kernel: Divide Event into ReadableEvent and WritableEvent

More hardware accurate. On the actual system, there is a differentiation between the signaler and signalee, they form a client/server relationship much like ServerPort and ClientPort.

src/core/CMakeLists.txt

@@ -97,8 +97,6 @@ add_library(core STATIC
     hle/kernel/client_session.cpp
     hle/kernel/client_session.h
     hle/kernel/errors.h
-    hle/kernel/event.cpp
-    hle/kernel/event.h
     hle/kernel/handle_table.cpp
     hle/kernel/handle_table.h
     hle/kernel/hle_ipc.cpp
@@ -111,6 +109,8 @@ add_library(core STATIC
     hle/kernel/object.h
     hle/kernel/process.cpp
     hle/kernel/process.h
+    hle/kernel/readable_event.cpp
+    hle/kernel/readable_event.h
     hle/kernel/resource_limit.cpp
     hle/kernel/resource_limit.h
     hle/kernel/scheduler.cpp
@@ -133,6 +133,8 @@ add_library(core STATIC
     hle/kernel/vm_manager.h
     hle/kernel/wait_object.cpp
     hle/kernel/wait_object.h
+    hle/kernel/writable_event.cpp
+    hle/kernel/writable_event.h
     hle/lock.cpp
     hle/lock.h
     hle/result.h

src/core/hle/kernel/event.cpp → src/core/hle/kernel/readable_event.cpp

@@ -4,50 +4,45 @@
 
 #include <algorithm>
 #include "common/assert.h"
-#include "core/hle/kernel/event.h"
 #include "core/hle/kernel/object.h"
+#include "core/hle/kernel/readable_event.h"
 #include "core/hle/kernel/thread.h"
+#include "core/hle/kernel/writable_event.h"
 
 namespace Kernel {
 
-Event::Event(KernelCore& kernel) : WaitObject{kernel} {}
-Event::~Event() = default;
+ReadableEvent::ReadableEvent(KernelCore& kernel) : WaitObject{kernel} {}
+ReadableEvent::~ReadableEvent() = default;
 
-SharedPtr<Event> Event::Create(KernelCore& kernel, ResetType reset_type, std::string name) {
-    SharedPtr<Event> evt(new Event(kernel));
+bool ReadableEvent::ShouldWait(Thread* thread) const {
+    return !writable_event->IsSignaled();
+}
 
-    evt->signaled = false;
-    evt->reset_type = reset_type;
-    evt->name = std::move(name);
+void ReadableEvent::Acquire(Thread* thread) {
+    ASSERT_MSG(!ShouldWait(thread), "object unavailable!");
 
-    return evt;
+    writable_event->ResetOnAcquire();
 }
 
-bool Event::ShouldWait(Thread* thread) const {
-    return !signaled;
+void ReadableEvent::AddWaitingThread(SharedPtr<Thread> thread) {
+    writable_event->AddWaitingThread(thread);
 }
 
-void Event::Acquire(Thread* thread) {
-    ASSERT_MSG(!ShouldWait(thread), "object unavailable!");
-
-    if (reset_type == ResetType::OneShot)
-        signaled = false;
+void ReadableEvent::RemoveWaitingThread(Thread* thread) {
+    writable_event->RemoveWaitingThread(thread);
 }
 
-void Event::Signal() {
-    signaled = true;
-    WakeupAllWaitingThreads();
+void ReadableEvent::Signal() {
+    writable_event->Signal();
 }
 
-void Event::Clear() {
-    signaled = false;
+void ReadableEvent::Clear() {
+    writable_event->Clear();
 }
 
-void Event::WakeupAllWaitingThreads() {
-    WaitObject::WakeupAllWaitingThreads();
-
-    if (reset_type == ResetType::Pulse)
-        signaled = false;
+void ReadableEvent::WakeupAllWaitingThreads() {
+    writable_event->WakeupAllWaitingThreads();
+    writable_event->ResetOnWakeup();
 }
 
 } // namespace Kernel

src/core/hle/kernel/readable_event.h

+// 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/object.h"
+#include "core/hle/kernel/wait_object.h"
+
+namespace Kernel {
+
+class KernelCore;
+class WritableEvent;
+
+class ReadableEvent final : public WaitObject {
+    friend class WritableEvent;
+
+public:
+    ~ReadableEvent() override;
+
+    std::string GetTypeName() const override {
+        return "ReadableEvent";
+    }
+    std::string GetName() const override {
+        return name;
+    }
+
+    static const HandleType HANDLE_TYPE = HandleType::Event;
+    HandleType GetHandleType() const override {
+        return HANDLE_TYPE;
+    }
+
+    bool ShouldWait(Thread* thread) const override;
+    void Acquire(Thread* thread) override;
+
+    void WakeupAllWaitingThreads() override;
+
+    void AddWaitingThread(SharedPtr<Thread> thread) override;
+    void RemoveWaitingThread(Thread* thread) override;
+
+    void Signal();
+    void Clear();
+
+    SharedPtr<WritableEvent> PromoteToWritable() const {
+        return writable_event;
+    }
+
+private:
+    explicit ReadableEvent(KernelCore& kernel);
+
+    SharedPtr<WritableEvent> writable_event; ///< WritableEvent associated with this ReadableEvent
+
+    std::string name; ///< Name of event (optional)
+};
+
+} // namespace Kernel

