uORBDeviceNode.hpp

/****************************************************************************
 *
 *   Copyright (c) 2012-2016 PX4 Development Team. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
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 *    used to endorse or promote products derived from this software
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#pragma once

#include "uORBCommon.hpp"
#include "uORBDeviceMaster.hpp"

#include <lib/cdev/CDev.hpp>

#include <containers/List.hpp>

namespace uORB
{
class DeviceNode;
class DeviceMaster;
class Manager;
}

class uORB::DeviceNode : public cdev::CDev, public ListNode<uORB::DeviceNode *>
{
public:
    DeviceNode(const struct orb_metadata *meta, const uint8_t instance, const char *path, uint8_t priority,
           uint8_t queue_size = 1);
    ~DeviceNode();

    // no copy, assignment, move, move assignment
    DeviceNode(const DeviceNode &) = delete;
    DeviceNode &operator=(const DeviceNode &) = delete;
    DeviceNode(DeviceNode &&) = delete;
    DeviceNode &operator=(DeviceNode &&) = delete;

    int open(cdev::file_t *filp) override;

    int close(cdev::file_t *filp) override;

    ssize_t read(cdev::file_t *filp, char *buffer, size_t buflen) override;

    ssize_t write(cdev::file_t *filp, const char *buffer, size_t buflen) override;

    int ioctl(cdev::file_t *filp, int cmd, unsigned long arg) override;

    static ssize_t    publish(const orb_metadata *meta, orb_advert_t handle, const void *data);

    static int        unadvertise(orb_advert_t handle);

#ifdef ORB_COMMUNICATOR
    static int16_t topic_advertised(const orb_metadata *meta, int priority);
    //static int16_t topic_unadvertised(const orb_metadata *meta, int priority);

    int16_t process_add_subscription(int32_t rateInHz);

    int16_t process_remove_subscription();

    int16_t process_received_message(int32_t length, uint8_t *data);
#endif /* ORB_COMMUNICATOR */

    void add_internal_subscriber();

    void remove_internal_subscriber();

    bool is_published() const { return _published; }

    int update_queue_size(unsigned int queue_size);

    bool print_statistics(bool reset);

    uint8_t get_queue_size() const { return _queue_size; }

    int8_t subscriber_count() const { return _subscriber_count; }

    uint32_t lost_message_count() const { return _lost_messages; }

    unsigned published_message_count() const { return _generation; }

    const orb_metadata *get_meta() const { return _meta; }

    const char *get_name() const { return _meta->o_name; }

    uint8_t get_instance() const { return _instance; }

    int get_priority() const { return _priority; }
    void set_priority(uint8_t priority) { _priority = priority; }

protected:

    pollevent_t poll_state(cdev::file_t *filp) override;

    void poll_notify_one(px4_pollfd_struct_t *fds, pollevent_t events) override;

private:
    struct UpdateIntervalData {
        struct hrt_call update_call;  
#ifndef __PX4_NUTTX
        uint64_t last_update; 
#endif
        unsigned  interval; 
        bool update_reported;
    };
    struct SubscriberData {
        ~SubscriberData() { if (update_interval) { delete (update_interval); } }

        unsigned  generation; 
        UpdateIntervalData *update_interval; 
        // these flags are only used if update_interval != null
        bool update_reported() const { return update_interval ? update_interval->update_reported : false; }
        void set_update_reported(bool update_reported_flag)
        { if (update_interval) { update_interval->update_reported = update_reported_flag; } }
    };

    const orb_metadata *_meta; 
    const uint8_t _instance; 
    uint8_t     *_data{nullptr};   
    hrt_abstime   _last_update{0}; 
    volatile unsigned   _generation{0};  
    uint8_t   _priority;  
    bool _published{false};  
    uint8_t _queue_size; 
    int8_t _subscriber_count{0};

    px4_task_t _publisher{0}; 
    // statistics
    uint32_t _lost_messages = 0; 
    inline static SubscriberData    *filp_to_sd(cdev::file_t *filp);

    void      update_deferred();

    static void   update_deferred_trampoline(void *arg);

    bool      appears_updated(SubscriberData *sd);

};