/* messaging - high level communication (send/receive messages) */
/* module's public interface exported to end user. */
-/* Copyright (c) 2003, 2004 Martin Quinson. All rights reserved. */
+/* Copyright (c) 2003-2007 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. */
#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
*
* 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
+ * 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.
- *
- * @{
+ * 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 1. 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 mechanism (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;
+ 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);
- 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);
+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);
-/** @} */
-/** @name 2. Callback declaration and use
+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.
*
*
* @{
*/
-
+
+ /** \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
*
* If the callback accepts the message, it should free it after use.
*/
- typedef int (*gras_msg_cb_t)(gras_socket_t expeditor,
- void *payload);
+ 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)
- 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);
+ /**
+ * @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)
-/** @} */
-/** @name 3. Message exchange */
+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
+ *
+ */
/** @{ */
- 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);
+/** \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.
+ */
-END_DECL()
+#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);
-#endif /* GRAS_MSG_H */
+/** @} */
+
+/** @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 */
+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
+ *
+ */
+/** @{ */
+
+/** @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);
+
+#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);
+
+
+/* @} */
+
+SG_END_DECL()
+#endif /* GRAS_MSG_H */
