kernel: invert session request handling flow

16 files changed, 381 insertions, 250 deletions

diff --git a/src/core/hle/kernel/hle_ipc.cpp b/src/core/hle/kernel/hle_ipc.cpp
index e4f43a053..fd354d484 100644
--- a/src/core/hle/kernel/hle_ipc.cpp
+++ b/src/core/hle/kernel/hle_ipc.cpp
@@ -16,6 +16,7 @@
 #include "core/hle/kernel/k_auto_object.h"
 #include "core/hle/kernel/k_handle_table.h"
 #include "core/hle/kernel/k_process.h"
+#include "core/hle/kernel/k_server_port.h"
 #include "core/hle/kernel/k_server_session.h"
 #include "core/hle/kernel/k_thread.h"
 #include "core/hle/kernel/kernel.h"
@@ -35,7 +36,21 @@ SessionRequestHandler::SessionRequestHandler(KernelCore& kernel_, const char* se
 }
 
 SessionRequestHandler::~SessionRequestHandler() {
-    kernel.ReleaseServiceThread(service_thread);
+    kernel.ReleaseServiceThread(service_thread.lock());
+}
+
+void SessionRequestHandler::AcceptSession(KServerPort* server_port) {
+    auto* server_session = server_port->AcceptSession();
+    ASSERT(server_session != nullptr);
+
+    RegisterSession(server_session, std::make_shared<SessionRequestManager>(kernel));
+}
+
+void SessionRequestHandler::RegisterSession(KServerSession* server_session,
+                                            std::shared_ptr<SessionRequestManager> manager) {
+    manager->SetSessionHandler(shared_from_this());
+    service_thread.lock()->RegisterServerSession(server_session, manager);
+    server_session->Close();
 }
 
 SessionRequestManager::SessionRequestManager(KernelCore& kernel_) : kernel{kernel_} {}
@@ -92,7 +107,7 @@ Result SessionRequestManager::HandleDomainSyncRequest(KServerSession* server_ses
     }
 
     // Set domain handlers in HLE context, used for domain objects (IPC interfaces) as inputs
-    context.SetSessionRequestManager(server_session->GetSessionRequestManager());
+    ASSERT(context.GetManager().get() == this);
 
     // If there is a DomainMessageHeader, then this is CommandType "Request"
     const auto& domain_message_header = context.GetDomainMessageHeader();
@@ -130,31 +145,6 @@ Result SessionRequestManager::HandleDomainSyncRequest(KServerSession* server_ses
     return ResultSuccess;
 }
 
-Result SessionRequestManager::QueueSyncRequest(KSession* parent,
-                                               std::shared_ptr<HLERequestContext>&& context) {
-    // Ensure we have a session request handler
-    if (this->HasSessionRequestHandler(*context)) {
-        if (auto strong_ptr = this->GetServiceThread().lock()) {
-            strong_ptr->QueueSyncRequest(*parent, std::move(context));
-        } else {
-            ASSERT_MSG(false, "strong_ptr is nullptr!");
-        }
-    } else {
-        ASSERT_MSG(false, "handler is invalid!");
-    }
-
-    return ResultSuccess;
-}
-
-void SessionRequestHandler::ClientConnected(KServerSession* session) {
-    session->GetSessionRequestManager()->SetSessionHandler(shared_from_this());
-
-    // Ensure our server session is tracked globally.
-    kernel.RegisterServerObject(session);
-}
-
-void SessionRequestHandler::ClientDisconnected(KServerSession* session) {}
-
 HLERequestContext::HLERequestContext(KernelCore& kernel_, Core::Memory::Memory& memory_,
                                      KServerSession* server_session_, KThread* thread_)
     : server_session(server_session_), thread(thread_), kernel{kernel_}, memory{memory_} {
@@ -214,7 +204,7 @@ void HLERequestContext::ParseCommandBuffer(const KHandleTable& handle_table, u32
         // Padding to align to 16 bytes
         rp.AlignWithPadding();
 
-        if (Session()->GetSessionRequestManager()->IsDomain() &&
+        if (GetManager()->IsDomain() &&
             ((command_header->type == IPC::CommandType::Request ||
               command_header->type == IPC::CommandType::RequestWithContext) ||
              !incoming)) {
@@ -223,7 +213,7 @@ void HLERequestContext::ParseCommandBuffer(const KHandleTable& handle_table, u32
             if (incoming || domain_message_header) {
                 domain_message_header = rp.PopRaw<IPC::DomainMessageHeader>();
             } else {
-                if (Session()->GetSessionRequestManager()->IsDomain()) {
+                if (GetManager()->IsDomain()) {
                     LOG_WARNING(IPC, "Domain request has no DomainMessageHeader!");
                 }
             }
@@ -316,12 +306,11 @@ Result HLERequestContext::WriteToOutgoingCommandBuffer(KThread& requesting_threa
     // Write the domain objects to the command buffer, these go after the raw untranslated data.
     // TODO(Subv): This completely ignores C buffers.
 
