15 files changed, 569 insertions, 352 deletions

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index eb8f643a2..1b44148f4 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -548,8 +548,6 @@ add_library(core STATIC
     hle/service/es/es.h
     hle/service/eupld/eupld.cpp
     hle/service/eupld/eupld.h
-    hle/service/event.cpp
-    hle/service/event.h
     hle/service/fatal/fatal.cpp
     hle/service/fatal/fatal.h
     hle/service/fatal/fatal_p.cpp
@@ -676,8 +674,6 @@ add_library(core STATIC
     hle/service/mm/mm_u.h
     hle/service/mnpp/mnpp_app.cpp
     hle/service/mnpp/mnpp_app.h
-    hle/service/mutex.cpp
-    hle/service/mutex.h
     hle/service/ncm/ncm.cpp
     hle/service/ncm/ncm.h
     hle/service/nfc/common/amiibo_crypto.cpp
@@ -790,6 +786,15 @@ add_library(core STATIC
     hle/service/nvnflinger/window.h
     hle/service/olsc/olsc.cpp
     hle/service/olsc/olsc.h
+    hle/service/os/event.cpp
+    hle/service/os/event.h
+    hle/service/os/multi_wait_holder.cpp
+    hle/service/os/multi_wait_holder.h
+    hle/service/os/multi_wait_utils.h
+    hle/service/os/multi_wait.cpp
+    hle/service/os/multi_wait.h
+    hle/service/os/mutex.cpp
+    hle/service/os/mutex.h
     hle/service/pcie/pcie.cpp
     hle/service/pcie/pcie.h
     hle/service/pctl/pctl.cpp
diff --git a/src/core/hle/service/am/applet.h b/src/core/hle/service/am/applet.h
index bce6f9050..b29ecdfed 100644
--- a/src/core/hle/service/am/applet.h
+++ b/src/core/hle/service/am/applet.h
@@ -9,8 +9,8 @@
 #include "common/math_util.h"
 #include "core/hle/service/apm/apm_controller.h"
 #include "core/hle/service/caps/caps_types.h"
-#include "core/hle/service/event.h"
 #include "core/hle/service/kernel_helpers.h"
+#include "core/hle/service/os/event.h"
 #include "core/hle/service/service.h"
 
 #include "core/hle/service/am/am_types.h"
diff --git a/src/core/hle/service/am/applet_data_broker.h b/src/core/hle/service/am/applet_data_broker.h
index 12326fd04..5a1d43c11 100644
--- a/src/core/hle/service/am/applet_data_broker.h
+++ b/src/core/hle/service/am/applet_data_broker.h
@@ -7,8 +7,8 @@
 #include <memory>
 #include <mutex>
 
-#include "core/hle/service/event.h"
 #include "core/hle/service/kernel_helpers.h"
+#include "core/hle/service/os/event.h"
 
 union Result;
 
diff --git a/src/core/hle/service/glue/time/worker.cpp b/src/core/hle/service/glue/time/worker.cpp
index f44f3077e..8787f2dcd 100644
--- a/src/core/hle/service/glue/time/worker.cpp
+++ b/src/core/hle/service/glue/time/worker.cpp
@@ -7,6 +7,7 @@
 #include "core/hle/service/glue/time/file_timestamp_worker.h"
 #include "core/hle/service/glue/time/standard_steady_clock_resource.h"
 #include "core/hle/service/glue/time/worker.h"
+#include "core/hle/service/os/multi_wait_utils.h"
 #include "core/hle/service/psc/time/common.h"
 #include "core/hle/service/psc/time/service_manager.h"
 #include "core/hle/service/psc/time/static.h"
@@ -143,82 +144,46 @@ void TimeWorker::ThreadFunc(std::stop_token stop_token) {
     Common::SetCurrentThreadName("TimeWorker");
     Common::SetCurrentThreadPriority(Common::ThreadPriority::Low);
 
-    enum class EventType {
-        Exit = 0,
-        IpmModuleService_GetEvent = 1,
-        PowerStateChange = 2,
-        SignalAlarms = 3,
-        UpdateLocalSystemClock = 4,
-        UpdateNetworkSystemClock = 5,
-        UpdateEphemeralSystemClock = 6,
-        UpdateSteadyClock = 7,
-        UpdateFileTimestamp = 8,
-        AutoCorrect = 9,
-        Max = 10,
-    };
-
-    s32 num_objs{};
-    std::array<Kernel::KSynchronizationObject*, static_cast<u32>(EventType::Max)> wait_objs{};
-    std::array<EventType, static_cast<u32>(EventType::Max)> wait_indices{};
-
-    const auto AddWaiter{
-        [&](Kernel::KSynchronizationObject* synchronization_object, EventType type) {
-            // Open a new reference to the object.
-            synchronization_object->Open();
-
-            // Insert into the list.
-            wait_indices[num_objs] = type;
-            wait_objs[num_objs++] = synchronization_object;
-        }};
-
     while (!stop_token.stop_requested()) {
-        SCOPE_EXIT({
-            for (s32 i = 0; i < num_objs; i++) {
-                wait_objs[i]->Close();
-            }
-        });
+        enum class EventType : s32 {
+            Exit = 0,
+            PowerStateChange = 1,
+            SignalAlarms = 2,
+            UpdateLocalSystemClock = 3,
+            UpdateNetworkSystemClock = 4,
+            UpdateEphemeralSystemClock = 5,
+            UpdateSteadyClock = 6,
+            UpdateFileTimestamp = 7,
+            AutoCorrect = 8,
+        };
+
+        s32 index{};
 
