// Visual Tools S.A. SPAIN
// Rapita Systems Ltd UK
// Evidence ITALY
-//
+//
// See http://www.frescor.org for a link to partners' websites
//
// FRESCOR project (FP6/2005/IST/5-034026) is funded
//
//
// based on previous work (FSF) done in the FIRST project
-//
+//
// Copyright (C) 2005 Mälardalen University, SWEDEN
// Scuola Superiore S.Anna, ITALY
// Universidad de Cantabria, SPAIN
// **//// /**///** ////////** /**//////**
// ** /** //** /** /** /**
// ** /** //** ******** /** /**
-// // // // //////// // //
+// // // // //////// // //
//
// FRSH(FRescor ScHeduler), pronounced "fresh"
//==============================================
#ifndef _FRSH_DISTRIBUTED_H_
#define _FRSH_DISTRIBUTED_H_
+/**
+ * @file frsh_distributed.h
+ **/
+
+
#include "frsh_distributed_types.h"
#include "frsh_core_types.h"
* This module defines the functions and typedefs for use in
* distributed applications.
*
+ * Each network is identified by its resource_id and FRSH hides its
+ * characteristics completely. The type of network is implied with
+ * its ID via a configuration table defined at compile time.
+ *
+ * FRSH uses the "message" as the atomic unit for every exchange.
+ * Queue sizes are measured in number of pending messages.
+ *
+ * FRSH provides a function to calculate the transmision time needed
+ * for a certain message size in a network as well as the maximum
+ * message size that can admit.
+ *
+ * Note also that package delivery guarantee is protocol dependent.
+ * For protocols in which the order is no guaranteed, the application
+ * needs to add extra info to detect possible package disorder.
+ *
+ * Summary of typical steps.
+ *
+ * 1. Map (internally in FRSH implementation)
+ * - node--> network_addresses
+ * - network --> resource_id's
+ * - unidirectional communication channel --> stream_id
+ * - other config --> protocol_info.
+ *
+ * 2. In a sending node:
+ * 2.1. Negotiates a "network contract" per communication channel
+ * that is used in the application. In the contract it is
+ * specified:
+ * - frsh_resource_type = FRSH_RT_NETWORK.
+ * - frsh_resource_id = <network id #>
+ * - budget: Time needed to send the required data per period.
+ * (you can use frsh_netinfo_*() functions for this).
+ * - period: Period of sendings.
+ * - Queueing info: How will sends be queued at sendEndpoint.
+ * - Other protocol dependent function in protocol_contract_info.
+ * 2.2. Create a send_endpoint per any unidirectional stream that will
+ * be used in sending
+ * resource_id --> the network through which the stream will
+ * flow (this is extra info needed for coherency
+ * with the bind).
+ * destinator --> network_address of the destination.
+ * stream_id --> the unidirectional communication channel.
+ * 2.3. Bind the send_endpoint to the network contract negotiated
+ * above.
+ * 2.4. The (processor) sending vres invokes frsh_send_(a)sync() to
+ * send the data through the corresponding stream.
+ *
+ * 3. In a receiving node:
+ * 3.1. Create a receive_endpoint per any unidirectional stream
+ * that will be used in receiving.
+ * 3.2. The processor expecting a reception of message invokes
+ * frsh_receive_(a)sync() to read the incoming data.
+ *
+ * 4. When all comunication is finished and the channel is no longer
+ * needed the nodes will destroy the send and receive endpoints
+ * and the network contract will be canceled.
+ **/
+
+/**
+ * frsh_distributed_init(void)
+ *
+ * This operation initializes all the installed networks and the structures
+ * that are necessary for the distributed module. Currently it is called by
+ * frsh_init so it is not necessary that the user calls it again.
