X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/2fad952ef4a63aedf6c8b2dc4e371de849f1e163..5a3ad5e2d39b008be6c9467aa387b8358076f12c:/include/gras/messages.h diff --git a/include/gras/messages.h b/include/gras/messages.h index bd56c82bd4..fd26c022ed 100644 --- a/include/gras/messages.h +++ b/include/gras/messages.h @@ -15,89 +15,234 @@ #include "gras/transport.h" #include "gras/datadesc.h" -BEGIN_DECL() +SG_BEGIN_DECL() /** @addtogroup GRAS_msg - * @brief Defining messages and callbacks, and exchanging messages (Communication facility) - * @{ + * @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. */ -/** @name Message declaration and retrival +/** @defgroup GRAS_msg_decl Message declaration and retrival + * @ingroup GRAS_msg * - * 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 + * GRAS messages can only accept one type of payload. See \ref GRAS_dd for + * more information on how to describe data in GRAS. + * + * 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. + * 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. + * 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); -/** @} */ + XBT_PUBLIC void gras_msgtype_declare (const char *name, + gras_datadesc_type_t payload); + XBT_PUBLIC 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) + XBT_PUBLIC gras_msgtype_t gras_msgtype_by_name (const char *name); + XBT_PUBLIC gras_msgtype_t gras_msgtype_by_name_or_null (const char *name); + XBT_PUBLIC gras_msgtype_t gras_msgtype_by_namev(const char *name, short int version); + XBT_PUBLIC gras_msgtype_t gras_msgtype_by_id(int id); + + XBT_PUBLIC void gras_msgtype_dumpall(void); + + +/** @} */ +/** @defgroup GRAS_msg_cb Callback declaration and use + * @ingroup GRAS_msg + * * - * 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. + * 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, created by the middleware only, never by user) */ + typedef struct s_gras_msg_cb_ctx *gras_msg_cb_ctx_t; + +XBT_PUBLIC void gras_msg_cb_ctx_free(gras_msg_cb_ctx_t ctx) ; +XBT_PUBLIC 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); + + XBT_PUBLIC void gras_cb_register (gras_msgtype_t msgtype, gras_msg_cb_t cb); + XBT_PUBLIC 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. */ -typedef int (*gras_cb_t)(gras_socket_t expeditor, - void *payload); -/** \brief Bind the given callback to the given message type +/** @{ */ + + + XBT_PUBLIC void gras_msg_send(gras_socket_t sock, + gras_msgtype_t msgtype, + void *payload); + XBT_PUBLIC void gras_msg_wait(double timeout, + gras_msgtype_t msgt_want, + gras_socket_t *expeditor, + void *payload); + XBT_PUBLIC void gras_msg_handleall(double period); + XBT_PUBLIC void gras_msg_handle(double timeOut); + +/** @} */ + +/** @defgroup GRAS_msg_rpc RPC specific functions + * @ingroup GRAS_msg * - * 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. + * 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. */ -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 */ +/* declaration */ +XBT_PUBLIC void gras_msgtype_declare_rpc(const char *name, + gras_datadesc_type_t payload_request, + gras_datadesc_type_t payload_answer); + +XBT_PUBLIC 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 */ +XBT_PUBLIC void gras_msg_rpccall(gras_socket_t server, + double timeOut, + gras_msgtype_t msgtype, + void *request, void *answer); +XBT_PUBLIC gras_msg_cb_ctx_t +gras_msg_rpc_async_call(gras_socket_t server, + double timeOut, + gras_msgtype_t msgtype, + void *request); +XBT_PUBLIC void gras_msg_rpc_async_wait(gras_msg_cb_ctx_t ctx, + void *answer); + +/* server side */ +XBT_PUBLIC 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 + * + */ /** @{ */ -/** \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); - -/*@}*/ - -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); + +XBT_PUBLIC 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); + +XBT_PUBLIC void gras_msg_wait_or(double timeout, + xbt_dynar_t msgt_want, + gras_msg_cb_ctx_t *ctx, + int *msgt_got, + void *payload); + + +/* @} */ + +SG_END_DECL() #endif /* GRAS_MSG_H */