/* amok_bandwidth - Bandwidth test facilities */
-/* Authors: Martin Quinson */
-/* Copyright (C) 2003, 2004 the OURAGAN project. */
+/* Copyright (c) 2003-2005 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 AMOK_BANDWIDTH_H
#define AMOK_BANDWIDTH_H
/* module handling */
+
+/** \addtogroup AMOK_bw
+ * \brief Test the bandwidth between two nodes
+ *
+ * This module allows you to retrieve the bandwidth between to arbitrary hosts,
+ * provided that they run some GRAS process which initialized this module.
+ *
+ * Retrieving the bandwidth is usually done by active measurment: one send
+ * a packet of known size, time how long it needs to go back and forth,
+ * and you get the bandwidth in Kb/s available on the wire.
+ *
+ * This is not as easy as it first seems to do so in GRAS. The first issue
+ * is that GRAS messages can get buffered, or the receiver cannot be
+ * waiting for the message when it arrives. This results in extra delays
+ * impacting the measurement quality. You thus have to setup a rendez-vous
+ * protocol. The second issue is that GRAS message do have an header, so
+ * figuring out their size is not trivial. Moreover, they get converted
+ * when the sender and receiver processor architecture are different,
+ * inducing extra delays. For this, GRAS provide the so-called measurement
+ * sockets. On them, you can send raw data which is not converted (see
+ * \ref GRAS_sock_meas).
+ *
+ * Solving all these problems is quite error prone and anoying, so we
+ * implemented this in the current module so that you don't have to do it
+ * yourself. The API is very simple. Use amok_bw_test() to get the BW
+ * between the local host and the specified peer, or amok_bw_request() to
+ * get the BW between two remote hosts. The elapsed time, as long as the
+ * achieved bandwidth is returned in the last arguments of the functions.
+ *
+ * All sizes are in kilo bytes. The \a buf_size is the size of the buffer
+ * (this is a socket parameter set automatically). The \a exp_size is the
+ * amount of data to send during an experiment. \a msg_size is the size
+ * of each message sent. These values allow you to study phenomenon such
+ * as TCP slow start (which are not correctly modelized by \ref SURF_API,
+ * yet). They are mimicked from the NWS API, and default values could be
+ * buf_size=32k, msg_size=16k and exp_size=64k. That means that the
+ * socket will be prepared to accept 32k in its buffer and then four
+ * messages of 16k will be sent (so that the total amount of data equals
+ * 64k). Of course, you can use other values if you want to.
+ *
+ * \todo Cleanup and implement the link saturation stuff.
+ *
+ * @{
+ */
+
void amok_bw_init(void);
void amok_bw_exit(void);
-
+void amok_bw_test(gras_socket_t peer,
+ unsigned long int buf_size,unsigned long int exp_size,unsigned long int msg_size,
+ /*OUT*/ double *sec, double *bw);
-/* ***************************************************************************
- * Bandwidth tests
- * ***************************************************************************/
-/**
- * amok_bw_test:
- * @peer: A (regular) socket at which the the host with which we should conduct the experiment can be contacted
- * @buf_size: Size of the socket buffer
- * @exp_size: Total size of data sent across the network
- * @msg_size: Size of each message sent. Ie, (@expSize % @msgSize) messages will be sent.
- * @sec: where the result (in seconds) should be stored.
- * @bw: observed Bandwidth (in Mb/s)
- *
- * Conduct a bandwidth test from the local process to the given peer.
- * This call is blocking until the end of the experiment.
- */
-gras_error_t amok_bw_test(gras_socket_t peer,
- unsigned int buf_size,unsigned int exp_size,unsigned int msg_size,
- /*OUT*/ double *sec, double *bw);
+void amok_bw_request(const char* from_name,unsigned int from_port,
+ const char* to_name,unsigned int to_port,
+ unsigned long int buf_size,unsigned long int exp_size,unsigned long int msg_size,
+ /*OUT*/ double *sec, double*bw);
+/** @} */
#if 0
-/**
- * grasbw_request:
- * @from_name: Name of the host we are asking to do a experiment with (to_name:to_port)
- * @from_port: port on which the process we are asking for an experiment is listening for message
- * @to_name: Name of the host with which we should conduct the experiment
- * @to_port: port on which the peer process is listening (for message, do not
- * give a raw socket here. The needed raw socket will be negociated between
- * the peers)
- * @bufSize: Size of the socket buffer
- * @expSize: Total size of data sent across the network
- * @msgSize: Size of each message sent. Ie, (@expSize % @msgSize) messages will be sent.
- * @sec: where the result (in seconds) should be stored.
- * @bw: observed Bandwidth (in Mb/s)
- *
- * Conduct a bandwidth test from the process from_host:from_port to to_host:to_port.
- * This call is blocking until the end of the experiment.
- */
-gras_error_t grasbw_request(const char* from_name,unsigned int from_port,
- const char* to_name,unsigned int to_port,
- unsigned int bufSize,unsigned int expSize,unsigned int msgSize,
- /*OUT*/ double *sec, double*bw);
-
/* ***************************************************************************
* Link saturation
* Ask the process 'from_name:from_port' to start to saturate the link between itself
* and to_name:to_name.
*/
-gras_error_t grasbw_saturate_start(const char* from_name,unsigned int from_port,
+void grasbw_saturate_start(const char* from_name,unsigned int from_port,
const char* to_name,unsigned int to_port,
unsigned int msgSize, unsigned int timeout);
* Ask the process 'from_name:from_port' to stop saturating the link between itself
* and to_name:to_name.
*/
-gras_error_t grasbw_saturate_stop(const char* from_name,unsigned int from_port,
+void grasbw_saturate_stop(const char* from_name,unsigned int from_port,
const char* to_name,unsigned int to_port);