-    if (server_session->GetSessionRequestManager()->IsDomain()) {
+    if (GetManager()->IsDomain()) {
         current_offset = domain_offset - static_cast<u32>(outgoing_domain_objects.size());
         for (auto& object : outgoing_domain_objects) {
-            server_session->GetSessionRequestManager()->AppendDomainHandler(std::move(object));
-            cmd_buf[current_offset++] = static_cast<u32_le>(
-                server_session->GetSessionRequestManager()->DomainHandlerCount());
+            GetManager()->AppendDomainHandler(std::move(object));
+            cmd_buf[current_offset++] = static_cast<u32_le>(GetManager()->DomainHandlerCount());
         }
     }
 
diff --git a/src/core/hle/kernel/hle_ipc.h b/src/core/hle/kernel/hle_ipc.h
index 1083638a9..67da8e7e1 100644
--- a/src/core/hle/kernel/hle_ipc.h
+++ b/src/core/hle/kernel/hle_ipc.h
@@ -45,11 +45,13 @@ class KAutoObject;
 class KernelCore;
 class KEvent;
 class KHandleTable;
+class KServerPort;
 class KProcess;
 class KServerSession;
 class KThread;
 class KReadableEvent;
 class KSession;
+class SessionRequestManager;
 class ServiceThread;
 
 enum class ThreadWakeupReason;
@@ -76,19 +78,9 @@ public:
     virtual Result HandleSyncRequest(Kernel::KServerSession& session,
                                      Kernel::HLERequestContext& context) = 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(KServerSession* 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(KServerSession* session);
+    void AcceptSession(KServerPort* server_port);
+    void RegisterSession(KServerSession* server_session,
+                         std::shared_ptr<SessionRequestManager> manager);
 
     std::weak_ptr<ServiceThread> GetServiceThread() const {
         return service_thread;
@@ -170,7 +162,6 @@ public:
 
     Result HandleDomainSyncRequest(KServerSession* server_session, HLERequestContext& context);
     Result CompleteSyncRequest(KServerSession* server_session, HLERequestContext& context);
-    Result QueueSyncRequest(KSession* parent, std::shared_ptr<HLERequestContext>&& context);
 
 private:
     bool convert_to_domain{};
@@ -350,11 +341,11 @@ public:
 
     template <typename T>
     std::shared_ptr<T> GetDomainHandler(std::size_t index) const {
-        return std::static_pointer_cast<T>(manager.lock()->DomainHandler(index).lock());
+        return std::static_pointer_cast<T>(GetManager()->DomainHandler(index).lock());
     }
 
     void SetSessionRequestManager(std::weak_ptr<SessionRequestManager> manager_) {
-        manager = std::move(manager_);
+        manager = manager_;
     }
 
     std::string Description() const;
@@ -363,6 +354,10 @@ public:
         return *thread;
     }
 
+    std::shared_ptr<SessionRequestManager> GetManager() const {
+        return manager.lock();
+    }
+
 private:
     friend class IPC::ResponseBuilder;
 
@@ -396,7 +391,7 @@ private:
     u32 handles_offset{};
     u32 domain_offset{};
 
-    std::weak_ptr<SessionRequestManager> manager;
+    std::weak_ptr<SessionRequestManager> manager{};
 
     KernelCore& kernel;
     Core::Memory::Memory& memory;
diff --git a/src/core/hle/kernel/k_client_port.cpp b/src/core/hle/kernel/k_client_port.cpp
index 3cb22ff4d..eaa2e094c 100644
--- a/src/core/hle/kernel/k_client_port.cpp
+++ b/src/core/hle/kernel/k_client_port.cpp
@@ -58,8 +58,7 @@ bool KClientPort::IsSignaled() const {
     return num_sessions < max_sessions;
 }
 
-Result KClientPort::CreateSession(KClientSession** out,
-                                  std::shared_ptr<SessionRequestManager> session_manager) {
+Result KClientPort::CreateSession(KClientSession** out) {
     // Reserve a new session from the resource limit.
     KScopedResourceReservation session_reservation(kernel.CurrentProcess()->GetResourceLimit(),
                                                    LimitableResource::Sessions);
@@ -104,7 +103,7 @@ Result KClientPort::CreateSession(KClientSession** out,
     }
 
     // Initialize the session.
-    session->Initialize(this, parent->GetName(), session_manager);
+    session->Initialize(this, parent->GetName());
 
     // Commit the session reservation.
     session_reservation.Commit();
diff --git a/src/core/hle/kernel/k_client_port.h b/src/core/hle/kernel/k_client_port.h
index e17eff28f..81046fb86 100644
--- a/src/core/hle/kernel/k_client_port.h
+++ b/src/core/hle/kernel/k_client_port.h
@@ -52,8 +52,7 @@ public:
     void Destroy() override;
     bool IsSignaled() const override;
 
-    Result CreateSession(KClientSession** out,
-                         std::shared_ptr<SessionRequestManager> session_manager = nullptr);
+    Result CreateSession(KClientSession** out);
 
 private:
     std::atomic<s32> num_sessions{};
diff --git a/src/core/hle/kernel/k_port.cpp b/src/core/hle/kernel/k_port.cpp
index 7a5a9dc2a..77d00ae2c 100644
--- a/src/core/hle/kernel/k_port.cpp
+++ b/src/core/hle/kernel/k_port.cpp
@@ -57,12 +57,6 @@ Result KPort::EnqueueSession(KServerSession* session) {
 
     server.EnqueueSession(session);
 
-    if (auto session_ptr = server.GetSessionRequestHandler().lock()) {
-        session_ptr->ClientConnected(server.AcceptSession());
-    } else {
-        ASSERT(false);
-    }
-
     return ResultSuccess;
 }
 
diff --git a/src/core/hle/kernel/k_server_port.cpp b/src/core/hle/kernel/k_server_port.cpp
index e968f26ad..12e0c3ffb 100644
--- a/src/core/hle/kernel/k_server_port.cpp
+++ b/src/core/hle/kernel/k_server_port.cpp
@@ -19,6 +19,8 @@ void KServerPort::Initialize(KPort* parent_port_, std::string&& name_) {
     // Set member variables.
     parent = parent_port_;
     name = std::move(name_);
+
+    kernel.RegisterServerObject(this);
 }
 
 bool KServerPort::IsLight() const {
@@ -62,9 +64,6 @@ void KServerPort::Destroy() {
     // Close our reference to our parent.
     parent->Close();
 
