Make Time functions go through the Platform layer.

src/platform/time.cc

Index: src/platform/time.cc
diff --git a/src/platform/time.cc b/src/platform/time.cc
index de0ca16473f6b5106485508653cfe797f6632c37..667ec854745cb0cc8d65d51a30d22f5e4cd7116d 100644
--- a/src/platform/time.cc
+++ b/src/platform/time.cc
@@ -37,8 +37,8 @@
 #include <cstring>
 
 #include "checks.h"
-#include "cpu.h"
 #include "platform.h"
+#include "v8.h"
 #if V8_OS_WIN
 #include "win32-headers.h"
 #endif
@@ -160,76 +160,16 @@ struct timespec TimeDelta::ToTimespec() const {
 
 #endif  // V8_OS_POSIX
 
-
-#if V8_OS_WIN
-
-// We implement time using the high-resolution timers so that we can get
-// timeouts which are smaller than 10-15ms. To avoid any drift, we
-// periodically resync the internal clock to the system clock.
-class Clock V8_FINAL {
- public:
-  Clock() : initial_ticks_(GetSystemTicks()), initial_time_(GetSystemTime()) {}
-
-  Time Now() {
-    // Time between resampling the un-granular clock for this API (1 minute).
-    const TimeDelta kMaxElapsedTime = TimeDelta::FromMinutes(1);
-
-    LockGuard<Mutex> lock_guard(&mutex_);
-
-    // Determine current time and ticks.
-    TimeTicks ticks = GetSystemTicks();
-    Time time = GetSystemTime();
-
-    // Check if we need to synchronize with the system clock due to a backwards
-    // time change or the amount of time elapsed.
-    TimeDelta elapsed = ticks - initial_ticks_;
-    if (time < initial_time_ || elapsed > kMaxElapsedTime) {
-      initial_ticks_ = ticks;
-      initial_time_ = time;
-      return time;
-    }
-
-    return initial_time_ + elapsed;
-  }
-
-  Time NowFromSystemTime() {
-    LockGuard<Mutex> lock_guard(&mutex_);
-    initial_ticks_ = GetSystemTicks();
-    initial_time_ = GetSystemTime();
-    return initial_time_;
-  }
-
- private:
-  static TimeTicks GetSystemTicks() {
-    return TimeTicks::Now();
-  }
-
-  static Time GetSystemTime() {
-    FILETIME ft;
-    ::GetSystemTimeAsFileTime(&ft);
-    return Time::FromFiletime(ft);
-  }
-
-  TimeTicks initial_ticks_;
-  Time initial_time_;
-  Mutex mutex_;
-};
-
-
-static LazyStaticInstance<Clock,
-    DefaultConstructTrait<Clock>,
-    ThreadSafeInitOnceTrait>::type clock = LAZY_STATIC_INSTANCE_INITIALIZER;
-
-
 Time Time::Now() {
-  return clock.Pointer()->Now();
+  return Time(V8::GetCurrentPlatform()->CurrentTime());
 }
 
 
 Time Time::NowFromSystemTime() {
-  return clock.Pointer()->NowFromSystemTime();
+  return Time(V8::GetCurrentPlatform()->CurrentTimeFromSystemTime());
 }
 
+#if V8_OS_WIN
 
 // Time between windows epoch and standard epoch.
 static const int64_t kTimeToEpochInMicroseconds = V8_INT64_C(11644473600000000);
@@ -270,20 +210,6 @@ FILETIME Time::ToFiletime() const {
 
 #elif V8_OS_POSIX
 
-Time Time::Now() {
-  struct timeval tv;
-  int result = gettimeofday(&tv, NULL);
-  ASSERT_EQ(0, result);
-  USE(result);
-  return FromTimeval(tv);
-}
-
-
-Time Time::NowFromSystemTime() {
-  return Now();
-}
-
-
 Time Time::FromTimespec(struct timespec ts) {
   ASSERT(ts.tv_nsec >= 0);
   ASSERT(ts.tv_nsec < static_cast<long>(kNanosecondsPerSecond));  // NOLINT
@@ -375,160 +301,18 @@ double Time::ToJsTime() const {
 }
 