-        num_objs = {};
-        wait_objs = {};
         if (m_pm_state_change_handler.m_priority != 0) {
-            AddWaiter(&m_event->GetReadableEvent(), EventType::Exit);
-            // TODO
-            // AddWaiter(gIPmModuleService::GetEvent(), 1);
-            AddWaiter(&m_alarm_worker.GetEvent(), EventType::PowerStateChange);
+            // TODO: gIPmModuleService::GetEvent() 1
+            index = WaitAny(m_system.Kernel(),
+                            &m_event->GetReadableEvent(), // 0
+                            &m_alarm_worker.GetEvent()    // 1
+            );
         } else {
-            AddWaiter(&m_event->GetReadableEvent(), EventType::Exit);
-            // TODO
-            // AddWaiter(gIPmModuleService::GetEvent(), 1);
-            AddWaiter(&m_alarm_worker.GetEvent(), EventType::PowerStateChange);
-            AddWaiter(&m_alarm_worker.GetTimerEvent().GetReadableEvent(), EventType::SignalAlarms);
-            AddWaiter(m_local_clock_event, EventType::UpdateLocalSystemClock);
-            AddWaiter(m_network_clock_event, EventType::UpdateNetworkSystemClock);
-            AddWaiter(m_ephemeral_clock_event, EventType::UpdateEphemeralSystemClock);
-            AddWaiter(&m_timer_steady_clock->GetReadableEvent(), EventType::UpdateSteadyClock);
-            AddWaiter(&m_timer_file_system->GetReadableEvent(), EventType::UpdateFileTimestamp);
-            AddWaiter(m_standard_user_auto_correct_clock_event, EventType::AutoCorrect);
+            // TODO: gIPmModuleService::GetEvent() 1
+            index = WaitAny(m_system.Kernel(),
+                            &m_event->GetReadableEvent(),                       // 0
+                            &m_alarm_worker.GetEvent(),                         // 1
+                            &m_alarm_worker.GetTimerEvent().GetReadableEvent(), // 2
+                            m_local_clock_event,                                // 3
+                            m_network_clock_event,                              // 4
+                            m_ephemeral_clock_event,                            // 5
+                            &m_timer_steady_clock->GetReadableEvent(),          // 6
+                            &m_timer_file_system->GetReadableEvent(),           // 7
+                            m_standard_user_auto_correct_clock_event            // 8
+            );
         }
 
-        s32 out_index{-1};
-        Kernel::KSynchronizationObject::Wait(m_system.Kernel(), &out_index, wait_objs.data(),
-                                             num_objs, -1);
-        ASSERT(out_index >= 0 && out_index < num_objs);
-
-        if (stop_token.stop_requested()) {
-            return;
-        }
-
-        switch (wait_indices[out_index]) {
+        switch (static_cast<EventType>(index)) {
         case EventType::Exit:
             return;
 
-        case EventType::IpmModuleService_GetEvent:
-            // TODO
-            // IPmModuleService::GetEvent()
-            // clear the event
-            // Handle power state change event
-            break;
-
         case EventType::PowerStateChange:
             m_alarm_worker.GetEvent().Clear();
             if (m_pm_state_change_handler.m_priority <= 1) {
@@ -235,19 +200,19 @@ void TimeWorker::ThreadFunc(std::stop_token stop_token) {
             m_local_clock_event->Clear();
 
             Service::PSC::Time::SystemClockContext context{};
-            auto res = m_local_clock->GetSystemClockContext(&context);
-            ASSERT(res == ResultSuccess);
+            R_ASSERT(m_local_clock->GetSystemClockContext(&context));
 
             m_set_sys->SetUserSystemClockContext(context);
-
             m_file_timestamp_worker.SetFilesystemPosixTime();
-        } break;
+            break;
+        }
 
         case EventType::UpdateNetworkSystemClock: {
             m_network_clock_event->Clear();
+
             Service::PSC::Time::SystemClockContext context{};
-            auto res = m_network_clock->GetSystemClockContext(&context);
-            ASSERT(res == ResultSuccess);
+            R_ASSERT(m_network_clock->GetSystemClockContext(&context));
+
             m_set_sys->SetNetworkSystemClockContext(context);
 
             s64 time{};
@@ -267,7 +232,8 @@ void TimeWorker::ThreadFunc(std::stop_token stop_token) {
             }
 
             m_file_timestamp_worker.SetFilesystemPosixTime();
-        } break;
+            break;
+        }
 
         case EventType::UpdateEphemeralSystemClock: {
             m_ephemeral_clock_event->Clear();
@@ -295,7 +261,8 @@ void TimeWorker::ThreadFunc(std::stop_token stop_token) {
             if (!g_ig_report_ephemeral_clock_context_set) {
                 g_ig_report_ephemeral_clock_context_set = true;
             }
-        } break;
+            break;
+        }
 
         case EventType::UpdateSteadyClock:
             m_timer_steady_clock->Clear();
@@ -314,21 +281,20 @@ void TimeWorker::ThreadFunc(std::stop_token stop_token) {
             m_standard_user_auto_correct_clock_event->Clear();
 
             bool automatic_correction{};
-            auto res = m_time_sm->IsStandardUserSystemClockAutomaticCorrectionEnabled(
-                &automatic_correction);
-            ASSERT(res == ResultSuccess);
+            R_ASSERT(m_time_sm->IsStandardUserSystemClockAutomaticCorrectionEnabled(
+                &automatic_correction));
 
             Service::PSC::Time::SteadyClockTimePoint time_point{};
-            res = m_time_sm->GetStandardUserSystemClockAutomaticCorrectionUpdatedTime(&time_point);
-            ASSERT(res == ResultSuccess);
+            R_ASSERT(
+                m_time_sm->GetStandardUserSystemClockAutomaticCorrectionUpdatedTime(&time_point));
 
             m_set_sys->SetUserSystemClockAutomaticCorrectionEnabled(automatic_correction);
             m_set_sys->SetUserSystemClockAutomaticCorrectionUpdatedTime(time_point);
-        } break;
+            break;
+        }
 
         default:
             UNREACHABLE();
-            break;
         }
     }
 }
diff --git a/src/core/hle/service/event.cpp b/src/core/hle/service/os/event.cpp
index 375660d72..ec52c17fd 100644
--- a/src/core/hle/service/event.cpp
+++ b/src/core/hle/service/os/event.cpp
@@ -2,8 +2,8 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include "core/hle/kernel/k_event.h"
-#include "core/hle/service/event.h"
 #include "core/hle/service/kernel_helpers.h"
+#include "core/hle/service/os/event.h"
 
