Merge pull request #5862 from bunnei/kevent

Kernel Rework: Refactor KEvent/KReadableEvent/KWritableEvent

21 files changed, 386 insertions, 291 deletions

diff --git a/src/core/hle/kernel/hle_ipc.cpp b/src/core/hle/kernel/hle_ipc.cpp
index c7b10ca7a..7ec62cf18 100644
--- a/src/core/hle/kernel/hle_ipc.cpp
+++ b/src/core/hle/kernel/hle_ipc.cpp
@@ -17,16 +17,16 @@
 #include "core/hle/kernel/errors.h"
 #include "core/hle/kernel/handle_table.h"
 #include "core/hle/kernel/hle_ipc.h"
+#include "core/hle/kernel/k_readable_event.h"
 #include "core/hle/kernel/k_scheduler.h"
 #include "core/hle/kernel/k_scoped_scheduler_lock_and_sleep.h"
 #include "core/hle/kernel/k_thread.h"
+#include "core/hle/kernel/k_writable_event.h"
 #include "core/hle/kernel/kernel.h"
 #include "core/hle/kernel/object.h"
 #include "core/hle/kernel/process.h"
-#include "core/hle/kernel/readable_event.h"
 #include "core/hle/kernel/server_session.h"
 #include "core/hle/kernel/time_manager.h"
-#include "core/hle/kernel/writable_event.h"
 #include "core/memory.h"
 
 namespace Kernel {
diff --git a/src/core/hle/kernel/hle_ipc.h b/src/core/hle/kernel/hle_ipc.h
index 9f764c79a..9a769781b 100644
--- a/src/core/hle/kernel/hle_ipc.h
+++ b/src/core/hle/kernel/hle_ipc.h
@@ -41,8 +41,8 @@ class KernelCore;
 class Process;
 class ServerSession;
 class KThread;
-class ReadableEvent;
-class WritableEvent;
+class KReadableEvent;
+class KWritableEvent;
 
 enum class ThreadWakeupReason;
 
diff --git a/src/core/hle/kernel/k_address_arbiter.cpp b/src/core/hle/kernel/k_address_arbiter.cpp
index 1685d25bb..f2f497dc4 100644
--- a/src/core/hle/kernel/k_address_arbiter.cpp
+++ b/src/core/hle/kernel/k_address_arbiter.cpp
@@ -120,7 +120,10 @@ ResultCode KAddressArbiter::SignalAndIncrementIfEqual(VAddr addr, s32 value, s32
         s32 user_value{};
         R_UNLESS(UpdateIfEqual(system, std::addressof(user_value), addr, value, value + 1),
                  Svc::ResultInvalidCurrentMemory);
-        R_UNLESS(user_value == value, Svc::ResultInvalidState);
+
+        if (user_value != value) {
+            return Svc::ResultInvalidState;
+        }
 
         auto it = thread_tree.nfind_light({addr, -1});
         while ((it != thread_tree.end()) && (count <= 0 || num_waiters < count) &&
@@ -211,7 +214,10 @@ ResultCode KAddressArbiter::SignalAndModifyByWaitingCountIfEqual(VAddr addr, s32
         }
 
         R_UNLESS(succeeded, Svc::ResultInvalidCurrentMemory);
-        R_UNLESS(user_value == value, Svc::ResultInvalidState);
+
+        if (user_value != value) {
+            return Svc::ResultInvalidState;
+        }
 
