6 files changed, 380 insertions, 418 deletions

diff --git a/src/common/logging/backend.cpp b/src/common/logging/backend.cpp
index 7ac30ad50..83ebb42d9 100644
--- a/src/common/logging/backend.cpp
+++ b/src/common/logging/backend.cpp
@@ -22,6 +22,7 @@ static std::shared_ptr<Logger> global_logger;
         SUB(Common, Memory) \
         CLS(Core) \
         SUB(Core, ARM11) \
+        SUB(Core, Timing) \
         CLS(Config) \
         CLS(Debug) \
         SUB(Debug, Emulated) \
diff --git a/src/common/logging/log.h b/src/common/logging/log.h
index 06b99b07a..bda3d633a 100644
--- a/src/common/logging/log.h
+++ b/src/common/logging/log.h
@@ -41,6 +41,7 @@ enum class Class : ClassType {
     Common_Memory,              ///< Memory mapping and management functions
     Core,                       ///< LLE emulation core
     Core_ARM11,                 ///< ARM11 CPU core
+    Core_Timing,                ///< CoreTiming functions
     Config,                     ///< Emulator configuration (including commandline)
     Debug,                      ///< Debugging tools
     Debug_Emulated,             ///< Debug messages from the emulated programs
diff --git a/src/core/arm/arm_interface.h b/src/core/arm/arm_interface.h
index 3b7209418..d3bd4a9a3 100644
--- a/src/core/arm/arm_interface.h
+++ b/src/core/arm/arm_interface.h
@@ -103,6 +103,8 @@ public:
         return num_instructions;
     }
 
+    s64 down_count; ///< A decreasing counter of remaining cycles before the next event, decreased by the cpu run loop
+
 protected:
 
     /**
diff --git a/src/core/arm/dyncom/arm_dyncom.cpp b/src/core/arm/dyncom/arm_dyncom.cpp
index a838fd25a..c779e3fd4 100644
--- a/src/core/arm/dyncom/arm_dyncom.cpp
+++ b/src/core/arm/dyncom/arm_dyncom.cpp
@@ -9,6 +9,8 @@
 #include "core/arm/dyncom/arm_dyncom.h"
 #include "core/arm/dyncom/arm_dyncom_interpreter.h"
 
+#include "core/core_timing.h"
+
 const static cpu_config_t s_arm11_cpu_info = {
     "armv6", "arm11", 0x0007b000, 0x0007f000, NONCACHE
 };
@@ -77,6 +79,9 @@ u64 ARM_DynCom::GetTicks() const {
 
 void ARM_DynCom::AddTicks(u64 ticks) {
     this->ticks += ticks;
+    down_count -= ticks;
+    if (down_count < 0)
+        CoreTiming::Advance();
 }
 
 void ARM_DynCom::ExecuteInstructions(int num_instructions) {
@@ -85,7 +90,8 @@ void ARM_DynCom::ExecuteInstructions(int num_instructions) {
     // Dyncom only breaks on instruction dispatch. This only happens on every instruction when
     // executing one instruction at a time. Otherwise, if a block is being executed, more
     // instructions may actually be executed than specified.
-    ticks += InterpreterMainLoop(state.get());
+    unsigned ticks_executed = InterpreterMainLoop(state.get());
+    AddTicks(ticks_executed);
 }
 
 void ARM_DynCom::SaveContext(ThreadContext& ctx) {
diff --git a/src/core/core_timing.cpp b/src/core/core_timing.cpp
index 321648b37..833199680 100644
--- a/src/core/core_timing.cpp
+++ b/src/core/core_timing.cpp
@@ -1,16 +1,14 @@
-// Copyright 2013 Dolphin Emulator Project / 2014 Citra Emulator Project
+// Copyright (c) 2012- PPSSPP Project / Dolphin Project.
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
-#include <vector>
-#include <cstdio>
 #include <atomic>
+#include <cstdio>
 #include <mutex>
+#include <vector>
 
 #include "common/chunk_file.h"
-#include "common/msg_handler.h"
-#include "common/string_util.h"
-
+#include "common/log.h"
 #include "core/core.h"
 #include "core/core_timing.h"
 
@@ -22,16 +20,15 @@ int g_clock_rate_arm11 = 268123480;
 
 namespace CoreTiming
 {
-
 struct EventType
 {
     EventType() {}
 
-    EventType(TimedCallback cb, const char *n)
+    EventType(TimedCallback cb, const char* n)
         : callback(cb), name(n) {}
 
     TimedCallback callback;
-    const char *name;
+    const char* name;
 };
 
 std::vector<EventType> event_types;
@@ -41,262 +38,247 @@ struct BaseEvent
     s64 time;
     u64 userdata;
     int type;
-    // Event *next;
 };
 
 typedef LinkedListItem<BaseEvent> Event;
 
