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Merge pull request #8650 from Kelebek1/vsync

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[Coretiming/NVNFlinger] Improve multi-core vsync timing, and core timing accuracy
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bunnei 2022-09-17 11:10:54 -07:00 committed by GitHub
commit 9c32f29af1
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GPG key ID: 4AEE18F83AFDEB23
4 changed files with 72 additions and 34 deletions
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4
src/common/thread.h
View file

@ -54,6 +54,10 @@ public:
is_set = false;
}
[[nodiscard]] bool IsSet() {
return is_set;
}
private:
std::condition_variable condvar;
std::mutex mutex;

45
src/core/core_timing.cpp
View file

@ -134,6 +134,7 @@ void CoreTiming::ScheduleLoopingEvent(std::chrono::nanoseconds start_time,
std::chrono::nanoseconds resched_time,
const std::shared_ptr<EventType>& event_type,
std::uintptr_t user_data, bool absolute_time) {
{
std::scoped_lock scope{basic_lock};
const auto next_time{absolute_time ? start_time : GetGlobalTimeNs() + start_time};
@ -141,6 +142,9 @@ void CoreTiming::ScheduleLoopingEvent(std::chrono::nanoseconds start_time,
Event{next_time.count(), event_fifo_id++, user_data, event_type, resched_time.count()});
std::push_heap(event_queue.begin(), event_queue.end(), std::greater<>());
}
event.Set();
}
void CoreTiming::UnscheduleEvent(const std::shared_ptr<EventType>& event_type,
@ -229,17 +233,17 @@ std::optional<s64> CoreTiming::Advance() {
basic_lock.lock();
if (evt.reschedule_time != 0) {
// If this event was scheduled into a pause, its time now is going to be way behind.
// Re-set this event to continue from the end of the pause.
auto next_time{evt.time + evt.reschedule_time};
if (evt.time < pause_end_time) {
next_time = pause_end_time + evt.reschedule_time;
}
const auto next_schedule_time{new_schedule_time.has_value()
? new_schedule_time.value().count()
: evt.reschedule_time};
// If this event was scheduled into a pause, its time now is going to be way behind.
// Re-set this event to continue from the end of the pause.
auto next_time{evt.time + next_schedule_time};
if (evt.time < pause_end_time) {
next_time = pause_end_time + next_schedule_time;
}
event_queue.emplace_back(
Event{next_time, event_fifo_id++, evt.user_data, evt.type, next_schedule_time});
std::push_heap(event_queue.begin(), event_queue.end(), std::greater<>());
@ -250,8 +254,7 @@ std::optional<s64> CoreTiming::Advance() {
}
if (!event_queue.empty()) {
const s64 next_time = event_queue.front().time - global_timer;
return next_time;
return event_queue.front().time;
} else {
return std::nullopt;
}
@ -264,11 +267,29 @@ void CoreTiming::ThreadLoop() {
paused_set = false;
const auto next_time = Advance();
if (next_time) {
if (*next_time > 0) {
std::chrono::nanoseconds next_time_ns = std::chrono::nanoseconds(*next_time);
event.WaitFor(next_time_ns);
// There are more events left in the queue, wait until the next event.
const auto wait_time = *next_time - GetGlobalTimeNs().count();
if (wait_time > 0) {
// Assume a timer resolution of 1ms.
static constexpr s64 TimerResolutionNS = 1000000;
// Sleep in discrete intervals of the timer resolution, and spin the rest.
const auto sleep_time = wait_time - (wait_time % TimerResolutionNS);
if (sleep_time > 0) {
event.WaitFor(std::chrono::nanoseconds(sleep_time));
}
while (!paused && !event.IsSet() && GetGlobalTimeNs().count() < *next_time) {
// Yield to reduce thread starvation.
std::this_thread::yield();
}
if (event.IsSet()) {
event.Reset();
}
}
} else {
// Queue is empty, wait until another event is scheduled and signals us to continue.
wait_set = true;
event.Wait();
}

42
src/core/hle/service/nvflinger/nvflinger.cpp
View file

@ -38,20 +38,16 @@ void NVFlinger::SplitVSync(std::stop_token stop_token) {
Common::SetCurrentThreadName(name.c_str());
Common::SetCurrentThreadPriority(Common::ThreadPriority::High);
s64 delay = 0;
while (!stop_token.stop_requested()) {
vsync_signal.wait(false);
vsync_signal.store(false);
guard->lock();
const s64 time_start = system.CoreTiming().GetGlobalTimeNs().count();
Compose();
const auto ticks = GetNextTicks();
const s64 time_end = system.CoreTiming().GetGlobalTimeNs().count();
const s64 time_passed = time_end - time_start;
const s64 next_time = std::max<s64>(0, ticks - time_passed - delay);
guard->unlock();
if (next_time > 0) {
std::this_thread::sleep_for(std::chrono::nanoseconds{next_time});
}
delay = (system.CoreTiming().GetGlobalTimeNs().count() - time_end) - next_time;
}
}
@ -66,27 +62,41 @@ NVFlinger::NVFlinger(Core::System& system_, HosBinderDriverServer& hos_binder_dr
guard = std::make_shared<std::mutex>();
// Schedule the screen composition events
composition_event = Core::Timing::CreateEvent(
multi_composition_event = Core::Timing::CreateEvent(
"ScreenComposition",
[this](std::uintptr_t, s64 time,
std::chrono::nanoseconds ns_late) -> std::optional<std::chrono::nanoseconds> {
vsync_signal.store(true);
vsync_signal.notify_all();
return std::chrono::nanoseconds(GetNextTicks());
});
single_composition_event = Core::Timing::CreateEvent(
"ScreenComposition",
[this](std::uintptr_t, s64 time,
std::chrono::nanoseconds ns_late) -> std::optional<std::chrono::nanoseconds> {
const auto lock_guard = Lock();
Compose();
return std::max(std::chrono::nanoseconds::zero(),
std::chrono::nanoseconds(GetNextTicks()) - ns_late);
return std::chrono::nanoseconds(GetNextTicks());
});
if (system.IsMulticore()) {
system.CoreTiming().ScheduleLoopingEvent(frame_ns, frame_ns, multi_composition_event);
vsync_thread = std::jthread([this](std::stop_token token) { SplitVSync(token); });
} else {
system.CoreTiming().ScheduleLoopingEvent(frame_ns, frame_ns, composition_event);
system.CoreTiming().ScheduleLoopingEvent(frame_ns, frame_ns, single_composition_event);
}
}
NVFlinger::~NVFlinger() {
if (!system.IsMulticore()) {
system.CoreTiming().UnscheduleEvent(composition_event, 0);
if (system.IsMulticore()) {
system.CoreTiming().UnscheduleEvent(multi_composition_event, {});
vsync_thread.request_stop();
vsync_signal.store(true);
vsync_signal.notify_all();
} else {
system.CoreTiming().UnscheduleEvent(single_composition_event, {});
}
for (auto& display : displays) {

5
src/core/hle/service/nvflinger/nvflinger.h
View file

@ -126,12 +126,15 @@ private:
u32 swap_interval = 1;
/// Event that handles screen composition.
std::shared_ptr<Core::Timing::EventType> composition_event;
std::shared_ptr<Core::Timing::EventType> multi_composition_event;
std::shared_ptr<Core::Timing::EventType> single_composition_event;
std::shared_ptr<std::mutex> guard;
Core::System& system;
std::atomic<bool> vsync_signal;
std::jthread vsync_thread;
KernelHelpers::ServiceContext service_context;