+ *
+ * 0: No error \n
+ * FRSH_ERR_INTERNAL_ERROR: protocol dependent internal errors \n
+ *
+ **/
+int frsh_distributed_init(void);
+
+//////////////////////////////////////////////////////////////////////
+// CONTRACT ASPECTS
+//////////////////////////////////////////////////////////////////////
+
+/**
+ * @defgroup distcontract Contract Info for Distributed Systems
+ * @ingroup distributed
+ *
+ * These functions help you calculate the needed budget for network
+ * contracts and also to include protocol dependent info in contract
+ * parameters.
+ *
* @{
**/
+/**
+ * frsh_network_get_max_message_size()
+ *
+ * This operation gives the maximum number of bytes that can be sent
+ * at a time through the send function when using the network designated by
+ * 'resource_id' and sending it to 'destination'.
+ *
+ * If the application needs to send bigger messages it will have to
+ * split them.
+ *
+ * Some protocols, like IP, are capable of sending large messages
+ * (and use fragmentation internally) but other protocols don't.
+ *
+ * @param[in] resource_id The network we want the tx time from.
+ * @param[in] destination The destination address
+ * @param[out] max_size The maximum number of bytes for each message
+ *
+ * @return
+ * FRSH_NO_ERROR \n
+ * FRSH_ERR_INTERNAL_ERROR: protocol dependent internal errors \n
+ * FRSH_ERR_NOT_INITIALIZED: if the protocol is not initialized \n
+ * FRSH_ERR_RESOURCE_ID_INVALID: if resource id does not represent
+ * a network accessible from the current processing node \n
+ * FRSH_ERR_BAD_ARGUMENT: if pointers are NULL or destination is
+ * invalid \n
+ *
+ **/
+int frsh_network_get_max_message_size
+ (const frsh_resource_id_t resource_id,
+ const frsh_network_address_t destination,
+ size_t *max_size);
+
+/**
+ * frsh_network_bytes_to_budget()
+ *
+ * This operation converts a number of bytes into a temporal budget for
+ * a specific network. Network overheads are not included here but are
+ * considered internally when negotiating a specific contract.
+ *
+ * @param[in] resource_id The network
+ * @param[in] nbytes Number of bytes
+ * @param[out] budget The network budget for nbytes
+ *
+ * @return
+ * FRSH_NO_ERROR \n
+ * FRSH_ERR_INTERNAL_ERROR: protocol dependent internal errors \n
+ * FRSH_ERR_NOT_INITIALIZED: if the protocol is not initialized \n
+ * FRSH_ERR_RESOURCE_ID_INVALID: if resource id does not represent
+ * a network accessible from the current processing node \n
+ * FRSH_ERR_BAD_ARGUMENT: if pointers are NULL or nbytes is less
+ * than zero \n
+ *
+ **/
+int frsh_network_bytes_to_budget
+ (const frsh_resource_id_t resource_id,
+ const size_t nbytes,
+ struct timespec *budget);
+
+/**
+ * frsh_network_budget_to_bytes()
+ *
+ * This operation converts a temporal budget into a number of bytes for
+ * a specific network. Network overheads are not included.
+ *
+ * @param[in] resource_id The network
+ * @param[in] budget The network budget for nbytes
+ * @param[out] nbytes Number of bytes
+ *
+ * @return
+ * FRSH_NO_ERROR \n
+ * FRSH_ERR_INTERNAL_ERROR: protocol dependent internal errors \n
+ * FRSH_ERR_NOT_INITIALIZED: if the protocol is not initialized \n
+ * FRSH_ERR_RESOURCE_ID_INVALID: if resource id does not represent
+ * a network accessible from the current processing node \n
+ * FRSH_ERR_BAD_ARGUMENT: if pointers are NULL or budget refers to
+ * an invalid time value \n
+ *
+ **/
+int frsh_network_budget_to_bytes
+ (const frsh_resource_id_t resource_id,
+ const struct timespec *budget,
+ size_t *nbytes);
+
+/**
+ * frsh_network_get_min_effective_budget()
+ *
+ * This operation gets the minimum effective budget for a network. Each message
+ * consumes a contracted budget in "chunks" (i.e: packets) that we call
+ * minimum effective budget.