-Event *first;
-Event *tsFirst;
-Event *tsLast;
+Event* first;
+Event* ts_first;
+Event* ts_last;
 
 // event pools
-Event *eventPool = 0;
-Event *eventTsPool = 0;
-int allocatedTsEvents = 0;
+Event* event_pool = 0;
+Event* event_ts_pool = 0;
+int allocated_ts_events = 0;
 // Optimization to skip MoveEvents when possible.
-std::atomic<u32> hasTsEvents;
+std::atomic<bool> has_ts_events(false);
 
-// Downcount has been moved to currentMIPS, to save a couple of clocks in every ARM JIT block
-// as we can already reach that structure through a register.
-int slicelength;
+int g_slice_length;
 
-MEMORY_ALIGNED16(s64) globalTimer;
-s64 idledCycles;
+s64 global_timer;
+s64 idled_cycles;
+s64 last_global_time_ticks;
+s64 last_global_time_us;
 
-static std::recursive_mutex externalEventSection;
+static std::recursive_mutex external_event_section;
 
 // Warning: not included in save state.
-void(*advanceCallback)(int cyclesExecuted) = nullptr;
+using AdvanceCallback = void(int cycles_executed);
+AdvanceCallback* advance_callback = nullptr;
+std::vector<MHzChangeCallback> mhz_change_callbacks;
 
-void SetClockFrequencyMHz(int cpuMhz)
-{
-    g_clock_rate_arm11 = cpuMhz * 1000000;
+void FireMhzChange() {
+    for (auto callback : mhz_change_callbacks)
+        callback();
+}
+
+void SetClockFrequencyMHz(int cpu_mhz) {
+    // When the mhz changes, we keep track of what "time" it was before hand.
+    // This way, time always moves forward, even if mhz is changed.
+    last_global_time_us = GetGlobalTimeUs();
+    last_global_time_ticks = GetTicks();
+
+    g_clock_rate_arm11 = cpu_mhz * 1000000;
     // TODO: Rescale times of scheduled events?
+
+    FireMhzChange();
 }
 
-int GetClockFrequencyMHz()
-{
+int GetClockFrequencyMHz() {
     return g_clock_rate_arm11 / 1000000;
 }
 
+u64 GetGlobalTimeUs() {
+    s64 ticks_since_last = GetTicks() - last_global_time_ticks;
+    int freq = GetClockFrequencyMHz();
+    s64 us_since_last = ticks_since_last / freq;
+    return last_global_time_us + us_since_last;
+}
 
-Event* GetNewEvent()
-{
-    if (!eventPool)
+Event* GetNewEvent() {
+    if (!event_pool)
         return new Event;
 
-    Event* ev = eventPool;
-    eventPool = ev->next;
-    return ev;
+    Event* event = event_pool;
+    event_pool = event->next;
+    return event;
 }
 
-Event* GetNewTsEvent()
-{
-    allocatedTsEvents++;
+Event* GetNewTsEvent() {
+    allocated_ts_events++;
 
-    if (!eventTsPool)
+    if (!event_ts_pool)
         return new Event;
 
-    Event* ev = eventTsPool;
-    eventTsPool = ev->next;
-    return ev;
+    Event* event = event_ts_pool;
+    event_ts_pool = event->next;
+    return event;
 }
 
-void FreeEvent(Event* ev)
-{
-    ev->next = eventPool;
-    eventPool = ev;
+void FreeEvent(Event* event) {
+    event->next = event_pool;
+    event_pool = event;
 }
 
-void FreeTsEvent(Event* ev)
-{
-    ev->next = eventTsPool;
-    eventTsPool = ev;
-    allocatedTsEvents--;
+void FreeTsEvent(Event* event) {
+    event->next = event_ts_pool;
+    event_ts_pool = event;
+    allocated_ts_events--;
 }
 
-int RegisterEvent(const char *name, TimedCallback callback)
-{
+int RegisterEvent(const char* name, TimedCallback callback) {
     event_types.push_back(EventType(callback, name));
     return (int)event_types.size() - 1;
 }
 
-void AntiCrashCallback(u64 userdata, int cyclesLate)
-{
-    LOG_CRITICAL(Core, "Savestate broken: an unregistered event was called.");
+void AntiCrashCallback(u64 userdata, int cycles_late) {
+    LOG_CRITICAL(Core_Timing, "Savestate broken: an unregistered event was called.");
     Core::Halt("invalid timing events");
 }
 
-void RestoreRegisterEvent(int event_type, const char *name, TimedCallback callback)
-{
+void RestoreRegisterEvent(int event_type, const char* name, TimedCallback callback) {
     if (event_type >= (int)event_types.size())
         event_types.resize(event_type + 1, EventType(AntiCrashCallback, "INVALID EVENT"));
 
     event_types[event_type] = EventType(callback, name);
 }
 
-void UnregisterAllEvents()
-{
+void UnregisterAllEvents() {
     if (first)
         PanicAlert("Cannot unregister events with events pending");
     event_types.clear();
 }
 
