X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/1e32d1f72606b96bb1abd9af359f1590528ec843..68ef5e4e1e45f787a75a6f5a08cec549a49043c1:/include/gras/messages.h diff --git a/include/gras/messages.h b/include/gras/messages.h index ca644b1a20..c513e2697c 100644 --- a/include/gras/messages.h +++ b/include/gras/messages.h @@ -1,85 +1,229 @@ /* $Id$ */ /* 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 -/*! C++ users need love */ -#ifndef BEGIN_DECL -# ifdef __cplusplus -# define BEGIN_DECL extern "C" { -# else -# define BEGIN_DECL -# endif -#endif - -/*! C++ users need love */ -#ifndef END_DECL -# ifdef __cplusplus -# define END_DECL } -# else -# define END_DECL -# endif -#endif -/* End of cruft for C++ */ - -BEGIN_DECL - -/* msgtype declaration and retrival */ -typedef struct s_gras_msgtype gras_msgtype_t; - -gras_error_t gras_msgtype_declare (const char *name, - gras_datadesc_type_t *payload); -gras_error_t gras_msgtype_declare_v(const char *name, - short int version, - gras_datadesc_type_t *payload); - -gras_error_t gras_msgtype_by_name (const char *name, - gras_msgtype_t **dst); -gras_error_t gras_msgtype_by_namev(const char *name, - short int version, - gras_msgtype_t **dst); - - -/** - * gras_cb_t: - * @msg: The message itself - * @Returns: true if the message was consumed by the callback. +#include "xbt/misc.h" +#include "gras/transport.h" +#include "gras/datadesc.h" + +SG_BEGIN_DECL() + +/** @addtogroup GRAS_msg + * @brief Defining messages and callbacks, and exchanging messages + * + * 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 \ref gras_msg_wait, it will be + * passed to the callback. + * + * For an example of use, please refer to \ref GRAS_ex_ping. The archive + * contains much more examples, but their are not properly integrated into + * this documentation yet. + */ + +/** @defgroup GRAS_msg_decl Message declaration and retrival + * @ingroup GRAS_msg + * + * GRAS messages can only accept one type of payload. See \ref GRAS_dd for + * more information on how to describe data in GRAS. * - * 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 you absolutely want use 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_msgtype_t gras_msgtype_by_id(int id); + +/** @} */ +/** @defgroup GRAS_msg_cb Callback declaration and use + * @ingroup GRAS_msg + * + * + * 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 Context of callbacks (opaque structure) */ + typedef struct s_gras_msg_cb_ctx *gras_msg_cb_ctx_t; + +gras_socket_t gras_msg_cb_ctx_from(gras_msg_cb_ctx_t ctx); + + /** \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_msg_cb_ctx_t ctx, + 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 + * + */ +/** @{ */ + + + 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); + +/** @} */ + +/** @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 */ +void gras_msgtype_declare_rpc(const char *name, + gras_datadesc_type_t payload_request, + gras_datadesc_type_t payload_answer); + +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 */ +void gras_msg_rpccall(gras_socket_t server, + double timeOut, + gras_msgtype_t msgtype, + void *request, void *answer); + +/* server side */ +void gras_msg_rpcreturn(double timeOut, gras_msg_cb_ctx_t ctx,void *answer); + + +/** @} */ + +/** @defgroup GRAS_msg_exchangeadv Message exchange (advanced interface) + * @ingroup GRAS_msg * - * If the callback accepts the message, it should free it after use. */ -typedef int (*gras_cb_t)(gras_socket_t *expeditor, - void *payload); -gras_error_t 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, - 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); - - -END_DECL +/** @{ */ + +/** @brief Message kind (internal enum) */ +typedef enum { + e_gras_msg_kind_unknown = 0, + + e_gras_msg_kind_oneway=1, /**< good old regular messages */ + + e_gras_msg_kind_rpccall=2, /**< RPC request */ + /* HACK: e_gras_msg_kind_rpccall also designate RPC message *type* in + msgtype_t, not only in msg_t*/ + e_gras_msg_kind_rpcanswer=3, /**< RPC successful answer */ + e_gras_msg_kind_rpcerror=4, /**< RPC failure on server (payload=exception); should not leak to user-space */ + + /* future: + call cancel, and others + even after: + forwarding request and other application level routing stuff + group communication + */ + + e_gras_msg_kind_count=5 /* sentinel, dont mess with */ +} e_gras_msg_kind_t; + + +/** @brief Message instance (internal struct) */ +typedef struct { + gras_socket_t expe; + e_gras_msg_kind_t kind; + gras_msgtype_t type; + unsigned long int ID; + void *payl; + int payl_size; +} s_gras_msg_t, *gras_msg_t; + +typedef int (*gras_msg_filter_t)(gras_msg_t msg,void *ctx); + + void gras_msg_wait_ext(double timeout, + gras_msgtype_t msgt_want, + gras_socket_t expe_want, + gras_msg_filter_t filter, + void *filter_ctx, + gras_msg_t msg_got); + + +/* @} */ + +SG_END_DECL() #endif /* GRAS_MSG_H */