/*
This file is part of GNUnet
- (C) 2009, 2011 Christian Grothoff (and other contributing authors)
+ (C) 2009-2013 Christian Grothoff (and other contributing authors)
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
#include "fragmentation.h"
+/**
+ * Absolute minimum delay we impose between sending and expecting ACK to arrive.
+ */
+#define MIN_ACK_DELAY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 1)
+
+
/**
* Fragmentation context.
*/
/**
* Current expected delay for ACKs.
*/
- struct GNUNET_TIME_Relative delay;
+ struct GNUNET_TIME_Relative ack_delay;
+
+ /**
+ * Current expected delay between messages.
+ */
+ struct GNUNET_TIME_Relative msg_delay;
/**
* Next allowed transmission time.
*/
unsigned int num_rounds;
+ /**
+ * How many transmission have we completed in this round?
+ */
+ unsigned int num_transmissions;
+
/**
* GNUNET_YES if we called 'proc' and are now waiting for 'GNUNET_FRAGMENT_transmission_done'
*/
GNUNET_assert (GNUNET_NO == fc->proc_busy);
if (0 == fc->acks)
return; /* all done */
-
/* calculate delay */
wrap = 0;
while (0 == (fc->acks & (1LL << fc->next_transmission)))
{
fc->next_transmission = (fc->next_transmission + 1) % 64;
- wrap |= (fc->next_transmission == 0);
+ wrap |= (0 == fc->next_transmission);
}
bit = fc->next_transmission;
size = ntohs (fc->msg->size);
sizeof (struct FragmentHeader);
else
fsize = fc->mtu;
- if (fc->tracker != NULL)
+ if (NULL != fc->tracker)
delay = GNUNET_BANDWIDTH_tracker_get_delay (fc->tracker, fsize);
else
delay = GNUNET_TIME_UNIT_ZERO;
- if (delay.rel_value > 0)
+ if (delay.rel_value_us > 0)
{
fc->task = GNUNET_SCHEDULER_add_delayed (delay, &transmit_next, fc);
return;
}
fc->next_transmission = (fc->next_transmission + 1) % 64;
- wrap |= (fc->next_transmission == 0);
+ wrap |= (0 == fc->next_transmission);
+ while (0 == (fc->acks & (1LL << fc->next_transmission)))
+ {
+ fc->next_transmission = (fc->next_transmission + 1) % 64;
+ wrap |= (0 == fc->next_transmission);
+ }
/* assemble fragmentation message */
mbuf = (const char *) &fc[1];
GNUNET_BANDWIDTH_tracker_consume (fc->tracker, fsize);
GNUNET_STATISTICS_update (fc->stats, _("# fragments transmitted"), 1,
GNUNET_NO);
- if (0 != fc->last_round.abs_value)
+ if (0 != fc->last_round.abs_value_us)
GNUNET_STATISTICS_update (fc->stats, _("# fragments retransmitted"), 1,
GNUNET_NO);
delay = GNUNET_BANDWIDTH_tracker_get_delay (fc->tracker, fsize);
else
delay = GNUNET_TIME_UNIT_ZERO;
+ delay = GNUNET_TIME_relative_max (delay,
+ GNUNET_TIME_relative_multiply (fc->msg_delay,
+ (1 << fc->num_rounds)));
if (wrap)
{
/* full round transmitted wait 2x delay for ACK before going again */
fc->num_rounds++;
- delay =
- GNUNET_TIME_relative_max (GNUNET_TIME_relative_multiply (delay, 2),
- GNUNET_TIME_relative_multiply (fc->delay,
- fc->num_rounds));
+ delay = GNUNET_TIME_relative_multiply (fc->ack_delay, 2);
/* never use zero, need some time for ACK always */
- delay = GNUNET_TIME_relative_max (GNUNET_TIME_UNIT_MILLISECONDS, delay);
- fc->last_round = GNUNET_TIME_absolute_get ();
+ delay = GNUNET_TIME_relative_max (MIN_ACK_DELAY, delay);
fc->wack = GNUNET_YES;
+ fc->last_round = GNUNET_TIME_absolute_get ();
+ GNUNET_STATISTICS_update (fc->stats, _("# fragments wrap arounds"), 1,
+ GNUNET_NO);
}
fc->proc_busy = GNUNET_YES;
fc->delay_until = GNUNET_TIME_relative_to_absolute (delay);
+ fc->num_transmissions++;
fc->proc (fc->proc_cls, &fh->header);
}
* @param stats statistics context
* @param mtu the maximum message size for each fragment
* @param tracker bandwidth tracker to use for flow control (can be NULL)
- * @param delay expected delay between fragment transmission