-void Init()
-{
-    //currentMIPS->downcount = INITIAL_SLICE_LENGTH;
-    //slicelength = INITIAL_SLICE_LENGTH;
-    globalTimer = 0;
-    idledCycles = 0;
-    hasTsEvents = 0;
+void Init() {
+    Core::g_app_core->down_count = INITIAL_SLICE_LENGTH;
+    g_slice_length = INITIAL_SLICE_LENGTH;
+    global_timer = 0;
+    idled_cycles = 0;
+    last_global_time_ticks = 0;
+    last_global_time_us = 0;
+    has_ts_events = 0;
+    mhz_change_callbacks.clear();
 }
 
-void Shutdown()
-{
+void Shutdown() {
     MoveEvents();
     ClearPendingEvents();
     UnregisterAllEvents();
 
-    while (eventPool)
-    {
-        Event *ev = eventPool;
-        eventPool = ev->next;
-        delete ev;
+    while (event_pool) {
+        Event* event = event_pool;
+        event_pool = event->next;
+        delete event;
     }
 
-    std::lock_guard<std::recursive_mutex> lk(externalEventSection);
-    while (eventTsPool)
-    {
-        Event *ev = eventTsPool;
-        eventTsPool = ev->next;
-        delete ev;
+    std::lock_guard<std::recursive_mutex> lock(external_event_section);
+    while (event_ts_pool) {
+        Event* event = event_ts_pool;
+        event_ts_pool = event->next;
+        delete event;
     }
 }
 
-u64 GetTicks()
-{
-    LOG_ERROR(Core, "Unimplemented function!");
-    return 0;
-    //return (u64)globalTimer + slicelength - currentMIPS->downcount;
+u64 GetTicks() {
+    return (u64)global_timer + g_slice_length - Core::g_app_core->down_count;
 }
 
-u64 GetIdleTicks()
-{
-    return (u64)idledCycles;
+u64 GetIdleTicks() {
+    return (u64)idled_cycles;
 }
 
 
 // This is to be called when outside threads, such as the graphics thread, wants to
 // schedule things to be executed on the main thread.
-void ScheduleEvent_Threadsafe(s64 cyclesIntoFuture, int event_type, u64 userdata)
-{
-    std::lock_guard<std::recursive_mutex> lk(externalEventSection);
-    Event *ne = GetNewTsEvent();
-    ne->time = GetTicks() + cyclesIntoFuture;
-    ne->type = event_type;
-    ne->next = 0;
-    ne->userdata = userdata;
-    if (!tsFirst)
-        tsFirst = ne;
-    if (tsLast)
-        tsLast->next = ne;
-    tsLast = ne;
-
-    hasTsEvents.store(1, std::memory_order_release);
+void ScheduleEvent_Threadsafe(s64 cycles_into_future, int event_type, u64 userdata) {
+    std::lock_guard<std::recursive_mutex> lock(external_event_section);
+    Event* new_event = GetNewTsEvent();
+    new_event->time = GetTicks() + cycles_into_future;
+    new_event->type = event_type;
+    new_event->next = 0;
+    new_event->userdata = userdata;
+    if (!ts_first)
+        ts_first = new_event;
+    if (ts_last)
+        ts_last->next = new_event;
+    ts_last = new_event;
+
+    has_ts_events = true;
 }
 
 // Same as ScheduleEvent_Threadsafe(0, ...) EXCEPT if we are already on the CPU thread
 // in which case the event will get handled immediately, before returning.
-void ScheduleEvent_Threadsafe_Immediate(int event_type, u64 userdata)
-{
+void ScheduleEvent_Threadsafe_Immediate(int event_type, u64 userdata) {
     if (false) //Core::IsCPUThread())
     {
-        std::lock_guard<std::recursive_mutex> lk(externalEventSection);
+        std::lock_guard<std::recursive_mutex> lock(external_event_section);
         event_types[event_type].callback(userdata, 0);
     }
     else
         ScheduleEvent_Threadsafe(0, event_type, userdata);
 }
 
-void ClearPendingEvents()
-{
-    while (first)
-    {
-        Event *e = first->next;
+void ClearPendingEvents() {
+    while (first) {
+        Event* event = first->next;
         FreeEvent(first);
-        first = e;
+        first = event;
     }
 }
 
