#ifndef MESSAGEQUEUE_H_ #define MESSAGEQUEUE_H_ #include #include #include #include #include #include "queue.h" //TODO this class assumes that MessageQueueId_t is the same size as void* (the FreeRTOS handle type), compiler will catch this but it might be nice to have something checking or even an always working solution // https://scaryreasoner.wordpress.com/2009/02/28/checking-sizeof-at-compile-time/ /** * @brief This class manages sending and receiving of message queue messages. * * @details Message queues are used to pass asynchronous messages between processes. * They work like post boxes, where all incoming messages are stored in FIFO * order. This class creates a new receiving queue and provides methods to fetch * received messages. Being a child of MessageQueueSender, this class also provides * methods to send a message to a user-defined or a default destination. In addition * it also provides a reply method to answer to the queue it received its last message * from. * * The MessageQueue should be used as "post box" for a single owning object. So all * message queue communication is "n-to-one". * For creating the queue, as well as sending and receiving messages, the class makes * use of the operating system calls provided. * * Please keep in mind that FreeRTOS offers * different calls for message queue operations if called from an ISR. * For now, the system context needs to be switched manually. * @ingroup osal * @ingroup message_queue */ class MessageQueue : public MessageQueueIF { friend class MessageQueueSenderIF; public: /** * @brief The constructor initializes and configures the message queue. * @details By making use of the according operating system call, a message queue is created * and initialized. The message depth - the maximum number of messages to be * buffered - may be set with the help of a parameter, whereas the message size is * automatically set to the maximum message queue message size. The operating system * sets the message queue id, or i case of failure, it is set to zero. * @param message_depth The number of messages to be buffered before passing an error to the * sender. Default is three. * @param max_message_size With this parameter, the maximum message size can be adjusted. * This should be left default. */ MessageQueue( size_t message_depth = 3, size_t max_message_size = MessageQueueMessage::MAX_MESSAGE_SIZE ); /** * @brief The destructor deletes the formerly created message queue. * @details This is accomplished by using the delete call provided by the operating system. */ virtual ~MessageQueue(); /** * This function is used to specify whether a message queue operation is called * from within an ISR or a task. FreeRTOS offers different functions for this task. * @param callContext */ void switchSystemContext(SystemContext callContext); /** * @brief This operation sends a message to the given destination. * @details It directly uses the sendMessage call of the MessageQueueSender parent, but passes its * queue id as "sentFrom" parameter. * @param sendTo This parameter specifies the message queue id of the destination message queue. * @param message A pointer to a previously created message, which is sent. * @param ignoreFault If set to true, the internal software fault counter is not incremented if queue is full. */ ReturnValue_t sendMessage(MessageQueueId_t sendTo, MessageQueueMessage* message, bool ignoreFault = false ); /** * @brief This operation sends a message to the default destination. * @details As in the sendMessage method, this function uses the sendToDefault call of the * MessageQueueSender parent class and adds its queue id as "sentFrom" information. * @param message A pointer to a previously created message, which is sent. */ ReturnValue_t sendToDefault( MessageQueueMessage* message ); /** * @brief This operation sends a message to the last communication partner. * @details This operation simplifies answering an incoming message by using the stored * lastParnter information as destination. If there was no message received yet * (i.e. lastPartner is zero), an error code is returned. * @param message A pointer to a previously created message, which is sent. */ ReturnValue_t reply( MessageQueueMessage* message ); /** * \brief With the sendMessage call, a queue message is sent to a receiving queue. * \details This method takes the message provided, adds the sentFrom information and passes * it on to the destination provided with an operating system call. The OS's return * value is returned. * \param sendTo This parameter specifies the message queue id to send the message to. * \param message This is a pointer to a previously created message, which is sent. * \param sentFrom The sentFrom information can be set to inject the sender's queue id into the message. * This variable is set to zero by default. * \param ignoreFault If set to true, the internal software fault counter is not incremented if queue is full. */ virtual ReturnValue_t sendMessageFrom( MessageQueueId_t sendTo, MessageQueueMessage* message, MessageQueueId_t sentFrom = NO_QUEUE, bool ignoreFault = false ); /** * \brief The sendToDefault method sends a queue message to the default destination. * \details In all other aspects, it works identical to the sendMessage method. * \param message This is a pointer to a previously created message, which is sent. * \param sentFrom The sentFrom information can be set to inject the sender's queue id into the message. * This variable is set to zero by default. */ virtual ReturnValue_t sendToDefaultFrom( MessageQueueMessage* message, MessageQueueId_t sentFrom = NO_QUEUE, bool ignoreFault = false ); /** * @brief This function reads available messages from the message queue and returns the sender. * @details It works identically to the other receiveMessage call, but in addition returns the * sender's queue id. * @param message A pointer to a message in which the received data is stored. * @param receivedFrom A pointer to a queue id in which the sender's id is stored. */ ReturnValue_t receiveMessage(MessageQueueMessage* message, MessageQueueId_t *receivedFrom); /** * @brief This function reads available messages from the message queue. * @details If data is available it is stored in the passed message pointer. The message's * original content is overwritten and the sendFrom information is stored in the * lastPartner attribute. Else, the lastPartner information remains untouched, the * message's content is cleared and the function returns immediately. * @param message A pointer to a message in which the received data is stored. */ ReturnValue_t receiveMessage(MessageQueueMessage* message); /** * Deletes all pending messages in the queue. * @param count The number of flushed messages. * @return RETURN_OK on success. */ ReturnValue_t flush(uint32_t* count); /** * @brief This method returns the message queue id of the last communication partner. */ MessageQueueId_t getLastPartner() const; /** * @brief This method returns the message queue id of this class's message queue. */ MessageQueueId_t getId() const; /** * \brief This method is a simple setter for the default destination. */ void setDefaultDestination(MessageQueueId_t defaultDestination); /** * \brief This method is a simple getter for the default destination. */ MessageQueueId_t getDefaultDestination() const; bool isDefaultDestinationSet() const; protected: /** * Implementation to be called from any send Call within MessageQueue and MessageQueueSenderIF * \details This method takes the message provided, adds the sentFrom information and passes * it on to the destination provided with an operating system call. The OS's return * value is returned. * \param sendTo This parameter specifies the message queue id to send the message to. * \param message This is a pointer to a previously created message, which is sent. * \param sentFrom The sentFrom information can be set to inject the sender's queue id into the message. * This variable is set to zero by default. * \param ignoreFault If set to true, the internal software fault counter is not incremented if queue is full. * \param context */ static ReturnValue_t sendMessageFromMessageQueue(MessageQueueId_t sendTo, MessageQueueMessage* message, MessageQueueId_t sentFrom = NO_QUEUE, bool ignoreFault=false, SystemContext callContex = SystemContext::task_context); static ReturnValue_t handleSendResult(BaseType_t result, bool ignoreFault); private: QueueHandle_t handle; MessageQueueId_t defaultDestination; MessageQueueId_t lastPartner; SystemContext callContext; //!< Stores the current system context }; #endif /* MESSAGEQUEUE_H_ */