-    // Release host emulation members.
-    session_handler.reset();
-
     // Ensure that the global list tracking server objects does not hold on to a reference.
     kernel.UnregisterServerObject(this);
 }
diff --git a/src/core/hle/kernel/k_server_port.h b/src/core/hle/kernel/k_server_port.h
index fd4f4bd20..5fc7ee683 100644
--- a/src/core/hle/kernel/k_server_port.h
+++ b/src/core/hle/kernel/k_server_port.h
@@ -27,24 +27,6 @@ public:
 
     void Initialize(KPort* parent_port_, std::string&& name_);
 
-    /// Whether or not this server port has an HLE handler available.
-    bool HasSessionRequestHandler() const {
-        return !session_handler.expired();
-    }
-
-    /// Gets the HLE handler for this port.
-    SessionRequestHandlerWeakPtr GetSessionRequestHandler() const {
-        return session_handler;
-    }
-
-    /**
-     * Sets the HLE handler template for the port. ServerSessions crated by connecting to this port
-     * will inherit a reference to this handler.
-     */
-    void SetSessionHandler(SessionRequestHandlerWeakPtr&& handler) {
-        session_handler = std::move(handler);
-    }
-
     void EnqueueSession(KServerSession* pending_session);
 
     KServerSession* AcceptSession();
@@ -65,7 +47,6 @@ private:
     void CleanupSessions();
 
     SessionList session_list;
-    SessionRequestHandlerWeakPtr session_handler;
     KPort* parent{};
 };
 
diff --git a/src/core/hle/kernel/k_server_session.cpp b/src/core/hle/kernel/k_server_session.cpp
index faf03fcc8..aa1941f01 100644
--- a/src/core/hle/kernel/k_server_session.cpp
+++ b/src/core/hle/kernel/k_server_session.cpp
@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2019 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <tuple>
@@ -33,12 +33,10 @@ KServerSession::KServerSession(KernelCore& kernel_)
 
 KServerSession::~KServerSession() = default;
 
-void KServerSession::Initialize(KSession* parent_session_, std::string&& name_,
-                                std::shared_ptr<SessionRequestManager> manager_) {
+void KServerSession::Initialize(KSession* parent_session_, std::string&& name_) {
     // Set member variables.
     parent = parent_session_;
     name = std::move(name_);
-    manager = manager_;
 }
 
 void KServerSession::Destroy() {
@@ -47,18 +45,99 @@ void KServerSession::Destroy() {
     this->CleanupRequests();
 
     parent->Close();
-
-    // Release host emulation members.
-    manager.reset();
-
-    // Ensure that the global list tracking server objects does not hold on to a reference.
-    kernel.UnregisterServerObject(this);
 }
 
 void KServerSession::OnClientClosed() {
-    if (manager && manager->HasSessionHandler()) {
-        manager->SessionHandler().ClientDisconnected(this);
+    KScopedLightLock lk{m_lock};
+
+    // Handle any pending requests.
+    KSessionRequest* prev_request = nullptr;
+    while (true) {
+        // Declare variables for processing the request.
+        KSessionRequest* request = nullptr;
+        KEvent* event = nullptr;
+        KThread* thread = nullptr;
+        bool cur_request = false;
+        bool terminate = false;
+
+        // Get the next request.
+        {
+            KScopedSchedulerLock sl{kernel};
+
+            if (m_current_request != nullptr && m_current_request != prev_request) {
+                // Set the request, open a reference as we process it.
+                request = m_current_request;
+                request->Open();
+                cur_request = true;
+
+                // Get thread and event for the request.
+                thread = request->GetThread();
+                event = request->GetEvent();
+
+                // If the thread is terminating, handle that.
+                if (thread->IsTerminationRequested()) {
+                    request->ClearThread();
+                    request->ClearEvent();
+                    terminate = true;
+                }
+
+                prev_request = request;
+            } else if (!m_request_list.empty()) {
+                // Pop the request from the front of the list.
+                request = std::addressof(m_request_list.front());
+                m_request_list.pop_front();
+
+                // Get thread and event for the request.
+                thread = request->GetThread();
+                event = request->GetEvent();
+            }
+        }
+
+        // If there are no requests, we're done.
+        if (request == nullptr) {
+            break;
+        }
+
+        // All requests must have threads.
+        ASSERT(thread != nullptr);
+
+        // Ensure that we close the request when done.
+        SCOPE_EXIT({ request->Close(); });
+
+        // If we're terminating, close a reference to the thread and event.
+        if (terminate) {
+            thread->Close();
+            if (event != nullptr) {
+                event->Close();
+            }
+        }
+
+        // If we need to, reply.
+        if (event != nullptr && !cur_request) {
+            // There must be no mappings.
+            ASSERT(request->GetSendCount() == 0);
+            ASSERT(request->GetReceiveCount() == 0);
+            ASSERT(request->GetExchangeCount() == 0);
+
+            // // Get the process and page table.
+            // KProcess *client_process = thread->GetOwnerProcess();
+            // auto &client_pt = client_process->GetPageTable();
+
+            // // Reply to the request.
+            // ReplyAsyncError(client_process, request->GetAddress(), request->GetSize(),
+            //                 ResultSessionClosed);
+
+            // // Unlock the buffer.
+            // // NOTE: Nintendo does not check the result of this.
+            // client_pt.UnlockForIpcUserBuffer(request->GetAddress(), request->GetSize());
+
+            // Signal the event.
+            event->Signal();
+        }
     }
+
+    // Notify.
+    this->NotifyAvailable(ResultSessionClosed);
 }
 
 bool KServerSession::IsSignaled() const {
@@ -73,24 +152,6 @@ bool KServerSession::IsSignaled() const {
     return !m_request_list.empty() && m_current_request == nullptr;
 }
 
