// Copyright 2016 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <tuple>
#include <utility>
#include "common/assert.h"
#include "common/common_types.h"
#include "common/logging/log.h"
#include "core/core.h"
#include "core/hle/ipc_helpers.h"
#include "core/hle/kernel/client_port.h"
#include "core/hle/kernel/client_session.h"
#include "core/hle/kernel/handle_table.h"
#include "core/hle/kernel/hle_ipc.h"
#include "core/hle/kernel/kernel.h"
#include "core/hle/kernel/process.h"
#include "core/hle/kernel/server_session.h"
#include "core/hle/kernel/session.h"
#include "core/hle/kernel/thread.h"
namespace Kernel {
ServerSession::ServerSession(KernelCore& kernel) : WaitObject{kernel} {}
ServerSession::~ServerSession() {
// This destructor will be called automatically when the last ServerSession handle is closed by
// the emulated application.
// Decrease the port's connection count.
if (parent->port) {
parent->port->ConnectionClosed();
}
parent->server = nullptr;
}
ResultVal<std::shared_ptr<ServerSession>> ServerSession::Create(KernelCore& kernel,
std::string name) {
std::shared_ptr<ServerSession> server_session = std::make_shared<ServerSession>(kernel);
server_session->name = std::move(name);
server_session->parent = nullptr;
return MakeResult(std::move(server_session));
}
bool ServerSession::ShouldWait(const Thread* thread) const {
// Closed sessions should never wait, an error will be returned from svcReplyAndReceive.
if (parent->client == nullptr)
return false;
// Wait if we have no pending requests, or if we're currently handling a request.
return pending_requesting_threads.empty() || currently_handling != nullptr;
}
void ServerSession::Acquire(Thread* thread) {
ASSERT_MSG(!ShouldWait(thread), "object unavailable!");
// We are now handling a request, pop it from the stack.
// TODO(Subv): What happens if the client endpoint is closed before any requests are made?
ASSERT(!pending_requesting_threads.empty());
currently_handling = pending_requesting_threads.back();
pending_requesting_threads.pop_back();
}
void ServerSession::ClientDisconnected() {
// We keep a shared pointer to the hle handler to keep it alive throughout
// the call to ClientDisconnected, as ClientDisconnected invalidates the
// hle_handler member itself during the course of the function executing.
std::shared_ptr<SessionRequestHandler> handler = hle_handler;
if (handler) {
// Note that after this returns, this server session's hle_handler is
// invalidated (set to null).
handler->ClientDisconnected(SharedFrom(this));
}
// Clean up the list of client threads with pending requests, they are unneeded now that the
// client endpoint is closed.
pending_requesting_threads.clear();
currently_handling = nullptr;
}
void ServerSession::AppendDomainRequestHandler(std::shared_ptr<SessionRequestHandler> handler) {
domain_request_handlers.push_back(std::move(handler));
}
std::size_t ServerSession::NumDomainRequestHandlers() const {
return domain_request_handlers.size();
}
ResultCode ServerSession::HandleDomainSyncRequest(Kernel::HLERequestContext& context) {
if (!context.HasDomainMessageHeader()) {
return RESULT_SUCCESS;
}
// Set domain handlers in HLE context, used for domain objects (IPC interfaces) as inputs
context.SetDomainRequestHandlers(domain_request_handlers);
// If there is a DomainMessageHeader, then this is CommandType "Request"
const auto& domain_message_header = context.GetDomainMessageHeader();
const u32 object_id{domain_message_header.object_id};
switch (domain_message_header.command) {
case IPC::DomainMessageHeader::CommandType::SendMessage:
if (object_id > domain_request_handlers.size()) {
LOG_CRITICAL(IPC,
"object_id {} is too big! This probably means a recent service call "
"to {} needed to return a new interface!",
object_id, name);
UNREACHABLE();
return RESULT_SUCCESS; // Ignore error if asserts are off
}
return domain_request_handlers[object_id - 1]->HandleSyncRequest(context);
case IPC::DomainMessageHeader::CommandType::CloseVirtualHandle: {
LOG_DEBUG(IPC, "CloseVirtualHandle, object_id=0x{:08X}", object_id);
domain_request_handlers[object_id - 1] = nullptr;
IPC::ResponseBuilder rb{context, 2};
rb.Push(RESULT_SUCCESS);
return RESULT_SUCCESS;
}
}
LOG_CRITICAL(IPC, "Unknown domain command={}",
static_cast<int>(domain_message_header.command.Value()));
ASSERT(false);
return RESULT_SUCCESS;
}
ResultCode ServerSession::HandleSyncRequest(std::shared_ptr<Thread> thread) {
// The ServerSession received a sync request, this means that there's new data available
// from its ClientSession, so wake up any threads that may be waiting on a svcReplyAndReceive or
// similar.
