/* messaging - high level communication (send/receive messages) */
/* module's public interface exported to end user. */
-/* Copyright (c) 2004 Martin Quinson. All rights reserved. */
+/* Copyright (c) 2003, 2004 Martin Quinson. All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
#include "gras/transport.h"
#include "gras/datadesc.h"
-BEGIN_DECL
+SG_BEGIN_DECL()
-/* msgtype declaration and retrival */
+/** @addtogroup GRAS_msg
+ * @brief Defining messages and callbacks, and exchanging messages (Communication facility)
+ *
+ * <center><table><tr><td><b>Top</b> <td> [\ref index]::[\ref GRAS_API]
+ * <tr><td><b>Prev</b> <td> [\ref GRAS_sock]
+ * <tr><td><b>Next</b> <td> [\ref GRAS_timer]
+ * <tr><td><b>Down</b> <td> [\ref GRAS_msg_decl] </table></center>
+ *
+ * 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.
+ */
+
+/** @defgroup GRAS_msg_decl Message declaration and retrival
+ * @ingroup GRAS_msg
+ *
+ * <center><table><tr><td><b>Top</b> <td> [\ref index]::[\ref GRAS_API]::[\ref GRAS_msg]
+ * <tr><td> Prev <td>
+ * <tr><td><b>Next</b> <td> [\ref GRAS_msg_cb] </table></center>
+ *
+ * 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
+ * \ref gras_datadesc_ref_generic).
+ *
+ * In order to ease the upgrade of GRAS applications, it is possible to \e version the messages, ie
+ * 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 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;
-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);
+ 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);
-gras_msgtype_t gras_msgtype_by_name (const char *name);
-gras_msgtype_t gras_msgtype_by_namev(const char *name,
- short int version);
+ gras_msgtype_t gras_msgtype_by_name (const char *name);
+ gras_msgtype_t gras_msgtype_by_namev(const char *name, short int version);
+ gras_msgtype_t gras_msgtype_by_id(int id);
-/**
- * gras_cb_t:
- * @msg: The message itself
- * @Returns: true if the message was consumed by the callback.
+/** @} */
+/** @defgroup GRAS_msg_cb Callback declaration and use
+ * @ingroup GRAS_msg
+ *
+ * <center><table><tr><td><b>Top</b> <td> [\ref index]::[\ref GRAS_API]::[\ref GRAS_msg]
+ * <tr><td><b>Prev</b> <td> [\ref GRAS_msg_decl]
+ * <tr><td><b>Next</b> <td> [\ref GRAS_msg_exchange] </table></center>
*
- * Type of message callback functions. Once a such a function is registered to
- * handle messages of a given type with RegisterCallback(), it will be called
- * each time such a message incomes.
+ * 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.
+ *
+ * @{
+ */
+
+ /** \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);
+
+/** @} */
+/** @defgroup GRAS_msg_exchange Message exchange
+ * @ingroup GRAS_msg
*
- * If the callback accepts the message, it should free it after use.
+ * <center><table><tr><td><b>Top</b> <td> [\ref index]::[\ref GRAS_API]::[\ref GRAS_msg]
+ * <tr><td><b>Prev</b> <td> [\ref GRAS_msg_cb]
+ * <tr><td> Next <td> </table></center>
*/
-typedef int (*gras_cb_t)(gras_socket_t expeditor,
- void *payload);
-void gras_cb_register (gras_msgtype_t msgtype,
- gras_cb_t cb);
-void gras_cb_unregister(gras_msgtype_t msgtype,
- gras_cb_t cb);
-
-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
+/** @{ */
+
+ void gras_msg_send(gras_socket_t sock,
+ gras_msgtype_t msgtype,
+ void *payload);
+ void gras_msg_wait(double timeout,
+ gras_msgtype_t msgt_want,
+ gras_socket_t *expeditor,
+ void *payload);
+ void gras_msg_handle(double timeOut);
+
+/* @} */
+
+SG_END_DECL()
#endif /* GRAS_MSG_H */