-Result KServerSession::QueueSyncRequest(KThread* thread, Core::Memory::Memory& memory) {
-    u32* cmd_buf{reinterpret_cast<u32*>(memory.GetPointer(thread->GetTLSAddress()))};
-    auto context = std::make_shared<HLERequestContext>(kernel, memory, this, thread);
-
-    context->PopulateFromIncomingCommandBuffer(kernel.CurrentProcess()->GetHandleTable(), cmd_buf);
-
-    return manager->QueueSyncRequest(parent, std::move(context));
-}
-
-Result KServerSession::CompleteSyncRequest(HLERequestContext& context) {
-    Result result = manager->CompleteSyncRequest(this, context);
-
-    // The calling thread is waiting for this request to complete, so wake it up.
-    context.GetThread().EndWait(result);
-
-    return result;
-}
-
 Result KServerSession::OnRequest(KSessionRequest* request) {
     // Create the wait queue.
     ThreadQueueImplForKServerSessionRequest wait_queue{kernel};
@@ -105,24 +166,16 @@ Result KServerSession::OnRequest(KSessionRequest* request) {
         // Check that we're not terminating.
         R_UNLESS(!GetCurrentThread(kernel).IsTerminationRequested(), ResultTerminationRequested);
 
-        if (manager) {
-            // HLE request.
-            auto& memory{kernel.System().Memory()};
-            this->QueueSyncRequest(GetCurrentThreadPointer(kernel), memory);
-        } else {
-            // Non-HLE request.
-
-            // Get whether we're empty.
-            const bool was_empty = m_request_list.empty();
+        // Get whether we're empty.
+        const bool was_empty = m_request_list.empty();
 
-            // Add the request to the list.
-            request->Open();
-            m_request_list.push_back(*request);
+        // Add the request to the list.
+        request->Open();
+        m_request_list.push_back(*request);
 
-            // If we were empty, signal.
-            if (was_empty) {
-                this->NotifyAvailable();
-            }
+        // If we were empty, signal.
+        if (was_empty) {
+            this->NotifyAvailable();
         }
 
         // If we have a request event, this is asynchronous, and we don't need to wait.
@@ -136,7 +189,7 @@ Result KServerSession::OnRequest(KSessionRequest* request) {
     return GetCurrentThread(kernel).GetWaitResult();
 }
 
-Result KServerSession::SendReply() {
+Result KServerSession::SendReply(bool is_hle) {
     // Lock the session.
     KScopedLightLock lk{m_lock};
 
@@ -171,13 +224,18 @@ Result KServerSession::SendReply() {
     Result result = ResultSuccess;
     if (!closed) {
         // If we're not closed, send the reply.
-        Core::Memory::Memory& memory{kernel.System().Memory()};
-        KThread* server_thread{GetCurrentThreadPointer(kernel)};
-        UNIMPLEMENTED_IF(server_thread->GetOwnerProcess() != client_thread->GetOwnerProcess());
+        if (is_hle) {
+            // HLE servers write directly to a pointer to the thread command buffer. Therefore
+            // the reply has already been written in this case.
+        } else {
+            Core::Memory::Memory& memory{kernel.System().Memory()};
+            KThread* server_thread{GetCurrentThreadPointer(kernel)};
+            UNIMPLEMENTED_IF(server_thread->GetOwnerProcess() != client_thread->GetOwnerProcess());
 
-        auto* src_msg_buffer = memory.GetPointer(server_thread->GetTLSAddress());
-        auto* dst_msg_buffer = memory.GetPointer(client_message);
-        std::memcpy(dst_msg_buffer, src_msg_buffer, client_buffer_size);
+            auto* src_msg_buffer = memory.GetPointer(server_thread->GetTLSAddress());
+            auto* dst_msg_buffer = memory.GetPointer(client_message);
+            std::memcpy(dst_msg_buffer, src_msg_buffer, client_buffer_size);
+        }
     } else {
         result = ResultSessionClosed;
     }
@@ -223,7 +281,8 @@ Result KServerSession::SendReply() {
     return result;
 }
 
-Result KServerSession::ReceiveRequest() {
+Result KServerSession::ReceiveRequest(std::shared_ptr<HLERequestContext>* out_context,
+                                      std::weak_ptr<SessionRequestManager> manager) {
     // Lock the session.
     KScopedLightLock lk{m_lock};
 
@@ -267,12 +326,22 @@ Result KServerSession::ReceiveRequest() {
 
     // Receive the message.
     Core::Memory::Memory& memory{kernel.System().Memory()};
-    KThread* server_thread{GetCurrentThreadPointer(kernel)};
-    UNIMPLEMENTED_IF(server_thread->GetOwnerProcess() != client_thread->GetOwnerProcess());
+    if (out_context != nullptr) {
+        // HLE request.
+        u32* cmd_buf{reinterpret_cast<u32*>(memory.GetPointer(client_message))};
+        *out_context = std::make_shared<HLERequestContext>(kernel, memory, this, client_thread);
+        (*out_context)->SetSessionRequestManager(manager);
+        (*out_context)
+            ->PopulateFromIncomingCommandBuffer(client_thread->GetOwnerProcess()->GetHandleTable(),
+                                                cmd_buf);
+    } else {
+        KThread* server_thread{GetCurrentThreadPointer(kernel)};
+        UNIMPLEMENTED_IF(server_thread->GetOwnerProcess() != client_thread->GetOwnerProcess());
 