 namespace Service {
 
diff --git a/src/core/hle/service/event.h b/src/core/hle/service/os/event.h
index cdbc4635a..cdbc4635a 100644
--- a/src/core/hle/service/event.h
+++ b/src/core/hle/service/os/event.h
diff --git a/src/core/hle/service/os/multi_wait.cpp b/src/core/hle/service/os/multi_wait.cpp
new file mode 100644
index 000000000..7b80d28be
--- /dev/null
+++ b/src/core/hle/service/os/multi_wait.cpp
@@ -0,0 +1,59 @@
+// SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "core/hle/kernel/k_hardware_timer.h"
+#include "core/hle/kernel/k_synchronization_object.h"
+#include "core/hle/kernel/kernel.h"
+#include "core/hle/kernel/svc_common.h"
+#include "core/hle/service/os/multi_wait.h"
+
+namespace Service {
+
+MultiWait::MultiWait() = default;
+MultiWait::~MultiWait() = default;
+
+MultiWaitHolder* MultiWait::WaitAny(Kernel::KernelCore& kernel) {
+    return this->TimedWaitImpl(kernel, -1);
+}
+
+MultiWaitHolder* MultiWait::TryWaitAny(Kernel::KernelCore& kernel) {
+    return this->TimedWaitImpl(kernel, 0);
+}
+
+MultiWaitHolder* MultiWait::TimedWaitAny(Kernel::KernelCore& kernel, s64 timeout_ns) {
+    return this->TimedWaitImpl(kernel, kernel.HardwareTimer().GetTick() + timeout_ns);
+}
+
+MultiWaitHolder* MultiWait::TimedWaitImpl(Kernel::KernelCore& kernel, s64 timeout_tick) {
+    std::array<MultiWaitHolder*, Kernel::Svc::ArgumentHandleCountMax> holders{};
+    std::array<Kernel::KSynchronizationObject*, Kernel::Svc::ArgumentHandleCountMax> objects{};
+
+    s32 out_index = -1;
+    s32 num_objects = 0;
+
+    for (auto it = m_wait_list.begin(); it != m_wait_list.end(); it++) {
+        ASSERT(num_objects < Kernel::Svc::ArgumentHandleCountMax);
+        holders[num_objects] = std::addressof(*it);
+        objects[num_objects] = it->GetNativeHandle();
+        num_objects++;
+    }
+
+    Kernel::KSynchronizationObject::Wait(kernel, std::addressof(out_index), objects.data(),
+                                         num_objects, timeout_tick);
+
+    if (out_index == -1) {
+        return nullptr;
+    } else {
+        return holders[out_index];
+    }
+}
+
+void MultiWait::MoveAll(MultiWait* other) {
+    while (!other->m_wait_list.empty()) {
+        MultiWaitHolder& holder = other->m_wait_list.front();
+        holder.UnlinkFromMultiWait();
+        holder.LinkToMultiWait(this);
+    }
+}
+
+} // namespace Service
diff --git a/src/core/hle/service/os/multi_wait.h b/src/core/hle/service/os/multi_wait.h
new file mode 100644
index 000000000..340c611b5
--- /dev/null
+++ b/src/core/hle/service/os/multi_wait.h
@@ -0,0 +1,36 @@
+// SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "core/hle/service/os/multi_wait_holder.h"
+
+namespace Kernel {
+class KernelCore;
+}
+
+namespace Service {
+
+class MultiWait final {
+public:
+    explicit MultiWait();
+    ~MultiWait();
+
+public:
+    MultiWaitHolder* WaitAny(Kernel::KernelCore& kernel);
+    MultiWaitHolder* TryWaitAny(Kernel::KernelCore& kernel);
+    MultiWaitHolder* TimedWaitAny(Kernel::KernelCore& kernel, s64 timeout_ns);
+    // TODO: SdkReplyAndReceive?
+
+    void MoveAll(MultiWait* other);
+
+private:
+    MultiWaitHolder* TimedWaitImpl(Kernel::KernelCore& kernel, s64 timeout_tick);
+
+private:
+    friend class MultiWaitHolder;
+    using ListType = Common::IntrusiveListMemberTraits<&MultiWaitHolder::m_list_node>::ListType;
+    ListType m_wait_list{};
+};
+
+} // namespace Service
diff --git a/src/core/hle/service/os/multi_wait_holder.cpp b/src/core/hle/service/os/multi_wait_holder.cpp
new file mode 100644
index 000000000..01efa045b
--- /dev/null
+++ b/src/core/hle/service/os/multi_wait_holder.cpp
@@ -0,0 +1,25 @@
+// SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "core/hle/service/os/multi_wait.h"
+#include "core/hle/service/os/multi_wait_holder.h"
+
+namespace Service {
+
+void MultiWaitHolder::LinkToMultiWait(MultiWait* multi_wait) {
+    if (m_multi_wait != nullptr) {
+        UNREACHABLE();
+    }
+
+    m_multi_wait = multi_wait;
+    m_multi_wait->m_wait_list.push_back(*this);
+}
+
+void MultiWaitHolder::UnlinkFromMultiWait() {
+    if (m_multi_wait) {
+        m_multi_wait->m_wait_list.erase(m_multi_wait->m_wait_list.iterator_to(*this));
+        m_multi_wait = nullptr;
+    }
+}
+
+} // namespace Service
diff --git a/src/core/hle/service/os/multi_wait_holder.h b/src/core/hle/service/os/multi_wait_holder.h
new file mode 100644
index 000000000..646395a3f
--- /dev/null
+++ b/src/core/hle/service/os/multi_wait_holder.h
@@ -0,0 +1,44 @@
+// SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "common/intrusive_list.h"
+
+namespace Kernel {
+class KSynchronizationObject;
+} // namespace Kernel
+
+namespace Service {
+
+class MultiWait;
+
+class MultiWaitHolder {
+public:
+    explicit MultiWaitHolder(Kernel::KSynchronizationObject* native_handle)
+        : m_native_handle(native_handle) {}
+
+    void LinkToMultiWait(MultiWait* multi_wait);
+    void UnlinkFromMultiWait();
+
+    void SetUserData(uintptr_t user_data) {