-void AddEventToQueue(Event* ne)
-{
-    Event* prev = nullptr;
-    Event** pNext = &first;
-    for (;;)
-    {
-        Event*& next = *pNext;
-        if (!next || ne->time < next->time)
-        {
-            ne->next = next;
-            next = ne;
+void AddEventToQueue(Event* new_event) {
+    Event* prev_event = nullptr;
+    Event** next_event = &first;
+    for (;;) {
+        Event*& next = *next_event;
+        if (!next || new_event->time < next->time) {
+            new_event->next = next;
+            next = new_event;
             break;
         }
-        prev = next;
-        pNext = &prev->next;
+        prev_event = next;
+        next_event = &prev_event->next;
     }
 }
 
-// This must be run ONLY from within the cpu thread
-// cyclesIntoFuture may be VERY inaccurate if called from anything else
-// than Advance
-void ScheduleEvent(s64 cyclesIntoFuture, int event_type, u64 userdata)
-{
-    Event *ne = GetNewEvent();
-    ne->userdata = userdata;
-    ne->type = event_type;
-    ne->time = GetTicks() + cyclesIntoFuture;
-    AddEventToQueue(ne);
+void ScheduleEvent(s64 cycles_into_future, int event_type, u64 userdata) {
+    Event* new_event = GetNewEvent();
+    new_event->userdata = userdata;
+    new_event->type = event_type;
+    new_event->time = GetTicks() + cycles_into_future;
+    AddEventToQueue(new_event);
 }
 
-// Returns cycles left in timer.
-s64 UnscheduleEvent(int event_type, u64 userdata)
-{
+s64 UnscheduleEvent(int event_type, u64 userdata) {
     s64 result = 0;
     if (!first)
         return result;
-    while (first)
-    {
-        if (first->type == event_type && first->userdata == userdata)
-        {
-            result = first->time - globalTimer;
+    while (first) {
+        if (first->type == event_type && first->userdata == userdata) {
+            result = first->time - GetTicks();
 
-            Event *next = first->next;
+            Event* next = first->next;
             FreeEvent(first);
             first = next;
-        }
-        else
-        {
+        } else {
             break;
         }
     }
     if (!first)
         return result;
-    Event *prev = first;
-    Event *ptr = prev->next;
-    while (ptr)
-    {
-        if (ptr->type == event_type && ptr->userdata == userdata)
-        {
-            result = ptr->time - globalTimer;
 
-            prev->next = ptr->next;
+    Event* prev_event = first;
+    Event* ptr = prev_event->next;
+
+    while (ptr) {
+        if (ptr->type == event_type && ptr->userdata == userdata) {
+            result = ptr->time - GetTicks();
+
+            prev_event->next = ptr->next;
             FreeEvent(ptr);
-            ptr = prev->next;
-        }
-        else
-        {
-            prev = ptr;
+            ptr = prev_event->next;
+        } else {
+            prev_event = ptr;
             ptr = ptr->next;
         }
     }
@@ -304,51 +286,44 @@ s64 UnscheduleEvent(int event_type, u64 userdata)
     return result;
 }
 
-s64 UnscheduleThreadsafeEvent(int event_type, u64 userdata)
-{
+s64 UnscheduleThreadsafeEvent(int event_type, u64 userdata) {
     s64 result = 0;
-    std::lock_guard<std::recursive_mutex> lk(externalEventSection);
-    if (!tsFirst)
+    std::lock_guard<std::recursive_mutex> lock(external_event_section);
+    if (!ts_first)
         return result;
-    while (tsFirst)
-    {
-        if (tsFirst->type == event_type && tsFirst->userdata == userdata)
-        {
-            result = tsFirst->time - globalTimer;
 
-            Event *next = tsFirst->next;
-            FreeTsEvent(tsFirst);
-            tsFirst = next;
-        }
-        else
-        {
+    while (ts_first) {
+        if (ts_first->type == event_type && ts_first->userdata == userdata) {
+            result = ts_first->time - GetTicks();
+
+            Event* next = ts_first->next;
+            FreeTsEvent(ts_first);
+            ts_first = next;
+        } else {
             break;
         }
     }
-    if (!tsFirst)
+
+    if (!ts_first)
     {
-        tsLast = nullptr;
+        ts_last = nullptr;
         return result;
     }
 
-    Event *prev = tsFirst;
-    Event *ptr = prev->next;
-    while (ptr)
-    {
-        if (ptr->type == event_type && ptr->userdata == userdata)
-        {
-            result = ptr->time - globalTimer;
-
-            prev->next = ptr->next;
-            if (ptr == tsLast)
-                tsLast = prev;
-            FreeTsEvent(ptr);
-            ptr = prev->next;
-        }
-        else
-        {
-            prev = ptr;
-            ptr = ptr->next;
+    Event* prev_event = ts_first;
+    Event* next = prev_event->next;
+    while (next) {
+        if (next->type == event_type && next->userdata == userdata) {
+            result = next->time - GetTicks();
+
+            prev_event->next = next->next;
+            if (next == ts_last)
+                ts_last = prev_event;
+            FreeTsEvent(next);
+            next = prev_event->next;
+        } else {
+            prev_event = next;
+            next = next->next;
         }
     }
 