+ *
+ * A negotiated contract, for N bytes in a period T, means that there is a
+ * virtual resource that reserves for the user:
+ *
+ * Ceiling ((N bytes) / budget_to_bytes (min_effective_budget)) "CHUNKS"
+ *
+ * Note that if the user decides not to send these N bytes at once but, say,
+ * one byte at a time, it will consume one "CHUNK" at a time and the reserved
+ * budget will become exhausted before sending all the bytes.
+ *
+ * @param[in] resource_id The network
+ * @param[out] budget The network budget
+ *
+ * @return
+ * FRSH_NO_ERROR \n
+ * FRSH_ERR_INTERNAL_ERROR: protocol dependent internal errors \n
+ * FRSH_ERR_NOT_INITIALIZED: if the protocol is not initialized \n
+ * FRSH_ERR_RESOURCE_ID_INVALID: if resource id does not represent
+ * a network accessible from the current processing node \n
+ * FRSH_ERR_BAD_ARGUMENT: if pointers are NULL \n
+ *
+ **/
+int frsh_network_get_min_effective_budget
+ (const frsh_resource_id_t resource_id,
+ struct timespec *budget);
+
+/**
+ * frsh_contract_set_queueing_info()
+ *
+ * This function adds queueing parameters that will be used in the
+ * sendEndpoint when the sendEndpoint is bound to the vres.
+ **/
+int frsh_contract_set_queueing_info(frsh_endpoint_queueing_info_t queueing_info,
+ frsh_contract_t *contract);
+
+/**
+ * frsh_contract_get_queueing_info()
+ *
+ * This function gets the queueing parameters that were specified in
+ * the network contract.
+ **/
+int frsh_contract_get_queueing_info(const frsh_contract_t *contract,
+ frsh_endpoint_queueing_info_t *queueing_info);
+
+/**
+ * frsh_contract_set_protocol_info
+ *
+ * We add protocol info to the contract
+ **/
+int frsh_contract_set_protocol_info(frsh_protocol_info_t protocol_info,
+ frsh_contract_t *contract);
+
+/**
+ * frsh_contract_get_protocol_info
+ *
+ * We get protocol info from the contract
+ **/
+int frsh_contract_get_protocol_info(frsh_contract_t *contract,
+ frsh_protocol_info_t *protocol_info);
+
+/**
+ * frsh_contract_marshal
+ *
+ * Convert a contract to a sequence of bytes of minimum size so it can
+ * be sent through the network with the minimum amount of bytes.
+ *
+ **/
+int frsh_contract_marshal(const frsh_contract_t *contract,
+ unsigned char *buffer,
+ const size_t buffer_size,
+ size_t *size);
+/**
+ * frsh_contract_unmarshal
+ *
+ * Convert a sequence of bytes generated by frsh_contract_marshal to a contract
+ *
+ **/
-#define FRSH_DISTRIBUTED_MODULE_SUPPORTED 1
+int frsh_contract_unmarshal(frsh_contract_t *contract,
+ const unsigned char *marshal_bytes,
+ const size_t size);
+/*@}*/
//////////////////////////////////////////////////////////////////////
// TRANSMISSION SERVICES
* @defgroup txservices Transmission services
* @ingroup distributed
*
- * These functions need to be called before doing any FRSH operation
- * (including contract initialization).
+ * These functions allow to create and manage endpoints for sending
+ * and receiving and to perform send and receive operations both
+ * synchronously (blocking) and asynchronously (non-blocking).
*
* @{
**/
/**
* frsh_send_endpoint_create()
*
- * This operation creates a unidirectional input
- * data endpoint through which, after the
- * corresponding binding, it is possible to send
- * data. network_id identifies the network to use,
- * receiver specifies the communication protocol
- * dependent information that is necessary to
- * address the receiving node, and port specifies
- * the communication protocol dependent information
- * that is necessary to get in contact with the
- * desired destination.