+        m_user_data = user_data;
+    }
+
+    uintptr_t GetUserData() const {
+        return m_user_data;
+    }
+
+    Kernel::KSynchronizationObject* GetNativeHandle() const {
+        return m_native_handle;
+    }
+
+private:
+    friend class MultiWait;
+    Common::IntrusiveListNode m_list_node{};
+    MultiWait* m_multi_wait{};
+    Kernel::KSynchronizationObject* m_native_handle{};
+    uintptr_t m_user_data{};
+};
+
+} // namespace Service
diff --git a/src/core/hle/service/os/multi_wait_utils.h b/src/core/hle/service/os/multi_wait_utils.h
new file mode 100644
index 000000000..96d3a10f3
--- /dev/null
+++ b/src/core/hle/service/os/multi_wait_utils.h
@@ -0,0 +1,109 @@
+// SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "core/hle/service/os/multi_wait.h"
+
+namespace Service {
+
+namespace impl {
+
+class AutoMultiWaitHolder {
+private:
+    MultiWaitHolder m_holder;
+
+public:
+    template <typename T>
+    explicit AutoMultiWaitHolder(MultiWait* multi_wait, T&& arg) : m_holder(arg) {
+        m_holder.LinkToMultiWait(multi_wait);
+    }
+
+    ~AutoMultiWaitHolder() {
+        m_holder.UnlinkFromMultiWait();
+    }
+
+    std::pair<MultiWaitHolder*, int> ConvertResult(const std::pair<MultiWaitHolder*, int> result,
+                                                   int index) {
+        if (result.first == std::addressof(m_holder)) {
+            return std::make_pair(static_cast<MultiWaitHolder*>(nullptr), index);
+        } else {
+            return result;
+        }
+    }
+};
+
+using WaitAnyFunction = decltype(&MultiWait::WaitAny);
+
+inline std::pair<MultiWaitHolder*, int> WaitAnyImpl(Kernel::KernelCore& kernel,
+                                                    MultiWait* multi_wait, WaitAnyFunction func,
+                                                    int) {
+    return std::pair<MultiWaitHolder*, int>((multi_wait->*func)(kernel), -1);
+}
+
+template <typename T, typename... Args>
+inline std::pair<MultiWaitHolder*, int> WaitAnyImpl(Kernel::KernelCore& kernel,
+                                                    MultiWait* multi_wait, WaitAnyFunction func,
+                                                    int index, T&& x, Args&&... args) {
+    AutoMultiWaitHolder holder(multi_wait, std::forward<T>(x));
+    return holder.ConvertResult(
+        WaitAnyImpl(kernel, multi_wait, func, index + 1, std::forward<Args>(args)...), index);
+}
+
+template <typename... Args>
+inline std::pair<MultiWaitHolder*, int> WaitAnyImpl(Kernel::KernelCore& kernel,
+                                                    MultiWait* multi_wait, WaitAnyFunction func,
+                                                    Args&&... args) {
+    return WaitAnyImpl(kernel, multi_wait, func, 0, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+inline std::pair<MultiWaitHolder*, int> WaitAnyImpl(Kernel::KernelCore& kernel,
+                                                    WaitAnyFunction func, Args&&... args) {
+    MultiWait temp_multi_wait;
+    return WaitAnyImpl(kernel, std::addressof(temp_multi_wait), func, 0,
+                       std::forward<Args>(args)...);
+}
+
+class NotBoolButInt {
+public:
+    constexpr NotBoolButInt(int v) : m_value(v) {}
+    constexpr operator int() const {
+        return m_value;
+    }
+    explicit operator bool() const = delete;
+
+private:
+    int m_value;
+};
+
+} // namespace impl
+
+template <typename... Args>
+    requires(sizeof...(Args) > 0)
+inline std::pair<MultiWaitHolder*, int> WaitAny(Kernel::KernelCore& kernel, MultiWait* multi_wait,
+                                                Args&&... args) {
+    return impl::WaitAnyImpl(kernel, &MultiWait::WaitAny, multi_wait, std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+    requires(sizeof...(Args) > 0)
+inline int WaitAny(Kernel::KernelCore& kernel, Args&&... args) {
+    return impl::WaitAnyImpl(kernel, &MultiWait::WaitAny, std::forward<Args>(args)...).second;
+}
+
+template <typename... Args>
+    requires(sizeof...(Args) > 0)
+inline std::pair<MultiWaitHolder*, int> TryWaitAny(Kernel::KernelCore& kernel,
+                                                   MultiWait* multi_wait, Args&&... args) {
+    return impl::WaitAnyImpl(kernel, &MultiWait::TryWaitAny, multi_wait,
+                             std::forward<Args>(args)...);
+}
+
+template <typename... Args>
+    requires(sizeof...(Args) > 0)
+inline impl::NotBoolButInt TryWaitAny(Kernel::KernelCore& kernel, Args&&... args) {
+    return impl::WaitAnyImpl(kernel, &MultiWait::TryWaitAny, std::forward<Args>(args)...).second;
+}
+
+} // namespace Service
diff --git a/src/core/hle/service/mutex.cpp b/src/core/hle/service/os/mutex.cpp
index b0ff71d1b..6009f4866 100644
--- a/src/core/hle/service/mutex.cpp
+++ b/src/core/hle/service/os/mutex.cpp
@@ -4,7 +4,7 @@
 #include "core/core.h"
 #include "core/hle/kernel/k_event.h"
 #include "core/hle/kernel/k_synchronization_object.h"
-#include "core/hle/service/mutex.h"
+#include "core/hle/service/os/mutex.h"
 
