gecko-dev/ipc/glue/MessageLink.h

260 lines
7.3 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: sw=4 ts=4 et :
*/
/* 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 ipc_glue_MessageLink_h
#define ipc_glue_MessageLink_h 1
#include "base/basictypes.h"
#include "base/message_loop.h"
#include "mozilla/WeakPtr.h"
#include "mozilla/ipc/Transport.h"
namespace mozilla {
namespace ipc {
class MessageChannel;
struct HasResultCodes
{
enum Result {
MsgProcessed,
MsgDropped,
MsgNotKnown,
MsgNotAllowed,
MsgPayloadError,
MsgProcessingError,
MsgRouteError,
MsgValueError
};
};
enum Side {
ParentSide,
ChildSide,
UnknownSide
};
enum ChannelState {
ChannelClosed,
ChannelOpening,
ChannelConnected,
ChannelTimeout,
ChannelClosing,
ChannelError
};
// What happens if Interrupt calls race?
enum RacyInterruptPolicy {
RIPError,
RIPChildWins,
RIPParentWins
};
class MessageListener
: protected HasResultCodes,
public mozilla::SupportsWeakPtr<MessageListener>
{
public:
MOZ_DECLARE_WEAKREFERENCE_TYPENAME(MessageListener)
typedef IPC::Message Message;
typedef IPC::MessageInfo MessageInfo;
virtual ~MessageListener() { }
virtual void OnChannelClose() = 0;
virtual void OnChannelError() = 0;
virtual Result OnMessageReceived(const Message& aMessage) = 0;
virtual Result OnMessageReceived(const Message& aMessage, Message *& aReply) = 0;
virtual Result OnCallReceived(const Message& aMessage, Message *& aReply) = 0;
virtual void OnProcessingError(Result aError, const char* aMsgName) = 0;
virtual void OnChannelConnected(int32_t peer_pid) {}
virtual bool OnReplyTimeout() {
return false;
}
// WARNING: This function is called with the MessageChannel monitor held.
virtual void IntentionalCrash() {
MOZ_CRASH("Intentional IPDL crash");
}
// The code here is only useful for fuzzing. It should not be used for any
// other purpose.
#ifdef DEBUG
// Returns true if we should simulate a timeout.
// WARNING: This is a testing-only function that is called with the
// MessageChannel monitor held. Don't do anything fancy here or we could
// deadlock.
virtual bool ArtificialTimeout() {
return false;
}
// Returns true if we want to cause the worker thread to sleep with the
// monitor unlocked.
virtual bool NeedArtificialSleep() {
return false;
}
// This function should be implemented to sleep for some amount of time on
// the worker thread. Will only be called if NeedArtificialSleep() returns
// true.
virtual void ArtificialSleep() {}
#else
bool ArtificialTimeout() { return false; }
bool NeedArtificialSleep() { return false; }
void ArtificialSleep() {}
#endif
virtual void OnEnteredCxxStack() {
NS_RUNTIMEABORT("default impl shouldn't be invoked");
}
virtual void OnExitedCxxStack() {
NS_RUNTIMEABORT("default impl shouldn't be invoked");
}
virtual void OnEnteredCall() {
NS_RUNTIMEABORT("default impl shouldn't be invoked");
}
virtual void OnExitedCall() {
NS_RUNTIMEABORT("default impl shouldn't be invoked");
}
virtual RacyInterruptPolicy MediateInterruptRace(const MessageInfo& parent,
const MessageInfo& child)
{
return RIPChildWins;
}
/**
* Return true if windows messages can be handled while waiting for a reply
* to a sync IPDL message.
*/
virtual bool HandleWindowsMessages(const Message& aMsg) const { return true; }
virtual void OnEnteredSyncSend() {
}
virtual void OnExitedSyncSend() {
}
virtual void ProcessRemoteNativeEventsInInterruptCall() {
}
// FIXME/bug 792652: this doesn't really belong here, but a
// large refactoring is needed to put it where it belongs.
virtual int32_t GetProtocolTypeId() = 0;
};
class MessageLink
{
public:
typedef IPC::Message Message;
explicit MessageLink(MessageChannel *aChan);
virtual ~MessageLink();
// n.b.: These methods all require that the channel monitor is
// held when they are invoked.
virtual void EchoMessage(Message *msg) = 0;
virtual void SendMessage(Message *msg) = 0;
virtual void SendClose() = 0;
virtual bool Unsound_IsClosed() const = 0;
virtual uint32_t Unsound_NumQueuedMessages() const = 0;
#ifdef MOZ_NUWA_PROCESS
// To be overridden by ProcessLink.
virtual void Block() {}
virtual void Unblock() {}
#endif
protected:
MessageChannel *mChan;
};
class ProcessLink
: public MessageLink,
public Transport::Listener
{
void OnCloseChannel();
void OnChannelOpened();
void OnTakeConnectedChannel();
void OnEchoMessage(Message* msg);
void AssertIOThread() const
{
MOZ_ASSERT(mIOLoop == MessageLoop::current(),
"not on I/O thread!");
}
public:
explicit ProcessLink(MessageChannel *chan);
virtual ~ProcessLink();
// The ProcessLink will register itself as the IPC::Channel::Listener on the
// transport passed here. If the transport already has a listener registered
// then a listener chain will be established (the ProcessLink listener
// methods will be called first and may call some methods on the original
// listener as well). Once the channel is closed (either via normal shutdown
// or a pipe error) the chain will be destroyed and the original listener
// will again be registered.
void Open(Transport* aTransport, MessageLoop *aIOLoop, Side aSide);
// Run on the I/O thread, only when using inter-process link.
// These methods acquire the monitor and forward to the
// similarly named methods in AsyncChannel below
// (OnMessageReceivedFromLink(), etc)
virtual void OnMessageReceived(Message&& msg) override;
virtual void OnChannelConnected(int32_t peer_pid) override;
virtual void OnChannelError() override;
virtual void EchoMessage(Message *msg) override;
virtual void SendMessage(Message *msg) override;
virtual void SendClose() override;
virtual bool Unsound_IsClosed() const override;
virtual uint32_t Unsound_NumQueuedMessages() const override;
#ifdef MOZ_NUWA_PROCESS
void Block() override {
mIsBlocked = true;
}
void Unblock() override {
mIsBlocked = false;
}
#endif
protected:
Transport* mTransport;
MessageLoop* mIOLoop; // thread where IO happens
Transport::Listener* mExistingListener; // channel's previous listener
#ifdef MOZ_NUWA_PROCESS
bool mIsToNuwaProcess;
bool mIsBlocked;
#endif
};
class ThreadLink : public MessageLink
{
public:
ThreadLink(MessageChannel *aChan, MessageChannel *aTargetChan);
virtual ~ThreadLink();
virtual void EchoMessage(Message *msg) override;
virtual void SendMessage(Message *msg) override;
virtual void SendClose() override;
virtual bool Unsound_IsClosed() const override;
virtual uint32_t Unsound_NumQueuedMessages() const override;
protected:
MessageChannel* mTargetChan;
};
} // namespace ipc
} // namespace mozilla
#endif // ifndef ipc_glue_MessageLink_h