         while ((it != thread_tree.end()) && (count <= 0 || num_waiters < count) &&
                (it->GetAddressArbiterKey() == addr)) {
diff --git a/src/core/hle/kernel/k_event.cpp b/src/core/hle/kernel/k_event.cpp
new file mode 100644
index 000000000..bb2fa4ad5
--- /dev/null
+++ b/src/core/hle/kernel/k_event.cpp
@@ -0,0 +1,32 @@
+// Copyright 2021 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/hle/kernel/k_event.h"
+#include "core/hle/kernel/k_readable_event.h"
+#include "core/hle/kernel/k_writable_event.h"
+
+namespace Kernel {
+
+KEvent::KEvent(KernelCore& kernel, std::string&& name) : Object{kernel, std::move(name)} {}
+
+KEvent::~KEvent() = default;
+
+std::shared_ptr<KEvent> KEvent::Create(KernelCore& kernel, std::string&& name) {
+    return std::make_shared<KEvent>(kernel, std::move(name));
+}
+
+void KEvent::Initialize() {
+    // Create our sub events.
+    readable_event = std::make_shared<KReadableEvent>(kernel, GetName() + ":Readable");
+    writable_event = std::make_shared<KWritableEvent>(kernel, GetName() + ":Writable");
+
+    // Initialize our sub sessions.
+    readable_event->Initialize(this);
+    writable_event->Initialize(this);
+
+    // Mark initialized.
+    initialized = true;
+}
+
+} // namespace Kernel
diff --git a/src/core/hle/kernel/k_event.h b/src/core/hle/kernel/k_event.h
new file mode 100644
index 000000000..2fb887129
--- /dev/null
+++ b/src/core/hle/kernel/k_event.h
@@ -0,0 +1,57 @@
+// Copyright 2021 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/hle/kernel/object.h"
+
+namespace Kernel {
+
+class KernelCore;
+class KReadableEvent;
+class KWritableEvent;
+
+class KEvent final : public Object {
+public:
+    explicit KEvent(KernelCore& kernel, std::string&& name);
+    ~KEvent() override;
+
+    static std::shared_ptr<KEvent> Create(KernelCore& kernel, std::string&& name);
+
+    void Initialize();
+
+    void Finalize() override {}
+
+    std::string GetTypeName() const override {
+        return "KEvent";
+    }
+
+    static constexpr HandleType HANDLE_TYPE = HandleType::Event;
+    HandleType GetHandleType() const override {
+        return HANDLE_TYPE;
+    }
+
+    std::shared_ptr<KReadableEvent>& GetReadableEvent() {
+        return readable_event;
+    }
+
+    std::shared_ptr<KWritableEvent>& GetWritableEvent() {
+        return writable_event;
+    }
+
+    const std::shared_ptr<KReadableEvent>& GetReadableEvent() const {
+        return readable_event;
+    }
+
+    const std::shared_ptr<KWritableEvent>& GetWritableEvent() const {
+        return writable_event;
+    }
+
+private:
+    std::shared_ptr<KReadableEvent> readable_event;
+    std::shared_ptr<KWritableEvent> writable_event;
+    bool initialized{};
+};
+
+} // namespace Kernel
diff --git a/src/core/hle/kernel/k_readable_event.cpp b/src/core/hle/kernel/k_readable_event.cpp
new file mode 100644
index 000000000..d8a42dbaf
--- /dev/null
+++ b/src/core/hle/kernel/k_readable_event.cpp
@@ -0,0 +1,57 @@
+// Copyright 2021 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include "common/assert.h"
+#include "common/common_funcs.h"
+#include "common/logging/log.h"
+#include "core/hle/kernel/errors.h"
+#include "core/hle/kernel/k_readable_event.h"
+#include "core/hle/kernel/k_scheduler.h"
+#include "core/hle/kernel/k_thread.h"
+#include "core/hle/kernel/kernel.h"
+#include "core/hle/kernel/object.h"
+#include "core/hle/kernel/svc_results.h"
+
+namespace Kernel {
+
+KReadableEvent::KReadableEvent(KernelCore& kernel, std::string&& name)
+    : KSynchronizationObject{kernel, std::move(name)} {}
+KReadableEvent::~KReadableEvent() = default;
+
+bool KReadableEvent::IsSignaled() const {
+    ASSERT(kernel.GlobalSchedulerContext().IsLocked());
+
+    return is_signaled;
+}
+
+ResultCode KReadableEvent::Signal() {
+    KScopedSchedulerLock lk{kernel};
+
+    if (!is_signaled) {
+        is_signaled = true;
+        NotifyAvailable();
+    }
+
+    return RESULT_SUCCESS;
+}
+
+ResultCode KReadableEvent::Clear() {
+    Reset();
+
+    return RESULT_SUCCESS;
+}
+
+ResultCode KReadableEvent::Reset() {
+    KScopedSchedulerLock lk{kernel};
+
+    if (!is_signaled) {
+        return Svc::ResultInvalidState;
+    }
+
+    is_signaled = false;
+    return RESULT_SUCCESS;
+}
+
+} // namespace Kernel
diff --git a/src/core/hle/kernel/k_readable_event.h b/src/core/hle/kernel/k_readable_event.h
new file mode 100644
index 000000000..e6f0fd900
--- /dev/null
+++ b/src/core/hle/kernel/k_readable_event.h
@@ -0,0 +1,51 @@
+// Copyright 2021 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/hle/kernel/k_synchronization_object.h"
+#include "core/hle/kernel/object.h"
+#include "core/hle/result.h"
+
+namespace Kernel {
+
+class KernelCore;
+class KEvent;
+
+class KReadableEvent final : public KSynchronizationObject {
+public:
+    explicit KReadableEvent(KernelCore& kernel, std::string&& name);
+    ~KReadableEvent() override;
+
+    std::string GetTypeName() const override {
+        return "KReadableEvent";
+    }
+
+    static constexpr HandleType HANDLE_TYPE = HandleType::ReadableEvent;
+    HandleType GetHandleType() const override {
+        return HANDLE_TYPE;
+    }
+
+    KEvent* GetParent() const {
+        return parent;
+    }
+
+    void Initialize(KEvent* parent_) {
+        is_signaled = false;
+        parent = parent_;
+    }
+
+    bool IsSignaled() const override;
+    void Finalize() override {}
+
+    ResultCode Signal();
+    ResultCode Clear();
+    ResultCode Reset();
+
+private:
+    bool is_signaled{};
+    KEvent* parent{};
+};
+
+} // namespace Kernel
diff --git a/src/core/hle/kernel/k_synchronization_object.cpp b/src/core/hle/kernel/k_synchronization_object.cpp
index a3b34f82f..140cc46a7 100644
--- a/src/core/hle/kernel/k_synchronization_object.cpp
+++ b/src/core/hle/kernel/k_synchronization_object.cpp
@@ -132,6 +132,9 @@ ResultCode KSynchronizationObject::Wait(KernelCore& kernel, s32* out_index,
 