-    auto* src_msg_buffer = memory.GetPointer(client_message);
-    auto* dst_msg_buffer = memory.GetPointer(server_thread->GetTLSAddress());
-    std::memcpy(dst_msg_buffer, src_msg_buffer, client_buffer_size);
+        auto* src_msg_buffer = memory.GetPointer(client_message);
+        auto* dst_msg_buffer = memory.GetPointer(server_thread->GetTLSAddress());
+        std::memcpy(dst_msg_buffer, src_msg_buffer, client_buffer_size);
+    }
 
     // We succeeded.
     return ResultSuccess;
diff --git a/src/core/hle/kernel/k_server_session.h b/src/core/hle/kernel/k_server_session.h
index 188aef4af..e4698d3f5 100644
--- a/src/core/hle/kernel/k_server_session.h
+++ b/src/core/hle/kernel/k_server_session.h
@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2019 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
@@ -16,21 +16,11 @@
 #include "core/hle/kernel/k_synchronization_object.h"
 #include "core/hle/result.h"
 
-namespace Core::Memory {
-class Memory;
-}
-
-namespace Core::Timing {
-class CoreTiming;
-struct EventType;
-} // namespace Core::Timing
-
 namespace Kernel {
 
 class HLERequestContext;
 class KernelCore;
 class KSession;
-class SessionRequestHandler;
 class SessionRequestManager;
 class KThread;
 
@@ -46,8 +36,7 @@ public:
 
     void Destroy() override;
 
-    void Initialize(KSession* parent_session_, std::string&& name_,
-                    std::shared_ptr<SessionRequestManager> manager_);
+    void Initialize(KSession* parent_session_, std::string&& name_);
 
     KSession* GetParent() {
         return parent;
@@ -60,32 +49,16 @@ public:
     bool IsSignaled() const override;
     void OnClientClosed();
 
-    /// Gets the session request manager, which forwards requests to the underlying service
-    std::shared_ptr<SessionRequestManager>& GetSessionRequestManager() {
-        return manager;
-    }
-
     /// TODO: flesh these out to match the real kernel
     Result OnRequest(KSessionRequest* request);
-    Result SendReply();
-    Result ReceiveRequest();
+    Result SendReply(bool is_hle = false);
+    Result ReceiveRequest(std::shared_ptr<HLERequestContext>* out_context = nullptr,
+                          std::weak_ptr<SessionRequestManager> manager = {});
 
 private:
     /// Frees up waiting client sessions when this server session is about to die
     void CleanupRequests();
 
-    /// Queues a sync request from the emulated application.
-    Result QueueSyncRequest(KThread* thread, Core::Memory::Memory& memory);
-
-    /// Completes a sync request from the emulated application.
-    Result CompleteSyncRequest(HLERequestContext& context);
-
-    /// This session's HLE request handlers; if nullptr, this is not an HLE server
-    std::shared_ptr<SessionRequestManager> manager;
-
-    /// When set to True, converts the session to a domain at the end of the command
-    bool convert_to_domain{};
-
     /// KSession that owns this KServerSession
     KSession* parent{};
 
diff --git a/src/core/hle/kernel/k_session.cpp b/src/core/hle/kernel/k_session.cpp
index ee05aa282..7a6534ac3 100644
--- a/src/core/hle/kernel/k_session.cpp
+++ b/src/core/hle/kernel/k_session.cpp
@@ -13,8 +13,7 @@ KSession::KSession(KernelCore& kernel_)
     : KAutoObjectWithSlabHeapAndContainer{kernel_}, server{kernel_}, client{kernel_} {}
 KSession::~KSession() = default;
 
-void KSession::Initialize(KClientPort* port_, const std::string& name_,
-                          std::shared_ptr<SessionRequestManager> manager_) {
+void KSession::Initialize(KClientPort* port_, const std::string& name_) {
     // Increment reference count.
     // Because reference count is one on creation, this will result
     // in a reference count of two. Thus, when both server and client are closed
@@ -26,7 +25,7 @@ void KSession::Initialize(KClientPort* port_, const std::string& name_,
     KAutoObject::Create(std::addressof(client));
 
     // Initialize our sub sessions.
-    server.Initialize(this, name_ + ":Server", manager_);
+    server.Initialize(this, name_ + ":Server");
     client.Initialize(this, name_ + ":Client");
 
     // Set state and name.
diff --git a/src/core/hle/kernel/k_session.h b/src/core/hle/kernel/k_session.h
index c6ead403b..93e5e6f71 100644
--- a/src/core/hle/kernel/k_session.h
+++ b/src/core/hle/kernel/k_session.h
@@ -21,8 +21,7 @@ public:
     explicit KSession(KernelCore& kernel_);
     ~KSession() override;
 
-    void Initialize(KClientPort* port_, const std::string& name_,
-                    std::shared_ptr<SessionRequestManager> manager_ = nullptr);
+    void Initialize(KClientPort* port_, const std::string& name_);
 
     void Finalize() override;
 
diff --git a/src/core/hle/kernel/kernel.cpp b/src/core/hle/kernel/kernel.cpp
index fdc774e30..29e122dfd 100644
--- a/src/core/hle/kernel/kernel.cpp
+++ b/src/core/hle/kernel/kernel.cpp
@@ -60,7 +60,6 @@ struct KernelCore::Impl {
         global_scheduler_context = std::make_unique<Kernel::GlobalSchedulerContext>(kernel);
         global_handle_table = std::make_unique<Kernel::KHandleTable>(kernel);
         global_handle_table->Initialize(KHandleTable::MaxTableSize);
-        default_service_thread = CreateServiceThread(kernel, "DefaultServiceThread");
 
         is_phantom_mode_for_singlecore = false;
 