+ * @param msg_delay initial delay to insert between fragment transmissions
+ * based on previous messages
+ * @param ack_delay expected delay between fragment transmission
* and ACK based on previous messages
* @param msg the message to fragment
* @param proc function to call for each fragment to transmit
GNUNET_FRAGMENT_context_create (struct GNUNET_STATISTICS_Handle *stats,
uint16_t mtu,
struct GNUNET_BANDWIDTH_Tracker *tracker,
- struct GNUNET_TIME_Relative delay,
+ struct GNUNET_TIME_Relative msg_delay,
+ struct GNUNET_TIME_Relative ack_delay,
const struct GNUNET_MessageHeader *msg,
GNUNET_FRAGMENT_MessageProcessor proc,
void *proc_cls)
fc->stats = stats;
fc->mtu = mtu;
fc->tracker = tracker;
- fc->delay = delay;
+ fc->ack_delay = ack_delay;
+ fc->msg_delay = msg_delay;
fc->msg = (const struct GNUNET_MessageHeader *) &fc[1];
fc->proc = proc;
fc->proc_cls = proc_cls;
const struct FragmentAcknowledgement *fa;
uint64_t abits;
struct GNUNET_TIME_Relative ndelay;
+ unsigned int ack_cnt;
+ unsigned int snd_cnt;
+ unsigned int i;
if (sizeof (struct FragmentAcknowledgement) != ntohs (msg->size))
{
if (ntohl (fa->fragment_id) != fc->fragment_id)
return GNUNET_SYSERR; /* not our ACK */
abits = GNUNET_ntohll (fa->bits);
- if ((GNUNET_YES == fc->wack) && (abits == (fc->acks & abits)))
+ if ( (GNUNET_YES == fc->wack) &&
+ (0 != fc->num_transmissions) )
{
/* normal ACK, can update running average of delay... */
fc->wack = GNUNET_NO;
ndelay = GNUNET_TIME_absolute_get_duration (fc->last_round);
- fc->delay.rel_value =
- (ndelay.rel_value * fc->num_rounds + 3 * fc->delay.rel_value) / 4;
+ fc->ack_delay.rel_value_us =
+ (ndelay.rel_value_us / fc->num_transmissions + 3 * fc->ack_delay.rel_value_us) / 4;
+ fc->num_transmissions = 0;
+ /* calculate ratio msg sent vs. msg acked */
+ ack_cnt = 0;
+ snd_cnt = 0;
+ for (i=0;i<64;i++)
+ {
+ if (1 == (fc->acks_mask & (1 << i)))
+ {
+ snd_cnt++;
+ if (0 == (abits & (1 << i)))
+ ack_cnt++;
+ }
+ }
+ if (0 == ack_cnt)
+ {
+ /* complete loss */
+ fc->msg_delay = GNUNET_TIME_relative_multiply (fc->msg_delay,
+ snd_cnt);
+ }
+ else if (snd_cnt > ack_cnt)
+ {
+ /* some loss, slow down proportionally */
+ fprintf (stderr, "Prop loss\n");
+ fc->msg_delay.rel_value_us = ((fc->msg_delay.rel_value_us * ack_cnt) / snd_cnt);
+ }
+ else if (100 < fc->msg_delay.rel_value_us)
+ {
+ fc->msg_delay.rel_value_us -= 100; /* try a bit faster */
+ }
+ fc->msg_delay = GNUNET_TIME_relative_min (fc->msg_delay,
+ GNUNET_TIME_UNIT_SECONDS);
}
GNUNET_STATISTICS_update (fc->stats,
_("# fragment acknowledgements received"), 1,
* resources).
*
* @param fc fragmentation context
- * @return average delay between transmission and ACK for the
- * last message, FOREVER if the message was not fully transmitted
+ * @param msg_delay where to store average delay between individual message transmissions the
+ * last message (OUT only)
+ * @param ack_delay where to store average delay between transmission and ACK for the
+ * last message, set to FOREVER if the message was not fully transmitted (OUT only)
*/
-struct GNUNET_TIME_Relative
-GNUNET_FRAGMENT_context_destroy (struct GNUNET_FRAGMENT_Context *fc)
+void
+GNUNET_FRAGMENT_context_destroy (struct GNUNET_FRAGMENT_Context *fc,
+ struct GNUNET_TIME_Relative *msg_delay,
+ struct GNUNET_TIME_Relative *ack_delay)
{
- struct GNUNET_TIME_Relative ret;
-
if (fc->task != GNUNET_SCHEDULER_NO_TASK)
GNUNET_SCHEDULER_cancel (fc->task);
- ret = fc->delay;
+ if (NULL != ack_delay)
+ *ack_delay = fc->ack_delay;
+ if (NULL != msg_delay)
+ *msg_delay = GNUNET_TIME_relative_multiply (fc->msg_delay,
+ fc->num_rounds);
GNUNET_free (fc);
- return ret;
}