gecko-dev/dom/canvas/WebGLContextLossHandler.cpp

111 строки
2.7 KiB
C++

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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 "WebGLContextLossHandler.h"
#include "mozilla/DebugOnly.h"
#include "nsINamed.h"
#include "nsISupportsImpl.h"
#include "nsITimer.h"
#include "nsThreadUtils.h"
#include "WebGLContext.h"
namespace mozilla {
class WatchdogTimerEvent final : public nsITimerCallback
, public nsINamed
{
const WeakPtr<WebGLContextLossHandler> mHandler;
public:
NS_DECL_ISUPPORTS
explicit WatchdogTimerEvent(WebGLContextLossHandler* handler)
: mHandler(handler)
{ }
NS_IMETHOD GetName(nsACString& aName) override
{
aName.AssignLiteral("WatchdogTimerEvent");
return NS_OK;
}
private:
virtual ~WatchdogTimerEvent() { }
NS_IMETHOD Notify(nsITimer*) override {
if (mHandler) {
mHandler->TimerCallback();
}
return NS_OK;
}
};
NS_IMPL_ISUPPORTS(WatchdogTimerEvent, nsITimerCallback, nsINamed)
////////////////////////////////////////
WebGLContextLossHandler::WebGLContextLossHandler(WebGLContext* webgl)
: mWebGL(webgl)
, mTimer(do_CreateInstance(NS_TIMER_CONTRACTID))
, mTimerPending(false)
, mShouldRunTimerAgain(false)
#ifdef DEBUG
, mEventTarget(GetCurrentThreadSerialEventTarget())
#endif
{
MOZ_ASSERT(mEventTarget);
}
WebGLContextLossHandler::~WebGLContextLossHandler()
{
const DebugOnly<nsISerialEventTarget*> callingThread = GetCurrentThreadSerialEventTarget();
MOZ_ASSERT(!callingThread || mEventTarget->IsOnCurrentThread());
}
////////////////////
void
WebGLContextLossHandler::RunTimer()
{
MOZ_ASSERT(mEventTarget->IsOnCurrentThread());
// If the timer was already running, don't restart it here. Instead,
// wait until the previous call is done, then fire it one more time.
// This is also an optimization to prevent unnecessary
// cross-communication between threads.
if (mTimerPending) {
mShouldRunTimerAgain = true;
return;
}
const RefPtr<WatchdogTimerEvent> event = new WatchdogTimerEvent(this);
const uint32_t kDelayMS = 1000;
mTimer->InitWithCallback(event, kDelayMS, nsITimer::TYPE_ONE_SHOT);
mTimerPending = true;
}
////////////////////
void
WebGLContextLossHandler::TimerCallback()
{
MOZ_ASSERT(mEventTarget->IsOnCurrentThread());
mTimerPending = false;
const bool runOnceMore = mShouldRunTimerAgain;
mShouldRunTimerAgain = false;
mWebGL->UpdateContextLossStatus();
if (runOnceMore && !mTimerPending) {
RunTimer();
}
}
} // namespace mozilla