 namespace Service {
 
diff --git a/src/core/hle/service/mutex.h b/src/core/hle/service/os/mutex.h
index 95ac9b117..95ac9b117 100644
--- a/src/core/hle/service/mutex.h
+++ b/src/core/hle/service/os/mutex.h
diff --git a/src/core/hle/service/server_manager.cpp b/src/core/hle/service/server_manager.cpp
index 8ef49387d..8c7f94c8c 100644
--- a/src/core/hle/service/server_manager.cpp
+++ b/src/core/hle/service/server_manager.cpp
@@ -20,50 +20,91 @@
 
 namespace Service {
 
-constexpr size_t MaximumWaitObjects = 0x40;
-
-enum HandleType {
+enum class UserDataTag {
     Port,
     Session,
     DeferEvent,
-    Event,
 };
 
-ServerManager::ServerManager(Core::System& system) : m_system{system}, m_serve_mutex{system} {
+class Port : public MultiWaitHolder, public Common::IntrusiveListBaseNode<Port> {
+public:
+    explicit Port(Kernel::KServerPort* server_port, SessionRequestHandlerFactory&& handler_factory)
+        : MultiWaitHolder(server_port), m_handler_factory(std::move(handler_factory)) {
+        this->SetUserData(static_cast<uintptr_t>(UserDataTag::Port));
+    }
+
+    ~Port() {
+        this->GetNativeHandle()->Close();
+    }
+
+    SessionRequestHandlerPtr CreateHandler() {
+        return m_handler_factory();
+    }
+
+private:
+    const SessionRequestHandlerFactory m_handler_factory;
+};
+
+class Session : public MultiWaitHolder, public Common::IntrusiveListBaseNode<Session> {
+public:
+    explicit Session(Kernel::KServerSession* server_session,
+                     std::shared_ptr<SessionRequestManager>&& manager)
+        : MultiWaitHolder(server_session), m_manager(std::move(manager)) {
+        this->SetUserData(static_cast<uintptr_t>(UserDataTag::Session));
+    }
+
+    ~Session() {
+        this->GetNativeHandle()->Close();
+    }
+
+    std::shared_ptr<SessionRequestManager>& GetManager() {
+        return m_manager;
+    }
+
+    std::shared_ptr<HLERequestContext>& GetContext() {
+        return m_context;
+    }
+
+private:
+    std::shared_ptr<SessionRequestManager> m_manager;
+    std::shared_ptr<HLERequestContext> m_context;
+};
+
+ServerManager::ServerManager(Core::System& system) : m_system{system}, m_selection_mutex{system} {
     // Initialize event.
-    m_event = Kernel::KEvent::Create(system.Kernel());
-    m_event->Initialize(nullptr);
+    m_wakeup_event = Kernel::KEvent::Create(system.Kernel());
+    m_wakeup_event->Initialize(nullptr);
 
     // Register event.
-    Kernel::KEvent::Register(system.Kernel(), m_event);
+    Kernel::KEvent::Register(system.Kernel(), m_wakeup_event);
+
+    // Link to holder.
+    m_wakeup_holder.emplace(std::addressof(m_wakeup_event->GetReadableEvent()));
+    m_wakeup_holder->LinkToMultiWait(std::addressof(m_deferred_list));
 }
 
 ServerManager::~ServerManager() {
     // Signal stop.
     m_stop_source.request_stop();
-    m_event->Signal();
+    m_wakeup_event->Signal();
 
     // Wait for processing to stop.
     m_stopped.Wait();
     m_threads.clear();
 
-    // Clean up server ports.
-    for (const auto& [port, handler] : m_ports) {
-        port->Close();
+    // Clean up ports.
+    for (auto it = m_servers.begin(); it != m_servers.end(); it = m_servers.erase(it)) {
+        delete std::addressof(*it);
     }
 
     // Clean up sessions.
-    for (const auto& [session, manager] : m_sessions) {
-        session->Close();
-    }
-
-    for (const auto& request : m_deferrals) {
-        request.session->Close();
+    for (auto it = m_sessions.begin(); it != m_sessions.end(); it = m_sessions.erase(it)) {
+        delete std::addressof(*it);
     }
 
-    // Close event.
-    m_event->GetReadableEvent().Close();
-    m_event->Close();
+    // Close wakeup event.
+    m_wakeup_event->GetReadableEvent().Close();
+    m_wakeup_event->Close();
 
     if (m_deferral_event) {
         m_deferral_event->GetReadableEvent().Close();
@@ -75,19 +116,19 @@ void ServerManager::RunServer(std::unique_ptr<ServerManager>&& server_manager) {
     server_manager->m_system.RunServer(std::move(server_manager));
 }
 
-Result ServerManager::RegisterSession(Kernel::KServerSession* session,
+Result ServerManager::RegisterSession(Kernel::KServerSession* server_session,
                                       std::shared_ptr<SessionRequestManager> manager) {
-    ASSERT(m_sessions.size() + m_ports.size() < MaximumWaitObjects);
-
     // We are taking ownership of the server session, so don't open it.
+    auto* session = new Session(server_session, std::move(manager));
+
     // Begin tracking the server session.
     {
-        std::scoped_lock ll{m_list_mutex};
-        m_sessions.emplace(session, std::move(manager));
+        std::scoped_lock ll{m_deferred_list_mutex};
+        m_sessions.push_back(*session);
     }
 
-    // Signal the wakeup event.
-    m_event->Signal();
+    // Register to wait on the session.
+    this->LinkToDeferredList(session);
 
     R_SUCCEED();
 }
@@ -95,21 +136,22 @@ Result ServerManager::RegisterSession(Kernel::KServerSession* session,
 Result ServerManager::RegisterNamedService(const std::string& service_name,
                                            SessionRequestHandlerFactory&& handler_factory,
                                            u32 max_sessions) {
-    ASSERT(m_sessions.size() + m_ports.size() < MaximumWaitObjects);
-
     // Add the new server to sm: and get the moved server port.
     Kernel::KServerPort* server_port{};
     R_ASSERT(m_system.ServiceManager().RegisterService(std::addressof(server_port), service_name,
                                                        max_sessions, handler_factory));
 
+    // We are taking ownership of the server port, so don't open it.
+    auto* server = new Port(server_port, std::move(handler_factory));
+
     // Begin tracking the server port.
     {
-        std::scoped_lock ll{m_list_mutex};
-        m_ports.emplace(server_port, std::move(handler_factory));
+        std::scoped_lock ll{m_deferred_list_mutex};
+        m_servers.push_back(*server);
     }
 
-    // Signal the wakeup event.
-    m_event->Signal();
+    // Register to wait on the server port.
+    this->LinkToDeferredList(server);
 
     R_SUCCEED();
 }
@@ -127,8 +169,6 @@ Result ServerManager::RegisterNamedService(const std::string& service_name,
 Result ServerManager::ManageNamedPort(const std::string& service_name,
                                       SessionRequestHandlerFactory&& handler_factory,
                                       u32 max_sessions) {
-    ASSERT(m_sessions.size() + m_ports.size() < MaximumWaitObjects);
-
     // Create a new port.
     auto* port = Kernel::KPort::Create(m_system.Kernel());
     port->Initialize(max_sessions, false, 0);
@@ -149,12 +189,18 @@ Result ServerManager::ManageNamedPort(const std::string& service_name,
     // Open a new reference to the server port.
     port->GetServerPort().Open();
 