- * It returns 0 if
- * successful. It returns FRSH_ERR_BAD_ARGUMENT if
- * the endpoint is null, if the network_id is not
- * valid, or if the receiver or the port do not
- * conform to their expected formats.
+ * This operation creates a unidirectional stream input endpoint
+ * through which, after the corresponding binding, it is possible to
+ * send data to a unicast or multicast destination.
+ *
+ * @param[in] resource_id Identifier of the network referred in the
+ * network contract as a resource_id.
+ * @param[in] destination FRSH abstraction of the protocol address for the
+ * destinator node.
+ * @param[in] stream_id Identifier of the communication channel between
+ * the nodes. Multiplexing is achieved by using
+ * different streams between the same nodes and the
+ * same network.
+ * @param[in] queueing_info Queueing params of the endpoint (size and
+ * policy).
+ * @param[in] protocol_info Optional protocol-dependent info.
+ * @param[out] endpoint Placeholder for the endpoint object.
**/
int frsh_send_endpoint_create
- (frsh_resource_id_t network_id,
- frsh_node_address_t receiver,
- frsh_port_t port,
- frsh_send_endpoint_t *endpoint);
+ (frsh_resource_id_t resource_id,
+ frsh_network_address_t destination,
+ frsh_stream_id_t stream_id,
+ frsh_send_endpoint_protocol_info_t protocol_info,
+ frsh_send_endpoint_t *endpoint);
/**
- * frsh_send_endpoint_destroy()
+ * frsh_send_endpoint_get_params()
*
- * This operation eliminates any resources reserved
- * for the referenced endpoint. If the endpoint is
- * bound to a network server, it is unbound from it
- * and can not be further used to invoke send
- * operations on it.
- * It returns 0 if successful,
- * or FRSH_ERR_BAD_ARGUMENT if the endpoint is not
- * valid.
+ * This operation returns in the variables associated to the
+ * endpoint at creation time.
**/
-int frsh_send_endpoint_destroy
- (frsh_send_endpoint_t *endpoint);
+int frsh_send_endpoint_get_params
+ (const frsh_send_endpoint_t endpoint,
+ frsh_resource_id_t *resource_id,
+ frsh_network_address_t *destination,
+ frsh_stream_id_t *stream,
+ frsh_send_endpoint_protocol_info_t *protocol_info);
/**
- * frsh_send_endpoint_get_params()
+ * frsh_send_endpoint_destroy()
*
- * This operation returns (except for those NULL
- * arguments) in the variables pointed to by
- * network_id, receiver, or port, the corresponding
- * parameters used in the creation of the given
- * send endpoint. It returns 0 if successful, or
- * FRSH_ERR_BAD_ARGUMENT if the endpoint is not
- * valid or all the other pointers are NULL.
+ * This operation eliminates any resources reserved for the referenced
+ * endpoint. Pending messages will be discarded and processor-vres
+ * waiting in a synchronous operation will be awoken with an error
+ * code.
**/
-int frsh_send_endpoint_get_params
- (const frsh_send_endpoint_t *endpoint,
- frsh_resource_id_t *network_id,
- frsh_node_address_t *receiver,
- frsh_port_t *port);
+int frsh_send_endpoint_destroy
+ (frsh_send_endpoint_t endpoint);
+
/**
- * frsh_endpoint_bind()
- *
- * This operation associates a send endpoint with a
- * server, which means that messages sent through
- * that endpoint will consume the server's reserved
- * bandwidth and its packets will be sent according
- * to the contract established for that server. If
- * the endpoint is already bound to another server,
- * it is effectively unbound from it and bound to
- * the specified one.
- * The operation returns 0 if successful, or
- * FRSH_ERR_BAD_ARGUMENT if the endpoint or the server
- * are not valid, it also fails with a
- * value of FRSH_ERR_ALREADY_BOUND if the server is
- * already bound to some other send endpoint.
