182 lines
8.6 KiB
C++
182 lines
8.6 KiB
C++
#ifndef MESSAGEQUEUE_H_
|
|
#define MESSAGEQUEUE_H_
|
|
|
|
#include "../../internalError/InternalErrorReporterIF.h"
|
|
#include "../../ipc/MessageQueueIF.h"
|
|
#include "../../ipc/MessageQueueMessage.h"
|
|
|
|
#include <mqueue.h>
|
|
/**
|
|
* @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".
|
|
*
|
|
* The creation of message queues, as well as sending and receiving messages,
|
|
* makes use of the operating system calls provided.
|
|
* @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(uint32_t messageDepth = 3,
|
|
size_t maxMessageSize = 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();
|
|
/**
|
|
* @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.
|
|
*/
|
|
virtual 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.
|
|
*/
|
|
virtual 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 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 With the sendMessage call, a queue message is sent to a receiving queue.
|
|
* \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, 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 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.
|
|
*/
|
|
static ReturnValue_t sendMessageFromMessageQueue(MessageQueueId_t sendTo,MessageQueueMessage* message, MessageQueueId_t sentFrom = NO_QUEUE,bool ignoreFault=false);
|
|
private:
|
|
/**
|
|
* @brief The class stores the queue id it got assigned from the operating system in this attribute.
|
|
* If initialization fails, the queue id is set to zero.
|
|
*/
|
|
MessageQueueId_t id;
|
|
/**
|
|
* @brief In this attribute, the queue id of the last communication partner is stored
|
|
* to allow for replying.
|
|
*/
|
|
MessageQueueId_t lastPartner;
|
|
/**
|
|
* @brief The message queue's name -a user specific information for the operating system- is
|
|
* generated automatically with the help of this static counter.
|
|
*/
|
|
/**
|
|
* \brief This attribute stores a default destination to send messages to.
|
|
* \details It is stored to simplify sending to always-the-same receiver. The attribute may
|
|
* be set in the constructor or by a setter call to setDefaultDestination.
|
|
*/
|
|
MessageQueueId_t defaultDestination;
|
|
|
|
/**
|
|
* The name of the message queue, stored for unlinking
|
|
*/
|
|
char name[5];
|
|
|
|
static uint16_t queueCounter;
|
|
|
|
ReturnValue_t handleError(mq_attr* attributes, uint32_t messageDepth);
|
|
};
|
|
|
|
#endif /* MESSAGEQUEUE_H_ */
|