 KSynchronizationObject::KSynchronizationObject(KernelCore& kernel) : Object{kernel} {}
 
+KSynchronizationObject::KSynchronizationObject(KernelCore& kernel, std::string&& name)
+    : Object{kernel, std::move(name)} {}
+
 KSynchronizationObject::~KSynchronizationObject() = default;
 
 void KSynchronizationObject::NotifyAvailable(ResultCode result) {
diff --git a/src/core/hle/kernel/k_synchronization_object.h b/src/core/hle/kernel/k_synchronization_object.h
index f65c71c28..5803718fd 100644
--- a/src/core/hle/kernel/k_synchronization_object.h
+++ b/src/core/hle/kernel/k_synchronization_object.h
@@ -33,6 +33,7 @@ public:
 
 protected:
     explicit KSynchronizationObject(KernelCore& kernel);
+    explicit KSynchronizationObject(KernelCore& kernel, std::string&& name);
     virtual ~KSynchronizationObject();
 
     void NotifyAvailable(ResultCode result);
diff --git a/src/core/hle/kernel/k_writable_event.cpp b/src/core/hle/kernel/k_writable_event.cpp
new file mode 100644
index 000000000..25c52edb2
--- /dev/null
+++ b/src/core/hle/kernel/k_writable_event.cpp
@@ -0,0 +1,27 @@
+// Copyright 2021 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/hle/kernel/k_event.h"
+#include "core/hle/kernel/k_readable_event.h"
+#include "core/hle/kernel/k_writable_event.h"
+
+namespace Kernel {
+
+KWritableEvent::KWritableEvent(KernelCore& kernel, std::string&& name)
+    : Object{kernel, std::move(name)} {}
+KWritableEvent::~KWritableEvent() = default;
+
+void KWritableEvent::Initialize(KEvent* parent_) {
+    parent = parent_;
+}
+
+ResultCode KWritableEvent::Signal() {
+    return parent->GetReadableEvent()->Signal();
+}
+
+ResultCode KWritableEvent::Clear() {
+    return parent->GetReadableEvent()->Clear();
+}
+
+} // namespace Kernel
diff --git a/src/core/hle/kernel/k_writable_event.h b/src/core/hle/kernel/k_writable_event.h
new file mode 100644
index 000000000..518f5448d
--- /dev/null
+++ b/src/core/hle/kernel/k_writable_event.h
@@ -0,0 +1,44 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/hle/kernel/object.h"
+#include "core/hle/result.h"
+
+namespace Kernel {
+
+class KernelCore;
+class KEvent;
+
+class KWritableEvent final : public Object {
+public:
+    explicit KWritableEvent(KernelCore& kernel, std::string&& name);
+    ~KWritableEvent() override;
+
+    std::string GetTypeName() const override {
+        return "KWritableEvent";
+    }
+
+    static constexpr HandleType HANDLE_TYPE = HandleType::WritableEvent;
+    HandleType GetHandleType() const override {
+        return HANDLE_TYPE;
+    }
+
+    void Initialize(KEvent* parent_);
+
+    void Finalize() override {}
+
+    ResultCode Signal();
+    ResultCode Clear();
+
+    KEvent* GetParent() const {
+        return parent;
+    }
+
+private:
+    KEvent* parent{};
+};
+
+} // namespace Kernel
diff --git a/src/core/hle/kernel/object.cpp b/src/core/hle/kernel/object.cpp
index 2c571792b..d7f40c403 100644
--- a/src/core/hle/kernel/object.cpp
+++ b/src/core/hle/kernel/object.cpp
@@ -8,7 +8,10 @@
 