-    // Begin tracking the server port.
+    // Transfer ownership into a new port object.
+    auto* server = new Port(std::addressof(port->GetServerPort()), std::move(handler_factory));
+
+    // Begin tracking the port.
     {
-        std::scoped_lock ll{m_list_mutex};
-        m_ports.emplace(std::addressof(port->GetServerPort()), std::move(handler_factory));
+        std::scoped_lock ll{m_deferred_list_mutex};
+        m_servers.push_back(*server);
     }
 
+    // Register to wait on the port.
+    this->LinkToDeferredList(server);
+
     // We succeeded.
     R_SUCCEED();
 }
@@ -173,6 +219,11 @@ Result ServerManager::ManageDeferral(Kernel::KEvent** out_event) {
     // Set the output.
     *out_event = m_deferral_event;
 
+    // Register to wait on the event.
+    m_deferral_holder.emplace(std::addressof(m_deferral_event->GetReadableEvent()));
+    m_deferral_holder->SetUserData(static_cast<uintptr_t>(UserDataTag::DeferEvent));
+    this->LinkToDeferredList(std::addressof(*m_deferral_holder));
+
     // We succeeded.
     R_SUCCEED();
 }
@@ -191,270 +242,185 @@ Result ServerManager::LoopProcess() {
     R_RETURN(this->LoopProcessImpl());
 }
 
-Result ServerManager::LoopProcessImpl() {
-    while (!m_stop_source.stop_requested()) {
-        R_TRY(this->WaitAndProcessImpl());
+void ServerManager::LinkToDeferredList(MultiWaitHolder* holder) {
+    // Link.
+    {
+        std::scoped_lock lk{m_deferred_list_mutex};
+        holder->LinkToMultiWait(std::addressof(m_deferred_list));
     }
 
-    R_SUCCEED();
+    // Signal the wakeup event.
+    m_wakeup_event->Signal();
 }
 
-Result ServerManager::WaitAndProcessImpl() {
-    Kernel::KScopedAutoObject<Kernel::KSynchronizationObject> wait_obj;
-    HandleType wait_type{};
+void ServerManager::LinkDeferred() {
+    std::scoped_lock lk{m_deferred_list_mutex};
+    m_multi_wait.MoveAll(std::addressof(m_deferred_list));
+}
 
+MultiWaitHolder* ServerManager::WaitSignaled() {
     // Ensure we are the only thread waiting for this server.
-    std::unique_lock sl{m_serve_mutex};
+    std::scoped_lock lk{m_selection_mutex};
 
-    // If we're done, return before we start waiting.
-    R_SUCCEED_IF(m_stop_source.stop_requested());
+    while (true) {
+        this->LinkDeferred();
 
-    // Wait for a tracked object to become signaled.
-    {
-        s32 num_objs{};
-        std::array<HandleType, MaximumWaitObjects> wait_types{};
-        std::array<Kernel::KSynchronizationObject*, MaximumWaitObjects> wait_objs{};
-
-        const auto AddWaiter{
-            [&](Kernel::KSynchronizationObject* synchronization_object, HandleType type) {
-                // Open a new reference to the object.
-                synchronization_object->Open();
-
-                // Insert into the list.
-                wait_types[num_objs] = type;
-                wait_objs[num_objs++] = synchronization_object;
-            }};
-
-        {
-            std::scoped_lock ll{m_list_mutex};
-
-            // Add all of our ports.
-            for (const auto& [port, handler] : m_ports) {
-                AddWaiter(port, HandleType::Port);
-            }
-
-            // Add all of our sessions.
-            for (const auto& [session, manager] : m_sessions) {
-                AddWaiter(session, HandleType::Session);
-            }
+        // If we're done, return before we start waiting.
+        if (m_stop_source.stop_requested()) {
+            return nullptr;
         }
 
-        // Add the deferral wakeup event.
-        if (m_deferral_event != nullptr) {
-            AddWaiter(std::addressof(m_deferral_event->GetReadableEvent()), HandleType::DeferEvent);
+        auto* selected = m_multi_wait.WaitAny(m_system.Kernel());
+        if (selected == std::addressof(*m_wakeup_holder)) {
+            // Clear and restart if we were woken up.
+            m_wakeup_event->Clear();
+        } else {
+            // Unlink and handle the event.
+            selected->UnlinkFromMultiWait();
+            return selected;
         }
+    }
+}
 
-        // Add the wakeup event.
-        AddWaiter(std::addressof(m_event->GetReadableEvent()), HandleType::Event);
-
-        // Clean up extra references on exit.
-        SCOPE_EXIT({
-            for (s32 i = 0; i < num_objs; i++) {
-                wait_objs[i]->Close();
-            }
-        });
-
-        // Wait for a signal.
-        s32 out_index{-1};
-        R_TRY_CATCH(Kernel::KSynchronizationObject::Wait(m_system.Kernel(), &out_index,
-                                                         wait_objs.data(), num_objs, -1)) {
-            R_CATCH(Kernel::ResultSessionClosed) {
-                // On session closed, index is updated and we don't want to return an error.
-            }
-        }
-        R_END_TRY_CATCH;
-        ASSERT(out_index >= 0 && out_index < num_objs);
+Result ServerManager::Process(MultiWaitHolder* holder) {
+    switch (static_cast<UserDataTag>(holder->GetUserData())) {
+    case UserDataTag::Session:
+        R_RETURN(this->OnSessionEvent(static_cast<Session*>(holder)));
+    case UserDataTag::Port:
+        R_RETURN(this->OnPortEvent(static_cast<Port*>(holder)));
+    case UserDataTag::DeferEvent:
+        R_RETURN(this->OnDeferralEvent());
+    default:
+        UNREACHABLE();
+    }
+}
 
-        // Set the output index.
-        wait_obj = wait_objs[out_index];
-        wait_type = wait_types[out_index];
+bool ServerManager::WaitAndProcessImpl() {
+    if (auto* signaled_holder = this->WaitSignaled(); signaled_holder != nullptr) {
+        R_ASSERT(this->Process(signaled_holder));
+        return true;
+    } else {
+        return false;
     }
+}
 
