diff options
Diffstat (limited to 'chrome/browser/sync/util/highres_timer_win.cc')
-rw-r--r-- | chrome/browser/sync/util/highres_timer_win.cc | 46 |
1 files changed, 0 insertions, 46 deletions
diff --git a/chrome/browser/sync/util/highres_timer_win.cc b/chrome/browser/sync/util/highres_timer_win.cc deleted file mode 100644 index 0d7323a..0000000 --- a/chrome/browser/sync/util/highres_timer_win.cc +++ /dev/null @@ -1,46 +0,0 @@ -// Copyright (c) 2009 The Chromium Authors. All rights reserved. -// Use of this source code is governed by a BSD-style license that can be -// found in the LICENSE file. -// -// High resolution timer functions for use in Windows. - -#include "chrome/browser/sync/util/highres_timer.h" - -bool HighresTimer::perf_freq_collected_ = false; -ULONGLONG HighresTimer::perf_freq_ = 0; - -ULONGLONG HighresTimer::GetElapsedMs() const { - ULONGLONG end_time = GetCurrentTicks(); - - // Scale to ms and round to nearest ms - rounding is important because - // otherwise the truncation error may accumulate e.g. in sums. - // - // Given infinite resolution, this expression could be written as: - // trunc((end - start (units:freq*sec))/freq (units:sec) * - // 1000 (unit:ms) + 1/2 (unit:ms)) - ULONGLONG freq = GetTimerFrequency(); - return ((end_time - start_ticks_) * 1000L + freq / 2) / freq; -} - -ULONGLONG HighresTimer::GetElapsedSec() const { - ULONGLONG end_time = GetCurrentTicks(); - - // Round to nearest ms - rounding is important because otherwise the - // truncation error may accumulate e.g. in sums. - // - // Given infinite resolution, this expression could be written as: - // trunc((end - start (units:freq*sec))/freq (unit:sec) + 1/2 (unit:sec)) - ULONGLONG freq = GetTimerFrequency(); - return ((end_time - start_ticks_) + freq / 2) / freq; -} - -void HighresTimer::CollectPerfFreq() { - LARGE_INTEGER freq; - - // Note that this is racy. It's OK, however, because even concurrent - // executions of this are idempotent. - if (::QueryPerformanceFrequency(&freq)) { - perf_freq_ = freq.QuadPart; - perf_freq_collected_ = true; - } -} |