 
-#if V8_OS_WIN
-
-class TickClock {
- public:
-  virtual ~TickClock() {}
-  virtual int64_t Now() = 0;
-  virtual bool IsHighResolution() = 0;
-};
-
-
-// Overview of time counters:
-// (1) CPU cycle counter. (Retrieved via RDTSC)
-// The CPU counter provides the highest resolution time stamp and is the least
-// expensive to retrieve. However, the CPU counter is unreliable and should not
-// be used in production. Its biggest issue is that it is per processor and it
-// is not synchronized between processors. Also, on some computers, the counters
-// will change frequency due to thermal and power changes, and stop in some
-// states.
-//
-// (2) QueryPerformanceCounter (QPC). The QPC counter provides a high-
-// resolution (100 nanoseconds) time stamp but is comparatively more expensive
-// to retrieve. What QueryPerformanceCounter actually does is up to the HAL.
-// (with some help from ACPI).
-// According to http://blogs.msdn.com/oldnewthing/archive/2005/09/02/459952.aspx
-// in the worst case, it gets the counter from the rollover interrupt on the
-// programmable interrupt timer. In best cases, the HAL may conclude that the
-// RDTSC counter runs at a constant frequency, then it uses that instead. On
-// multiprocessor machines, it will try to verify the values returned from
-// RDTSC on each processor are consistent with each other, and apply a handful
-// of workarounds for known buggy hardware. In other words, QPC is supposed to
-// give consistent result on a multiprocessor computer, but it is unreliable in
-// reality due to bugs in BIOS or HAL on some, especially old computers.
-// With recent updates on HAL and newer BIOS, QPC is getting more reliable but
-// it should be used with caution.
-//
-// (3) System time. The system time provides a low-resolution (typically 10ms
-// to 55 milliseconds) time stamp but is comparatively less expensive to
-// retrieve and more reliable.
-class HighResolutionTickClock V8_FINAL : public TickClock {
- public:
-  explicit HighResolutionTickClock(int64_t ticks_per_second)
-      : ticks_per_second_(ticks_per_second) {
-    ASSERT_LT(0, ticks_per_second);
-  }
-  virtual ~HighResolutionTickClock() {}
-
-  virtual int64_t Now() V8_OVERRIDE {
-    LARGE_INTEGER now;
-    BOOL result = QueryPerformanceCounter(&now);
-    ASSERT(result);
-    USE(result);
-
-    // Intentionally calculate microseconds in a round about manner to avoid
-    // overflow and precision issues. Think twice before simplifying!
-    int64_t whole_seconds = now.QuadPart / ticks_per_second_;
-    int64_t leftover_ticks = now.QuadPart % ticks_per_second_;
-    int64_t ticks = (whole_seconds * Time::kMicrosecondsPerSecond) +
-        ((leftover_ticks * Time::kMicrosecondsPerSecond) / ticks_per_second_);
-
-    // Make sure we never return 0 here, so that TimeTicks::HighResolutionNow()
-    // will never return 0.
-    return ticks + 1;
-  }
-
-  virtual bool IsHighResolution() V8_OVERRIDE {
-    return true;
-  }
-
- private:
-  int64_t ticks_per_second_;
-};
-
-
-class RolloverProtectedTickClock V8_FINAL : public TickClock {
- public:
-  // We initialize rollover_ms_ to 1 to ensure that we will never
-  // return 0 from TimeTicks::HighResolutionNow() and TimeTicks::Now() below.
-  RolloverProtectedTickClock() : last_seen_now_(0), rollover_ms_(1) {}
-  virtual ~RolloverProtectedTickClock() {}
-
-  virtual int64_t Now() V8_OVERRIDE {
-    LockGuard<Mutex> lock_guard(&mutex_);
-    // We use timeGetTime() to implement TimeTicks::Now(), which rolls over
-    // every ~49.7 days. We try to track rollover ourselves, which works if
-    // TimeTicks::Now() is called at least every 49 days.
-    // Note that we do not use GetTickCount() here, since timeGetTime() gives
-    // more predictable delta values, as described here:
-    // http://blogs.msdn.com/b/larryosterman/archive/2009/09/02/what-s-the-difference-between-gettickcount-and-timegettime.aspx
-    // timeGetTime() provides 1ms granularity when combined with
-    // timeBeginPeriod(). If the host application for V8 wants fast timers, it
-    // can use timeBeginPeriod() to increase the resolution.
-    DWORD now = timeGetTime();
-    if (now < last_seen_now_) {
-      rollover_ms_ += V8_INT64_C(0x100000000);  // ~49.7 days.
-    }
-    last_seen_now_ = now;
-    return (now + rollover_ms_) * Time::kMicrosecondsPerMillisecond;
-  }
-
-  virtual bool IsHighResolution() V8_OVERRIDE {
-    return false;
-  }
-
- private:
-  Mutex mutex_;
-  DWORD last_seen_now_;
-  int64_t rollover_ms_;
-};
-
-
-static LazyStaticInstance<RolloverProtectedTickClock,
-    DefaultConstructTrait<RolloverProtectedTickClock>,
-    ThreadSafeInitOnceTrait>::type tick_clock =
-        LAZY_STATIC_INSTANCE_INITIALIZER;
-
-
-struct CreateHighResTickClockTrait {
-  static TickClock* Create() {
-    // Check if the installed hardware supports a high-resolution performance
-    // counter, and if not fallback to the low-resolution tick clock.
-    LARGE_INTEGER ticks_per_second;
-    if (!QueryPerformanceFrequency(&ticks_per_second)) {
-      return tick_clock.Pointer();
-    }
-
-    // On Athlon X2 CPUs (e.g. model 15) the QueryPerformanceCounter
-    // is unreliable, fallback to the low-resolution tick clock.
-    CPU cpu;
-    if (strcmp(cpu.vendor(), "AuthenticAMD") == 0 && cpu.family() == 15) {
-      return tick_clock.Pointer();
-    }
-
-    return new HighResolutionTickClock(ticks_per_second.QuadPart);
-  }
-};
-
-
-static LazyDynamicInstance<TickClock,
-    CreateHighResTickClockTrait,
-    ThreadSafeInitOnceTrait>::type high_res_tick_clock =
-        LAZY_DYNAMIC_INSTANCE_INITIALIZER;
-
-
 TimeTicks TimeTicks::Now() {
+  TimeTicks ticks = TimeTicks(i::V8::GetCurrentPlatform()->TimeTicksNow());
   // Make sure we never return 0 here.
-  TimeTicks ticks(tick_clock.Pointer()->Now());
   ASSERT(!ticks.IsNull());
   return ticks;
 }
 
