gecko-dev/ipc/glue/BackgroundParent.h
Nika Layzell f001853338 Bug 1799692 - Part 1: Introduce ThreadsafeContentParentHandle, r=asuth
This introduces a new type to ContentParent which acts as a weak handle to the
actor and is safe to hold and manipulate from any thread.

This replaces accesses of the `ContentParent` type from the background thread,
as they were error-prone due to ContentParent not being threadsafe-refcounted.

The bulk of this patch is piping the new type through to the places it is
required, and removing now-unecessary extra complexity.

Differential Revision: https://phabricator.services.mozilla.com/D162346
2022-11-29 20:41:46 +00:00

114 lines
3.3 KiB
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/* -*- 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/. */
#ifndef mozilla_ipc_backgroundparent_h__
#define mozilla_ipc_backgroundparent_h__
#include "base/process.h"
#include "mozilla/Attributes.h"
#include "mozilla/dom/ContentParent.h"
#include "nsStringFwd.h"
#include "nsTArrayForwardDeclare.h"
#ifdef DEBUG
# include "nsXULAppAPI.h"
#endif
template <class>
struct already_AddRefed;
namespace mozilla {
namespace net {
class SocketProcessBridgeParent;
class SocketProcessParent;
} // namespace net
namespace dom {
class BlobImpl;
class ContentParent;
} // namespace dom
namespace ipc {
class BackgroundStarterParent;
class PBackgroundParent;
class PBackgroundStarterParent;
template <class PFooSide>
class Endpoint;
// This class is not designed for public consumption beyond the few static
// member functions.
class BackgroundParent final {
friend class mozilla::ipc::BackgroundStarterParent;
friend class mozilla::dom::ContentParent;
friend class mozilla::net::SocketProcessBridgeParent;
friend class mozilla::net::SocketProcessParent;
using ProcessId = base::ProcessId;
using BlobImpl = mozilla::dom::BlobImpl;
using ContentParent = mozilla::dom::ContentParent;
using ThreadsafeContentParentHandle =
mozilla::dom::ThreadsafeContentParentHandle;
public:
// This function allows the caller to determine if the given parent actor
// corresponds to a child actor from another process or a child actor from a
// different thread in the same process.
// This function may only be called on the background thread.
static bool IsOtherProcessActor(PBackgroundParent* aBackgroundActor);
// This function returns a handle to the ContentParent associated with the
// parent actor if the parent actor corresponds to a child actor from another
// content process. If the parent actor corresponds to a child actor from a
// different thread in the same process then this function returns null.
//
// This function may only be called on the background thread.
static ThreadsafeContentParentHandle* GetContentParentHandle(
PBackgroundParent* aBackgroundActor);
static uint64_t GetChildID(PBackgroundParent* aBackgroundActor);
private:
// Only called by ContentParent for cross-process actors.
static bool AllocStarter(ContentParent* aContent,
Endpoint<PBackgroundStarterParent>&& aEndpoint);
// Called by SocketProcessBridgeParent and SocketProcessParent for
// cross-process actors.
static bool AllocStarter(Endpoint<PBackgroundStarterParent>&& aEndpoint);
};
// Implemented in BackgroundImpl.cpp.
bool IsOnBackgroundThread();
#ifdef DEBUG
// Implemented in BackgroundImpl.cpp.
void AssertIsOnBackgroundThread();
#else
inline void AssertIsOnBackgroundThread() {}
#endif // DEBUG
inline void AssertIsInMainProcess() { MOZ_ASSERT(XRE_IsParentProcess()); }
inline void AssertIsInMainOrSocketProcess() {
MOZ_ASSERT(XRE_IsParentProcess() || XRE_IsSocketProcess());
}
} // namespace ipc
} // namespace mozilla
#endif // mozilla_ipc_backgroundparent_h__