added semaphore implementations

osal/FreeRTOS/BinSemaphUsingTask.cpp

@@ -0,0 +1,91 @@
+#include <framework/osal/FreeRTOS/BinSemaphUsingTask.h>
+#include <framework/osal/FreeRTOS/TaskManagement.h>
+#include <framework/serviceinterface/ServiceInterfaceStream.h>
+
+BinarySemaphoreUsingTask::BinarySemaphoreUsingTask() {
+	handle = TaskManagement::getCurrentTaskHandle();
+	if(handle == nullptr) {
+		sif::error << "Could not retrieve task handle. Please ensure the"
+				"constructor was called inside a task." << std::endl;
+	}
+	xTaskNotifyGive(handle);
+}
+
+BinarySemaphoreUsingTask::~BinarySemaphoreUsingTask() {
+	// Clear notification value on destruction.
+	xTaskNotifyAndQuery(handle, 0, eSetValueWithOverwrite, nullptr);
+}
+
+ReturnValue_t BinarySemaphoreUsingTask::acquire(uint32_t timeoutMs) {
+	TickType_t timeout = SemaphoreIF::NO_TIMEOUT;
+	if(timeoutMs == SemaphoreIF::MAX_TIMEOUT) {
+		timeout = SemaphoreIF::MAX_TIMEOUT;
+	}
+	else if(timeoutMs > SemaphoreIF::NO_TIMEOUT){
+		timeout = pdMS_TO_TICKS(timeoutMs);
+	}
+	return acquireWithTickTimeout(timeout);
+}
+
+ReturnValue_t BinarySemaphoreUsingTask::acquireWithTickTimeout(
+        TickType_t timeoutTicks) {
+	BaseType_t returncode = ulTaskNotifyTake(pdTRUE, timeoutTicks);
+	if (returncode == pdPASS) {
+		return HasReturnvaluesIF::RETURN_OK;
+	}
+	else {
+		return SemaphoreIF::SEMAPHORE_TIMEOUT;
+	}
+}
+
+ReturnValue_t BinarySemaphoreUsingTask::release() {
+	return release(this->handle);
+}
+
+ReturnValue_t BinarySemaphoreUsingTask::release(
+		TaskHandle_t taskHandle) {
+	if(getSemaphoreCounter(taskHandle) == 1) {
+		return SemaphoreIF::SEMAPHORE_NOT_OWNED;
+	}
+	BaseType_t returncode = xTaskNotifyGive(taskHandle);
+	if (returncode == pdPASS) {
+		return HasReturnvaluesIF::RETURN_OK;
+	}
+	else {
+		// This should never happen.
+		return HasReturnvaluesIF::RETURN_FAILED;
+	}
+}
+
+TaskHandle_t BinarySemaphoreUsingTask::getTaskHandle() {
+	return handle;
+}
+
+uint8_t BinarySemaphoreUsingTask::getSemaphoreCounter() const {
+	return getSemaphoreCounter(this->handle);
+}
+
+uint8_t BinarySemaphoreUsingTask::getSemaphoreCounter(
+		TaskHandle_t taskHandle) {
+	uint32_t notificationValue;
+	xTaskNotifyAndQuery(taskHandle, 0, eNoAction, &notificationValue);
+	return notificationValue;
+}
+
+// Be careful with the stack size here. This is called from an ISR!
+ReturnValue_t BinarySemaphoreUsingTask::releaseFromISR(
+		TaskHandle_t taskHandle, BaseType_t * higherPriorityTaskWoken) {
+	if(getSemaphoreCounterFromISR(taskHandle, higherPriorityTaskWoken) == 1) {
+		return SemaphoreIF::SEMAPHORE_NOT_OWNED;
+	}
+	vTaskNotifyGiveFromISR(taskHandle, higherPriorityTaskWoken);
+	return HasReturnvaluesIF::RETURN_OK;
+}
+
+uint8_t BinarySemaphoreUsingTask::getSemaphoreCounterFromISR(
+		TaskHandle_t taskHandle, BaseType_t* higherPriorityTaskWoken) {
+	uint32_t notificationValue = 0;
+	xTaskNotifyAndQueryFromISR(taskHandle, 0, eNoAction, &notificationValue,
+			higherPriorityTaskWoken);
+	return notificationValue;
+}

