зеркало из https://github.com/mozilla/gecko-dev.git
60 строки
2.2 KiB
C++
60 строки
2.2 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
|
|
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
#include "MainThreadIdlePeriod.h"
|
|
|
|
#include "mozilla/Maybe.h"
|
|
#include "mozilla/Preferences.h"
|
|
#include "nsRefreshDriver.h"
|
|
#include "nsThreadUtils.h"
|
|
|
|
// The amount of idle time (milliseconds) reserved for a long idle period.
|
|
static const double kLongIdlePeriodMS = 50.0;
|
|
|
|
// The minimum amount of time (milliseconds) required for an idle period to be
|
|
// scheduled on the main thread. N.B. layout.idle_period.time_limit adds
|
|
// padding at the end of the idle period, which makes the point in time that we
|
|
// expect to become busy again be:
|
|
// now + kMinIdlePeriodMS + layout.idle_period.time_limit
|
|
static const double kMinIdlePeriodMS = 3.0;
|
|
|
|
static const uint32_t kMaxTimerThreadBound = 5; // milliseconds
|
|
static const uint32_t kMaxTimerThreadBoundClamp = 15; // milliseconds
|
|
|
|
namespace mozilla {
|
|
|
|
NS_IMETHODIMP
|
|
MainThreadIdlePeriod::GetIdlePeriodHint(TimeStamp* aIdleDeadline) {
|
|
MOZ_ASSERT(NS_IsMainThread());
|
|
MOZ_ASSERT(aIdleDeadline);
|
|
|
|
TimeStamp now = TimeStamp::Now();
|
|
TimeStamp currentGuess =
|
|
now + TimeDuration::FromMilliseconds(kLongIdlePeriodMS);
|
|
|
|
currentGuess = nsRefreshDriver::GetIdleDeadlineHint(currentGuess);
|
|
currentGuess = NS_GetTimerDeadlineHintOnCurrentThread(currentGuess,
|
|
kMaxTimerThreadBound);
|
|
|
|
// If the idle period is too small, then just return a null time
|
|
// to indicate we are busy. Otherwise return the actual deadline.
|
|
TimeDuration minIdlePeriod = TimeDuration::FromMilliseconds(kMinIdlePeriodMS);
|
|
bool busySoon = currentGuess.IsNull() ||
|
|
(now >= (currentGuess - minIdlePeriod)) ||
|
|
currentGuess < mLastIdleDeadline;
|
|
|
|
if (!busySoon) {
|
|
*aIdleDeadline = mLastIdleDeadline = currentGuess;
|
|
}
|
|
|
|
return NS_OK;
|
|
}
|
|
|
|
/* static */
|
|
float MainThreadIdlePeriod::GetLongIdlePeriod() { return kLongIdlePeriodMS; }
|
|
|
|
} // namespace mozilla
|