+ typedef int (*gras_msg_cb_t) (gras_msg_cb_ctx_t ctx, void *payload);
+
+ /**
+ * @brief Bind the given callback to the given message type (described by its name)
+ * @hideinitializer
+ *
+ * Several callbacks can be attached to a given message type. The lastly added one will get the message first, and
+ * if it returns a non-null value, the message will be passed to the second one.
+ * And so on until one of the callbacks accepts the message.
+ *
+ * Using gras_cb_register is a bit slower than using gras_cb_register_ since GRAS
+ * has to search for the given msgtype in the hash table, but you don't care in most case.
+ */
+#define gras_cb_register(msgtype_name, cb) gras_cb_register_(gras_msgtype_by_name(msgtype_name),cb)
+
+ /**
+ * @brief Unbind the given callback to the given message type (described by its name)
+ * @hideinitializer
+ *
+ * Using gras_cb_unregister is a bit slower than using gras_cb_unregister_ since GRAS
+ * has to search for the given msgtype in the hash table, but you don't care in most case.
+ */
+#define gras_cb_unregister(msgtype_name, cb) gras_cb_unregister_(gras_msgtype_by_name(msgtype_name),cb)
+
+XBT_PUBLIC(void) gras_cb_register_(gras_msgtype_t msgtype, gras_msg_cb_t cb);
+XBT_PUBLIC(void) gras_cb_unregister_(gras_msgtype_t msgtype,
+ gras_msg_cb_t cb);
+
+/** @} */
+
+/** @defgroup GRAS_msg_exchange Message exchange
+ * @ingroup GRAS_msg
+ *
+ */
+/** @{ */
+
+/** \brief Send the data pointed by \a payload as a message \a msgname on the \a sock
+ * @hideinitializer
+ *
+ * Using gras_msg_wait() is a bit slower than using gras_msg_wait_() since GRAS
+ * has to search for the given msgtype in the hash table.
+ */
+#define gras_msg_send(sock,name,payload) gras_msg_send_(sock,gras_msgtype_by_name(name),payload)
+XBT_PUBLIC(void) gras_msg_send_(gras_socket_t sock,
+ gras_msgtype_t msgtype, void *payload);
+
+/** \brief Waits for a message to come in over a given socket
+ * @hideinitializer
+ * @param timeout: How long should we wait for this message.
+ * @param msgt_want: type of awaited msg
+ * @param[out] expeditor: where to create a socket to answer the incomming message
+ * @param[out] payload: where to write the payload of the incomming message
+ * @return the error code (or no_error).
+ *
+ * Every message of another type received before the one waited will be queued
+ * and used by subsequent call to this function or gras_msg_handle().
+ *
+ * Using gras_msg_wait() is a bit slower than using gras_msg_wait_() since GRAS
+ * has to search for the given msgtype in the hash table.
+ */
+
+#define gras_msg_wait(timeout,msgt_want,expeditor,payload) gras_msg_wait_(timeout,gras_msgtype_by_name(msgt_want),expeditor,payload)
+XBT_PUBLIC(void) gras_msg_wait_(double timeout,
+ gras_msgtype_t msgt_want,
+ gras_socket_t * expeditor, void *payload);
+XBT_PUBLIC(void) gras_msg_handleall(double period);
+XBT_PUBLIC(void) gras_msg_handle(double timeOut);
+
+/** @} */
+
+/** @defgroup GRAS_msg_rpc RPC specific functions
+ * @ingroup GRAS_msg
+ *
+ * Remote Procedure Call (RPC) are a classical mecanism to request a service
+ * from a remote host. Using this set of functions, you let GRAS doing most of
+ * the work of sending the request, wait for an answer, make sure it is the
+ * right answer from the right host and so on. Any exception raised on the
+ * server is also passed over the network to the client.
+ *
+ * Callbacks are attached to RPC incomming messages the regular way using
+ * \ref gras_cb_register.
+ *
+ * For an example of use, check the examples/gras/rpc directory of the distribution.
+ */
+/** @{ */
+
+/* declaration */
+XBT_PUBLIC(void) gras_msgtype_declare_rpc(const char *name,
+ gras_datadesc_type_t
+ payload_request,
+ gras_datadesc_type_t
+ payload_answer);
+
+XBT_PUBLIC(void) gras_msgtype_declare_rpc_v(const char *name,
+ short int version,
+ gras_datadesc_type_t
+ payload_request,
+ gras_datadesc_type_t
+ payload_answer);
+
+/* client side */
+
+/** @brief Conduct a RPC call
+ * @hideinitializer
+ */
+#define gras_msg_rpccall(server,timeout,msg,req,ans) gras_msg_rpccall_(server,timeout,gras_msgtype_by_name(msg),req,ans)
+XBT_PUBLIC(void) gras_msg_rpccall_(gras_socket_t server,
+ double timeOut,
+ gras_msgtype_t msgtype,
+ void *request, void *answer);
+XBT_PUBLIC(gras_msg_cb_ctx_t)
+
+/** @brief Launch a RPC call, but do not block for the answer
+ * @hideinitializer
+ */
+#define gras_msg_rpc_async_call(server,timeout,msg,req) gras_msg_rpc_async_call_(server,timeout,gras_msgtype_by_name(msg),req)
+ gras_msg_rpc_async_call_(gras_socket_t server,
+ double timeOut,
+ gras_msgtype_t msgtype, void *request);
+XBT_PUBLIC(void) gras_msg_rpc_async_wait(gras_msg_cb_ctx_t ctx, void *answer);