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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* 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 "SoftwareVsyncSource.h"
#include "base/task.h"
#include "gfxPlatform.h"
#include "nsThreadUtils.h"
using namespace mozilla;
SoftwareVsyncSource::SoftwareVsyncSource() {
MOZ_ASSERT(NS_IsMainThread());
mGlobalDisplay = new SoftwareDisplay();
}
SoftwareVsyncSource::~SoftwareVsyncSource() {
MOZ_ASSERT(NS_IsMainThread());
mGlobalDisplay = nullptr;
}
SoftwareDisplay::SoftwareDisplay() : mVsyncEnabled(false) {
// Mimic 60 fps
MOZ_ASSERT(NS_IsMainThread());
const double rate = 1000.0 / (double)gfxPlatform::GetSoftwareVsyncRate();
mVsyncRate = mozilla::TimeDuration::FromMilliseconds(rate);
mVsyncThread = new base::Thread("SoftwareVsyncThread");
MOZ_RELEASE_ASSERT(mVsyncThread->Start(),
"GFX: Could not start software vsync thread");
}
SoftwareDisplay::~SoftwareDisplay() = default;
void SoftwareDisplay::EnableVsync() {
MOZ_ASSERT(mVsyncThread->IsRunning());
if (NS_IsMainThread()) {
if (mVsyncEnabled) {
return;
}
mVsyncEnabled = true;
mVsyncThread->message_loop()->PostTask(NewRunnableMethod(
"SoftwareDisplay::EnableVsync", this, &SoftwareDisplay::EnableVsync));
return;
}
MOZ_ASSERT(IsInSoftwareVsyncThread());
TimeStamp vsyncTime = TimeStamp::Now();
TimeStamp outputTime = vsyncTime + mVsyncRate;
NotifyVsync(vsyncTime, outputTime);
}
void SoftwareDisplay::DisableVsync() {
MOZ_ASSERT(mVsyncThread->IsRunning());
if (NS_IsMainThread()) {
if (!mVsyncEnabled) {
return;
}
mVsyncEnabled = false;
mVsyncThread->message_loop()->PostTask(NewRunnableMethod(
"SoftwareDisplay::DisableVsync", this, &SoftwareDisplay::DisableVsync));
return;
}
MOZ_ASSERT(IsInSoftwareVsyncThread());
if (mCurrentVsyncTask) {
mCurrentVsyncTask->Cancel();
mCurrentVsyncTask = nullptr;
}
}
bool SoftwareDisplay::IsVsyncEnabled() {
MOZ_ASSERT(NS_IsMainThread());
return mVsyncEnabled;
}
bool SoftwareDisplay::IsInSoftwareVsyncThread() {
return mVsyncThread->thread_id() == PlatformThread::CurrentId();
}
void SoftwareDisplay::NotifyVsync(const mozilla::TimeStamp& aVsyncTimestamp,
const mozilla::TimeStamp& aOutputTimestamp) {
MOZ_ASSERT(IsInSoftwareVsyncThread());
mozilla::TimeStamp displayVsyncTime = aVsyncTimestamp;
mozilla::TimeStamp now = mozilla::TimeStamp::Now();
// Posted tasks can only have integer millisecond delays
// whereas TimeDurations can have floating point delays.
// Thus the vsync timestamp can be in the future, which large parts
// of the system can't handle, including animations. Force the timestamp to be
// now.
if (aVsyncTimestamp > now) {
displayVsyncTime = now;
}
Display::NotifyVsync(displayVsyncTime, aOutputTimestamp);
// Prevent skew by still scheduling based on the original
// vsync timestamp
ScheduleNextVsync(aVsyncTimestamp);
}
mozilla::TimeDuration SoftwareDisplay::GetVsyncRate() { return mVsyncRate; }
void SoftwareDisplay::ScheduleNextVsync(mozilla::TimeStamp aVsyncTimestamp) {
MOZ_ASSERT(IsInSoftwareVsyncThread());
mozilla::TimeStamp nextVsync = aVsyncTimestamp + mVsyncRate;
mozilla::TimeDuration delay = nextVsync - mozilla::TimeStamp::Now();
if (delay.ToMilliseconds() < 0) {
delay = mozilla::TimeDuration::FromMilliseconds(0);
nextVsync = mozilla::TimeStamp::Now();
}
TimeStamp outputTime = nextVsync + mVsyncRate;
mCurrentVsyncTask =
NewCancelableRunnableMethod<mozilla::TimeStamp, mozilla::TimeStamp>(
"SoftwareDisplay::NotifyVsync", this, &SoftwareDisplay::NotifyVsync,
nextVsync, outputTime);
RefPtr<Runnable> addrefedTask = mCurrentVsyncTask;
mVsyncThread->message_loop()->PostDelayedTask(addrefedTask.forget(),
delay.ToMilliseconds());
}
void SoftwareDisplay::Shutdown() {
MOZ_ASSERT(NS_IsMainThread());
DisableVsync();
mVsyncThread->Stop();
delete mVsyncThread;
}