- * It fails with FRSH_ERR_WRONG_NETWORK if the server
- * network id is not the same as the one in the endpoint
+ * frsh_send_endpoint_bind()
+ *
+ * This operation associates a send endpoint with a network vres,
+ * which means that messages sent through this endpoint will consume
+ * the vres's reserved bandwidth and its packets will be sent
+ * according to the contract established for that vres.
+ *
+ * If the endpoint is already bound to another vres, it is effectively
+ * unbound from it and bound to the specified one. However if a vres
+ * is already bound to another endpoint an error is returned.
+ *
+ * A consistency check is done in which the resource_id specified at
+ * endpoint creation must correspond to the resource_id of the vres
+ * contract.
+ *
+ * @return 0 if successful \n
+ * FRSH_ERR_BAD_ARGUMENT if the endpoint or the vres are not
+ * valid \n
+ * FRSH_ERR_ALREADY_BOUND if the vres is already bound to some
+ * other send endpoint \n
+ * FRSH_ERR_WRONG_NETWORK if the vres network id is not the same
+ * as the one in the endpoint \n
**/
-int frsh_endpoint_bind
+int frsh_send_endpoint_bind
(frsh_vres_id_t vres,
- frsh_send_endpoint_t *endpoint);
+ frsh_send_endpoint_t endpoint);
/**
- * frsh_endpoint_unbind()
- *
- * This operation unbinds a send endpoint from a
- * server. Endpoints with no server associated
- * cannot be used to send data, and they stay in
- * that state until they are either eliminated or
- * bound again. The operation fails with
- * FRSH_ERR_NOT_BOUND if the endpoint has no server
- * bound
+ * frsh_send_endpoint_unbind()
+ *
+ * This operation unbinds a send endpoint from a vres. Endpoints with
+ * no vres associated cannot be used to send data, and they stay in
+ * that state until they are either eliminated or bound again.
+ *
+ * @return 0 if successful \n
+ * FRSH_ERR_NOT_BOUND if the endpoint was not bound \n
**/
-int frsh_endpoint_unbind
- (frsh_send_endpoint_t *endpoint);
+int frsh_send_endpoint_unbind
+ (frsh_send_endpoint_t endpoint);
/**
- * frsh_endpoint_get_vres_id()
+ * frsh_send_endpoint_get_vres_id()
+ *
+ * This operation copies the id of the vres that is bound to the
+ * specified send endpoint into the variable pointed to by vres.
*
- * This operation copies the id of the server that
- * is bound to the specified send endpoint into the
- * variable pointed to by server. It returns 0 if
- * successful, or FRSH_ERR_BAD_ARGUMENT if the
- * endpoint is not valid or server is NULL
+ * @return 0 if successful \n
+ * FRSH_ERR_NOT_BOUND if the endpoint was not bound \n
+ * FRSH_ERR_BAD_ARGUMENT if the endpoint is not valid or vres
+ * is NULL \n
**/
-int frsh_endpoint_get_vres_id
- (const frsh_send_endpoint_t *endpoint,
- frsh_vres_id_t *server);
+int frsh_send_endpoint_get_vres_id
+ (const frsh_send_endpoint_t endpoint,
+ frsh_vres_id_t *vres);
/**
- * frsh_send()
+ * frsh_send_async()
*
* This operation sends a message stored in msg and of length size
* through the given endpoint. The operation is non-blocking and
- * returns immediately. An internal frsh service will schedule the
- * sending of messages and implement the communications sporadic server
- * corresponding to the network server bound to the given endpoint.