osal/FreeRTOS/BinSemaphUsingTask.h

@@ -0,0 +1,75 @@
+#ifndef FRAMEWORK_OSAL_FREERTOS_BINSEMAPHUSINGTASK_H_
+#define FRAMEWORK_OSAL_FREERTOS_BINSEMAPHUSINGTASK_H_
+
+#include <framework/returnvalues/HasReturnvaluesIF.h>
+#include <framework/tasks/SemaphoreIF.h>
+
+#include <freertos/FreeRTOS.h>
+#include <freertos/task.h>
+
+/**
+ * @brief 	Binary Semaphore implementation using the task notification value.
+ * 			The notification value should therefore not be used
+ * 			for other purposes.
+ * @details
+ * Additional information: https://www.freertos.org/RTOS-task-notifications.html
+ * and general semaphore documentation.
+ */
+class BinarySemaphoreUsingTask: public SemaphoreIF,
+		public HasReturnvaluesIF {
+public:
+	static const uint8_t INTERFACE_ID = CLASS_ID::SEMAPHORE_IF;
+
+	//! @brief Default ctor
+	BinarySemaphoreUsingTask();
+	//! @brief Default dtor
+	virtual~ BinarySemaphoreUsingTask();
+
+	ReturnValue_t acquire(uint32_t timeoutMs =
+	        SemaphoreIF::NO_TIMEOUT) override;
+	ReturnValue_t release() override;
+	uint8_t getSemaphoreCounter() const override;
+	static uint8_t getSemaphoreCounter(TaskHandle_t taskHandle);
+	static uint8_t getSemaphoreCounterFromISR(TaskHandle_t taskHandle,
+			BaseType_t* higherPriorityTaskWoken);
+
+	/**
+	 * Same as acquire() with timeout in FreeRTOS ticks.
+	 * @param timeoutTicks
+	 * @return - @c RETURN_OK on success
+	 *         - @c RETURN_FAILED on failure
+	 */
+	ReturnValue_t acquireWithTickTimeout(TickType_t timeoutTicks =
+	        SemaphoreIF::NO_TIMEOUT);
+
+	/**
+	 * Get handle to the task related to the semaphore.
+	 * @return
+	 */
+	TaskHandle_t getTaskHandle();
+
+	 /**
+	 * Wrapper function to give back semaphore from handle
+	 * @param semaphore
+	 * @return - @c RETURN_OK on success
+	 *         - @c RETURN_FAILED on failure
+	 */
+	static ReturnValue_t release(TaskHandle_t taskToNotify);
+
+	/**
+	 * Wrapper function to give back semaphore from handle when called from an ISR
+	 * @param semaphore
+	 * @param higherPriorityTaskWoken This will be set to pdPASS if a task with
+	 * a higher priority was unblocked. A context switch should be requested
+	 * from an ISR if this is the case (see TaskManagement functions)
+	 * @return - @c RETURN_OK on success
+	 *         - @c RETURN_FAILED on failure
+	 */
+	static ReturnValue_t releaseFromISR(TaskHandle_t taskToNotify,
+				BaseType_t * higherPriorityTaskWoken);
+
+protected:
+	TaskHandle_t handle;
+};
+
+#endif /* FRAMEWORK_OSAL_FREERTOS_BINSEMAPHUSINGTASK_H_ */

