/* -*- 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() {} void SoftwareDisplay::EnableVsync() { MOZ_ASSERT(mVsyncThread->IsRunning()); if (NS_IsMainThread()) { if (mVsyncEnabled) { return; } mVsyncEnabled = true; mVsyncThread->message_loop()->PostTask( NewRunnableMethod(this, &SoftwareDisplay::EnableVsync)); return; } MOZ_ASSERT(IsInSoftwareVsyncThread()); NotifyVsync(mozilla::TimeStamp::Now()); } void SoftwareDisplay::DisableVsync() { MOZ_ASSERT(mVsyncThread->IsRunning()); if (NS_IsMainThread()) { if (!mVsyncEnabled) { return; } mVsyncEnabled = false; mVsyncThread->message_loop()->PostTask( NewRunnableMethod(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(mozilla::TimeStamp aVsyncTimestamp) { 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); // 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(); } mCurrentVsyncTask = NewCancelableRunnableMethod<mozilla::TimeStamp>(this, &SoftwareDisplay::NotifyVsync, nextVsync); RefPtr<Runnable> addrefedTask = mCurrentVsyncTask; mVsyncThread->message_loop()->PostDelayedTask( addrefedTask.forget(), delay.ToMilliseconds()); } void SoftwareDisplay::Shutdown() { MOZ_ASSERT(NS_IsMainThread()); DisableVsync(); mVsyncThread->Stop(); delete mVsyncThread; }