- * Messages sent through the same endpoint are received in the same
- * order in which they were sent It returns 0 if successful, but it
- * fails with FRSH_ERR_BAD_ARGUMENT if endpoint is not valid; it fails
- * with FRSH_ERR_NOT_BOUND is not bound to a valid server; it fails with
- * FRSH_ERR_TOO_LARGE if the message is too large for the network
- * protocol; it fails with FRSH_ERR_BUFFER_FULL if the sending queue is
- * full
+ * returns immediately.
+ *
+ * An internal frsh service will schedule the sending of messages and
+ * implement the communications sporadic vres corresponding to the
+ * network vres bound to the given endpoint.
+ *
+ * @returns 0 if successful \n
+ * FRSH_ERR_BAD_ARGUMENT if endpoint is not valid \n
+ * FRSH_ERR_NOT_BOUND if endpoint is not bound to a valid vres \n
+ * FRSH_ERR_TOO_LARGE if the message is too large for the
+ * network protocol \n
+ * FRSH_ERR_BUFFER_FULL if the message has been discarded
+ * because the queue is full (and does not
+ * have the policy FRSH_QP_OLDEST \n
+ **/
+int frsh_send_async
+ (const frsh_send_endpoint_t endpoint,
+ const void *msg,
+ const size_t size);
+
+/**
+ * frsh_send_sync()
+ *
+ * Similar to previous function but now the sending vres gets blocked
+ * until the message is processed.
**/
-int frsh_send
- (const frsh_send_endpoint_t *endpoint,
+int frsh_send_sync
+ (const frsh_send_endpoint_t endpoint,
void *msg,
size_t size);
+/**
+ * frsh_send_endpoint_get_status()
+ *
+ * This function tells the number of messages still pending in the
+ * endpoint queue, whether the network is up or down with some
+ * optional information which is protocol_dependent.
+ **/
+int frsh_send_endpoint_get_status
+ (const frsh_send_endpoint_t endpoint,
+ int *number_pending_msg,
+ frsh_endpoint_network_status_t *network_status,
+ frsh_protocol_status_t *protocol_status);
+
/**
* frsh_receive_endpoint_create()
*
- * This operation creates a receive endpoint with all the information
- * that is necessary to receive information from the specified network
- * and port It returns 0 if successful, but it fails with
- * FRSH_ERR_BAD_ARGUMENT if the port or the network id are not valid.
+ * This operation creates a receive endpoint associated with a
+ * undirectional stream within a network interface of the node.
+ *
+ * Receiving endpoints are not bound to any network vres, this is
+ * because don't originate any traffic.
+ *
+ * Note that the protocol address is not needed for reception because
+ * it can be determined internally by FRSH based on the resource_id.
+ *
+ * Note also that messages may come from diferent originators.
+ *
+ * @param[in] resource_id Id of the network from which we listen.
+ * @param[in] stream_id Id of the stream within the network.
+ * @param[in] queueing_info Buffering information(queue size and
+ * policy).
+ * @param[in] protocol_info Extra protocol info opaque for the
+ * application.
+ * @param[in] endpoin Placeholder for the endpoint object.
+ *
+ * @return 0 if successful \n
+ * FRSH_ERR_BAD_ARGUMENT if the stream or the network id are not
+ * valid \n
**/
int frsh_receive_endpoint_create
- (frsh_resource_id_t network_id,
- frsh_port_t port,
+ (frsh_resource_id_t resource_id,
+ frsh_stream_id_t stream_id,
+ frsh_endpoint_queueing_info_t queueing_info,
+ frsh_receive_endpoint_protocol_info_t protocol_info,
frsh_receive_endpoint_t *endpoint);
/**
- * frsh_receive_endpoint_destroy()
+ * frsh_receive_endpoint_get_params()
*
- * This operation eliminates any resources reserved
- * for the referenced endpoint. it
- * can not be further used to invoke receive
- * operations on it.It returns 0 if successful, but it fails with
- * FRSH_ERR_BAD_ARGUMENT if endpoint is NULL or not valid.
+ * This operation returns in the variables associated to the
+ * endpoint at creation time.