osal/FreeRTOS/BinarySemaphore.cpp

@@ -0,0 +1,103 @@
+#include <framework/osal/FreeRTOS/BinarySemaphore.h>
+#include <framework/osal/FreeRTOS/TaskManagement.h>
+#include <framework/serviceinterface/ServiceInterfaceStream.h>
+
+BinarySemaphore::BinarySemaphore() {
+	handle = xSemaphoreCreateBinary();
+	if(handle == nullptr) {
+		sif::error << "Semaphore: Binary semaph creation failure" << std::endl;
+	}
+	// Initiated semaphore must be given before it can be taken.
+	xSemaphoreGive(handle);
+}
+
+BinarySemaphore::~BinarySemaphore() {
+	vSemaphoreDelete(handle);
+}
+
+BinarySemaphore::BinarySemaphore(BinarySemaphore&& s) {
+    handle = xSemaphoreCreateBinary();
+    if(handle == nullptr) {
+        sif::error << "Binary semaphore creation failure" << std::endl;
+    }
+    xSemaphoreGive(handle);
+}
+
+BinarySemaphore& BinarySemaphore::operator =(
+        BinarySemaphore&& s) {
+    if(&s != this) {
+        handle = xSemaphoreCreateBinary();
+        if(handle == nullptr) {
+            sif::error << "Binary semaphore creation failure" << std::endl;
+        }
+        xSemaphoreGive(handle);
+    }
+    return *this;
+}
+
+ReturnValue_t BinarySemaphore::acquire(uint32_t timeoutMs) {
+	TickType_t timeout = SemaphoreIF::NO_TIMEOUT;
+	if(timeoutMs == SemaphoreIF::MAX_TIMEOUT) {
+	    timeout = SemaphoreIF::MAX_TIMEOUT;
+	}
+	else if(timeoutMs > SemaphoreIF::NO_TIMEOUT){
+	    timeout = pdMS_TO_TICKS(timeoutMs);
+	}
+	return acquireWithTickTimeout(timeout);
+}
+
+ReturnValue_t BinarySemaphore::acquireWithTickTimeout(TickType_t timeoutTicks) {
+	if(handle == nullptr) {
+		return SemaphoreIF::SEMAPHORE_INVALID;
+	}
+
+	BaseType_t returncode = xSemaphoreTake(handle, timeoutTicks);
+	if (returncode == pdPASS) {
+		return HasReturnvaluesIF::RETURN_OK;
+	}
+	else {
+		return SemaphoreIF::SEMAPHORE_TIMEOUT;
+	}
+}
+
+ReturnValue_t BinarySemaphore::release() {
+	return release(handle);
+}
+
+ReturnValue_t BinarySemaphore::release(SemaphoreHandle_t semaphore) {
+	if (semaphore == nullptr) {
+		return SemaphoreIF::SEMAPHORE_INVALID;
+	}
+	BaseType_t returncode = xSemaphoreGive(semaphore);
+	if (returncode == pdPASS) {
+		return HasReturnvaluesIF::RETURN_OK;
+	}
+	else {
+		return SemaphoreIF::SEMAPHORE_NOT_OWNED;
+	}
+}
+
+uint8_t BinarySemaphore::getSemaphoreCounter() const {
+	return uxSemaphoreGetCount(handle);
+}
+
+SemaphoreHandle_t BinarySemaphore::getSemaphore() {
+	return handle;
+}
+
+
+// Be careful with the stack size here. This is called from an ISR!
+ReturnValue_t BinarySemaphore::releaseFromISR(
+		SemaphoreHandle_t semaphore, BaseType_t * higherPriorityTaskWoken) {
+	if (semaphore == nullptr) {
+		return SemaphoreIF::SEMAPHORE_INVALID;
+	}
+	BaseType_t returncode = xSemaphoreGiveFromISR(semaphore,
+			higherPriorityTaskWoken);
+	if (returncode == pdPASS) {
+		return HasReturnvaluesIF::RETURN_OK;
+	}
+	else {
+		return SemaphoreIF::SEMAPHORE_NOT_OWNED;
+	}
+}