 namespace Kernel {
 
-Object::Object(KernelCore& kernel) : kernel{kernel}, object_id{kernel.CreateNewObjectID()} {}
+Object::Object(KernelCore& kernel_)
+    : kernel{kernel_}, object_id{kernel_.CreateNewObjectID()}, name{"[UNKNOWN KERNEL OBJECT]"} {}
+Object::Object(KernelCore& kernel_, std::string&& name_)
+    : kernel{kernel_}, object_id{kernel_.CreateNewObjectID()}, name{std::move(name_)} {}
 Object::~Object() = default;
 
 bool Object::IsWaitable() const {
@@ -21,6 +24,7 @@ bool Object::IsWaitable() const {
         return true;
 
     case HandleType::Unknown:
+    case HandleType::Event:
     case HandleType::WritableEvent:
     case HandleType::SharedMemory:
     case HandleType::TransferMemory:
diff --git a/src/core/hle/kernel/object.h b/src/core/hle/kernel/object.h
index be7fcb5fb..501e58b33 100644
--- a/src/core/hle/kernel/object.h
+++ b/src/core/hle/kernel/object.h
@@ -18,6 +18,7 @@ using Handle = u32;
 
 enum class HandleType : u32 {
     Unknown,
+    Event,
     WritableEvent,
     ReadableEvent,
     SharedMemory,
@@ -34,7 +35,8 @@ enum class HandleType : u32 {
 
 class Object : NonCopyable, public std::enable_shared_from_this<Object> {
 public:
-    explicit Object(KernelCore& kernel);
+    explicit Object(KernelCore& kernel_);
+    explicit Object(KernelCore& kernel_, std::string&& name_);
     virtual ~Object();
 
     /// Returns a unique identifier for the object. For debugging purposes only.
@@ -46,7 +48,7 @@ public:
         return "[BAD KERNEL OBJECT TYPE]";
     }
     virtual std::string GetName() const {
-        return "[UNKNOWN KERNEL OBJECT]";
+        return name;
     }
     virtual HandleType GetHandleType() const = 0;
 
@@ -69,6 +71,7 @@ protected:
 
 private:
     std::atomic<u32> object_id{0};
+    std::string name;
 };
 
 template <typename T>
diff --git a/src/core/hle/kernel/process.cpp b/src/core/hle/kernel/process.cpp
index afdb27c54..2286b292d 100644
--- a/src/core/hle/kernel/process.cpp
+++ b/src/core/hle/kernel/process.cpp
@@ -23,6 +23,7 @@
 #include "core/hle/kernel/memory/page_table.h"
 #include "core/hle/kernel/memory/slab_heap.h"
 #include "core/hle/kernel/process.h"
+#include "core/hle/kernel/svc_results.h"
 #include "core/hle/lock.h"
 #include "core/memory.h"
 #include "core/settings.h"
@@ -241,18 +242,16 @@ void Process::UnregisterThread(const KThread* thread) {
     thread_list.remove(thread);
 }
 
-ResultCode Process::ClearSignalState() {
-    KScopedSchedulerLock lock(system.Kernel());
-    if (status == ProcessStatus::Exited) {
-        LOG_ERROR(Kernel, "called on a terminated process instance.");
-        return ERR_INVALID_STATE;
-    }
+ResultCode Process::Reset() {
+    // Lock the process and the scheduler.
+    KScopedLightLock lk(state_lock);
+    KScopedSchedulerLock sl{kernel};
 
-    if (!is_signaled) {
-        LOG_ERROR(Kernel, "called on a process instance that isn't signaled.");
-        return ERR_INVALID_STATE;
-    }
+    // Validate that we're in a state that we can reset.
+    R_UNLESS(status != ProcessStatus::Exited, Svc::ResultInvalidState);
+    R_UNLESS(is_signaled, Svc::ResultInvalidState);
 
+    // Clear signaled.
     is_signaled = false;
     return RESULT_SUCCESS;
 }
diff --git a/src/core/hle/kernel/process.h b/src/core/hle/kernel/process.h
index c8af76ce8..320b0f347 100644
--- a/src/core/hle/kernel/process.h
+++ b/src/core/hle/kernel/process.h
@@ -312,7 +312,7 @@ public:
     /// @pre The process must be in a signaled state. If this is called on a
     ///      process instance that is not signaled, ERR_INVALID_STATE will be
     ///      returned.
-    ResultCode ClearSignalState();
+    ResultCode Reset();
 
