rtos2-utils/include/sta/rtos/patterns/barrier.hpp

/*
 * barrier.hpp
 *
 *  Created on: Mar 16, 2024
 *      Author: Dario
 */

#ifndef RTOS2_UTILS_STA_PATTERNS_BARRIER_HPP
#define RTOS2_UTILS_STA_PATTERNS_BARRIER_HPP

#include <sta/rtos/mutex.hpp>
#include <sta/rtos/event.hpp>

#include <set>


namespace sta
{
	class Barrier {
	public:
		/**
		 * @brief Construct a new Barrier object
		 * 
		 * @param name The name of the mutex used for this barrier.
		 * @param waitTime The minimum time that needs to pass until the barrier can open again.
		 */
		Barrier(const char* name, uint32_t waitTime = 0);

		/**
		 * @brief Adds the currently running thread to the threads the barrier waits for.
		 * 
		 */
		void subscribe();

		/**
		 * 
		 * @return uint8_t Returns the number of threads currently subscribed to this barrier
		 */
		uint8_t getNumSubscribedThreads();

		/**
		 * 
		 * @return uint8_t Returns the number of threads that have entered the barrier and are waiting now.
		 */
		uint8_t getNumEntered();

		/**
		 * 
		 * @return uint8_t Returns the number of threads that have left the barrier so far.
		 */
		uint8_t getNumLeft();

		void setMinimumWaitDuration(uint32_t duration);

		/**
		 * @brief Wait for the barrier to open again. Sets this state into waiting state.
		 * 
		 */
		void wait();

		/**
		 * @brief Method for an external thread to wait for the barrier to open without subscribing to it. 
		 * 
		 * @note This means that the barrier doesn't wait for this thread.
		 * 
		 */
		void externalWait();
	private:
		RtosMutex mutex_;
		RtosEvent flag_;

		uint32_t waitTime_;
		uint32_t lastTime_;

		std::set<osThreadId_t> threads_;
		uint8_t nThreads_;
		uint8_t nEntered_;
		uint8_t nLeft_;
	};
}  // namespace sta

#endif /* RTOS2_UTILS_STA_PATTERNS_BARRIER_HPP_ */