X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/c42000db0f347a26ac1645d830ac949194ec4da0..07db45c31602a15fae0e244e856f8a34b971686e:/include/gras/messages.h diff --git a/include/gras/messages.h b/include/gras/messages.h index 96e8152cd3..1a025195c0 100644 --- a/include/gras/messages.h +++ b/include/gras/messages.h @@ -1,15 +1,12 @@ /* $Id$ */ /* messaging - high level communication (send/receive messages) */ - /* module's public interface exported to end user. */ -/* Authors: Martin Quinson */ -/* Copyright (C) 2003, 2004 Martin Quinson. */ +/* 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. */ - + * under the terms of the license (GNU LGPL) which comes with this package. */ #ifndef GRAS_MESSAGES_H #define GRAS_MESSAGES_H @@ -18,50 +15,116 @@ #include "gras/transport.h" #include "gras/datadesc.h" -BEGIN_DECL - -/* msgtype declaration and retrival */ -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); - -gras_msgtype_t *gras_msgtype_by_name (const char *name); -gras_msgtype_t *gras_msgtype_by_namev(const char *name, - short int version); +BEGIN_DECL() + +/** @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. + * + * @{ + */ -/** - * gras_cb_t: - * @msg: The message itself - * @Returns: true if the message was consumed by the callback. +/** @name 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 + * \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 mecanism (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); +/** @} */ + +/** @name 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. + * + * @{ + */ + +/** \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) * - * 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. + * 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); -void gras_cb_register (gras_msgtype_t *msgtype, - gras_cb_t cb); -void gras_cb_unregister(gras_msgtype_t *msgtype, - gras_cb_t cb); - -gras_error_t gras_msg_send(gras_socket_t *sock, - gras_msgtype_t *msgtype, +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. + */ +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); + +/** @} */ +/** @name 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); -gras_error_t gras_msg_wait(double timeout, - gras_msgtype_t *msgt_want, - gras_socket_t **expeditor, - void *payload); -gras_error_t gras_msg_handle(double timeOut); +xbt_error_t gras_msg_handle(double timeOut); +/*@}*/ -END_DECL +END_DECL() #endif /* GRAS_MSG_H */