/*
This file is part of GNUnet
- (C) 2009, 2011 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2009-2013 GNUnet e.V.
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
You should have received a copy of the GNU General Public License
along with GNUnet; see the file COPYING. If not, write to the
- Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
*/
/**
* @file src/fragmentation/fragmentation.c
#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.
GNUNET_FRAGMENT_MessageProcessor proc;
/**
- * Closure for 'proc'.
+ * Closure for @e proc.
*/
void *proc_cls;
uint64_t acks;
/**
- * Bitfield with all possible bits for 'acks' (used to mask the
+ * Bitfield with all possible bits for @e acks (used to mask the
* ack we get back).
*/
uint64_t acks_mask;
/**
* Task performing work for the fragmenter.
*/
- GNUNET_SCHEDULER_TaskIdentifier task;
+ struct GNUNET_SCHEDULER_Task *task;
/**
* Our fragmentation ID. (chosen at random)
unsigned int next_transmission;
/**
- * GNUNET_YES if we called 'proc' and are now waiting for 'GNUNET_FRAGMENT_transmission_done'
+ * How many rounds of transmission have we completed so far?
+ */
+ unsigned int num_rounds;
+
+ /**
+ * How many transmission have we completed in this round?
+ */
+ unsigned int num_transmissions;
+
+ /**
+ * #GNUNET_YES if we called @e proc and are now waiting for #GNUNET_FRAGMENT_context_transmission_done()
*/
int8_t proc_busy;
/**
- * GNUNET_YES if we are waiting for an ACK.
+ * #GNUNET_YES if we are waiting for an ACK.
*/
int8_t wack;
* Target fragment size.
*/
uint16_t mtu;
-
+
};
+/**
+ * Convert an ACK message to a printable format suitable for logging.
+ *
+ * @param ack message to print
+ * @return ack in human-readable format
+ */
+const char *
+GNUNET_FRAGMENT_print_ack (const struct GNUNET_MessageHeader *ack)
+{
+ static char buf[128];
+ const struct FragmentAcknowledgement *fa;
+
+ if (sizeof (struct FragmentAcknowledgement) !=
+ htons (ack->size))
+ return "<malformed ack>";
+ fa = (const struct FragmentAcknowledgement *) ack;
+ GNUNET_snprintf (buf,
+ sizeof (buf),
+ "%u-%llX",
+ ntohl (fa->fragment_id),
+ GNUNET_ntohll (fa->bits));
+ return buf;
+}
+
+
/**
* Transmit the next fragment to the other peer.
*
- * @param cls the 'struct GNUNET_FRAGMENT_Context'
- * @param tc scheduler context
+ * @param cls the `struct GNUNET_FRAGMENT_Context`
*/
static void
-transmit_next (void *cls,
- const struct GNUNET_SCHEDULER_TaskContext *tc)
+transmit_next (void *cls)
{
struct GNUNET_FRAGMENT_Context *fc = cls;
char msg[fc->mtu];
size_t fsize;
int wrap;
- fc->task = GNUNET_SCHEDULER_NO_TASK;
+ fc->task = NULL;
GNUNET_assert (GNUNET_NO == fc->proc_busy);
if (0 == fc->acks)
- return; /* all done */
-
+ 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);
- }
+ while (0 == (fc->acks & (1LL << fc->next_transmission)))
+ {
+ fc->next_transmission = (fc->next_transmission + 1) % 64;
+ wrap |= (0 == fc->next_transmission);
+ }
bit = fc->next_transmission;
size = ntohs (fc->msg->size);
if (bit == size / (fc->mtu - sizeof (struct FragmentHeader)))
- fsize = size % (fc->mtu - sizeof (struct FragmentHeader)) + sizeof (struct FragmentHeader);
+ fsize =
+ (size % (fc->mtu - sizeof (struct FragmentHeader))) +
+ sizeof (struct FragmentHeader);
else
fsize = fc->mtu;
- if (fc->tracker != NULL)
+ if (NULL != fc->tracker)
delay = GNUNET_BANDWIDTH_tracker_get_delay (fc->tracker,
- fsize);
+ fsize);
else
delay = GNUNET_TIME_UNIT_ZERO;
- if (delay.rel_value > 0)
- {
- fc->task = GNUNET_SCHEDULER_add_delayed (delay,
- &transmit_next,
- fc);
- return;
- }
+ if (delay.rel_value_us > 0)