osal/FreeRTOS/BinarySemaphore.h

@@ -0,0 +1,107 @@
+#ifndef FRAMEWORK_OSAL_FREERTOS_BINARYSEMPAHORE_H_
+#define FRAMEWORK_OSAL_FREERTOS_BINARYSEMPAHORE_H_
+
+#include <framework/returnvalues/HasReturnvaluesIF.h>
+#include <framework/tasks/SemaphoreIF.h>
+
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+
+/**
+ * @brief 	OS Tool to achieve synchronization of between tasks or between
+ * 			task and ISR. The default semaphore implementation creates a
+ * 			binary semaphore, which can only be taken once.
+ * @details
+ * Documentation: https://www.freertos.org/Embedded-RTOS-Binary-Semaphores.html
+ *
+ * Please note that if the semaphore implementation is only related to
+ * the synchronization of one task, the new task notifications can be used,
+ * also see the BinSemaphUsingTask and CountingSemaphUsingTask classes.
+ * These use the task notification value instead of a queue and are
+ * faster and more efficient.
+ *
+ * @author 	R. Mueller
+ * @ingroup osal
+ */
+class BinarySemaphore: public SemaphoreIF,
+		public HasReturnvaluesIF {
+public:
+	static const uint8_t INTERFACE_ID = CLASS_ID::SEMAPHORE_IF;
+
+	//! @brief Default ctor
+	BinarySemaphore();
+	//! @brief Copy ctor, deleted explicitely.
+	BinarySemaphore(const BinarySemaphore&) = delete;
+	//! @brief Copy assignment, deleted explicitely.
+	BinarySemaphore& operator=(const BinarySemaphore&) = delete;
+	//! @brief Move ctor
+	BinarySemaphore (BinarySemaphore &&);
+	//! @brief Move assignment
+	BinarySemaphore & operator=(BinarySemaphore &&);
+	//! @brief Destructor
+	virtual ~BinarySemaphore();
+
+	uint8_t getSemaphoreCounter() const override;
+
+	/**
+	 * Take the binary semaphore.
+	 * If the semaphore has already been taken, the task will be blocked
+	 * for a maximum of #timeoutMs or until the semaphore is given back,
+	 * for example by an ISR or another task.
+	 * @param timeoutMs
+	 * @return -@c RETURN_OK on success
+	 *         -@c SemaphoreIF::SEMAPHORE_TIMEOUT on timeout
+	 */
+	ReturnValue_t acquire(uint32_t timeoutMs =
+	       	   SemaphoreIF::NO_TIMEOUT) override;
+
+	/**
+	 * Same as lockBinarySemaphore() with timeout in FreeRTOS ticks.
+	 * @param timeoutTicks
+	 * @return -@c RETURN_OK on success
+	 *         -@c SemaphoreIF::SEMAPHORE_TIMEOUT on timeout
+	 */
+	ReturnValue_t  acquireWithTickTimeout(TickType_t timeoutTicks =
+	        BinarySemaphore::NO_TIMEOUT);
+
+	/**
+	 * Release the binary semaphore.
+	 * @return -@c RETURN_OK on success
+	 *         -@c SemaphoreIF::SEMAPHORE_NOT_OWNED if the semaphores is
+	 *         	already available.
+	 */
+	ReturnValue_t release() override;
+
+	/**
+	 * Get Handle to the semaphore.
+	 * @return
+	 */
+	SemaphoreHandle_t getSemaphore();
+
+	 /**
+	 * Wrapper function to give back semaphore from handle
+	 * @param semaphore
+	 * @return -@c RETURN_OK on success
+	 *         -@c SemaphoreIF::SEMAPHORE_NOT_OWNED if the semaphores is
+	 *         	already available.
+	 */
+	static ReturnValue_t release(SemaphoreHandle_t semaphore);
+
+	/**
+	 * Wrapper function to give back semaphore from handle when called from an ISR
+	 * @param semaphore
+	 * @param higherPriorityTaskWoken This will be set to pdPASS if a task with
+	 * a higher priority was unblocked. A context switch from an ISR should
+	 * then be requested (see TaskManagement functions)
+	 * @return -@c RETURN_OK on success
+	 *         -@c SemaphoreIF::SEMAPHORE_NOT_OWNED if the semaphores is
+	 *         	already available.
+	 */
+	static ReturnValue_t releaseFromISR(SemaphoreHandle_t semaphore,
+				BaseType_t * higherPriorityTaskWoken);
+
+protected:
+	SemaphoreHandle_t handle;
+};
+
+#endif /* FRAMEWORK_OSAL_FREERTOS_BINARYSEMPAHORE_H_ */

