Merge pull request #3396 from FernandoS27/prometheus-1

Implement SpinLocks, Fibers and a Host Timer

1 files changed, 206 insertions, 0 deletions

diff --git a/src/core/host_timing.cpp b/src/core/host_timing.cpp
new file mode 100644
index 000000000..2f40de1a1
--- /dev/null
+++ b/src/core/host_timing.cpp
@@ -0,0 +1,206 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/host_timing.h"
+
+#include <algorithm>
+#include <mutex>
+#include <string>
+#include <tuple>
+
+#include "common/assert.h"
+#include "core/core_timing_util.h"
+
+namespace Core::HostTiming {
+
+std::shared_ptr<EventType> CreateEvent(std::string name, TimedCallback&& callback) {
+    return std::make_shared<EventType>(std::move(callback), std::move(name));
+}
+
+struct CoreTiming::Event {
+    u64 time;
+    u64 fifo_order;
+    u64 userdata;
+    std::weak_ptr<EventType> type;
+
+    // Sort by time, unless the times are the same, in which case sort by
+    // the order added to the queue
+    friend bool operator>(const Event& left, const Event& right) {
+        return std::tie(left.time, left.fifo_order) > std::tie(right.time, right.fifo_order);
+    }
+
+    friend bool operator<(const Event& left, const Event& right) {
+        return std::tie(left.time, left.fifo_order) < std::tie(right.time, right.fifo_order);
+    }
+};
+
+CoreTiming::CoreTiming() {
+    clock =
+        Common::CreateBestMatchingClock(Core::Hardware::BASE_CLOCK_RATE, Core::Hardware::CNTFREQ);
+}
+
+CoreTiming::~CoreTiming() = default;
+
+void CoreTiming::ThreadEntry(CoreTiming& instance) {
+    instance.ThreadLoop();
+}
+
+void CoreTiming::Initialize() {
+    event_fifo_id = 0;
+    const auto empty_timed_callback = [](u64, s64) {};
+    ev_lost = CreateEvent("_lost_event", empty_timed_callback);
+    timer_thread = std::make_unique<std::thread>(ThreadEntry, std::ref(*this));
+}
+
+void CoreTiming::Shutdown() {
+    paused = true;
+    shutting_down = true;
+    event.Set();
+    timer_thread->join();
+    ClearPendingEvents();
+    timer_thread.reset();
+    has_started = false;
+}
+
+void CoreTiming::Pause(bool is_paused) {
+    paused = is_paused;
+}
+
+void CoreTiming::SyncPause(bool is_paused) {
+    if (is_paused == paused && paused_set == paused) {
+        return;
+    }
+    Pause(is_paused);
+    event.Set();
+    while (paused_set != is_paused)
+        ;
+}
+
+bool CoreTiming::IsRunning() const {
+    return !paused_set;
+}
+
+bool CoreTiming::HasPendingEvents() const {
+    return !(wait_set && event_queue.empty());
+}
+
+void CoreTiming::ScheduleEvent(s64 ns_into_future, const std::shared_ptr<EventType>& event_type,
+                               u64 userdata) {
+    basic_lock.lock();
+    const u64 timeout = static_cast<u64>(GetGlobalTimeNs().count() + ns_into_future);
+
+    event_queue.emplace_back(Event{timeout, event_fifo_id++, userdata, event_type});
+
+    std::push_heap(event_queue.begin(), event_queue.end(), std::greater<>());
+    basic_lock.unlock();
+    event.Set();
+}
+
+void CoreTiming::UnscheduleEvent(const std::shared_ptr<EventType>& event_type, u64 userdata) {
+    basic_lock.lock();
+    const auto itr = std::remove_if(event_queue.begin(), event_queue.end(), [&](const Event& e) {
+        return e.type.lock().get() == event_type.get() && e.userdata == userdata;
+    });
+
+    // Removing random items breaks the invariant so we have to re-establish it.
+    if (itr != event_queue.end()) {
+        event_queue.erase(itr, event_queue.end());
+        std::make_heap(event_queue.begin(), event_queue.end(), std::greater<>());
+    }
+    basic_lock.unlock();
+}
+
+void CoreTiming::AddTicks(std::size_t core_index, u64 ticks) {
+    ticks_count[core_index] += ticks;
+}
+
+void CoreTiming::ResetTicks(std::size_t core_index) {
+    ticks_count[core_index] = 0;
+}
+
+u64 CoreTiming::GetCPUTicks() const {
+    return clock->GetCPUCycles();
+}
+
+u64 CoreTiming::GetClockTicks() const {
+    return clock->GetClockCycles();
+}
+
+void CoreTiming::ClearPendingEvents() {
+    event_queue.clear();
+}
+
+void CoreTiming::RemoveEvent(const std::shared_ptr<EventType>& event_type) {
+    basic_lock.lock();
+
+    const auto itr = std::remove_if(event_queue.begin(), event_queue.end(), [&](const Event& e) {
+        return e.type.lock().get() == event_type.get();
+    });
+
+    // Removing random items breaks the invariant so we have to re-establish it.
+    if (itr != event_queue.end()) {
+        event_queue.erase(itr, event_queue.end());
+        std::make_heap(event_queue.begin(), event_queue.end(), std::greater<>());
+    }
+    basic_lock.unlock();
+}
+
+std::optional<u64> CoreTiming::Advance() {
+    advance_lock.lock();
+    basic_lock.lock();
+    global_timer = GetGlobalTimeNs().count();
+
+    while (!event_queue.empty() && event_queue.front().time <= global_timer) {
+        Event evt = std::move(event_queue.front());
+        std::pop_heap(event_queue.begin(), event_queue.end(), std::greater<>());
+        event_queue.pop_back();
+        basic_lock.unlock();
+
+        if (auto event_type{evt.type.lock()}) {
+            event_type->callback(evt.userdata, global_timer - evt.time);
+        }
+
+        basic_lock.lock();
+    }
+
+    if (!event_queue.empty()) {
+        const u64 next_time = event_queue.front().time - global_timer;
+        basic_lock.unlock();
+        advance_lock.unlock();
+        return next_time;
+    } else {
+        basic_lock.unlock();
+        advance_lock.unlock();
+        return std::nullopt;
+    }
+}
+
+void CoreTiming::ThreadLoop() {
+    has_started = true;
+    while (!shutting_down) {
+        while (!paused) {
+            paused_set = false;
+            const auto next_time = Advance();
+            if (next_time) {
+                std::chrono::nanoseconds next_time_ns = std::chrono::nanoseconds(*next_time);
+                event.WaitFor(next_time_ns);
+            } else {
+                wait_set = true;
+                event.Wait();
+            }
+            wait_set = false;
+        }
+        paused_set = true;
+    }
+}
+
+std::chrono::nanoseconds CoreTiming::GetGlobalTimeNs() const {
+    return clock->GetTimeNS();
+}
+
+std::chrono::microseconds CoreTiming::GetGlobalTimeUs() const {
+    return clock->GetTimeUS();
+}
+
+} // namespace Core::HostTiming