-/* $Id$ */
-
/* 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) 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. */
-
+ * under the terms of the license (GNU LGPL) which comes with this package. */
#ifndef GRAS_MESSAGES_H
#define GRAS_MESSAGES_H
#include "gras/transport.h"
#include "gras/datadesc.h"
-BEGIN_DECL
+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.
+ *
+ * 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;
+
+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);
-/* msgtype declaration and retrival */
-typedef struct s_gras_msgtype gras_msgtype_t;
+/** \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.
+ */
-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);
+#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_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.
+/** @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);
-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);
+#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 */