     /**
      * Loads process-specifics configuration info with metadata provided
diff --git a/src/core/hle/kernel/readable_event.cpp b/src/core/hle/kernel/readable_event.cpp
deleted file mode 100644
index 596d01479..000000000
--- a/src/core/hle/kernel/readable_event.cpp
+++ /dev/null
@@ -1,52 +0,0 @@
-// Copyright 2014 Citra Emulator Project
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#include <algorithm>
-#include "common/assert.h"
-#include "common/logging/log.h"
-#include "core/hle/kernel/errors.h"
-#include "core/hle/kernel/k_scheduler.h"
-#include "core/hle/kernel/k_thread.h"
-#include "core/hle/kernel/kernel.h"
-#include "core/hle/kernel/object.h"
-#include "core/hle/kernel/readable_event.h"
-
-namespace Kernel {
-
-ReadableEvent::ReadableEvent(KernelCore& kernel) : KSynchronizationObject{kernel} {}
-ReadableEvent::~ReadableEvent() = default;
-
-void ReadableEvent::Signal() {
-    if (is_signaled) {
-        return;
-    }
-
-    is_signaled = true;
-    NotifyAvailable();
-}
-
-bool ReadableEvent::IsSignaled() const {
-    ASSERT(kernel.GlobalSchedulerContext().IsLocked());
-
-    return is_signaled;
-}
-
-void ReadableEvent::Clear() {
-    is_signaled = false;
-}
-
-ResultCode ReadableEvent::Reset() {
-    KScopedSchedulerLock lock(kernel);
-    if (!is_signaled) {
-        LOG_TRACE(Kernel, "Handle is not signaled! object_id={}, object_type={}, object_name={}",
-                  GetObjectId(), GetTypeName(), GetName());
-        return ERR_INVALID_STATE;
-    }
-
-    Clear();
-
-    return RESULT_SUCCESS;
-}
-
-} // namespace Kernel
diff --git a/src/core/hle/kernel/readable_event.h b/src/core/hle/kernel/readable_event.h
deleted file mode 100644
index 2195710c2..000000000
--- a/src/core/hle/kernel/readable_event.h
+++ /dev/null
@@ -1,59 +0,0 @@
-// Copyright 2014 Citra Emulator Project
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#pragma once
-
-#include "core/hle/kernel/k_synchronization_object.h"
-#include "core/hle/kernel/object.h"
-
-union ResultCode;
-
-namespace Kernel {
-
-class KernelCore;
-class WritableEvent;
-
-class ReadableEvent final : public KSynchronizationObject {
-    friend class WritableEvent;
-
-public:
-    ~ReadableEvent() override;
-
-    std::string GetTypeName() const override {
-        return "ReadableEvent";
-    }
-    std::string GetName() const override {
-        return name;
-    }
-
-    static constexpr HandleType HANDLE_TYPE = HandleType::ReadableEvent;
-    HandleType GetHandleType() const override {
-        return HANDLE_TYPE;
-    }
-
-    /// Unconditionally clears the readable event's state.
-    void Clear();
-
-    /// Clears the readable event's state if and only if it
-    /// has already been signaled.
-    ///
-    /// @pre The event must be in a signaled state. If this event
-    ///      is in an unsignaled state and this function is called,
-    ///      then ERR_INVALID_STATE will be returned.
-    ResultCode Reset();
-
-    void Signal();
-
-    bool IsSignaled() const override;
-
-    void Finalize() override {}
-
-private:
-    explicit ReadableEvent(KernelCore& kernel);
-
-    bool is_signaled{};
-    std::string name; ///< Name of event (optional)
-};
-
-} // namespace Kernel
diff --git a/src/core/hle/kernel/svc.cpp b/src/core/hle/kernel/svc.cpp
index 74eb90100..edf208eff 100644
--- a/src/core/hle/kernel/svc.cpp
+++ b/src/core/hle/kernel/svc.cpp
@@ -14,6 +14,7 @@
 #include "common/fiber.h"
 #include "common/logging/log.h"
 #include "common/microprofile.h"
+#include "common/scope_exit.h"
 #include "common/string_util.h"
 #include "core/arm/exclusive_monitor.h"
 #include "core/core.h"
@@ -26,18 +27,20 @@
 #include "core/hle/kernel/handle_table.h"
 #include "core/hle/kernel/k_address_arbiter.h"
 #include "core/hle/kernel/k_condition_variable.h"
+#include "core/hle/kernel/k_event.h"
+#include "core/hle/kernel/k_readable_event.h"
 #include "core/hle/kernel/k_resource_limit.h"
 #include "core/hle/kernel/k_scheduler.h"
 #include "core/hle/kernel/k_scoped_scheduler_lock_and_sleep.h"
 #include "core/hle/kernel/k_synchronization_object.h"
 #include "core/hle/kernel/k_thread.h"
+#include "core/hle/kernel/k_writable_event.h"
 #include "core/hle/kernel/kernel.h"
 #include "core/hle/kernel/memory/memory_block.h"
 #include "core/hle/kernel/memory/memory_layout.h"
 #include "core/hle/kernel/memory/page_table.h"
 #include "core/hle/kernel/physical_core.h"
 #include "core/hle/kernel/process.h"
-#include "core/hle/kernel/readable_event.h"
 #include "core/hle/kernel/shared_memory.h"
 #include "core/hle/kernel/svc.h"
 #include "core/hle/kernel/svc_results.h"
@@ -45,7 +48,6 @@
 #include "core/hle/kernel/svc_wrap.h"
 #include "core/hle/kernel/time_manager.h"
 #include "core/hle/kernel/transfer_memory.h"
-#include "core/hle/kernel/writable_event.h"
 #include "core/hle/lock.h"
 #include "core/hle/result.h"
 #include "core/hle/service/service.h"
@@ -1725,20 +1727,28 @@ static ResultCode CloseHandle32(Core::System& system, Handle handle) {
 static ResultCode ResetSignal(Core::System& system, Handle handle) {
     LOG_DEBUG(Kernel_SVC, "called handle 0x{:08X}", handle);
 
