/** @addtogroup GRAS_msg
* @brief Defining messages and callbacks, and exchanging messages (Communication facility)
+ *
+ * There is two way to receive messages in GRAS. The first one is to
+ * register a given function as callback to a given type of messages (see
+ * \ref gras_cb_register and associated section). But you can also
+ * explicitely wait for a given message with the \ref gras_msg_wait
+ * function.
+ *
+ * Usually, both ways are not intended to be mixed of a given type of
+ * messages. But if you do so, it shouldn't trigger any issue. If the
+ * message arrives when gras_msg_wait is blocked, then it will be routed
+ * to it. If it arrives when before or after gras_msg_wait, it will be
+ * passed to the callback.
+ *
+ * For an example of use, please refer to \ref GRAS_ex_ping.
+ *
* @{
*/
-/** @name Message declaration and retrival
+/** @name 1. Message declaration and retrival
*
* GRAS messages can only accept one type of payload. If you absolutely want to declare a message
* able to convey several datatypes, you can always say that it conveys a generic reference (see
* to add a version number to the message (by default, the version is set to 0). Any messages of the
* wrong version will be ignored by the applications not providing any specific callback for them.
*
- * This mecanism (stolen from the dynamic loader one) should ensure you to change the semantic of a given
+ * This mechanism (stolen from the dynamic loader one) should ensure you to change the semantic of a given
* message while still understanding the old one.
*/
/** @{ */
/** \brief Opaque type */
typedef struct s_gras_msgtype *gras_msgtype_t;
-/** \brief declare a new message type of the given name. It only accepts the given datadesc as payload */
-void gras_msgtype_declare (const char *name,
- gras_datadesc_type_t payload);
-/** \brief declare a new versionned message type of the given name and payload. */
-void gras_msgtype_declare_v(const char *name,
- short int version,
- gras_datadesc_type_t payload);
-
-/** \brief retrive an existing message type from its name. */
-gras_msgtype_t gras_msgtype_by_name (const char *name);
-/** \brief retrive an existing message type from its name and version number. */
-gras_msgtype_t gras_msgtype_by_namev(const char *name,
- short int version);
-/** @} */
+ void gras_msgtype_declare (const char *name,
+ gras_datadesc_type_t payload);
+ void gras_msgtype_declare_v(const char *name,
+ short int version,
+ gras_datadesc_type_t payload);
-/** @name Callback declaration and use */
-/** @{ */
-/** \brief Type of message callback functions.
- * \param msg: The message itself
- * \return true if the message was consumed by the callback, false if the message was
- * refused by the callback (and should be passed to the next callback of the stack for
- * this message)
- *
- * Once a such a function is registered to handle messages of a given type with
- * \ref gras_cb_register(), it will be called each time such a message arrives.
- *
- * If the callback accepts the message, it should free it after use.
- */
-typedef int (*gras_cb_t)(gras_socket_t expeditor,
- void *payload);
-/** \brief Bind the given callback to the given message type
- *
- * Several callbacks can be attached to a given message type. The lastly added one will get the message first, and
- * if it returns false, the message will be passed to the second one.
- * And so on until one of the callbacks accepts the message.
+ gras_msgtype_t gras_msgtype_by_name (const char *name);
+ gras_msgtype_t gras_msgtype_by_namev(const char *name, short int version);
+
+/** @} */
+/** @name 2. Callback declaration and use
+ *
+ * This is how to register a given function so that it gets called when a
+ * given type of message arrives.
+ *
+ * You can register several callbacks to the same kind of messages, and
+ * they will get stacked. The lastly added callback gets the message first.
+ * If it consumes the message, it should return a true value when done. If
+ * not, it should return 0, and the message will be passed to the second
+ * callback of the stack, if any.
+ *
+ * @{
*/
-void gras_cb_register (gras_msgtype_t msgtype,
- gras_cb_t cb);
-/** \brief Unbind the given callback from the given message type */
-void gras_cb_unregister(gras_msgtype_t msgtype,
- gras_cb_t cb);
+
+ /** \brief Type of message callback functions.
+ *
+ * \param expeditor: a socket to contact who sent this message
+ * \param payload: the message itself
+ *
+ * \return true if the message was consumed by the callback,
+ * false if the message was refused by the callback (and should be
+ * passed to the next callback of the stack for this message)
+ *
+ * Once a such a function is registered to handle messages of a given
+ * type with \ref gras_cb_register(), it will be called each time such
+ * a message arrives (unless a gras_msg_wait() intercepts it on arrival).
+ *
+ * If the callback accepts the message, it should free it after use.
+ */
+ typedef int (*gras_msg_cb_t)(gras_socket_t expeditor,
+ void *payload);
+
+ void gras_cb_register (gras_msgtype_t msgtype, gras_msg_cb_t cb);
+ void gras_cb_unregister(gras_msgtype_t msgtype, gras_msg_cb_t cb);
/** @} */
-/** @name Message exchange */
+/** @name 3. Message exchange */
/** @{ */
-/** \brief Send the data pointed by \a payload as a message of type \a msgtype to the peer \a sock */
-xbt_error_t 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. */
-xbt_error_t gras_msg_wait(double timeout,
- gras_msgtype_t msgt_want,
- gras_socket_t *expeditor,
- void *payload);
-xbt_error_t gras_msg_handle(double timeOut);
-
-/*@}*/
+
+ xbt_error_t gras_msg_send(gras_socket_t sock,
+ gras_msgtype_t msgtype,
+ void *payload);
+ xbt_error_t gras_msg_wait(double timeout,
+ gras_msgtype_t msgt_want,
+ gras_socket_t *expeditor,
+ void *payload);
+ xbt_error_t gras_msg_handle(double timeOut);
+
+/* @} */
END_DECL()
