1 files changed, 92 insertions, 0 deletions

diff --git a/src/audio_core/audio_event.h b/src/audio_core/audio_event.h
new file mode 100644
index 000000000..82dd32dca
--- /dev/null
+++ b/src/audio_core/audio_event.h
@@ -0,0 +1,92 @@
+// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <array>
+#include <atomic>
+#include <chrono>
+#include <condition_variable>
+#include <mutex>
+
+namespace AudioCore {
+/**
+ * Responsible for the input/output events, set by the stream backend when buffers are consumed, and
+ * waited on by the audio manager. These callbacks signal the game's events to keep the audio buffer
+ * recycling going.
+ * In a real Switch this is not a seprate class, and exists entirely within the audio manager.
+ * On the Switch it's implemented more simply through a MultiWaitEventHolder, where it can
+ * wait on multiple events at once, and the events are not needed by the backend.
+ */
+class Event {
+public:
+    enum class Type {
+        AudioInManager,
+        AudioOutManager,
+        FinalOutputRecorderManager,
+        Max,
+    };
+
+    /**
+     * Convert a manager type to an index.
+     *
+     * @param type - The manager type to convert
+     * @return The index of the type.
+     */
+    size_t GetManagerIndex(Type type) const;
+
+    /**
+     * Set an audio event to true or false.
+     *
+     * @param type      - The manager type to signal.
+     * @param signalled - Its signal state.
+     */
+    void SetAudioEvent(Type type, bool signalled);
+
+    /**
+     * Check if the given manager type is signalled.
+     *
+     * @param type - The manager type to check.
+     * @return True if the event is signalled, otherwise false.
+     */
+    bool CheckAudioEventSet(Type type) const;
+
+    /**
+     * Get the lock for audio events.
+     *
+     * @return Reference to the lock.
+     */
+    std::mutex& GetAudioEventLock();
+
+    /**
+     * Get the manager event, this signals the audio manager to release buffers and signal the game
+     * for more.
+     *
+     * @return Reference to the condition variable.
+     */
+    std::condition_variable_any& GetAudioEvent();
+
+    /**
+     * Wait on the manager_event.
+     *
+     * @param l       - Lock held by the wait.
+     * @param timeout - Timeout for the wait. This is 2 seconds by default.
+     * @return True if the wait timed out, otherwise false if signalled.
+     */
+    bool Wait(std::unique_lock<std::mutex>& l, std::chrono::seconds timeout);
+
+    /**
+     * Reset all manager events.
+     */
+    void ClearEvents();
+
+private:
+    /// Lock, used bythe audio manager
+    std::mutex event_lock;
+    /// Array of events, one per system type (see Type), last event is used to terminate
+    std::array<std::atomic<bool>, 4> events_signalled;
+    /// Event to signal the audio manager
+    std::condition_variable_any manager_event;
+};
+
+} // namespace AudioCore