+    // Get the current handle table.
     const auto& handle_table = system.Kernel().CurrentProcess()->GetHandleTable();
 
-    auto event = handle_table.Get<ReadableEvent>(handle);
-    if (event) {
-        return event->Reset();
+    // Try to reset as readable event.
+    {
+        auto readable_event = handle_table.Get<KReadableEvent>(handle);
+        if (readable_event) {
+            return readable_event->Reset();
+        }
     }
 
-    auto process = handle_table.Get<Process>(handle);
-    if (process) {
-        return process->ClearSignalState();
+    // Try to reset as process.
+    {
+        auto process = handle_table.Get<Process>(handle);
+        if (process) {
+            return process->Reset();
+        }
     }
 
-    LOG_ERROR(Kernel_SVC, "Invalid handle (0x{:08X})", handle);
-    return ERR_INVALID_HANDLE;
+    LOG_ERROR(Kernel_SVC, "invalid handle (0x{:08X})", handle);
+
+    return Svc::ResultInvalidHandle;
 }
 
 static ResultCode ResetSignal32(Core::System& system, Handle handle) {
@@ -1866,80 +1876,92 @@ static ResultCode SetThreadCoreMask32(Core::System& system, Handle thread_handle
     return SetThreadCoreMask(system, thread_handle, core_id, affinity_mask);
 }
 
-static ResultCode CreateEvent(Core::System& system, Handle* write_handle, Handle* read_handle) {
-    LOG_DEBUG(Kernel_SVC, "called");
+static ResultCode SignalEvent(Core::System& system, Handle event_handle) {
+    LOG_DEBUG(Kernel_SVC, "called, event_handle=0x{:08X}", event_handle);
 
-    auto& kernel = system.Kernel();
-    const auto [readable_event, writable_event] =
-        WritableEvent::CreateEventPair(kernel, "CreateEvent");
+    // Get the current handle table.
+    const HandleTable& handle_table = system.Kernel().CurrentProcess()->GetHandleTable();
 
-    HandleTable& handle_table = kernel.CurrentProcess()->GetHandleTable();
+    // Get the writable event.
+    auto writable_event = handle_table.Get<KWritableEvent>(event_handle);
+    R_UNLESS(writable_event, Svc::ResultInvalidHandle);
 
-    const auto write_create_result = handle_table.Create(writable_event);
-    if (write_create_result.Failed()) {
-        return write_create_result.Code();
-    }
-    *write_handle = *write_create_result;
-
-    const auto read_create_result = handle_table.Create(readable_event);
-    if (read_create_result.Failed()) {
-        handle_table.Close(*write_create_result);
-        return read_create_result.Code();
-    }
-    *read_handle = *read_create_result;
-
-    LOG_DEBUG(Kernel_SVC,
-              "successful. Writable event handle=0x{:08X}, Readable event handle=0x{:08X}",
-              *write_create_result, *read_create_result);
-    return RESULT_SUCCESS;
+    return writable_event->Signal();
 }
 