 
 TimeTicks TimeTicks::HighResolutionNow() {
+  TimeTicks ticks = TimeTicks(
+      i::V8::GetCurrentPlatform()->TimeTicksHighResNow());
   // Make sure we never return 0 here.
-  TimeTicks ticks(high_res_tick_clock.Pointer()->Now());
   ASSERT(!ticks.IsNull());
   return ticks;
 }
@@ -536,56 +320,7 @@ TimeTicks TimeTicks::HighResolutionNow() {
 
 // static
 bool TimeTicks::IsHighResolutionClockWorking() {
-  return high_res_tick_clock.Pointer()->IsHighResolution();
+  return i::V8::GetCurrentPlatform()->TimeTicksHasHighRes();
 }
 
-#else  // V8_OS_WIN
-
-TimeTicks TimeTicks::Now() {
-  return HighResolutionNow();
-}
-
-
-TimeTicks TimeTicks::HighResolutionNow() {
-  int64_t ticks;
-#if V8_OS_MACOSX
-  static struct mach_timebase_info info;
-  if (info.denom == 0) {
-    kern_return_t result = mach_timebase_info(&info);
-    ASSERT_EQ(KERN_SUCCESS, result);
-    USE(result);
-  }
-  ticks = (mach_absolute_time() / Time::kNanosecondsPerMicrosecond *
-           info.numer / info.denom);
-#elif V8_OS_SOLARIS
-  ticks = (gethrtime() / Time::kNanosecondsPerMicrosecond);
-#elif V8_LIBRT_NOT_AVAILABLE
-  // TODO(bmeurer): This is a temporary hack to support cross-compiling
-  // Chrome for Android in AOSP. Remove this once AOSP is fixed, also
-  // cleanup the tools/gyp/v8.gyp file.
-  struct timeval tv;
-  int result = gettimeofday(&tv, NULL);
-  ASSERT_EQ(0, result);
-  USE(result);
-  ticks = (tv.tv_sec * Time::kMicrosecondsPerSecond + tv.tv_usec);
-#elif V8_OS_POSIX
-  struct timespec ts;
-  int result = clock_gettime(CLOCK_MONOTONIC, &ts);
-  ASSERT_EQ(0, result);
-  USE(result);
-  ticks = (ts.tv_sec * Time::kMicrosecondsPerSecond +
-           ts.tv_nsec / Time::kNanosecondsPerMicrosecond);
-#endif  // V8_OS_MACOSX
-  // Make sure we never return 0 here.
-  return TimeTicks(ticks + 1);
-}
-
-
-// static
-bool TimeTicks::IsHighResolutionClockWorking() {
-  return true;
-}
-
-#endif  // V8_OS_WIN
-
 } }  // namespace v8::internal