X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/8c354c48ec90c997cc7213ce96ca97d882934166..806d1314d9398af51ffd016c95b39d173960c659:/include/gras/messages.h diff --git a/include/gras/messages.h b/include/gras/messages.h index 1f891d12a8..5bf5fae803 100644 --- a/include/gras/messages.h +++ b/include/gras/messages.h @@ -1,9 +1,8 @@ -/* $Id$ */ - /* 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) 2004, 2005, 2006, 2007, 2009, 2010. The SimGrid Team. + * 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. */ @@ -15,50 +14,294 @@ #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 + * + * 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. + * + * 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); +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); + +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(const char *) gras_msgtype_get_name(gras_msgtype_t type); + +XBT_PUBLIC(void) gras_msgtype_dumpall(void); + + +/** @} */ +/** @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, 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); + + /** + * @brief Bind the given callback to the given message type (described by its name) + * @hideinitializer + * + * Several callbacks can be attached to a given message type. The lastly added one will get the message first, and + * if it returns a non-null value, the message will be passed to the second one. + * And so on until one of the callbacks accepts the message. + * + * Using gras_cb_register is a bit slower than using gras_cb_register_ since GRAS + * has to search for the given msgtype in the hash table, but you don't care in most case. + */ +#define gras_cb_register(msgtype_name, cb) gras_cb_register_(gras_msgtype_by_name(msgtype_name),cb) + + /** + * @brief Unbind the given callback to the given message type (described by its name) + * @hideinitializer + * + * Using gras_cb_unregister is a bit slower than using gras_cb_unregister_ since GRAS + * has to search for the given msgtype in the hash table, but you don't care in most case. + */ +#define gras_cb_unregister(msgtype_name, cb) gras_cb_unregister_(gras_msgtype_by_name(msgtype_name),cb) + +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 + * + */ +/** @{ */ + +/** \brief Send the data pointed by \a payload as a message \a msgname on the \a sock + * @hideinitializer + * + * Using gras_msg_wait() is a bit slower than using gras_msg_wait_() since GRAS + * has to search for the given msgtype in the hash table. + */ +#define gras_msg_send(sock,name,payload) gras_msg_send_(sock,gras_msgtype_by_name(name),payload) +XBT_PUBLIC(void) 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 + * @hideinitializer + * @param timeout: How long should we wait for this message. + * @param msgt_want: type of awaited msg + * @param[out] expeditor: where to create a socket to answer the incomming message + * @param[out] payload: where to write the payload of the incomming message + * @return the error code (or no_error). + * + * Every message of another type received before the one waited will be queued + * and used by subsequent call to this function or gras_msg_handle(). + * + * Using gras_msg_wait() is a bit slower than using gras_msg_wait_() since GRAS + * has to search for the given msgtype in the hash table. + */ -gras_msgtype_t gras_msgtype_by_name (const char *name); -gras_msgtype_t gras_msgtype_by_namev(const char *name, - short int version); +#define gras_msg_wait(timeout,msgt_want,expeditor,payload) gras_msg_wait_(timeout,gras_msgtype_by_name(msgt_want),expeditor,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); -/** - * gras_cb_t: - * @msg: The message itself - * @Returns: true if the message was consumed by the callback. +/** @} */ + +/** @defgroup GRAS_msg_rpc RPC specific functions + * @ingroup GRAS_msg * - * 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. + * 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 */ +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 */ + +/** @brief Conduct a RPC call + * @hideinitializer + */ +#define gras_msg_rpccall(server,timeout,msg,req,ans) gras_msg_rpccall_(server,timeout,gras_msgtype_by_name(msg),req,ans) +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) + +/** @brief Launch a RPC call, but do not block for the answer + * @hideinitializer + */ +#define gras_msg_rpc_async_call(server,timeout,msg,req) gras_msg_rpc_async_call_(server,timeout,gras_msgtype_by_name(msg),req) + 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 * - * 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); +/** @{ */ + +/** @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_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); +#define gras_msg_wait_ext(timeout, msg, expe, filter, fctx,got) gras_msg_wait_ext_(timeout, gras_msgtype_by_name(msg), expe, filter, fctx,got) +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); -END_DECL -#endif /* GRAS_MSG_H */ +/* @} */ +SG_END_DECL() +#endif /* GRAS_MSG_H */