-static ResultCode CreateEvent32(Core::System& system, Handle* write_handle, Handle* read_handle) {
-    return CreateEvent(system, write_handle, read_handle);
+static ResultCode SignalEvent32(Core::System& system, Handle event_handle) {
+    return SignalEvent(system, event_handle);
 }
 
-static ResultCode ClearEvent(Core::System& system, Handle handle) {
-    LOG_TRACE(Kernel_SVC, "called, event=0x{:08X}", handle);
+static ResultCode ClearEvent(Core::System& system, Handle event_handle) {
+    LOG_TRACE(Kernel_SVC, "called, event_handle=0x{:08X}", event_handle);
 
+    // Get the current handle table.
     const auto& handle_table = system.Kernel().CurrentProcess()->GetHandleTable();
 
-    auto writable_event = handle_table.Get<WritableEvent>(handle);
-    if (writable_event) {
-        writable_event->Clear();
-        return RESULT_SUCCESS;
+    // Try to clear the writable event.
+    {
+        auto writable_event = handle_table.Get<KWritableEvent>(event_handle);
+        if (writable_event) {
+            return writable_event->Clear();
+        }
     }
 
-    auto readable_event = handle_table.Get<ReadableEvent>(handle);
-    if (readable_event) {
-        readable_event->Clear();
-        return RESULT_SUCCESS;
+    // Try to clear the readable event.
+    {
+        auto readable_event = handle_table.Get<KReadableEvent>(event_handle);
+        if (readable_event) {
+            return readable_event->Clear();
+        }
     }
 
-    LOG_ERROR(Kernel_SVC, "Event handle does not exist, handle=0x{:08X}", handle);
-    return ERR_INVALID_HANDLE;
+    LOG_ERROR(Kernel_SVC, "Event handle does not exist, event_handle=0x{:08X}", event_handle);
+
+    return Svc::ResultInvalidHandle;
 }
 
-static ResultCode ClearEvent32(Core::System& system, Handle handle) {
-    return ClearEvent(system, handle);
+static ResultCode ClearEvent32(Core::System& system, Handle event_handle) {
+    return ClearEvent(system, event_handle);
 }
 
-static ResultCode SignalEvent(Core::System& system, Handle handle) {
-    LOG_DEBUG(Kernel_SVC, "called. Handle=0x{:08X}", handle);
+static ResultCode CreateEvent(Core::System& system, Handle* out_write, Handle* out_read) {
+    LOG_DEBUG(Kernel_SVC, "called");
+
+    // Get the kernel reference and handle table.
+    auto& kernel = system.Kernel();
+    HandleTable& handle_table = kernel.CurrentProcess()->GetHandleTable();
+
+    // Create a new event.
+    const auto event = KEvent::Create(kernel, "CreateEvent");
+    R_UNLESS(event != nullptr, Svc::ResultOutOfResource);
 
-    HandleTable& handle_table = system.Kernel().CurrentProcess()->GetHandleTable();
-    auto writable_event = handle_table.Get<WritableEvent>(handle);
+    // Initialize the event.
+    event->Initialize();
 
-    if (!writable_event) {
-        LOG_ERROR(Kernel_SVC, "Non-existent writable event handle used (0x{:08X})", handle);
-        return ERR_INVALID_HANDLE;
+    // Add the writable event to the handle table.
+    const auto write_create_result = handle_table.Create(event->GetWritableEvent());
+    if (write_create_result.Failed()) {
+        return write_create_result.Code();
+    }
+    *out_write = *write_create_result;
+
+    // Add the writable event to the handle table.
+    auto handle_guard = SCOPE_GUARD({ handle_table.Close(*write_create_result); });
+
+    // Add the readable event to the handle table.
+    const auto read_create_result = handle_table.Create(event->GetReadableEvent());
+    if (read_create_result.Failed()) {
+        return read_create_result.Code();
     }
+    *out_read = *read_create_result;
 
-    writable_event->Signal();
+    // We succeeded.
+    handle_guard.Cancel();
     return RESULT_SUCCESS;
 }
 