@@ -356,271 +331,217 @@ s64 UnscheduleThreadsafeEvent(int event_type, u64 userdata)
 }
 
 // Warning: not included in save state.
-void RegisterAdvanceCallback(void(*callback)(int cyclesExecuted))
-{
-    advanceCallback = callback;
+void RegisterAdvanceCallback(AdvanceCallback* callback) {
+    advance_callback = callback;
 }
 
-bool IsScheduled(int event_type)
-{
+void RegisterMHzChangeCallback(MHzChangeCallback callback) {
+    mhz_change_callbacks.push_back(callback);
+}
+
+bool IsScheduled(int event_type) {
     if (!first)
         return false;
-    Event *e = first;
-    while (e) {
-        if (e->type == event_type)
+    Event* event = first;
+    while (event) {
+        if (event->type == event_type)
             return true;
-        e = e->next;
+        event = event->next;
     }
     return false;
 }
 
-void RemoveEvent(int event_type)
-{
+void RemoveEvent(int event_type) {
     if (!first)
         return;
-    while (first)
-    {
-        if (first->type == event_type)
-        {
+    while (first) {
+        if (first->type == event_type) {
             Event *next = first->next;
             FreeEvent(first);
             first = next;
-        }
-        else
-        {
+        } else {
             break;
         }
     }
     if (!first)
         return;
-    Event *prev = first;
-    Event *ptr = prev->next;
-    while (ptr)
-    {
-        if (ptr->type == event_type)
-        {
-            prev->next = ptr->next;
-            FreeEvent(ptr);
-            ptr = prev->next;
-        }
-        else
-        {
-            prev = ptr;
-            ptr = ptr->next;
+    Event* prev = first;
+    Event* next = prev->next;
+    while (next) {
+        if (next->type == event_type) {
+            prev->next = next->next;
+            FreeEvent(next);
+            next = prev->next;
+        } else {
+            prev = next;
+            next = next->next;
         }
     }
 }
 
-void RemoveThreadsafeEvent(int event_type)
-{
-    std::lock_guard<std::recursive_mutex> lk(externalEventSection);
-    if (!tsFirst)
-    {
+void RemoveThreadsafeEvent(int event_type) {
+    std::lock_guard<std::recursive_mutex> lock(external_event_section);
+    if (!ts_first)
         return;
-    }
-    while (tsFirst)
-    {
-        if (tsFirst->type == event_type)
-        {
-            Event *next = tsFirst->next;
-            FreeTsEvent(tsFirst);
-            tsFirst = next;
-        }
-        else
-        {
+
+    while (ts_first) {
+        if (ts_first->type == event_type) {
+            Event* next = ts_first->next;
+            FreeTsEvent(ts_first);
+            ts_first = next;
+        } else {
             break;
         }
     }
-    if (!tsFirst)
-    {
-        tsLast = nullptr;
+
+    if (!ts_first) {
+        ts_last = nullptr;
         return;
     }
-    Event *prev = tsFirst;
-    Event *ptr = prev->next;
-    while (ptr)
-    {
-        if (ptr->type == event_type)
-        {
-            prev->next = ptr->next;
-            if (ptr == tsLast)
-                tsLast = prev;
-            FreeTsEvent(ptr);
-            ptr = prev->next;
-        }
-        else
-        {
-            prev = ptr;
-            ptr = ptr->next;
+
+    Event* prev = ts_first;
+    Event* next = prev->next;
+    while (next) {
+        if (next->type == event_type) {
+            prev->next = next->next;
+            if (next == ts_last)
+                ts_last = prev;
+            FreeTsEvent(next);
+            next = prev->next;
+        } else {
+            prev = next;
+            next = next->next;
         }
     }
 }
 
-void RemoveAllEvents(int event_type)
-{
+void RemoveAllEvents(int event_type) {
     RemoveThreadsafeEvent(event_type);
     RemoveEvent(event_type);
 }
 
-//This raise only the events required while the fifo is processing data
-void ProcessFifoWaitEvents()
-{
-    while (first)
-    {
-        if (first->time <= globalTimer)
-        {
-            //LOG(TIMER, "[Scheduler] %s (%lld, %lld) ",
-            //    first->name ? first->name : "?", (u64)globalTimer, (u64)first->time);
+// This raise only the events required while the fifo is processing data
+void ProcessFifoWaitEvents() {
+    while (first) {
+        if (first->time <= (s64)GetTicks()) {
             Event* evt = first;
             first = first->next;
-            event_types[evt->type].callback(evt->userdata, (int)(globalTimer - evt->time));
+            event_types[evt->type].callback(evt->userdata, (int)(GetTicks() - evt->time));
             FreeEvent(evt);
-        }
-        else
-        {
+        } else {
             break;
         }
     }
 }
 