-    // Process what we just received, temporarily removing the object so it is
-    // not processed concurrently by another thread.
-    {
-        switch (wait_type) {
-        case HandleType::Port: {
-            // Port signaled.
-            auto* port = wait_obj->DynamicCast<Kernel::KServerPort*>();
-            SessionRequestHandlerFactory handler_factory;
-
-            // Remove from tracking.
-            {
-                std::scoped_lock ll{m_list_mutex};
-                ASSERT(m_ports.contains(port));
-                m_ports.at(port).swap(handler_factory);
-                m_ports.erase(port);
-            }
-
-            // Allow other threads to serve.
-            sl.unlock();
-
-            // Finish.
-            R_RETURN(this->OnPortEvent(port, std::move(handler_factory)));
-        }
-        case HandleType::Session: {
-            // Session signaled.
-            auto* session = wait_obj->DynamicCast<Kernel::KServerSession*>();
-            std::shared_ptr<SessionRequestManager> manager;
-
-            // Remove from tracking.
-            {
-                std::scoped_lock ll{m_list_mutex};
-                ASSERT(m_sessions.contains(session));
-                m_sessions.at(session).swap(manager);
-                m_sessions.erase(session);
-            }
-
-            // Allow other threads to serve.
-            sl.unlock();
-
-            // Finish.
-            R_RETURN(this->OnSessionEvent(session, std::move(manager)));
-        }
-        case HandleType::DeferEvent: {
-            // Clear event.
-            ASSERT(R_SUCCEEDED(m_deferral_event->Clear()));
-
-            // Drain the list of deferrals while we process.
-            std::list<RequestState> deferrals;
-            {
-                std::scoped_lock ll{m_list_mutex};
-                m_deferrals.swap(deferrals);
-            }
-
-            // Allow other threads to serve.
-            sl.unlock();
-
-            // Finish.
-            R_RETURN(this->OnDeferralEvent(std::move(deferrals)));
-        }
-        case HandleType::Event: {
-            // Clear event and finish.
-            R_RETURN(m_event->Clear());
-        }
-        default: {
-            UNREACHABLE();
-        }
-        }
+Result ServerManager::LoopProcessImpl() {
+    while (!m_stop_source.stop_requested()) {
+        this->WaitAndProcessImpl();
     }
+
+    R_SUCCEED();
 }
 
-Result ServerManager::OnPortEvent(Kernel::KServerPort* port,
-                                  SessionRequestHandlerFactory&& handler_factory) {
+Result ServerManager::OnPortEvent(Port* server) {
     // Accept a new server session.
-    Kernel::KServerSession* session = port->AcceptSession();
-    ASSERT(session != nullptr);
+    auto* server_port = static_cast<Kernel::KServerPort*>(server->GetNativeHandle());
+    Kernel::KServerSession* server_session = server_port->AcceptSession();
+    ASSERT(server_session != nullptr);
 
     // Create the session manager and install the handler.
     auto manager = std::make_shared<SessionRequestManager>(m_system.Kernel(), *this);
-    manager->SetSessionHandler(handler_factory());
+    manager->SetSessionHandler(server->CreateHandler());
 
-    // Track the server session.
-    {
-        std::scoped_lock ll{m_list_mutex};
-        m_ports.emplace(port, std::move(handler_factory));
-        m_sessions.emplace(session, std::move(manager));
-    }
+    // Create and register the new session.
+    this->RegisterSession(server_session, std::move(manager));
 
-    // Signal the wakeup event.
-    m_event->Signal();
+    // Resume tracking the port.
+    this->LinkToDeferredList(server);
 
     // We succeeded.
     R_SUCCEED();
 }
 
-Result ServerManager::OnSessionEvent(Kernel::KServerSession* session,
-                                     std::shared_ptr<SessionRequestManager>&& manager) {
-    Result rc{ResultSuccess};
+Result ServerManager::OnSessionEvent(Session* session) {
+    Result res = ResultSuccess;
 
     // Try to receive a message.
-    std::shared_ptr<HLERequestContext> context;
-    rc = session->ReceiveRequestHLE(&context, manager);
+    auto* server_session = static_cast<Kernel::KServerSession*>(session->GetNativeHandle());
+    res = server_session->ReceiveRequestHLE(&session->GetContext(), session->GetManager());
 
     // If the session has been closed, we're done.
-    if (rc == Kernel::ResultSessionClosed) {
-        // Close the session.
-        session->Close();
-
-        // Finish.
+    if (res == Kernel::ResultSessionClosed) {
+        this->DestroySession(session);
         R_SUCCEED();
     }
-    ASSERT(R_SUCCEEDED(rc));
 
-    RequestState request{
-        .session = session,
-        .context = std::move(context),
-        .manager = std::move(manager),
-    };
+    R_ASSERT(res);
 
     // Complete the sync request with deferral handling.
-    R_RETURN(this->CompleteSyncRequest(std::move(request)));
+    R_RETURN(this->CompleteSyncRequest(session));
 }
 
-Result ServerManager::CompleteSyncRequest(RequestState&& request) {
-    Result rc{ResultSuccess};
-    Result service_rc{ResultSuccess};
+Result ServerManager::CompleteSyncRequest(Session* session) {
+    Result res = ResultSuccess;
+    Result service_res = ResultSuccess;
 
     // Mark the request as not deferred.
-    request.context->SetIsDeferred(false);
+    session->GetContext()->SetIsDeferred(false);
 
     // Complete the request. We have exclusive access to this session.
-    service_rc = request.manager->CompleteSyncRequest(request.session, *request.context);
+    auto* server_session = static_cast<Kernel::KServerSession*>(session->GetNativeHandle());
+    service_res =
+        session->GetManager()->CompleteSyncRequest(server_session, *session->GetContext());
 
     // If we've been deferred, we're done.
-    if (request.context->GetIsDeferred()) {
-        // Insert into deferral list.
-        std::scoped_lock ll{m_list_mutex};
-        m_deferrals.emplace_back(std::move(request));
+    if (session->GetContext()->GetIsDeferred()) {
+        // Insert into deferred session list.
+        std::scoped_lock ll{m_deferred_list_mutex};
+        m_deferred_sessions.push_back(session);
 
