msach@0: 
msach@0: /*
msach@0:  * For a detailed description see header file.
msach@0:  */
msach@0: 
msach@0: #include "LossyCom.h"
msach@0: 
msach@0: #include "VMS_Implementations/VMS_impl/vmalloc.h"
msach@0: 
msach@0: /*
msach@0:  * Initializes the central exchange structure.
msach@0:  * Allocates memory to fit the number of endpoints.
msach@0:  * Returns NULL if an error occurs.
msach@0:  */
msach@0: lossyCom__exchange_t* lossyCom__initialize(uint16_t numEndpoints)
msach@0: {
msach@0:     lossyCom__exchange_t* exchange;
msach@0:     
msach@0:     exchange = VMS_WL__malloc(sizeof(lossyCom__exchange_t));
msach@0:     if(exchange == NULL)
msach@0:         return NULL;
msach@0:     
msach@0:     exchange->triggerCounter = 0;
msach@0:     exchange->numEndpoints = numEndpoints;
msach@0:     exchange->outboxArray = VMS_WL__malloc(sizeof(lossyCom__msg_t)*numEndpoints);
msach@0:     if(exchange->outboxArray == NULL){
msach@0:         VMS_WL__free(exchange);
msach@0:         return NULL;
msach@0:     }
msach@0:     
msach@0:     return exchange;    
msach@0: }
msach@0: 
msach@1: /*
msach@1:  * Connects the local endpoint to the central exchange structure.
msach@1:  * This registers a message handler that handles all the incomming messages.
msach@1:  * Also an endpointID is set this ID has to be between 0 and total number of
msach@1:  * endpoints-1 and the number has to be unique.
msach@1:  */
msach@0: void lossyCom__initialize_endpoint(lossyCom__endpoint_t* localEndpoint,
msach@0:                                    lossyCom__exchange_t* centralExchange,
msach@0:                                    lossyCom__endpointID_t endpointID,
msach@1:                                    lossyCom__msgHandler msgHandler,
msach@1:                                    void* msgHandlerData)
msach@0: {
msach@0:     localEndpoint->localTriggerCopy = 0;
msach@0:     localEndpoint->endpointID = endpointID;
msach@1:     localEndpoint->centralExchange = centralExchange;
msach@1:     localEndpoint->msgHandler = msgHandler;
msach@1:     localEndpoint->msgHandlerData = msgHandlerData;
msach@0: }
msach@0: 
msach@1: /*
msach@1:  * This broadcasts a message to all connected receivers
msach@1:  */
msach@0: void inline lossyCom__broadcastMsg(lossyCom__endpoint_t* localEndpoint,
msach@0:                                    lossyCom__msgBody_t msg)
msach@0: {
msach@0:     lossyCom__sendMsg(localEndpoint,
msach@0:                       BROADCAST_ID,
msach@0:                       msg);
msach@0: }
msach@0: 
msach@1: /*
msach@1:  * This sends a message another endpoint. Again it is not guaranteed that the 
msach@1:  * message is received. But in most cases it will.
msach@1:  */
msach@0: void inline lossyCom__sendMsg(lossyCom__endpoint_t* localEndpoint,
msach@0:                        lossyCom__endpointID_t receiverEndpointID,
msach@0:                        lossyCom__msgBody_t msg)
msach@0: {
msach@0:     lossyCom__msg_t msgDraft;
msach@0:     uint16_t triggerCopy;
msach@0:     
msach@1:     //build message
msach@0:     msgDraft = (0 | msg);
msach@0:     msgDraft |= ((lossyCom__msg_t)receiverEndpointID << ENDPOINT_ID_SHIFT);
msach@0:     
msach@1:     triggerCopy = localEndpoint->centralExchange->triggerCounter +1;
msach@0:     msgDraft |= ((lossyCom__msg_t)triggerCopy << TRIGGER_SHIFT);
msach@0:     
msach@0:     //write msg to central exchange
msach@1:     localEndpoint->centralExchange->outboxArray[localEndpoint->endpointID] =
msach@0:             msgDraft;
msach@0:     
msach@1:     localEndpoint->centralExchange->triggerCounter = triggerCopy;
msach@0: }
msach@0: 
msach@0: void inline lossyCom__receiveMsg(lossyCom__endpoint_t* localEndpoint)
msach@0: {
msach@1:     uint16_t currentTriggerCopy;
msach@0:     lossyCom__endpointID_t senderEndpointID;
msach@0:     lossyCom__msg_t msgCopy;
msach@0:     uint16_t msgTrigger;
msach@0:     lossyCom__msgBody_t msgBody;
msach@0:     
msach@0:     senderEndpointID = 0;
msach@1:     currentTriggerCopy = localEndpoint->centralExchange->triggerCounter;
msach@1:     
msach@0:     //new message arrived if trigger counter is higher than the last time read
msach@1:     while(senderEndpointID < localEndpoint->centralExchange->numEndpoints)
msach@0:     {
msach@0:         if(senderEndpointID != localEndpoint->endpointID)
msach@0:         {
msach@1:             msgCopy = localEndpoint->centralExchange->outboxArray[senderEndpointID];
msach@0:             msgTrigger = 0xFFFF & (msgCopy >> TRIGGER_SHIFT);
msach@1:             // check if the message is new (msg trigger > archived trigger)
msach@1:             // and already valid (msgTrigger <= currentTriggerCopy)
msach@0:             if(msgTrigger > localEndpoint->localTriggerCopy &&
msach@1:                     msgTrigger <= currentTriggerCopy)
msach@0:             {
msach@1:                 //let the message handler parse the message
msach@0:                 msgBody = 0xFFFFFFFF & msgCopy;
msach@1:                 (*(localEndpoint->msgHandler))(senderEndpointID,
msach@1:                                                msgBody,
msach@1:                                                localEndpoint->msgHandlerData);
msach@0:             }
msach@0:         }
msach@0:         senderEndpointID++;
msach@0:     }
msach@0:     //save last parsed msg
msach@1:     localEndpoint->localTriggerCopy = currentTriggerCopy;
msach@0: }