Kernel::HLERequestContext context(SharedFrom(this), thread);
u32* cmd_buf = (u32*)Memory::GetPointer(thread->GetTLSAddress());
context.PopulateFromIncomingCommandBuffer(kernel.CurrentProcess()->GetHandleTable(), cmd_buf);
ResultCode result = RESULT_SUCCESS;
// If the session has been converted to a domain, handle the domain request
if (IsDomain() && context.HasDomainMessageHeader()) {
result = HandleDomainSyncRequest(context);
// If there is no domain header, the regular session handler is used
} else if (hle_handler != nullptr) {
// If this ServerSession has an associated HLE handler, forward the request to it.
result = hle_handler->HandleSyncRequest(context);
}
if (thread->GetStatus() == ThreadStatus::Running) {
// Put the thread to sleep until the server replies, it will be awoken in
// svcReplyAndReceive for LLE servers.
thread->SetStatus(ThreadStatus::WaitIPC);
if (hle_handler != nullptr) {
// For HLE services, we put the request threads to sleep for a short duration to
// simulate IPC overhead, but only if the HLE handler didn't put the thread to sleep for
// other reasons like an async callback. The IPC overhead is needed to prevent
// starvation when a thread only does sync requests to HLE services while a
// lower-priority thread is waiting to run.
// This delay was approximated in a homebrew application by measuring the average time
// it takes for svcSendSyncRequest to return when performing the SetLcdForceBlack IPC
// request to the GSP:GPU service in a n3DS with firmware 11.6. The measured values have
// a high variance and vary between models.
static constexpr u64 IPCDelayNanoseconds = 39000;
thread->WakeAfterDelay(IPCDelayNanoseconds);
} else {
// Add the thread to the list of threads that have issued a sync request with this
// server.
pending_requesting_threads.push_back(std::move(thread));
}
}
// If this ServerSession does not have an HLE implementation, just wake up the threads waiting
// on it.
WakeupAllWaitingThreads();
// Handle scenario when ConvertToDomain command was issued, as we must do the conversion at the
// end of the command such that only commands following this one are handled as domains
if (convert_to_domain) {
ASSERT_MSG(IsSession(), "ServerSession is already a domain instance.");
domain_request_handlers = {hle_handler};
convert_to_domain = false;
}
return result;
}
ServerSession::SessionPair ServerSession::CreateSessionPair(KernelCore& kernel,
const std::string& name,
std::shared_ptr<ClientPort> port) {
auto server_session = ServerSession::Create(kernel, name + "_Server").Unwrap();
std::shared_ptr<ClientSession> client_session = std::make_shared<ClientSession>(kernel);
client_session->name = name + "_Client";
std::shared_ptr<Session> parent(new Session);
parent->client = client_session.get();
parent->server = server_session.get();
parent->port = std::move(port);
client_session->parent = parent;
server_session->parent = parent;
return std::make_pair(std::move(server_session), std::move(client_session));
}
} // namespace Kernel