         // Finish.
         R_SUCCEED();
     }
 
     // Send the reply.
-    rc = request.session->SendReplyHLE();
+    res = server_session->SendReplyHLE();
 
     // If the session has been closed, we're done.
-    if (rc == Kernel::ResultSessionClosed || service_rc == IPC::ResultSessionClosed) {
-        // Close the session.
-        request.session->Close();
-
-        // Finish.
+    if (res == Kernel::ResultSessionClosed || service_res == IPC::ResultSessionClosed) {
+        this->DestroySession(session);
         R_SUCCEED();
     }
 
-    ASSERT(R_SUCCEEDED(rc));
-    ASSERT(R_SUCCEEDED(service_rc));
-
-    // Reinsert the session.
-    {
-        std::scoped_lock ll{m_list_mutex};
-        m_sessions.emplace(request.session, std::move(request.manager));
-    }
+    R_ASSERT(res);
+    R_ASSERT(service_res);
 
-    // Signal the wakeup event.
-    m_event->Signal();
+    // We succeeded, so we can process future messages on this session.
+    this->LinkToDeferredList(session);
 
-    // We succeeded.
     R_SUCCEED();
 }
 
-Result ServerManager::OnDeferralEvent(std::list<RequestState>&& deferrals) {
-    ON_RESULT_FAILURE {
-        std::scoped_lock ll{m_list_mutex};
-        m_deferrals.splice(m_deferrals.end(), deferrals);
-    };
+Result ServerManager::OnDeferralEvent() {
+    // Clear event before grabbing the list.
+    m_deferral_event->Clear();
 
-    while (!deferrals.empty()) {
-        RequestState request = deferrals.front();
-        deferrals.pop_front();
+    // Get and clear list.
+    const auto deferrals = [&] {
+        std::scoped_lock lk{m_deferred_list_mutex};
+        return std::move(m_deferred_sessions);
+    }();
 
-        // Try again to complete the request.
-        R_TRY(this->CompleteSyncRequest(std::move(request)));
+    // Relink deferral event.
+    this->LinkToDeferredList(std::addressof(*m_deferral_holder));
+
+    // For each session, try again to complete the request.
+    for (auto* session : deferrals) {
+        R_ASSERT(this->CompleteSyncRequest(session));
     }
 
     R_SUCCEED();
 }
 
+void ServerManager::DestroySession(Session* session) {
+    // Unlink.
+    {
+        std::scoped_lock lk{m_deferred_list_mutex};
+        m_sessions.erase(m_sessions.iterator_to(*session));
+    }
+
+    // Free the session.
+    delete session;
+}
+
 } // namespace Service
diff --git a/src/core/hle/service/server_manager.h b/src/core/hle/service/server_manager.h
index c4bc07262..5173ce46e 100644
--- a/src/core/hle/service/server_manager.h
+++ b/src/core/hle/service/server_manager.h
@@ -3,18 +3,17 @@
 
 #pragma once
 
-#include <functional>
 #include <list>
-#include <map>
 #include <mutex>
-#include <string_view>
+#include <optional>
 #include <vector>
 
 #include "common/polyfill_thread.h"
 #include "common/thread.h"
 #include "core/hle/result.h"
 #include "core/hle/service/hle_ipc.h"
-#include "core/hle/service/mutex.h"
+#include "core/hle/service/os/multi_wait.h"
+#include "core/hle/service/os/mutex.h"
 
 namespace Core {
 class System;
@@ -24,11 +23,13 @@ namespace Kernel {
 class KEvent;
 class KServerPort;
 class KServerSession;
-class KSynchronizationObject;
 } // namespace Kernel
 
 namespace Service {
 
+class Port;
+class Session;
+
 class ServerManager {
 public:
     explicit ServerManager(Core::System& system);
@@ -52,34 +53,40 @@ public:
     static void RunServer(std::unique_ptr<ServerManager>&& server);
 
 private:
-    struct RequestState;
-
+    void LinkToDeferredList(MultiWaitHolder* holder);
+    void LinkDeferred();
+    MultiWaitHolder* WaitSignaled();
+    Result Process(MultiWaitHolder* holder);
+    bool WaitAndProcessImpl();
     Result LoopProcessImpl();
-    Result WaitAndProcessImpl();
-    Result OnPortEvent(Kernel::KServerPort* port, SessionRequestHandlerFactory&& handler_factory);
-    Result OnSessionEvent(Kernel::KServerSession* session,
-                          std::shared_ptr<SessionRequestManager>&& manager);
-    Result OnDeferralEvent(std::list<RequestState>&& deferrals);
-    Result CompleteSyncRequest(RequestState&& state);
+
+    Result OnPortEvent(Port* port);
+    Result OnSessionEvent(Session* session);
+    Result OnDeferralEvent();
+    Result CompleteSyncRequest(Session* session);
+
+private:
+    void DestroySession(Session* session);
 
 private:
     Core::System& m_system;
-    Mutex m_serve_mutex;
-    std::mutex m_list_mutex;
+    Mutex m_selection_mutex;
 
-    // Guest state tracking
-    std::map<Kernel::KServerPort*, SessionRequestHandlerFactory> m_ports{};
-    std::map<Kernel::KServerSession*, std::shared_ptr<SessionRequestManager>> m_sessions{};
-    Kernel::KEvent* m_event{};
+    // Events
+    Kernel::KEvent* m_wakeup_event{};
     Kernel::KEvent* m_deferral_event{};
 
-    // Deferral tracking
-    struct RequestState {
-        Kernel::KServerSession* session;
-        std::shared_ptr<HLERequestContext> context;
-        std::shared_ptr<SessionRequestManager> manager;
-    };
-    std::list<RequestState> m_deferrals{};
+    // Deferred wait list
+    std::mutex m_deferred_list_mutex{};
+    MultiWait m_deferred_list{};
+
+    // Guest state tracking
+    MultiWait m_multi_wait{};
+    Common::IntrusiveListBaseTraits<Port>::ListType m_servers{};
+    Common::IntrusiveListBaseTraits<Session>::ListType m_sessions{};
+    std::list<Session*> m_deferred_sessions{};
+    std::optional<MultiWaitHolder> m_wakeup_holder{};
+    std::optional<MultiWaitHolder> m_deferral_holder{};
 
     // Host state tracking
     Common::Event m_stopped{};