gecko-dev/gfx/vr/VRThread.cpp
Kearwood Gilbert 7a3eb1a6a2 Bug 1494556 - Remove VRListenerThread r=daoshengmu
We are refactoring much of the code in gfx/vr, moving
most of the code that runs in the VRListenerThread into
it's own process.  The remaining code will be non-blocking
once this refactoring is complete.

In order to resolve some shutdown crashes, it is simpler
to remove the VRListenerThread and the related code
starting and stopping this thread.  If this is done
prior to completion of the refactoring for Bug 1473399
(Enable VRService thread by default), there would be a
regression in responsiveness during detection of VR
hardware due to blocking API calls moving off the thread.

Differential Revision: https://phabricator.services.mozilla.com/D7227

--HG--
extra : moz-landing-system : lando
2018-10-02 21:17:05 +00:00

152 lines
3.5 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 "VRThread.h"
#include "nsDebug.h"
#include "nsThreadManager.h"
#include "nsThreadUtils.h"
#include "VRManager.h"
namespace mozilla {
namespace gfx {
static const uint32_t kDefaultThreadLifeTime = 60; // in 60 seconds.
static const uint32_t kDelayPostTaskTime = 20000; // in 20000 ms.
VRThread::VRThread(const nsCString& aName)
: mThread(nullptr)
, mLifeTime(kDefaultThreadLifeTime)
, mStarted(false)
{
mName = aName;
}
VRThread::~VRThread()
{
Shutdown();
}
void
VRThread::Start()
{
if (!mThread) {
nsresult rv = NS_NewNamedThread(mName, getter_AddRefs(mThread));
MOZ_ASSERT(mThread);
if (NS_FAILED(rv)) {
MOZ_ASSERT(false, "Failed to create a vr thread.");
}
RefPtr<Runnable> runnable =
NewRunnableMethod<TimeStamp>(
"gfx::VRThread::CheckLife", this, &VRThread::CheckLife, TimeStamp::Now());
// Post it to the main thread for tracking the lifetime.
nsCOMPtr<nsIThread> mainThread;
rv = NS_GetMainThread(getter_AddRefs(mainThread));
if (NS_FAILED(rv)) {
NS_WARNING("VRThread::Start() could not get Main thread");
return;
}
mainThread->DelayedDispatch(runnable.forget(), kDelayPostTaskTime);
}
mStarted = true;
mLastActiveTime = TimeStamp::Now();
}
void
VRThread::Shutdown()
{
if (mThread) {
if (nsThreadManager::get().IsNSThread()) {
mThread->Shutdown();
} else {
NS_WARNING("VRThread::Shutdown() may only be called from an XPCOM thread");
NS_DispatchToMainThread(NS_NewRunnableFunction(
"VRThread::Shutdown",
[thread = mThread]() {
thread->Shutdown();
}));
}
mThread = nullptr;
}
mStarted = false;
}
const nsCOMPtr<nsIThread>
VRThread::GetThread() const
{
return mThread;
}
void
VRThread::PostTask(already_AddRefed<Runnable> aTask)
{
PostDelayedTask(std::move(aTask), 0);
}
void
VRThread::PostDelayedTask(already_AddRefed<Runnable> aTask,
uint32_t aTime)
{
MOZ_ASSERT(mStarted, "Must call Start() before posting tasks.");
MOZ_ASSERT(mThread);
mLastActiveTime = TimeStamp::Now();
if (!aTime) {
mThread->Dispatch(std::move(aTask), NS_DISPATCH_NORMAL);
} else {
mThread->DelayedDispatch(std::move(aTask), aTime);
}
}
void
VRThread::CheckLife(TimeStamp aCheckTimestamp)
{
// VR system is going to shutdown.
if (!mStarted) {
Shutdown();
return;
}
const TimeDuration timeout = TimeDuration::FromSeconds(mLifeTime);
if ((aCheckTimestamp - mLastActiveTime) > timeout) {
Shutdown();
} else {
RefPtr<Runnable> runnable =
NewRunnableMethod<TimeStamp>(
"gfx::VRThread::CheckLife", this, &VRThread::CheckLife, TimeStamp::Now());
// Post it to the main thread for tracking the lifetime.
nsCOMPtr<nsIThread> mainThread;
nsresult rv = NS_GetMainThread(getter_AddRefs(mainThread));
if (NS_FAILED(rv)) {
NS_WARNING("VRThread::CheckLife() could not get Main thread");
return;
}
mainThread->DelayedDispatch(runnable.forget(), kDelayPostTaskTime);
}
}
void
VRThread::SetLifeTime(uint32_t aLifeTime)
{
mLifeTime = aLifeTime;
}
uint32_t
VRThread::GetLifeTime()
{
return mLifeTime;
}
bool
VRThread::IsActive()
{
return !!mThread;
}
} // namespace gfx
} // namespace mozilla