X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/2539fff313cbd67c45b8490f7961e45e358d9ba2..0ee6fdb41d9ba663184bdd4d48f79ef28a0e6fbb:/include/gras/messages.h diff --git a/include/gras/messages.h b/include/gras/messages.h index 88ae103f98..8158b0b90c 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 +15,106 @@ #include "gras/transport.h" #include "gras/datadesc.h" -BEGIN_DECL +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. + * + * @{ + */ -/* msgtype 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 + * \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); - -gras_msgtype_t gras_msgtype_by_name (const char *name); -gras_msgtype_t gras_msgtype_by_namev(const char *name, - short int version); - -/** - * gras_cb_t: - * @msg: The message itself - * @Returns: true if the message was consumed by the callback. - * - * 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. - * - * If the callback accepts the message, it should free it after use. + 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); + +/** @} */ +/** @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. + * + * @{ */ -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 + + /** \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 3. Message exchange */ +/** @{ */ + + 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() #endif /* GRAS_MSG_H */