audio_out_manager.h

// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
// SPDX-License-Identifier: MPL-2.0

#pragma once

#include <array>
#include <mutex>

#include <audio_core/renderer/audio_device.h>

namespace Core {
class System;
}

namespace AudioCore::AudioOut {
class Out;

constexpr size_t MaxOutSessions = 12;
/**
 * Manages all audio out sessions.
 */
class Manager {
public:
    explicit Manager(Core::System& system);

    /**
     * Acquire a free session id for opening a new audio out.
     *
     * @param session_id - Output session_id.
     * @return Result code.
     */
    Result AcquireSessionId(size_t& session_id);

    /**
     * Release a session id on close.
     *
     * @param session_id - Session id to free.
     */
    void ReleaseSessionId(size_t session_id);

    /**
     * Link this manager to the main audio manager.
     *
     * @return Result code.
     */
    Result LinkToManager();

    /**
     * Start the audio out manager.
     */
    void Start();

    /**
     * Callback function, called by the audio manager when the audio out event is signalled.
     */
    void BufferReleaseAndRegister();

    /**
     * Get a list of audio out device names.
     *
     * @oaram names     - Output container to write names to.
     * @return Number of names written.
     */
    u32 GetAudioOutDeviceNames(
        std::vector<AudioRenderer::AudioDevice::AudioDeviceName>& names) const;

    /// Core system
    Core::System& system;
    /// Array of session ids
    std::array<size_t, MaxOutSessions> session_ids{};
    /// Array of resource user ids
    std::array<size_t, MaxOutSessions> applet_resource_user_ids{};
    /// Pointer to each open session
    std::array<std::shared_ptr<Out>, MaxOutSessions> sessions{};
    /// The number of free sessions
    size_t num_free_sessions{};
    /// The next session id to be taken
    size_t next_session_id{};
    /// The next session id to be freed
    size_t free_session_id{};
    /// Whether this is linked to the audio manager
    bool linked_to_manager{};
    /// Whether the sessions have been started
    bool sessions_started{};
    /// Protect state due to audio manager callback
    std::recursive_mutex mutex{};
};

} // namespace AudioCore::AudioOut