-void MoveEvents()
-{
-    hasTsEvents.store(0, std::memory_order_release);
+void MoveEvents() {
+    has_ts_events = false;
 
-    std::lock_guard<std::recursive_mutex> lk(externalEventSection);
+    std::lock_guard<std::recursive_mutex> lock(external_event_section);
     // Move events from async queue into main queue
-    while (tsFirst)
-    {
-        Event *next = tsFirst->next;
-        AddEventToQueue(tsFirst);
-        tsFirst = next;
+    while (ts_first) {
+        Event* next = ts_first->next;
+        AddEventToQueue(ts_first);
+        ts_first = next;
     }
-    tsLast = nullptr;
+    ts_last = nullptr;
 
     // Move free events to threadsafe pool
-    while (allocatedTsEvents > 0 && eventPool)
-    {
-        Event *ev = eventPool;
-        eventPool = ev->next;
-        ev->next = eventTsPool;
-        eventTsPool = ev;
-        allocatedTsEvents--;
+    while (allocated_ts_events > 0 && event_pool) {
+        Event* event = event_pool;
+        event_pool = event->next;
+        event->next = event_ts_pool;
+        event_ts_pool = event;
+        allocated_ts_events--;
     }
 }
 
-void Advance()
-{
-    LOG_ERROR(Core, "Unimplemented function!");
-    //int cyclesExecuted = slicelength - currentMIPS->downcount;
-    //globalTimer += cyclesExecuted;
-    //currentMIPS->downcount = slicelength;
-
-    //if (Common::AtomicLoadAcquire(hasTsEvents))
-    //    MoveEvents();
-    //ProcessFifoWaitEvents();
-
-    //if (!first)
-    //{
-    //    // WARN_LOG(TIMER, "WARNING - no events in queue. Setting currentMIPS->downcount to 10000");
-    //    currentMIPS->downcount += 10000;
-    //}
-    //else
-    //{
-    //    slicelength = (int)(first->time - globalTimer);
-    //    if (slicelength > MAX_SLICE_LENGTH)
-    //        slicelength = MAX_SLICE_LENGTH;
-    //    currentMIPS->downcount = slicelength;
-    //}
-    //if (advanceCallback)
-    //    advanceCallback(cyclesExecuted);
-}
-
-void LogPendingEvents()
-{
-    Event *ptr = first;
-    while (ptr)
-    {
-        //INFO_LOG(TIMER, "PENDING: Now: %lld Pending: %lld Type: %d", globalTimer, ptr->time, ptr->type);
-        ptr = ptr->next;
-    }
+void ForceCheck() {
+    int cycles_executed = g_slice_length - Core::g_app_core->down_count;
+    global_timer += cycles_executed;
+    // This will cause us to check for new events immediately.
+    Core::g_app_core->down_count = 0;
+    // But let's not eat a bunch more time in Advance() because of this.
+    g_slice_length = 0;
 }
 
-void Idle(int maxIdle)
-{
-    LOG_ERROR(Core, "Unimplemented function!");
-    //int cyclesDown = currentMIPS->downcount;
-    //if (maxIdle != 0 && cyclesDown > maxIdle)
-    //    cyclesDown = maxIdle;
-
-    //if (first && cyclesDown > 0)
-    //{
-    //    int cyclesExecuted = slicelength - currentMIPS->downcount;
-    //    int cyclesNextEvent = (int) (first->time - globalTimer);
-
-    //    if (cyclesNextEvent < cyclesExecuted + cyclesDown)
-    //    {
-    //        cyclesDown = cyclesNextEvent - cyclesExecuted;
-    //        // Now, now... no time machines, please.
-    //        if (cyclesDown < 0)
-    //            cyclesDown = 0;
-    //    }
-    //}
-
-    //INFO_LOG(TIME, "Idle for %i cycles! (%f ms)", cyclesDown, cyclesDown / (float)(g_clock_rate_arm11 * 0.001f));
-
-    //idledCycles += cyclesDown;
-    //currentMIPS->downcount -= cyclesDown;
-    //if (currentMIPS->downcount == 0)
-    //    currentMIPS->downcount = -1;
-}
-
-std::string GetScheduledEventsSummary()
-{
-    Event *ptr = first;
-    std::string text = "Scheduled events\n";
-    text.reserve(1000);
-    while (ptr)
-    {
-        unsigned int t = ptr->type;
-        if (t >= event_types.size())
-            PanicAlert("Invalid event type"); // %i", t);
-        const char *name = event_types[ptr->type].name;
-        if (!name)
-            name = "[unknown]";
+void Advance() {
+    int cycles_executed = g_slice_length - Core::g_app_core->down_count;
+    global_timer += cycles_executed;
+    Core::g_app_core->down_count = g_slice_length;
 
