added semaphore implementations

osal/FreeRTOS/CountingSemaphore.h

@@ -0,0 +1,34 @@
+#ifndef FRAMEWORK_OSAL_FREERTOS_COUNTINGSEMAPHORE_H_
+#define FRAMEWORK_OSAL_FREERTOS_COUNTINGSEMAPHORE_H_
+#include <framework/osal/FreeRTOS/BinarySemaphore.h>
+
+/**
+ * @brief 	Counting semaphores, which can be acquire more than once.
+ * @details
+ * See: https://www.freertos.org/CreateCounting.html
+ * API of counting semaphores is almost identical to binary semaphores,
+ * so we just inherit from binary semaphore and provide the respective
+ * constructors.
+ */
+class CountingSemaphore: public BinarySemaphore {
+public:
+	CountingSemaphore(const uint8_t maxCount, uint8_t initCount);
+	//! @brief Copy ctor, disabled
+	CountingSemaphore(const CountingSemaphore&) = delete;
+	//! @brief Copy assignment, disabled
+	CountingSemaphore& operator=(const CountingSemaphore&) = delete;
+	//! @brief Move ctor
+	CountingSemaphore (CountingSemaphore &&);
+	//! @brief Move assignment
+	CountingSemaphore & operator=(CountingSemaphore &&);
+
+	/* Same API as binary semaphore otherwise. acquire() can be called
+	 * until there are not semaphores left and release() can be called
+	 * until maxCount is reached. */
+	uint8_t getMaxCount() const;
+private:
+	const uint8_t maxCount;
+	uint8_t initCount = 0;
+};
+
+#endif /* FRAMEWORK_OSAL_FREERTOS_COUNTINGSEMAPHORE_H_ */