osal/FreeRTOS/CountingSemaphUsingTask.cpp

@@ -0,0 +1,110 @@
+#include <framework/osal/FreeRTOS/CountingSemaphUsingTask.h>
+#include <framework/osal/FreeRTOS/TaskManagement.h>
+#include <framework/serviceinterface/ServiceInterfaceStream.h>
+
+CountingSemaphoreUsingTask::CountingSemaphoreUsingTask(const uint8_t maxCount,
+		uint8_t initCount): maxCount(maxCount) {
+	if(initCount > maxCount) {
+		sif::error << "CountingSemaphoreUsingTask: Max count bigger than "
+				"intial cout. Setting initial count to max count." << std::endl;
+		initCount = maxCount;
+	}
+
+	handle = TaskManagement::getCurrentTaskHandle();
+	if(handle == nullptr) {
+		sif::error << "CountingSemaphoreUsingTask: Could not retrieve task "
+				"handle. Please ensure the constructor was called inside a "
+				"task." << std::endl;
+	}
+
+	uint32_t oldNotificationValue;
+	xTaskNotifyAndQuery(handle, 0, eSetValueWithOverwrite,
+			&oldNotificationValue);
+	if(oldNotificationValue != 0) {
+		sif::warning << "CountinSemaphoreUsingTask: Semaphore initiated but "
+				"current notification value is not 0. Please ensure the "
+				"notification value is not used for other purposes!" << std::endl;
+	}
+	for(int i = 0; i < initCount; i++) {
+		xTaskNotifyGive(handle);
+	}
+}
+
+CountingSemaphoreUsingTask::~CountingSemaphoreUsingTask() {
+	// Clear notification value on destruction.
+	// If this is not desired, don't call the destructor
+	// (or implement a boolean which disables the reset)
+	xTaskNotifyAndQuery(handle, 0, eSetValueWithOverwrite, nullptr);
+}
+
+ReturnValue_t CountingSemaphoreUsingTask::acquire(uint32_t timeoutMs) {
+	TickType_t timeout = SemaphoreIF::NO_TIMEOUT;
+	if(timeoutMs == SemaphoreIF::MAX_TIMEOUT) {
+		timeout = SemaphoreIF::MAX_TIMEOUT;
+	}
+	else if(timeoutMs > SemaphoreIF::NO_TIMEOUT){
+		timeout = pdMS_TO_TICKS(timeoutMs);
+	}
+	return acquireWithTickTimeout(timeout);
+
+}
+
+ReturnValue_t CountingSemaphoreUsingTask::acquireWithTickTimeout(
+		TickType_t timeoutTicks) {
+	// Decrement notfication value without resetting it.
+	BaseType_t oldCount = ulTaskNotifyTake(pdFALSE, timeoutTicks);
+	if (getSemaphoreCounter() == oldCount - 1) {
+		return HasReturnvaluesIF::RETURN_OK;
+	}
+	else {
+		return SemaphoreIF::SEMAPHORE_TIMEOUT;
+	}
+}
+
+ReturnValue_t CountingSemaphoreUsingTask::release() {
+	if(getSemaphoreCounter() == maxCount) {
+		return SemaphoreIF::SEMAPHORE_NOT_OWNED;
+	}
+	return release(handle);
+}
+
+ReturnValue_t CountingSemaphoreUsingTask::release(
+		TaskHandle_t taskToNotify) {
+	BaseType_t returncode = xTaskNotifyGive(taskToNotify);
+	if (returncode == pdPASS) {
+		return HasReturnvaluesIF::RETURN_OK;
+	}
+	else {
+		// This should never happen.
+		return HasReturnvaluesIF::RETURN_FAILED;
+	}
+}
+
+
+uint8_t CountingSemaphoreUsingTask::getSemaphoreCounter() const {
+	uint32_t notificationValue = 0;
+	xTaskNotifyAndQuery(handle, 0, eNoAction, &notificationValue);
+	return notificationValue;
+}
+
+TaskHandle_t CountingSemaphoreUsingTask::getTaskHandle() {
+	return handle;
+}
+
+ReturnValue_t CountingSemaphoreUsingTask::releaseFromISR(
+		TaskHandle_t taskToNotify, BaseType_t* higherPriorityTaskWoken) {
+	vTaskNotifyGiveFromISR(taskToNotify, higherPriorityTaskWoken);
+	return HasReturnvaluesIF::RETURN_OK;
+}
+
+uint8_t CountingSemaphoreUsingTask::getSemaphoreCounterFromISR(
+		TaskHandle_t task, BaseType_t* higherPriorityTaskWoken) {
+	uint32_t notificationValue;
+	xTaskNotifyAndQueryFromISR(task, 0, eNoAction, &notificationValue,
+			higherPriorityTaskWoken);
+	return notificationValue;
+}
+
+uint8_t CountingSemaphoreUsingTask::getMaxCount() const {
+	return maxCount;
+}

