crashpad/util/misc/clock_win.cc
Robert Sesek f16e4eb9ff Implement SleepNanoseconds() on Windows.
This uses the naïve implementation originally written
https://codereview.chromium.org/807973002/#ps180001.

Bug: crashpad:192
Change-Id: Id00908dafb8886d6163a8b17213d3b7c33b81963
Reviewed-on: https://chromium-review.googlesource.com/606998
Commit-Queue: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Mark Mentovai <mark@chromium.org>
2017-08-08 22:11:42 +00:00

57 lines
1.8 KiB
C++

// Copyright 2014 The Crashpad Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "util/misc/clock.h"
#include <windows.h>
#include <sys/types.h>
namespace {
LARGE_INTEGER QpcFrequencyInternal() {
LARGE_INTEGER frequency;
QueryPerformanceFrequency(&frequency);
return frequency;
}
int64_t QpcFrequency() {
static LARGE_INTEGER frequency = QpcFrequencyInternal();
return frequency.QuadPart;
}
} // namespace
namespace crashpad {
uint64_t ClockMonotonicNanoseconds() {
LARGE_INTEGER time;
QueryPerformanceCounter(&time);
int64_t frequency = QpcFrequency();
int64_t whole_seconds = time.QuadPart / frequency;
int64_t leftover_ticks = time.QuadPart % frequency;
constexpr int64_t kNanosecondsPerSecond = static_cast<const int64_t>(1E9);
return (whole_seconds * kNanosecondsPerSecond) +
((leftover_ticks * kNanosecondsPerSecond) / frequency);
}
void SleepNanoseconds(uint64_t nanoseconds) {
// This is both inaccurate (will be way too long for short sleeps) and
// incorrect (can sleep for less than requested). But it's what's available
// without implementing a busy loop.
constexpr uint64_t kNanosecondsPerMillisecond = static_cast<uint64_t>(1E6);
Sleep(static_cast<DWORD>(nanoseconds / kNanosecondsPerMillisecond));
}
} // namespace crashpad