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/* -*- Mode: C++; tab-width: 2; 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/. */
#ifndef GMPServiceChild_h_
#define GMPServiceChild_h_
#include "GMPService.h"
#include "MediaResult.h"
#include "base/process.h"
#include "mozilla/dom/PContent.h"
#include "mozilla/gmp/PGMPServiceChild.h"
#include "mozilla/MozPromise.h"
#include "nsIAsyncShutdown.h"
#include "nsRefPtrHashtable.h"
namespace mozilla::gmp {
class GMPContentParent;
class GMPServiceChild;
class GeckoMediaPluginServiceChild : public GeckoMediaPluginService,
public nsIAsyncShutdownBlocker {
friend class GMPServiceChild;
public:
static already_AddRefed<GeckoMediaPluginServiceChild> GetSingleton();
nsresult Init() override;
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_NSIASYNCSHUTDOWNBLOCKER
NS_IMETHOD HasPluginForAPI(const nsACString& aAPI,
const nsTArray<nsCString>& aTags,
bool* aRetVal) override;
NS_IMETHOD GetNodeId(const nsAString& aOrigin,
const nsAString& aTopLevelOrigin,
const nsAString& aGMPName,
UniquePtr<GetNodeIdCallback>&& aCallback) override;
NS_DECL_NSIOBSERVER
void SetServiceChild(RefPtr<GMPServiceChild>&& aServiceChild);
void RemoveGMPContentParent(GMPContentParent* aGMPContentParent);
static void UpdateGMPCapabilities(
nsTArray<mozilla::dom::GMPCapabilityData>&& aCapabilities);
void BeginShutdown();
protected:
void InitializePlugins(nsISerialEventTarget*) override {
// Nothing to do here.
}
RefPtr<GetGMPContentParentPromise> GetContentParent(
GMPCrashHelper* aHelper, const NodeIdVariant& aNodeIdVariant,
const nsACString& aAPI, const nsTArray<nsCString>& aTags) override;
private:
friend class OpenPGMPServiceChild;
~GeckoMediaPluginServiceChild() override;
typedef MozPromise<GMPServiceChild*, MediaResult, /* IsExclusive = */ true>
GetServiceChildPromise;
RefPtr<GetServiceChildPromise> GetServiceChild();
nsTArray<MozPromiseHolder<GetServiceChildPromise>> mGetServiceChildPromises;
RefPtr<GMPServiceChild> mServiceChild;
// Shutdown blocker management. A shutdown blocker is used to ensure that
// we do not shutdown until all content parents are removed from
// GMPServiceChild::mContentParents.
//
// The following rules let us shutdown block (and thus we shouldn't
// violate them):
// - We will only call GetContentParent if mShuttingDownOnGMPThread is false.
// - mShuttingDownOnGMPThread will become true once profile teardown is
// observed in the parent process (and once GMPServiceChild receives a
// message from GMPServiceParent) or if we block shutdown (which implies
// we're in shutdown).
// - If we currently have mPendingGetContentParents > 0 or parents in
// GMPServiceChild::mContentParents we should block shutdown so such
// parents can be cleanly shutdown.
// therefore
// - We can block shutdown at xpcom-will-shutdown until our content parents
// are handled.
// - Because once mShuttingDownOnGMPThread is true we cannot add new content
// parents, we know that when mShuttingDownOnGMPThread && all content
// parents are handled we'll never add more and it's safe to stop blocking
// shutdown.
// this relies on
// - Once we're shutting down, we need to ensure all content parents are
// shutdown and removed. Failure to do so will result in a shutdown stall.
// Note that at the time of writing there are significant differences in how
// xpcom shutdown is handled in release and non-release builds. For example,
// in release builds content processes are exited early, so xpcom shutdown
// is not observed (and not blocked by blockers). This is important to keep
// in mind when testing the shutdown blocking machinery (you won't see most
// of it be invoked in release).
// All of these members should only be used on the GMP thread unless
// otherwise noted!
// Add a shutdown blocker. Main thread only. Should only be called once when
// we init the service.
nsresult AddShutdownBlocker();
// Remove a shutdown blocker. Should be called once at most and only when
// mShuttingDownOnGMPThread. Prefer RemoveShutdownBlockerIfNeeded unless
// absolutely certain you need to call this directly.
void RemoveShutdownBlocker();
// Remove shutdown blocker if the following conditions are met:
// - mShuttingDownOnGMPThread.
// - !mServiceChild->HaveContentParents.
// - mPendingGetContentParents == 0.
// - mShutdownBlockerHasBeenAdded.
void RemoveShutdownBlockerIfNeeded();
#ifdef DEBUG
// Track if we've added a shutdown blocker for sanity checking. Main thread
// only.
bool mShutdownBlockerAdded = false;
#endif // DEBUG
// The number of GetContentParent calls that have not yet been resolved or
// rejected. We use this value to help determine if we need to block
// shutdown. Should only be used on GMP thread to avoid races.
uint32_t mPendingGetContentParents = 0;
// End shutdown blocker management.
};
class GMPServiceChild : public PGMPServiceChild {
public:
// Mark AddRef and Release as `final`, as they overload pure virtual
// implementations in PGMPServiceChild.
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(GMPServiceChild, final)
explicit GMPServiceChild() = default;
already_AddRefed<GMPContentParent> GetBridgedGMPContentParent(
ProcessId aOtherPid, ipc::Endpoint<PGMPContentParent>&& endpoint);
void RemoveGMPContentParent(GMPContentParent* aGMPContentParent);
void GetAlreadyBridgedTo(nsTArray<ProcessId>& aAlreadyBridgedTo);
static bool Create(Endpoint<PGMPServiceChild>&& aGMPService);
ipc::IPCResult RecvBeginShutdown() override;
bool HaveContentParents() const;
private:
~GMPServiceChild() = default;
nsRefPtrHashtable<nsUint64HashKey, GMPContentParent> mContentParents;
};
} // namespace mozilla::gmp
#endif // GMPServiceChild_h_
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