@@ -86,6 +85,8 @@ struct KernelCore::Impl {
         }
 
         RegisterHostThread();
+
+        default_service_thread = CreateServiceThread(kernel, "DefaultServiceThread");
     }
 
     void InitializeCores() {
@@ -703,6 +704,15 @@ struct KernelCore::Impl {
         return port;
     }
 
+    void RegisterNamedServiceHandler(std::string name, KServerPort* server_port) {
+        auto search = service_interface_handlers.find(name);
+        if (search == service_interface_handlers.end()) {
+            return;
+        }
+
+        search->second(system.ServiceManager(), server_port);
+    }
+
     void RegisterServerObject(KAutoObject* server_object) {
         std::scoped_lock lk(server_objects_lock);
         server_objects.insert(server_object);
@@ -715,7 +725,7 @@ struct KernelCore::Impl {
 
     std::weak_ptr<Kernel::ServiceThread> CreateServiceThread(KernelCore& kernel,
                                                              const std::string& name) {
-        auto service_thread = std::make_shared<Kernel::ServiceThread>(kernel, 1, name);
+        auto service_thread = std::make_shared<Kernel::ServiceThread>(kernel, name);
 
         service_threads_manager.QueueWork(
             [this, service_thread]() { service_threads.emplace(service_thread); });
@@ -774,6 +784,7 @@ struct KernelCore::Impl {
     /// Map of named ports managed by the kernel, which can be retrieved using
     /// the ConnectToPort SVC.
     std::unordered_map<std::string, ServiceInterfaceFactory> service_interface_factory;
+    std::unordered_map<std::string, ServiceInterfaceHandlerFn> service_interface_handlers;
     NamedPortTable named_ports;
     std::unordered_set<KAutoObject*> server_objects;
     std::unordered_set<KAutoObject*> registered_objects;
@@ -981,10 +992,19 @@ void KernelCore::RegisterNamedService(std::string name, ServiceInterfaceFactory&
     impl->service_interface_factory.emplace(std::move(name), factory);
 }
 
+void KernelCore::RegisterInterfaceForNamedService(std::string name,
+                                                  ServiceInterfaceHandlerFn&& handler) {
+    impl->service_interface_handlers.emplace(std::move(name), handler);
+}
+
 KClientPort* KernelCore::CreateNamedServicePort(std::string name) {
     return impl->CreateNamedServicePort(std::move(name));
 }
 
+void KernelCore::RegisterNamedServiceHandler(std::string name, KServerPort* server_port) {
+    impl->RegisterNamedServiceHandler(std::move(name), server_port);
+}
+
 void KernelCore::RegisterServerObject(KAutoObject* server_object) {
     impl->RegisterServerObject(server_object);
 }
diff --git a/src/core/hle/kernel/kernel.h b/src/core/hle/kernel/kernel.h
index 266be2bc4..670f93ee3 100644
--- a/src/core/hle/kernel/kernel.h
+++ b/src/core/hle/kernel/kernel.h
@@ -45,6 +45,7 @@ class KPort;
 class KProcess;
 class KResourceLimit;
 class KScheduler;
+class KServerPort;
 class KServerSession;
 class KSession;
 class KSessionRequest;
@@ -63,6 +64,8 @@ class TimeManager;
 using ServiceInterfaceFactory =
     std::function<KClientPort&(Service::SM::ServiceManager&, Core::System&)>;
 
+using ServiceInterfaceHandlerFn = std::function<void(Service::SM::ServiceManager&, KServerPort*)>;
+
 namespace Init {
 struct KSlabResourceCounts;
 }
@@ -192,9 +195,15 @@ public:
     /// Registers a named HLE service, passing a factory used to open a port to that service.
     void RegisterNamedService(std::string name, ServiceInterfaceFactory&& factory);
 
+    /// Registers a setup function for the named HLE service.
+    void RegisterInterfaceForNamedService(std::string name, ServiceInterfaceHandlerFn&& handler);
+
     /// Opens a port to a service previously registered with RegisterNamedService.
     KClientPort* CreateNamedServicePort(std::string name);
 
+    /// Accepts a session on a port created by CreateNamedServicePort.
+    void RegisterNamedServiceHandler(std::string name, KServerPort* server_port);
+
     /// Registers a server session or port with the gobal emulation state, to be freed on shutdown.
     /// This is necessary because we do not emulate processes for HLE sessions and ports.
     void RegisterServerObject(KAutoObject* server_object);
diff --git a/src/core/hle/kernel/service_thread.cpp b/src/core/hle/kernel/service_thread.cpp
index d23d76706..1fc2edf52 100644
--- a/src/core/hle/kernel/service_thread.cpp
+++ b/src/core/hle/kernel/service_thread.cpp
@@ -1,15 +1,17 @@
-// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-#include <condition_variable>
 #include <functional>
 #include <mutex>
 #include <thread>
 #include <vector>
-#include <queue>
 
 #include "common/scope_exit.h"
 #include "common/thread.h"
+#include "core/hle/ipc_helpers.h"
+#include "core/hle/kernel/hle_ipc.h"
+#include "core/hle/kernel/k_event.h"
+#include "core/hle/kernel/k_scoped_resource_reservation.h"
 #include "core/hle/kernel/k_session.h"
 #include "core/hle/kernel/k_thread.h"
 #include "core/hle/kernel/kernel.h"
@@ -19,101 +21,201 @@ namespace Kernel {
 
 class ServiceThread::Impl final {
 public:
-    explicit Impl(KernelCore& kernel, std::size_t num_threads, const std::string& name);
+    explicit Impl(KernelCore& kernel, const std::string& service_name);
     ~Impl();
 
