robot_time/include/robot/wall_timer.h

290 lines
8.6 KiB
C++

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#ifndef ROBOT_WALL_TIMER_H
#define ROBOT_WALL_TIMER_H
#include <robot/walltime.h>
#include "robot_time_decl.h"
#include <functional>
#include <thread>
#include <mutex>
#include <atomic>
#include <condition_variable>
#include <memory>
namespace robot
{
/**
* @brief Structure containing information about a wall timer event
*
* Similar to ros::WallTimerEvent, this structure is passed to wall timer callbacks
* and contains timing information about the current and previous timer events.
* Uses wall-clock time (not affected by simulated time).
*/
struct ROBOT_TIME_DECL WallTimerEvent
{
/**
* @brief The time when the current callback was actually called (wall-clock time)
*/
WallTime current_real;
/**
* @brief The time when the current callback was expected to be called (wall-clock time)
*/
WallTime current_expected;
/**
* @brief The time when the previous callback was actually called (wall-clock time)
*/
WallTime last_real;
/**
* @brief The time when the previous callback was expected to be called (wall-clock time)
*/
WallTime last_expected;
/**
* @brief The time between the last two callbacks (wall-clock duration)
*/
WallDuration last_duration;
/**
* @brief Default constructor
*/
WallTimerEvent()
: current_real(WallTime::now())
, current_expected(WallTime::now())
, last_real(WallTime())
, last_expected(WallTime())
, last_duration(WallDuration())
{}
};
/**
* @class WallTimer
* @brief A class to call a callback function at a specified rate using wall-clock time
*
* This class is similar to ros::WallTimer. It creates a separate thread that
* calls a callback function at a specified period. The callback receives
* a WallTimerEvent structure containing timing information.
*
* Unlike Timer, WallTimer always uses wall-clock time and is not affected
* by simulated time. This makes it ideal for:
* - Performance monitoring
* - Real-time deadlines
* - Hardware interfaces
* - Profiling and benchmarking
*
* Example usage:
* @code
* void myCallback(const robot::WallTimerEvent& event) {
* // Do something periodically
* }
*
* robot::WallTimer timer(robot::WallDuration(1.0), myCallback);
* timer.start();
* // ... later ...
* timer.stop();
* @endcode
*/
class ROBOT_TIME_DECL WallTimer
{
public:
/**
* @brief Callback function type for wall timer events
*/
using Callback = std::function<void(const WallTimerEvent&)>;
/**
* @brief Default constructor - creates an uninitialized timer
* Timer must be assigned or constructed with parameters before use
*/
WallTimer();
/**
* @brief Constructor
* @param period The period between timer callbacks (wall-clock duration)
* @param callback The callback function to call
* @param oneshot If true, the timer will only fire once. If false, it will fire repeatedly.
* @param autostart If true, the timer will start automatically. If false, you must call start().
*/
WallTimer(const WallDuration& period,
const Callback& callback,
bool oneshot = false,
bool autostart = true);
/**
* @brief Constructor with member function pointer
* @param period The period between timer callbacks (wall-clock duration)
* @param callback Member function pointer to call
* @param obj Object instance to call the member function on
* @param oneshot If true, the timer will only fire once. If false, it will fire repeatedly.
* @param autostart If true, the timer will start automatically. If false, you must call start().
*
* Example:
* @code
* class MyClass {
* void callback(const robot::WallTimerEvent& event) { }
* };
* MyClass obj;
* robot::WallTimer timer(robot::WallDuration(1.0), &MyClass::callback, &obj);
* @endcode
*/
template<typename T>
WallTimer(const WallDuration& period,
void (T::*callback)(const WallTimerEvent&),
T* obj,
bool oneshot = false,
bool autostart = true)
: WallTimer(period,
[obj, callback](const WallTimerEvent& event) { (obj->*callback)(event); },
oneshot,
autostart)
{}
/**
* @brief Copy constructor
*/
WallTimer(const WallTimer& rhs);
/**
* @brief Destructor - stops the timer and joins the thread
*/
~WallTimer();
/**
* @brief Start the timer. Does nothing if the timer is already started.
*/
void start();
/**
* @brief Stop the timer. Once this call returns, no more callbacks will be called.
* Does nothing if the timer is already stopped.
*/
void stop();
/**
* @brief Set the period of this timer
* @param period The new period between timer callbacks
* @param reset Whether to reset the timer. If true, timer ignores elapsed time and next callback occurs at now()+period
*/
void setPeriod(const WallDuration& period, bool reset = true);
/**
* @brief Check if the timer has been started
* @return True if the timer is running, false otherwise
*/
bool hasStarted() const;
/**
* @brief Check if the timer is valid (has a callback)
* @return True if the timer is valid, false otherwise
*/
bool isValid() const;
/**
* @brief Check if the timer has any pending events to call
* @return True if there are pending events, false otherwise
*/
bool hasPending() const;
/**
* @brief Check if the timer is one-shot
* @return True if the timer is one-shot, false if it repeats
*/
bool isOneShot() const;
/**
* @brief Set whether the timer is one-shot
* @param oneshot If true, the timer will only fire once
*/
void setOneShot(bool oneshot);
/**
* @brief Get the timer period
* @return The period between timer callbacks
*/
WallDuration getPeriod() const;
/**
* @brief Conversion to bool (for checking validity)
*/
operator void*() const;
/**
* @brief Equality operator
*/
bool operator==(const WallTimer& rhs) const;
/**
* @brief Inequality operator
*/
bool operator!=(const WallTimer& rhs) const;
/**
* @brief Less-than operator (for ordering in containers)
*/
bool operator<(const WallTimer& rhs) const;
// Non-copyable assignment
WallTimer& operator=(const WallTimer&) = delete;
// Movable
WallTimer(WallTimer&& other) noexcept;
WallTimer& operator=(WallTimer&& other) noexcept;
private:
/**
* @brief The timer thread function
*/
void timerThread();
WallDuration period_; ///< Period between callbacks
Callback callback_; ///< Callback function
bool oneshot_; ///< Whether timer is one-shot
std::atomic<bool> running_; ///< Whether timer is running
std::atomic<bool> should_stop_; ///< Flag to stop the timer thread
std::thread thread_; ///< Timer thread
mutable std::mutex mutex_; ///< Mutex for thread safety
std::condition_variable cv_; ///< Condition variable for timing
WallTime last_real_; ///< Last actual callback time
WallTime last_expected_; ///< Last expected callback time
};
} // namespace robot
#endif // ROBOT_WALL_TIMER_H