If a breakpoint has been set
* for this event, OnEvent calls the event handlers of the registered breakpoint observers.
* The current thread then is halted until Resume() is called from another thread (or until
* emulation is stopped).
* @param event Event which has happened
* @param data Optional data pointer (pass nullptr if unused). Needs to remain valid until
* Resume() is called.
*/
void OnEvent(Event event, void* data) {
// This check is left in the header to allow the compiler to inline it.
if (!breakpoints[(int)event].enabled)
return;
// For the rest of event handling, call a separate function.
DoOnEvent(event, data);
}
void DoOnEvent(Event event, void* data);
/**
* Resume from the current breakpoint.
* @warning Calling this from the same thread that OnEvent was called in will cause a deadlock.
* Calling from any other thread is safe.
*/
void Resume();
/**
* Delete all set breakpoints and resume emulation.
*/
void ClearBreakpoints() {
for (auto& bp : breakpoints) {
bp.enabled = false;
}
Resume();
}
// TODO: Evaluate if access to these members should be hidden behind a public interface.
std::array<BreakPoint, static_cast<int>(Event::NumEvents)> breakpoints;
Event active_breakpoint{};
bool at_breakpoint = false;
private:
/**
* Private default constructor to make sure people always construct this through Construct()
* instead.
*/
DebugContext() = default;
/// Mutex protecting current breakpoint state and the observer list.
std::mutex breakpoint_mutex;
/// Used by OnEvent to wait for resumption.
std::condition_variable resume_from_breakpoint;
/// List of registered observers
std::list<BreakPointObserver*> breakpoint_observers;
};
} // namespace Tegra
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