**/
-int frsh_receive_endpoint_destroy
- (frsh_receive_endpoint_t *endpoint);
+int frsh_receive_endpoint_get_params
+ (const frsh_receive_endpoint_t endpoint,
+ frsh_resource_id_t *resource_id,
+ frsh_stream_id_t *stream,
+ frsh_endpoint_queueing_info_t *queueing_info,
+ frsh_receive_endpoint_protocol_info_t *protocol_info);
/**
- * frsh_receive_endpoint_get_parameters()
- *
- * This operation returns in the variables the_network_id,
- * and port, the corresponding
- * parameters used in the creation of the given
- * receive endpoint. It returns 0 if successful, but it fails with
- * FRSH_ERR_BAD_ARGUMENT if endpoint is NULL or not valid or network_id
- * or port are NULL
+ * frsh_receive_endpoint_destroy()
+ *
+ * This operation eliminates any resources reserved for the referenced
+ * endpoint. Pending messages will be discarded and processor-vres
+ * waiting in a synchronous operation will be awoken with an error
+ * code.
**/
-int frsh_receive_endpoint_get_parameters
- (frsh_receive_endpoint_t *endpoint,
- frsh_resource_id_t *network_id,
- frsh_port_t *the_port);
+int frsh_receive_endpoint_destroy
+ (frsh_receive_endpoint_t endpoint);
+
/**
- * frsh_receive()
+ * frsh_receive_sync()
*
* If there are no messages available in the specified receive endpoint
* this operation blocks the calling thread waiting for a message to be
- * received. When a message is available, if its size is less than or
- * equal to the buffersize, the function stores it in the variable
+ * received.
+ *
+ * When a message is available, if its size is less than or
+ * equal to the buffer_size, the function stores it in the variable
* pointed to by buffer and puts the number of bytes received in the
- * variable pointed to by messagesize. The function fails with
- * FRSH_ERR_NO_SPACE if the buffersize is too small for the message
- * received (in which case the message is lost), or with
- * FRSH_ERR_BAD_ARGUMENT if the endpoint is not valid, or if buffer or
- * messagesize are NULL. Messages arriving at a receiver buffer that
- * is full will be silently discarded. The application is responsible
- * of reading the receive endpoints with appropriate regularity, or of
- * using a sequence number or some other mechanism to detect any lost
- * messages.
- **/
-int frsh_receive
- (const frsh_receive_endpoint_t *endpoint,
- void *buffer,
- size_t buffersize,
- size_t *messagesize);
-
-/**
- * frsh_try_receive()
+ * variable pointed to by message size.
+ *
+ * The function fails with FRSH_ERR_NO_SPACE if the buffersize is
+ * too small for the message received. In this case the message is
+ * lost.
+ *
+ * Messages arriving at a destination buffer that is full will be
+ * silently discarded (details in the queueing policy of the
+ * endpoint). The application is responsible of reading the receive
+ * endpoints with appropriate regularity, or of using a sequence
+ * number or some other mechanism to detect any lost messages.
*
- * This operation is the same as frsh_receive, except
- * that if there are no messages available in the
- * specified receive endpoint at the time of the call
- * the operation returns with an error of
- * FRSH_ERR_NO_MESSAGES
+ * @return 0 if successful \n
+ * FRSH_ERR_BAD_ARGUMENT if the endpoint is not valid, or if
+ * buffer or message_size are NULL.\n
+ * FRSH_ERR_NO_SPACE if the message size is bigger than the
+ * provided buffer \n
**/
-int frsh_try_receive
- (const frsh_receive_endpoint_t *endpoint,
- void *buffer,
- size_t buffersize,
- size_t *messagesize);
-
-/*@}*/
-
-//////////////////////////////////////////////////////////////////////
-// GETTING CONFIGURATION INFORMATION
-//////////////////////////////////////////////////////////////////////
+int frsh_receive_sync
+ (const frsh_receive_endpoint_t endpoint,
+ void *buffer,
+ size_t buffer_size,
+ size_t *message_size,
+ frsh_network_address_t *from);
/**
- * @defgroup distgetconfig Getting Configuration Dependent Information
- * @ingroup distributed
+ * frsh_receive_async()
*
- * These functions provide information on parameters such as
- * transmission time and packet size.
