suyu/src/core/hle/kernel/hle_ipc.h
Yuri Kunde Schlesner 92ca422088 Kernel: Allow clearing request_objects to re-use buffer space
Reduces the necessary allocation to max(in_handles, out_handles) rather
than (in_handles + out_handles).
2017-06-11 13:10:21 -07:00

133 lines
5.2 KiB
C++

// Copyright 2017 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <array>
#include <memory>
#include <vector>
#include "common/common_types.h"
#include "common/swap.h"
#include "core/hle/ipc.h"
#include "core/hle/kernel/kernel.h"
#include "core/hle/kernel/server_session.h"
namespace Service {
class ServiceFrameworkBase;
}
namespace Kernel {
class HandleTable;
class Process;
/**
* Interface implemented by HLE Session handlers.
* This can be provided to a ServerSession in order to hook into several relevant events
* (such as a new connection or a SyncRequest) so they can be implemented in the emulator.
*/
class SessionRequestHandler : public std::enable_shared_from_this<SessionRequestHandler> {
public:
virtual ~SessionRequestHandler() = default;
/**
* Handles a sync request from the emulated application.
* @param server_session The ServerSession that was triggered for this sync request,
* it should be used to differentiate which client (As in ClientSession) we're answering to.
* TODO(Subv): Use a wrapper structure to hold all the information relevant to
* this request (ServerSession, Originator thread, Translated command buffer, etc).
* @returns ResultCode the result code of the translate operation.
*/
virtual void HandleSyncRequest(SharedPtr<ServerSession> server_session) = 0;
/**
* Signals that a client has just connected to this HLE handler and keeps the
* associated ServerSession alive for the duration of the connection.
* @param server_session Owning pointer to the ServerSession associated with the connection.
*/
void ClientConnected(SharedPtr<ServerSession> server_session);
/**
* Signals that a client has just disconnected from this HLE handler and releases the
* associated ServerSession.
* @param server_session ServerSession associated with the connection.
*/
void ClientDisconnected(SharedPtr<ServerSession> server_session);
protected:
/// List of sessions that are connected to this handler.
/// A ServerSession whose server endpoint is an HLE implementation is kept alive by this list
// for the duration of the connection.
std::vector<SharedPtr<ServerSession>> connected_sessions;
};
/**
* Class containing information about an in-flight IPC request being handled by an HLE service
* implementation. Services should avoid using old global APIs (e.g. Kernel::GetCommandBuffer()) and
* when possible use the APIs in this class to service the request.
*
* HLE handle protocol
* ===================
*
* To avoid needing HLE services to keep a separate handle table, or having to directly modify the
* requester's table, a tweaked protocol is used to receive and send handles in requests. The kernel
* will decode the incoming handles into object pointers and insert a id in the buffer where the
* handle would normally be. The service then calls GetIncomingHandle() with that id to get the
* pointer to the object. Similarly, instead of inserting a handle into the command buffer, the
* service calls AddOutgoingHandle() and stores the returned id where the handle would normally go.
*
* The end result is similar to just giving services their own real handle tables, but since these
* ids are local to a specific context, it avoids requiring services to manage handles for objects
* across multiple calls and ensuring that unneeded handles are cleaned up.
*/
class HLERequestContext {
public:
~HLERequestContext();
/// Returns a pointer to the IPC command buffer for this request.
u32* CommandBuffer() {
return cmd_buf.data();
}
/**
* Returns the session through which this request was made. This can be used as a map key to
* access per-client data on services.
*/
SharedPtr<ServerSession> Session() const {
return session;
}
/**
* Resolves a object id from the request command buffer into a pointer to an object. See the
* "HLE handle protocol" section in the class documentation for more details.
*/
SharedPtr<Object> GetIncomingHandle(u32 id_from_cmdbuf) const;
/**
* Adds an outgoing object to the response, returning the id which should be used to reference
* it. See the "HLE handle protocol" section in the class documentation for more details.
*/
u32 AddOutgoingHandle(SharedPtr<Object> object);
/**
* Discards all Objects from the context, invalidating all ids. This may be called after reading
* out all incoming objects, so that the buffer memory can be re-used for outgoing handles, but
* this is not required.
*/
void ClearIncomingObjects();
private:
friend class Service::ServiceFrameworkBase;
ResultCode PopulateFromIncomingCommandBuffer(const u32_le* src_cmdbuf, Process& src_process,
HandleTable& src_table);
ResultCode WriteToOutgoingCommandBuffer(u32_le* dst_cmdbuf, Process& dst_process,
HandleTable& dst_table) const;
std::array<u32, IPC::COMMAND_BUFFER_LENGTH> cmd_buf;
SharedPtr<ServerSession> session;
std::vector<SharedPtr<Object>> request_handles;
};
} // namespace Kernel