-    void QueueSyncRequest(KSession& session, std::shared_ptr<HLERequestContext>&& context);
+    void WaitAndProcessImpl();
+    void SessionClosed(KServerSession* server_session,
+                       std::shared_ptr<SessionRequestManager> manager);
+    void LoopProcess();
+
+    void RegisterServerSession(KServerSession* session,
+                               std::shared_ptr<SessionRequestManager> manager);
 
 private:
-    std::vector<std::jthread> threads;
-    std::queue<std::function<void()>> requests;
-    std::mutex queue_mutex;
-    std::condition_variable_any condition;
-    const std::string service_name;
+    KernelCore& kernel;
+
+    std::jthread m_thread;
+    std::mutex m_session_mutex;
+    std::vector<KServerSession*> m_sessions;
+    std::vector<std::shared_ptr<SessionRequestManager>> m_managers;
+    KEvent* m_wakeup_event;
+    KProcess* m_process;
+    std::atomic<bool> m_shutdown_requested;
+    const std::string m_service_name;
 };
 
-ServiceThread::Impl::Impl(KernelCore& kernel, std::size_t num_threads, const std::string& name)
-    : service_name{name} {
-    for (std::size_t i = 0; i < num_threads; ++i) {
-        threads.emplace_back([this, &kernel](std::stop_token stop_token) {
-            Common::SetCurrentThreadName(std::string{service_name}.c_str());
+void ServiceThread::Impl::WaitAndProcessImpl() {
+    // Create local list of waitable sessions.
+    std::vector<KSynchronizationObject*> objs;
+    std::vector<std::shared_ptr<SessionRequestManager>> managers;
 
-            // Wait for first request before trying to acquire a render context
-            {
-                std::unique_lock lock{queue_mutex};
-                condition.wait(lock, stop_token, [this] { return !requests.empty(); });
-            }
+    {
+        // Lock to get the list.
+        std::scoped_lock lk{m_session_mutex};
 
-            if (stop_token.stop_requested()) {
-                return;
-            }
+        // Resize to the needed quantity.
+        objs.resize(m_sessions.size() + 1);
+        managers.resize(m_managers.size());
 
-            // Allocate a dummy guest thread for this host thread.
-            kernel.RegisterHostThread();
+        // Copy to our local list.
+        std::copy(m_sessions.begin(), m_sessions.end(), objs.begin());
+        std::copy(m_managers.begin(), m_managers.end(), managers.begin());
 
-            while (true) {
-                std::function<void()> task;
+        // Insert the wakeup event at the end.
+        objs.back() = &m_wakeup_event->GetReadableEvent();
+    }
 
-                {
-                    std::unique_lock lock{queue_mutex};
-                    condition.wait(lock, stop_token, [this] { return !requests.empty(); });
+    // Wait on the list of sessions.
+    s32 index{-1};
+    Result rc = KSynchronizationObject::Wait(kernel, &index, objs.data(),
+                                             static_cast<s32>(objs.size()), -1);
+    ASSERT(!rc.IsFailure());
+
+    // If this was the wakeup event, clear it and finish.
+    if (index >= static_cast<s64>(objs.size() - 1)) {
+        m_wakeup_event->Clear();
+        return;
+    }
 
-                    if (stop_token.stop_requested()) {
-                        return;
-                    }
+    // This event is from a server session.
+    auto* server_session = static_cast<KServerSession*>(objs[index]);
+    auto& manager = managers[index];
 
-                    if (requests.empty()) {
-                        continue;
-                    }
+    // Fetch the HLE request context.
+    std::shared_ptr<HLERequestContext> context;
+    rc = server_session->ReceiveRequest(&context, manager);
 
-                    task = std::move(requests.front());
-                    requests.pop();
-                }
+    // If the session was closed, handle that.
+    if (rc == ResultSessionClosed) {
+        SessionClosed(server_session, manager);
 
-                task();
-            }
-        });
+        // Finish.
+        return;
     }
+
+    // TODO: handle other cases
+    ASSERT(rc == ResultSuccess);
+
+    // Perform the request.
+    Result service_rc = manager->CompleteSyncRequest(server_session, *context);
+
+    // Reply to the client.
+    rc = server_session->SendReply(true);
+
+    if (rc == ResultSessionClosed || service_rc == IPC::ERR_REMOTE_PROCESS_DEAD) {
+        SessionClosed(server_session, manager);
+        return;
+    }
+
+    // TODO: handle other cases
+    ASSERT(rc == ResultSuccess);
+    ASSERT(service_rc == ResultSuccess);
 }
 
-void ServiceThread::Impl::QueueSyncRequest(KSession& session,
-                                           std::shared_ptr<HLERequestContext>&& context) {
+void ServiceThread::Impl::SessionClosed(KServerSession* server_session,
+                                        std::shared_ptr<SessionRequestManager> manager) {
     {
-        std::unique_lock lock{queue_mutex};
+        // Lock to get the list.
+        std::scoped_lock lk{m_session_mutex};
+
+        // Get the index of the session.
+        const auto index =
+            std::find(m_sessions.begin(), m_sessions.end(), server_session) - m_sessions.begin();
+        ASSERT(index < static_cast<s64>(m_sessions.size()));
+
+        // Remove the session and its manager.
+        m_sessions.erase(m_sessions.begin() + index);
+        m_managers.erase(m_managers.begin() + index);
+    }
 
-        auto* server_session{&session.GetServerSession()};
+    // Close our reference to the server session.
+    server_session->Close();
+}
 
-        // Open a reference to the session to ensure it is not closes while the service request
-        // completes asynchronously.
-        server_session->Open();
+void ServiceThread::Impl::LoopProcess() {
+    Common::SetCurrentThreadName(m_service_name.c_str());
 