osal/FreeRTOS/CountingSemaphUsingTask.h

@@ -0,0 +1,100 @@
+#ifndef FRAMEWORK_OSAL_FREERTOS_COUNTINGSEMAPHUSINGTASK_H_
+#define FRAMEWORK_OSAL_FREERTOS_COUNTINGSEMAPHUSINGTASK_H_
+
+#include <framework/osal/FreeRTOS/CountingSemaphUsingTask.h>
+#include <framework/tasks/SemaphoreIF.h>
+
+extern "C" {
+#include <freertos/FreeRTOS.h>
+#include <freertos/task.h>
+}
+
+/**
+ * @brief 	Couting Semaphore implementation which uses the notification value
+ * 			of the task. The notification value should therefore not be used
+ * 			for other purposes.
+ * @details
+ *  Additional information: https://www.freertos.org/RTOS-task-notifications.html
+ *  and general semaphore documentation.
+ */
+class CountingSemaphoreUsingTask: public SemaphoreIF {
+public:
+	CountingSemaphoreUsingTask(const uint8_t maxCount, uint8_t initCount);
+	virtual ~CountingSemaphoreUsingTask();
+
+	/**
+	 * Acquire the counting semaphore.
+	 * If no semaphores are available, the task will be blocked
+	 * for a maximum of #timeoutMs or until one is given back,
+	 * for example by an ISR or another task.
+	 * @param timeoutMs
+	 * @return -@c RETURN_OK on success
+	 *         -@c SemaphoreIF::SEMAPHORE_TIMEOUT on timeout
+	 */
+	ReturnValue_t acquire(uint32_t timeoutMs = SemaphoreIF::NO_TIMEOUT) override;
+
+	/**
+	 * Release a semaphore, increasing the number of available counting
+	 * semaphores up to the #maxCount value.
+	 * @return -@c RETURN_OK on success
+	 *         -@c SemaphoreIF::SEMAPHORE_NOT_OWNED if #maxCount semaphores are
+	 *         	already available.
+	 */
+	ReturnValue_t release() override;
+
+	uint8_t getSemaphoreCounter() const override;
+	/**
+	 * Get the semaphore counter from an ISR.
+	 * @param task
+	 * @param higherPriorityTaskWoken This will be set to pdPASS if a task with
+	 * a higher priority was unblocked. A context switch should be requested
+	 * from an ISR if this is the case (see TaskManagement functions)
+	 * @return
+	 */
+	static uint8_t getSemaphoreCounterFromISR(TaskHandle_t task,
+			BaseType_t* higherPriorityTaskWoken);
+
+	/**
+	 * Acquire with a timeout value in ticks
+	 * @param timeoutTicks
+	 * @return -@c RETURN_OK on success
+	 *         -@c SemaphoreIF::SEMAPHORE_TIMEOUT on timeout
+	 */
+	ReturnValue_t acquireWithTickTimeout(
+			TickType_t timeoutTicks = SemaphoreIF::NO_TIMEOUT);
+
+	/**
+	 * Get handle to the task related to the semaphore.
+	 * @return
+	 */
+	TaskHandle_t getTaskHandle();
+
+	/**
+	 * Release semaphore of task by supplying task handle
+	 * @param taskToNotify
+	 * @return -@c RETURN_OK on success
+	 *         -@c SemaphoreIF::SEMAPHORE_NOT_OWNED if #maxCount semaphores are
+	 *         	already available.
+	 */
+	static ReturnValue_t release(TaskHandle_t taskToNotify);
+	/**
+	 * Release seamphore of a task from an ISR.
+	 * @param taskToNotify
+	 * @param higherPriorityTaskWoken This will be set to pdPASS if a task with
+	 * a higher priority was unblocked. A context switch should be requested
+	 * from an ISR if this is the case (see TaskManagement functions)
+	 * @return -@c RETURN_OK on success
+	 *         -@c SemaphoreIF::SEMAPHORE_NOT_OWNED if #maxCount semaphores are
+	 *         	already available.
+	 */
+	static ReturnValue_t releaseFromISR(TaskHandle_t taskToNotify,
+			BaseType_t* higherPriorityTaskWoken);
+
+	uint8_t getMaxCount() const;
+
+private:
+	TaskHandle_t handle;
+	const uint8_t maxCount;
+};
+
+#endif /* FRAMEWORK_OSAL_FREERTOS_COUNTINGSEMAPHUSINGTASK_H_ */