-static ResultCode SignalEvent32(Core::System& system, Handle handle) {
-    return SignalEvent(system, handle);
+static ResultCode CreateEvent32(Core::System& system, Handle* out_write, Handle* out_read) {
+    return CreateEvent(system, out_write, out_read);
 }
 
 static ResultCode GetProcessInfo(Core::System& system, u64* out, Handle process_handle, u32 type) {
diff --git a/src/core/hle/kernel/svc_results.h b/src/core/hle/kernel/svc_results.h
index 7b897fbce..204cd989d 100644
--- a/src/core/hle/kernel/svc_results.h
+++ b/src/core/hle/kernel/svc_results.h
@@ -11,6 +11,7 @@ namespace Kernel::Svc {
 constexpr ResultCode ResultNoSynchronizationObject{ErrorModule::Kernel, 57};
 constexpr ResultCode ResultTerminationRequested{ErrorModule::Kernel, 59};
 constexpr ResultCode ResultInvalidAddress{ErrorModule::Kernel, 102};
+constexpr ResultCode ResultOutOfResource{ErrorModule::Kernel, 103};
 constexpr ResultCode ResultInvalidCurrentMemory{ErrorModule::Kernel, 106};
 constexpr ResultCode ResultInvalidPriority{ErrorModule::Kernel, 112};
 constexpr ResultCode ResultInvalidCoreId{ErrorModule::Kernel, 113};
diff --git a/src/core/hle/kernel/writable_event.cpp b/src/core/hle/kernel/writable_event.cpp
deleted file mode 100644
index 142212ee4..000000000
--- a/src/core/hle/kernel/writable_event.cpp
+++ /dev/null
@@ -1,41 +0,0 @@
-// Copyright 2014 Citra Emulator Project
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#include <algorithm>
-#include "common/assert.h"
-#include "core/hle/kernel/k_thread.h"
-#include "core/hle/kernel/kernel.h"
-#include "core/hle/kernel/object.h"
-#include "core/hle/kernel/readable_event.h"
-#include "core/hle/kernel/writable_event.h"
-
-namespace Kernel {
-
-WritableEvent::WritableEvent(KernelCore& kernel) : Object{kernel} {}
-WritableEvent::~WritableEvent() = default;
-
-EventPair WritableEvent::CreateEventPair(KernelCore& kernel, std::string name) {
-    std::shared_ptr<WritableEvent> writable_event(new WritableEvent(kernel));
-    std::shared_ptr<ReadableEvent> readable_event(new ReadableEvent(kernel));
-
-    writable_event->name = name + ":Writable";
-    writable_event->readable = readable_event;
-    readable_event->name = name + ":Readable";
-
-    return {std::move(readable_event), std::move(writable_event)};
-}
-
-std::shared_ptr<ReadableEvent> WritableEvent::GetReadableEvent() const {
-    return readable;
-}
-
-void WritableEvent::Signal() {
-    readable->Signal();
-}
-
-void WritableEvent::Clear() {
-    readable->Clear();
-}
-
-} // namespace Kernel
diff --git a/src/core/hle/kernel/writable_event.h b/src/core/hle/kernel/writable_event.h
deleted file mode 100644
index 467eb2c21..000000000
--- a/src/core/hle/kernel/writable_event.h
+++ /dev/null
@@ -1,60 +0,0 @@
-// Copyright 2014 Citra Emulator Project
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#pragma once
-
-#include <memory>
-
-#include "core/hle/kernel/object.h"
-
-namespace Kernel {
-
-class KernelCore;
-class ReadableEvent;
-class WritableEvent;
-
-struct EventPair {
-    std::shared_ptr<ReadableEvent> readable;
-    std::shared_ptr<WritableEvent> writable;
-};
-
-class WritableEvent final : public Object {
-public:
-    ~WritableEvent() override;
-
-    /**
-     * Creates an event
-     * @param kernel The kernel instance to create this event under.
-     * @param name Optional name of event
-     */
-    static EventPair CreateEventPair(KernelCore& kernel, std::string name = "Unknown");
-
-    std::string GetTypeName() const override {
-        return "WritableEvent";
-    }
-    std::string GetName() const override {
-        return name;
-    }
-
-    static constexpr HandleType HANDLE_TYPE = HandleType::WritableEvent;
-    HandleType GetHandleType() const override {
-        return HANDLE_TYPE;
-    }
-
-    std::shared_ptr<ReadableEvent> GetReadableEvent() const;
-
-    void Signal();
-    void Clear();
-
-    void Finalize() override {}
-
-private:
-    explicit WritableEvent(KernelCore& kernel);
-
-    std::shared_ptr<ReadableEvent> readable;
-
-    std::string name; ///< Name of event (optional)
-};
-
-} // namespace Kernel