+ * This operation is similar to the previous one but it works in a non
+ * blocking (asynchronous) fashion. If no message is available it
+ * returns with error FRSH_NO_MESSAGE.
*
- * @{
+ * @return 0 if successful \n
+ * FRSH_ERR_BAD_ARGUMENT if the endpoint is not valid, or if
+ * buffer or message_size are NULL \n
+ * FRSH_NO_MESSAGE if no messages are available in the queue \n
+ * FRSH_ERR_NO_SPACE if the message size is bigger than the
+ * provided buffer \n
**/
+int frsh_receive_async
+ (const frsh_receive_endpoint_t endpoint,
+ void *buffer,
+ size_t buffer_size,
+ size_t *message_size,
+ frsh_network_address_t *from);
-/**
- * frsh_netconfig_set_packet_tx_time()
- *
- * This operation puts in the variable pointed to by budget
- * the transmission time that it takes to send a packet
- * through the network designated by network_id, when there
- * is no contention, but including any network overheads. It
- * is used to calculate the minimum and maximum budgets used
- * in the preparation of network contracts. The effective
- * network utilization budget (usually called bandwidth) is
- * always assiged as a number of packets per time unit, so
- * the time used in the negotiation of contracts will be
- * internally transformed into the corresponding necessary
- * number of packets. It returns FRSH_ERR_BAD_ARGUMENT if
- * network_id is not a valid identifier or if budget is a
- * NULL pointer.
- **/
-int frsh_netconfig_set_packet_tx_time
- (frsh_resource_id_t network_id,
- struct timespec *budget);
/**
- * frsh_netconfig_set_packet_size()
- *
- * This operation puts in the variable pointed to by
- * packet_size the maximum number of bytes that can be sent
- * in a packet through the network designated by network_id.
- * It is usually a configuration value and it helps the user
- * application to calculate the number of packets it will
- * need to reserve for the periodic transmision of its
- * messages and consequently prepare the corresponding
- * contracts. It returns FRSH_ERR_BAD_ARGUMENT if network_id
- * is not a valid identifier or if packet_size is a NULL
- * pointer.
+ * frsh_receive_endpoint_get_status
+ *
+ * This function tells the number of messages still pending in the
+ * endpoint queue, whether the network is up or down and some optional
+ * information which is protocol dependent.
**/
-int frsh_netconfig_set_packet_size
- (frsh_resource_id_t network_id,
- size_t *packet_size);
+int frsh_receive_endpoint_get_status
+ (const frsh_receive_endpoint_t endpoint,
+ int *number_pending_messages,
+ frsh_endpoint_network_status_t *network_status,
+ frsh_protocol_status_t *protocol_status);
-/**
- * frsh_netconfig_set_max_message_size()
- *
- * This operation is used to obtain the maximum number of
- * packets of which a message can be formed, for the
- * specified network. A message is defined as the piece of
- * information used in a send operation. Since the value
- * returned by this operation is measured in packet units,
- * the effective size can be calculated multiplying this
- * value by the size of a packet. When the value returned by
- * this operation is larger than 1 it means the
- * implementation will make the partition of messages into
- * packets and its recomposition at the receiving node. It
- * returns FRSH_ERR_BAD_ARGUMENT if network_id is not a valid
- * identifier or the pointer max_msg_size is NULL
- **/
-int frsh_netconfig_set_max_message_size
- (frsh_resource_id_t network_id,
- size_t *max_msg_size);
/*@}*/
-
#endif // _FRSH_DISTRIBUTED_H_
projects / frescor / frsh-include.git / blobdiff