osal/FreeRTOS/CountingSemaphore.cpp

@@ -0,0 +1,43 @@
+#include <framework/osal/FreeRTOS/CountingSemaphore.h>
+#include <framework/serviceinterface/ServiceInterfaceStream.h>
+#include <framework/osal/FreeRTOS/TaskManagement.h>
+
+#include <freertos/semphr.h>
+
+// Make sure #define configUSE_COUNTING_SEMAPHORES 1 is set in
+// free FreeRTOSConfig.h file.
+CountingSemaphore::CountingSemaphore(const uint8_t maxCount, uint8_t initCount):
+		maxCount(maxCount), initCount(initCount) {
+	if(initCount > maxCount) {
+		sif::error << "CountingSemaphoreUsingTask: Max count bigger than "
+				"intial cout. Setting initial count to max count." << std::endl;
+		initCount = maxCount;
+	}
+
+	handle = xSemaphoreCreateCounting(maxCount, initCount);
+	if(handle == nullptr) {
+		sif::error << "CountingSemaphore: Creation failure" << std::endl;
+	}
+}
+
+CountingSemaphore::CountingSemaphore(CountingSemaphore&& other):
+		maxCount(other.maxCount), initCount(other.initCount) {
+	handle = xSemaphoreCreateCounting(other.maxCount, other.initCount);
+	if(handle == nullptr) {
+		sif::error << "CountingSemaphore: Creation failure" << std::endl;
+	}
+}
+
+CountingSemaphore& CountingSemaphore::operator =(
+		CountingSemaphore&& other) {
+	handle = xSemaphoreCreateCounting(other.maxCount, other.initCount);
+	if(handle == nullptr) {
+		sif::error << "CountingSemaphore: Creation failure" << std::endl;
+	}
+	return * this;
+}
+
+
+uint8_t CountingSemaphore::getMaxCount() const {
+	return maxCount;
+}

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_ */