src/core/hle/kernel/writable_event.cpp

+// 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/kernel.h"
+#include "core/hle/kernel/object.h"
+#include "core/hle/kernel/readable_event.h"
+#include "core/hle/kernel/thread.h"
+#include "core/hle/kernel/writable_event.h"
+
+namespace Kernel {
+
+WritableEvent::WritableEvent(KernelCore& kernel) : WaitObject{kernel} {}
+WritableEvent::~WritableEvent() = default;
+
+std::tuple<SharedPtr<WritableEvent>, SharedPtr<ReadableEvent>> WritableEvent::CreateEventPair(
+    KernelCore& kernel, ResetType reset_type, std::string name) {
+    SharedPtr<WritableEvent> writable_event(new WritableEvent(kernel));
+    SharedPtr<ReadableEvent> readable_event(new ReadableEvent(kernel));
+
+    writable_event->name = name + ":Writable";
+    writable_event->signaled = false;
+    writable_event->reset_type = reset_type;
+    readable_event->name = name + ":Readable";
+    readable_event->writable_event = writable_event;
+
+    return std::make_tuple(std::move(writable_event), std::move(readable_event));
+}
+
+SharedPtr<WritableEvent> WritableEvent::CreateRegisteredEventPair(KernelCore& kernel,
+                                                                  ResetType reset_type,
+                                                                  std::string name) {
+    auto [writable_event, readable_event] = CreateEventPair(kernel, reset_type, name);
+    kernel.AddNamedEvent(name, std::move(readable_event));
+    return std::move(writable_event);
+}
+
+bool WritableEvent::ShouldWait(Thread* thread) const {
+    return !signaled;
+}
+
+void WritableEvent::Acquire(Thread* thread) {
+    ASSERT_MSG(!ShouldWait(thread), "object unavailable!");
+
+    if (reset_type == ResetType::OneShot)
+        signaled = false;
+}
+
+void WritableEvent::Signal() {
+    signaled = true;
+    WakeupAllWaitingThreads();
+}
+
+void WritableEvent::Clear() {
+    signaled = false;
+}
+
+void WritableEvent::ResetOnAcquire() {
+    if (reset_type == ResetType::OneShot)
+        Clear();
+}
+
+void WritableEvent::ResetOnWakeup() {
+    if (reset_type == ResetType::Pulse)
+        Clear();
+}
+
+bool WritableEvent::IsSignaled() const {
+    return signaled;
+}
+
+void WritableEvent::WakeupAllWaitingThreads() {
+    WaitObject::WakeupAllWaitingThreads();
+
+    if (reset_type == ResetType::Pulse)
+        signaled = false;
+}
+
+} // namespace Kernel

src/core/hle/kernel/event.h → src/core/hle/kernel/writable_event.h

@@ -11,20 +11,33 @@
 namespace Kernel {
 
 class KernelCore;
+class ReadableEvent;
 
-class Event final : public WaitObject {
+class WritableEvent final : public WaitObject {
 public:
+    ~WritableEvent() override;
+
     /**
      * Creates an event
      * @param kernel The kernel instance to create this event under.
      * @param reset_type ResetType describing how to create event
      * @param name Optional name of event
      */
-    static SharedPtr<Event> Create(KernelCore& kernel, ResetType reset_type,
-                                   std::string name = "Unknown");
+    static std::tuple<SharedPtr<WritableEvent>, SharedPtr<ReadableEvent>> CreateEventPair(
+        KernelCore& kernel, ResetType reset_type, std::string name = "Unknown");
+
+    /**
+     * Creates an event and registers it in the kernel's named event table
+     * @param kernel The kernel instance to create this event under.
+     * @param reset_type ResetType describing how to create event
+     * @param name name of event
+     */
+    static SharedPtr<WritableEvent> CreateRegisteredEventPair(KernelCore& kernel,
+                                                              ResetType reset_type,
+                                                              std::string name);
 
     std::string GetTypeName() const override {
-        return "Event";
+        return "WritableEvent";
     }
     std::string GetName() const override {
         return name;
@@ -46,10 +59,12 @@ public:
 
     void Signal();
     void Clear();
+    void ResetOnAcquire();
+    void ResetOnWakeup();
+    bool IsSignaled() const;
 
 private:
-    explicit Event(KernelCore& kernel);
-    ~Event() override;
+    explicit WritableEvent(KernelCore& kernel);
 
     ResetType reset_type; ///< Current ResetType