[Base] Add chrono support

- WinSystemClock is a FILETIME clock without scaling, can convert to
  system_time
- XSystemClock is a FILTETIME clock with scaling applied, can only
  convert to WinSystemClock

src/xenia/kernel/xboxkrnl/xboxkrnl_rtl.cc

@@ -13,6 +13,7 @@
 #include <string>
 
 #include "xenia/base/atomic.h"
+#include "xenia/base/chrono.h"
 #include "xenia/base/logging.h"
 #include "xenia/base/string.h"
 #include "xenia/base/threading.h"
@@ -21,7 +22,6 @@
 #include "xenia/kernel/util/shim_utils.h"
 #include "xenia/kernel/xboxkrnl/xboxkrnl_private.h"
 #include "xenia/kernel/xboxkrnl/xboxkrnl_threading.h"
-#include "xenia/kernel/xclock.h"
 #include "xenia/kernel/xevent.h"
 #include "xenia/kernel/xthread.h"
 
@@ -511,7 +511,10 @@ static_assert_size(X_TIME_FIELDS, 16);
 // https://docs.microsoft.com/en-us/windows-hardware/drivers/ddi/wdm/nf-wdm-rtltimetotimefields
 void RtlTimeToTimeFields_entry(lpqword_t time_ptr,
                                pointer_t<X_TIME_FIELDS> time_fields_ptr) {
-  auto tp = XClock::to_sys(XClock::from_file_time(time_ptr.value()));
+  // Use host clock because we don't want scaling to be applied, just conversion
+  using xe::chrono::WinSystemClock;
+  auto tp =
+      WinSystemClock::to_sys(WinSystemClock::from_file_time(time_ptr.value()));
   auto dp = date::floor<date::days>(tp);
   auto year_month_day = date::year_month_day{dp};
   auto weekday = date::weekday{dp};
@@ -531,6 +534,7 @@ DECLARE_XBOXKRNL_EXPORT1(RtlTimeToTimeFields, kNone, kImplemented);
 // https://docs.microsoft.com/en-us/windows-hardware/drivers/ddi/wdm/nf-wdm-rtltimefieldstotime
 dword_result_t RtlTimeFieldsToTime_entry(
     pointer_t<X_TIME_FIELDS> time_fields_ptr, lpqword_t time_ptr) {
+  using xe::chrono::WinSystemClock;
   if (time_fields_ptr->year < 1601 || time_fields_ptr->month < 1 ||
       time_fields_ptr->month > 12 || time_fields_ptr->day < 1 ||
       time_fields_ptr->day > 31 || time_fields_ptr->hour > 23 ||
@@ -551,7 +555,7 @@ dword_result_t RtlTimeFieldsToTime_entry(
   time += std::chrono::minutes{time_fields_ptr->minute};
   time += std::chrono::seconds{time_fields_ptr->second};
   time += std::chrono::milliseconds{time_fields_ptr->milliseconds};
-  *time_ptr = XClock::to_file_time(XClock::from_sys(time));
+  *time_ptr = WinSystemClock::to_file_time(WinSystemClock::from_sys(time));
   return 1;
 }
 DECLARE_XBOXKRNL_EXPORT1(RtlTimeFieldsToTime, kNone, kImplemented);

src/xenia/kernel/xclock.h

@@ -1,80 +0,0 @@
-/**
- ******************************************************************************
- * Xenia : Xbox 360 Emulator Research Project                                 *
- ******************************************************************************
- * Copyright 2020 Ben Vanik. All rights reserved.                             *
- * Released under the BSD license - see LICENSE in the root for more details. *
- ******************************************************************************
- */
-
-#ifndef XENIA_KERNEL_XCLOCK_H_
-#define XENIA_KERNEL_XCLOCK_H_
-
-#include <chrono>
-
-#include "xenia/base/clock.h"
-
-// https://github.com/HowardHinnant/date/commit/5ba1c1ad8514362dba596f228eb20eb13f63d948#r33275526
-#define HAS_UNCAUGHT_EXCEPTIONS 1
-#include "third_party/date/include/date/date.h"
-
-namespace xe {
-namespace kernel {
-
-struct XClock {
-  using rep = int64_t;
-  using period = std::ratio_multiply<std::ratio<100>, std::nano>;
-  using duration = std::chrono::duration<rep, period>;
-  using time_point = std::chrono::time_point<XClock>;
-  static constexpr bool is_steady = false;
-
-  static time_point now() noexcept {
-    return from_file_time(Clock::QueryGuestSystemTime());
-  }
-
-  static uint64_t to_file_time(time_point const& tp) noexcept {
-    return static_cast<uint64_t>(tp.time_since_epoch().count());
-  }
-
-  static time_point from_file_time(uint64_t const& tp) noexcept {
-    return time_point{duration{tp}};
-  }
-
-  static std::chrono::system_clock::time_point to_sys(time_point const& tp) {
-    // TODO(gibbed): verify behavior under Linux
-    using sys_duration = std::chrono::system_clock::duration;
-    using sys_time = std::chrono::system_clock::time_point;
-    auto dp = tp;
-    dp += system_clock_delta();
-    auto cdp = std::chrono::time_point_cast<sys_duration>(dp);
-    return sys_time{cdp.time_since_epoch()};
-  }
-
-  static time_point from_sys(std::chrono::system_clock::time_point const& tp) {
-    // TODO(gibbed): verify behavior under Linux
-    auto ctp = std::chrono::time_point_cast<duration>(tp);
-    auto dp = time_point{ctp.time_since_epoch()};
-    dp -= system_clock_delta();
-    return dp;
-  }
-
- private:
-  // The delta between std::chrono::system_clock (Jan 1 1970) and Xenon file
-  // time (Jan 1 1601), in seconds. In the spec std::chrono::system_clock's
-  // epoch is undefined, but C++20 cements it as Jan 1 1970.
-  static constexpr std::chrono::seconds system_clock_delta() {
-    auto filetime_epoch = date::year{1601} / date::month{1} / date::day{1};
-    auto system_clock_epoch = date::year{1970} / date::month{1} / date::day{1};
-    std::chrono::system_clock::time_point fp{
-        static_cast<date::sys_days>(filetime_epoch)};
-    std::chrono::system_clock::time_point sp{
-        static_cast<date::sys_days>(system_clock_epoch)};
-    return std::chrono::floor<std::chrono::seconds>(fp.time_since_epoch() -
-                                                    sp.time_since_epoch());
-  }
-};
-
-}  // namespace kernel
-}  // namespace xe
-
-#endif  // XENIA_KERNEL_XCLOCK_H_