-        text += Common::StringFromFormat("%s : %i %08x%08x\n", name, (int)ptr->time,
-                                        (u32)(ptr->userdata >> 32), (u32)(ptr->userdata));
+    if (has_ts_events)
+        MoveEvents();
+    ProcessFifoWaitEvents();
 
-        ptr = ptr->next;
+    if (!first) {
+        if (g_slice_length < 10000) {
+            g_slice_length += 10000;
+            Core::g_app_core->down_count += g_slice_length;
+        }
+    } else {
+        // Note that events can eat cycles as well.
+        int target = (int)(first->time - global_timer);
+        if (target > MAX_SLICE_LENGTH)
+            target = MAX_SLICE_LENGTH;
+
+        const int diff = target - g_slice_length;
+        g_slice_length += diff;
+        Core::g_app_core->down_count += diff;
     }
-    return text;
+    if (advance_callback)
+        advance_callback(cycles_executed);
 }
 
-void Event_DoState(PointerWrap &p, BaseEvent *ev)
-{
-    p.Do(*ev);
+void LogPendingEvents() {
+    Event* event = first;
+    while (event) {
+        //LOG_TRACE(Core_Timing, "PENDING: Now: %lld Pending: %lld Type: %d", globalTimer, next->time, next->type);
+        event = event->next;
+    }
 }
 
-void DoState(PointerWrap &p)
-{
-    std::lock_guard<std::recursive_mutex> lk(externalEventSection);
+void Idle(int max_idle) {
+    int cycles_down = Core::g_app_core->down_count;
+    if (max_idle != 0 && cycles_down > max_idle)
+        cycles_down = max_idle;
 
-    auto s = p.Section("CoreTiming", 1);
-    if (!s)
-        return;
+    if (first && cycles_down > 0) {
+        int cycles_executed = g_slice_length - Core::g_app_core->down_count;
+        int cycles_next_event = (int)(first->time - global_timer);
 
-    int n = (int)event_types.size();
-    p.Do(n);
-    // These (should) be filled in later by the modules.
-    event_types.resize(n, EventType(AntiCrashCallback, "INVALID EVENT"));
+        if (cycles_next_event < cycles_executed + cycles_down) {
+            cycles_down = cycles_next_event - cycles_executed;
+            // Now, now... no time machines, please.
+            if (cycles_down < 0)
+                cycles_down = 0;
+        }
+    }
 
-    p.DoLinkedList<BaseEvent, GetNewEvent, FreeEvent, Event_DoState>(first, (Event **)nullptr);
-    p.DoLinkedList<BaseEvent, GetNewTsEvent, FreeTsEvent, Event_DoState>(tsFirst, &tsLast);
+    LOG_TRACE(Core_Timing, "Idle for %i cycles! (%f ms)", cycles_down, cycles_down / (float)(g_clock_rate_arm11 * 0.001f));
 
-    p.Do(g_clock_rate_arm11);
-    p.Do(slicelength);
-    p.Do(globalTimer);
-    p.Do(idledCycles);
+    idled_cycles += cycles_down;
+    Core::g_app_core->down_count -= cycles_down;
+    if (Core::g_app_core->down_count == 0)
+        Core::g_app_core->down_count = -1;
+}
+
+std::string GetScheduledEventsSummary() {
+    Event* event = first;
+    std::string text = "Scheduled events\n";
+    text.reserve(1000);
+    while (event) {
+        unsigned int t = event->type;
+        if (t >= event_types.size())
+            PanicAlert("Invalid event type"); // %i", t);
+        const char* name = event_types[event->type].name;
+        if (!name)
+            name = "[unknown]";
+        text += Common::StringFromFormat("%s : %i %08x%08x\n", name, (int)event->time, 
+                (u32)(event->userdata >> 32), (u32)(event->userdata));
+        event = event->next;
+    }
+    return text;
 }
 
 } // namespace
diff --git a/src/core/core_timing.h b/src/core/core_timing.h
index 496234538..d62ff3604 100644
--- a/src/core/core_timing.h
+++ b/src/core/core_timing.h
@@ -1,9 +1,11 @@
-// Copyright 2013 Dolphin Emulator Project / 2014 Citra Emulator Project
+// Copyright (c) 2012- PPSSPP Project / Dolphin Project.
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
 #pragma once
 
+#include <string>
+
 // This is a system to schedule events into the emulated machine's future. Time is measured
 // in main CPU clock cycles.
 
@@ -12,14 +14,14 @@
 
 // See HW/SystemTimers.cpp for the main part of Dolphin's usage of this scheduler.
 