-        requests.emplace([server_session, context{std::move(context)}]() {
-            // Close the reference.
-            SCOPE_EXIT({ server_session->Close(); });
+    kernel.RegisterHostThread();
 
-            // Complete the service request.
-            server_session->CompleteSyncRequest(*context);
-        });
+    while (!m_shutdown_requested.load()) {
+        WaitAndProcessImpl();
     }
-    condition.notify_one();
+}
+
+void ServiceThread::Impl::RegisterServerSession(KServerSession* server_session,
+                                                std::shared_ptr<SessionRequestManager> manager) {
+    // Open the server session.
+    server_session->Open();
+
+    {
+        // Lock to get the list.
+        std::scoped_lock lk{m_session_mutex};
+
+        // Insert the session and manager.
+        m_sessions.push_back(server_session);
+        m_managers.push_back(manager);
+    }
+
+    // Signal the wakeup event.
+    m_wakeup_event->Signal();
 }
 
 ServiceThread::Impl::~Impl() {
-    condition.notify_all();
-    for (auto& thread : threads) {
-        thread.request_stop();
-        thread.join();
+    // Shut down the processing thread.
+    m_shutdown_requested.store(true);
+    m_wakeup_event->Signal();
+    m_thread.join();
+
+    // Lock mutex.
+    m_session_mutex.lock();
+
+    // Close all remaining sessions.
+    for (size_t i = 0; i < m_sessions.size(); i++) {
+        m_sessions[i]->Close();
     }
+
+    // Close event.
+    m_wakeup_event->GetReadableEvent().Close();
+    m_wakeup_event->Close();
+
+    // Close process.
+    m_process->Close();
+}
+
+ServiceThread::Impl::Impl(KernelCore& kernel_, const std::string& service_name)
+    : kernel{kernel_}, m_service_name{service_name} {
+    // Initialize process.
+    m_process = KProcess::Create(kernel);
+    KProcess::Initialize(m_process, kernel.System(), service_name,
+                         KProcess::ProcessType::KernelInternal, kernel.GetSystemResourceLimit());
+
+    // Reserve a new event from the process resource limit
+    KScopedResourceReservation event_reservation(m_process, LimitableResource::Events);
+    ASSERT(event_reservation.Succeeded());
+
+    // Initialize event.
+    m_wakeup_event = KEvent::Create(kernel);
+    m_wakeup_event->Initialize(m_process);
+
+    // Commit the event reservation.
+    event_reservation.Commit();
+
+    // Register the event.
+    KEvent::Register(kernel, m_wakeup_event);
+
+    // Start thread.
+    m_thread = std::jthread([this] { LoopProcess(); });
 }
 
-ServiceThread::ServiceThread(KernelCore& kernel, std::size_t num_threads, const std::string& name)
-    : impl{std::make_unique<Impl>(kernel, num_threads, name)} {}
+ServiceThread::ServiceThread(KernelCore& kernel, const std::string& name)
+    : impl{std::make_unique<Impl>(kernel, name)} {}
 
 ServiceThread::~ServiceThread() = default;
 
-void ServiceThread::QueueSyncRequest(KSession& session,
-                                     std::shared_ptr<HLERequestContext>&& context) {
-    impl->QueueSyncRequest(session, std::move(context));
+void ServiceThread::RegisterServerSession(KServerSession* session,
+                                          std::shared_ptr<SessionRequestManager> manager) {
+    impl->RegisterServerSession(session, manager);
 }
 
 } // namespace Kernel
diff --git a/src/core/hle/kernel/service_thread.h b/src/core/hle/kernel/service_thread.h
index c5896f2bd..fb4325531 100644
--- a/src/core/hle/kernel/service_thread.h
+++ b/src/core/hle/kernel/service_thread.h
@@ -11,13 +11,15 @@ namespace Kernel {
 class HLERequestContext;
 class KernelCore;
 class KSession;
+class SessionRequestManager;
 
 class ServiceThread final {
 public:
-    explicit ServiceThread(KernelCore& kernel, std::size_t num_threads, const std::string& name);
+    explicit ServiceThread(KernelCore& kernel, const std::string& name);
     ~ServiceThread();
 
-    void QueueSyncRequest(KSession& session, std::shared_ptr<HLERequestContext>&& context);
+    void RegisterServerSession(KServerSession* session,
+                               std::shared_ptr<SessionRequestManager> manager);
 
 private:
     class Impl;
diff --git a/src/core/hle/kernel/svc.cpp b/src/core/hle/kernel/svc.cpp
index 4aca5b27d..8d2c7d6b7 100644
--- a/src/core/hle/kernel/svc.cpp
+++ b/src/core/hle/kernel/svc.cpp
@@ -24,6 +24,7 @@
 #include "core/hle/kernel/k_memory_block.h"
 #include "core/hle/kernel/k_memory_layout.h"
 #include "core/hle/kernel/k_page_table.h"
+#include "core/hle/kernel/k_port.h"
 #include "core/hle/kernel/k_process.h"
 #include "core/hle/kernel/k_readable_event.h"
 #include "core/hle/kernel/k_resource_limit.h"
@@ -382,10 +383,11 @@ static Result ConnectToNamedPort(Core::System& system, Handle* out, VAddr port_n
 
     // Create a session.
     KClientSession* session{};
-    R_TRY(port->CreateSession(std::addressof(session),
-                              std::make_shared<SessionRequestManager>(kernel)));
+    R_TRY(port->CreateSession(std::addressof(session)));
     port->Close();
 
+    kernel.RegisterNamedServiceHandler(port_name, &port->GetParent()->GetServerPort());
+
     // Register the session in the table, close the extra reference.
     handle_table.Register(*out, session);
     session->Close();