tasks/SemaphoreIF.h

@@ -1,8 +1,49 @@
 #ifndef FRAMEWORK_TASKS_SEMAPHOREIF_H_
 #define FRAMEWORK_TASKS_SEMAPHOREIF_H_
+#include <framework/returnvalues/FwClassIds.h>
+#include <framework/returnvalues/HasReturnvaluesIF.h>
+#include <cstdint>
 
+/**
+ * @brief 	Generic interface for semaphores, which can be used to achieve
+ * 			task synchronization.
+ */
+class SemaphoreIF {
+	//!< Needs to be defined in implementation.
+	static const uint32_t NO_TIMEOUT;
+	static const uint8_t INTERFACE_ID = CLASS_ID::SEMAPHORE_IF;
 
+	//! Semaphore timeout
+	static constexpr ReturnValue_t SEMAPHORE_TIMEOUT = MAKE_RETURN_CODE(1);
+	//! The current semaphore can not be given, because it is not owned
+	static constexpr ReturnValue_t SEMAPHORE_NOT_OWNED = MAKE_RETURN_CODE(2);
+	static constexpr ReturnValue_t SEMAPHORE_NULLPOINTER = MAKE_RETURN_CODE(3);
 
+	/**
+	 * Generic call to acquire a semaphore.
+	 * If there are no more semaphores to be taken (for a counting semaphore,
+	 * a semaphore may be taken more than once), the taks will block
+	 * for a maximum of timeoutMs while trying to acquire the semaphore.
+	 * This can be used to achieve task synchrnization.
+	 * @param timeoutMs
+	 * @return
+	 */
+	ReturnValue_t acquire(uint32_t timeoutMs) = 0;
 
+	/**
+	 * Corrensponding call to release a semaphore.
+	 * @return
+	 */
+	ReturnValue_t release() = 0;
+
+	/**
+	 * If the semaphore is a counting semaphore then the semaphores current
+	 * count value is returned. If the semaphore is a binary semaphore then 1
+	 * is returned if the semaphore is available, and 0 is returned if the
+	 * semaphore is not available.
+	 * @return
+	 */
+	uint8_t getSemaphoreCounter() = 0;
+};
 
 #endif /* FRAMEWORK_TASKS_SEMAPHOREIF_H_ */