gecko-dev/ipc/glue/ProtocolUtils.h

179 lines
4.8 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 mozilla_ipc_ProtocolUtils_h
#define mozilla_ipc_ProtocolUtils_h 1
#include "base/process.h"
#include "base/process_util.h"
#include "chrome/common/ipc_message_utils.h"
#include "prenv.h"
#include "IPCMessageStart.h"
#include "mozilla/ipc/FileDescriptor.h"
#include "mozilla/ipc/Shmem.h"
#include "mozilla/ipc/Transport.h"
// WARNING: this takes into account the private, special-message-type
// enum in ipc_channel.h. They need to be kept in sync.
namespace {
// XXX the max message ID is actually kuint32max now ... when this
// changed, the assumptions of the special message IDs changed in that
// they're not carving out messages from likely-unallocated space, but
// rather carving out messages from the end of space allocated to
// protocol 0. Oops! We can get away with this until protocol 0
// starts approaching its 65,536th message.
enum {
CHANNEL_OPENED_MESSAGE_TYPE = kuint16max - 5,
SHMEM_DESTROYED_MESSAGE_TYPE = kuint16max - 4,
SHMEM_CREATED_MESSAGE_TYPE = kuint16max - 3,
GOODBYE_MESSAGE_TYPE = kuint16max - 2
// kuint16max - 1 is used by ipc_channel.h.
};
}
namespace mozilla {
namespace ipc {
class AsyncChannel;
// Used to pass references to protocol actors across the wire.
// Actors created on the parent-side have a positive ID, and actors
// allocated on the child side have a negative ID.
struct ActorHandle
{
int mId;
};
// Used internally to represent a "trigger" that might cause a state
// transition. Triggers are normalized across parent+child to Send
// and Recv (instead of child-in, child-out, parent-in, parent-out) so
// that they can share the same state machine implementation. To
// further normalize, |Send| is used for 'call', |Recv| for 'answer'.
struct Trigger
{
enum Action { Send, Recv };
Trigger(Action action, int32_t msg) :
mAction(action),
mMsg(msg)
{}
Action mAction;
int32_t mMsg;
};
template<class ListenerT>
class /*NS_INTERFACE_CLASS*/ IProtocolManager
{
public:
enum ActorDestroyReason {
FailedConstructor,
Deletion,
AncestorDeletion,
NormalShutdown,
AbnormalShutdown
};
typedef base::ProcessHandle ProcessHandle;
virtual int32_t Register(ListenerT*) = 0;
virtual int32_t RegisterID(ListenerT*, int32_t) = 0;
virtual ListenerT* Lookup(int32_t) = 0;
virtual void Unregister(int32_t) = 0;
virtual void RemoveManagee(int32_t, ListenerT*) = 0;
virtual Shmem::SharedMemory* CreateSharedMemory(
size_t, SharedMemory::SharedMemoryType, bool, int32_t*) = 0;
virtual bool AdoptSharedMemory(Shmem::SharedMemory*, int32_t*) = 0;
virtual Shmem::SharedMemory* LookupSharedMemory(int32_t) = 0;
virtual bool IsTrackingSharedMemory(Shmem::SharedMemory*) = 0;
virtual bool DestroySharedMemory(Shmem&) = 0;
// XXX odd ducks, acknowledged
virtual ProcessHandle OtherProcess() const = 0;
virtual AsyncChannel* GetIPCChannel() = 0;
};
inline bool
LoggingEnabled()
{
#if defined(DEBUG)
return !!PR_GetEnv("MOZ_IPC_MESSAGE_LOG");
#else
return false;
#endif
}
inline void
ProtocolErrorBreakpoint(const char* aMsg)
{
// Bugs that generate these error messages can be tough to
// reproduce. Log always in the hope that someone finds the error
// message.
printf_stderr("IPDL protocol error: %s\n", aMsg);
}
typedef IPCMessageStart ProtocolId;
struct PrivateIPDLInterface {};
bool
Bridge(const PrivateIPDLInterface&,
AsyncChannel*, base::ProcessHandle, AsyncChannel*, base::ProcessHandle,
ProtocolId);
bool
Open(const PrivateIPDLInterface&,
AsyncChannel*, base::ProcessHandle, Transport::Mode,
ProtocolId);
bool
UnpackChannelOpened(const PrivateIPDLInterface&,
const IPC::Message&,
TransportDescriptor*, base::ProcessId*, ProtocolId*);
} // namespace ipc
} // namespace mozilla
namespace IPC {
template <>
struct ParamTraits<mozilla::ipc::ActorHandle>
{
typedef mozilla::ipc::ActorHandle paramType;
static void Write(Message* aMsg, const paramType& aParam)
{
IPC::WriteParam(aMsg, aParam.mId);
}
static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
{
int id;
if (IPC::ReadParam(aMsg, aIter, &id)) {
aResult->mId = id;
return true;
}
return false;
}
static void Log(const paramType& aParam, std::wstring* aLog)
{
aLog->append(StringPrintf(L"(%d)", aParam.mId));
}
};
} // namespace IPC
#endif // mozilla_ipc_ProtocolUtils_h