-// The int cyclesLate that the callbacks get is how many cycles late it was.
+// The int cycles_late that the callbacks get is how many cycles late it was.
 // So to schedule a new event on a regular basis:
 // inside callback:
-//   ScheduleEvent(periodInCycles - cyclesLate, callback, "whatever")
+//   ScheduleEvent(periodInCycles - cycles_late, callback, "whatever")
 
-#include "common/common.h"
+#include <functional>
 
-class PointerWrap;
+#include "common/common.h"
 
 extern int g_clock_rate_arm11;
 
@@ -55,55 +57,84 @@ inline s64 cyclesToUs(s64 cycles) {
     return cycles / (g_clock_rate_arm11 / 1000000);
 }
 
-namespace CoreTiming {
+inline u64 cyclesToMs(s64 cycles) {
+    return cycles / (g_clock_rate_arm11 / 1000);
+}
 
+namespace CoreTiming
+{
 void Init();
 void Shutdown();
 
-typedef void(*TimedCallback)(u64 userdata, int cyclesLate);
+typedef void(*MHzChangeCallback)();
+typedef std::function<void(u64 userdata, int cycles_late)> TimedCallback;
 
 u64 GetTicks();
 u64 GetIdleTicks();
-
-// Returns the event_type identifier.
-int RegisterEvent(const char *name, TimedCallback callback);
-// For save states.
+u64 GetGlobalTimeUs();
+
+/**
+ * Registers an event type with the specified name and callback
+ * @param name Name of the event type
+ * @param callback Function that will execute when this event fires
+ * @returns An identifier for the event type that was registered
+ */
+int RegisterEvent(const char* name, TimedCallback callback);
+/// For save states.
 void RestoreRegisterEvent(int event_type, const char *name, TimedCallback callback);
 void UnregisterAllEvents();
 
-// userdata MAY NOT CONTAIN POINTERS. userdata might get written and reloaded from disk,
-// when we implement state saves.
-void ScheduleEvent(s64 cyclesIntoFuture, int event_type, u64 userdata = 0);
-void ScheduleEvent_Threadsafe(s64 cyclesIntoFuture, int event_type, u64 userdata = 0);
+/// userdata MAY NOT CONTAIN POINTERS. userdata might get written and reloaded from disk,
+/// when we implement state saves.
+/**
+ * Schedules an event to run after the specified number of cycles, 
+ * with an optional parameter to be passed to the callback handler.
+ * This must be run ONLY from within the cpu thread.
+ * @param cycles_into_future The number of cycles after which this event will be fired
+ * @param event_type The event type to fire, as returned from RegisterEvent
+ * @param userdata Optional parameter to pass to the callback when fired
+ */
+void ScheduleEvent(s64 cycles_into_future, int event_type, u64 userdata = 0);
+
+void ScheduleEvent_Threadsafe(s64 cycles_into_future, int event_type, u64 userdata = 0);
 void ScheduleEvent_Threadsafe_Immediate(int event_type, u64 userdata = 0);
+
+/**
+ * Unschedules an event with the specified type and userdata
+ * @param event_type The type of event to unschedule, as returned from RegisterEvent
+ * @param userdata The userdata that identifies this event, as passed to ScheduleEvent
+ * @returns The remaining ticks until the next invocation of the event callback
+ */
 s64 UnscheduleEvent(int event_type, u64 userdata);
+
 s64 UnscheduleThreadsafeEvent(int event_type, u64 userdata);
 
 void RemoveEvent(int event_type);
 void RemoveThreadsafeEvent(int event_type);
 void RemoveAllEvents(int event_type);
 bool IsScheduled(int event_type);
+/// Runs any pending events and updates downcount for the next slice of cycles
 void Advance();
 void MoveEvents();
 void ProcessFifoWaitEvents();
+void ForceCheck();
 
-// Pretend that the main CPU has executed enough cycles to reach the next event.
+/// Pretend that the main CPU has executed enough cycles to reach the next event.
 void Idle(int maxIdle = 0);
 
-// Clear all pending events. This should ONLY be done on exit or state load.
+/// Clear all pending events. This should ONLY be done on exit or state load.
 void ClearPendingEvents();
 
 void LogPendingEvents();
 
-// Warning: not included in save states.
-void RegisterAdvanceCallback(void(*callback)(int cyclesExecuted));
+/// Warning: not included in save states.
+void RegisterAdvanceCallback(void(*callback)(int cycles_executed));
+void RegisterMHzChangeCallback(MHzChangeCallback callback);
 
 std::string GetScheduledEventsSummary();
 
-void DoState(PointerWrap &p);
-
-void SetClockFrequencyMHz(int cpuMhz);
+void SetClockFrequencyMHz(int cpu_mhz);
 int GetClockFrequencyMHz();
-extern int slicelength;
+extern int g_slice_length;
 
 } // namespace