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Fragmentation logic delays transmission of next fragment by %s\n",
+ GNUNET_STRINGS_relative_time_to_string (delay,
+ GNUNET_YES));
+ 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];
- fh = (struct FragmentHeader*) msg;
+ mbuf = (const char *) &fc[1];
+ fh = (struct FragmentHeader *) msg;
fh->header.size = htons (fsize);
fh->header.type = htons (GNUNET_MESSAGE_TYPE_FRAGMENT);
fh->fragment_id = htonl (fc->fragment_id);
- fh->total_size = fc->msg->size; /* already in big-endian */
+ fh->total_size = fc->msg->size; /* already in big-endian */
fh->offset = htons ((fc->mtu - sizeof (struct FragmentHeader)) * bit);
- memcpy (&fh[1],
- &mbuf[bit * (fc->mtu - sizeof (struct FragmentHeader))],
- fsize - sizeof (struct FragmentHeader));
+ memcpy (&fh[1], &mbuf[bit * (fc->mtu - sizeof (struct FragmentHeader))],
+ fsize - sizeof (struct FragmentHeader));
if (NULL != fc->tracker)
- GNUNET_BANDWIDTH_tracker_consume (fc->tracker, fsize);
+ GNUNET_BANDWIDTH_tracker_consume (fc->tracker, fsize);
GNUNET_STATISTICS_update (fc->stats,
- _("# fragments transmitted"),
- 1, GNUNET_NO);
- if (0 != fc->last_round.abs_value)
+ _("# fragments transmitted"),
+ 1,
+ GNUNET_NO);
+ if (0 != fc->last_round.abs_value_us)
GNUNET_STATISTICS_update (fc->stats,
- _("# fragments retransmitted"),
- 1, GNUNET_NO);
+ _("# fragments retransmitted"),
+ 1,
+ GNUNET_NO);
/* select next message to calculate delay */
bit = fc->next_transmission;
fsize = fc->mtu;
if (NULL != fc->tracker)
delay = GNUNET_BANDWIDTH_tracker_get_delay (fc->tracker,
- fsize);
+ fsize);
else
delay = GNUNET_TIME_UNIT_ZERO;
+ delay = GNUNET_TIME_relative_max (delay,
+ GNUNET_TIME_relative_multiply (fc->msg_delay,
+ (1ULL << fc->num_rounds)));
if (wrap)
- {
- /* full round transmitted wait 2x delay for ACK before going again */
- delay = GNUNET_TIME_relative_max (GNUNET_TIME_relative_multiply (delay, 2),
- fc->delay);
- /* 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 ();
- fc->wack = GNUNET_YES;
- }
+ {
+ /* full round transmitted wait 2x delay for ACK before going again */
+ 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 (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->proc (fc->proc_cls, &fh->header);
+ fc->num_transmissions++;
+ fc->proc (fc->proc_cls,
+ &fh->header);
}
/**
* Create a fragmentation context for the given message.
- * Fragments the message into fragments of size "mtu" or
- * less. Calls 'proc' on each un-acknowledged fragment,
- * using both the expected 'delay' between messages and
- * acknowledgements and the given 'tracker' to guide the
- * frequency of calls to 'proc'.
+ * Fragments the message into fragments of size @a mtu or
+ * less. Calls @a proc on each un-acknowledged fragment,
+ * using both the expected @a msg_delay between messages and
+ * acknowledgements and the given @a tracker to guide the
+ * frequency of calls to @a proc.
*
* @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
- * @param proc_cls closure for proc
+ * @param proc_cls closure for @a proc
* @return the fragmentation context
*/
struct GNUNET_FRAGMENT_Context *
GNUNET_FRAGMENT_context_create (struct GNUNET_STATISTICS_Handle *stats,
- uint16_t mtu,
- struct GNUNET_BANDWIDTH_Tracker *tracker,
- struct GNUNET_TIME_Relative delay,
- const struct GNUNET_MessageHeader *msg,
- GNUNET_FRAGMENT_MessageProcessor proc,
- void *proc_cls)
+ uint16_t mtu,
+ struct GNUNET_BANDWIDTH_Tracker *tracker,
+ struct GNUNET_TIME_Relative msg_delay,
+ struct GNUNET_TIME_Relative ack_delay,
+ const struct GNUNET_MessageHeader *msg,
+ GNUNET_FRAGMENT_MessageProcessor proc,
+ void *proc_cls)
{
struct GNUNET_FRAGMENT_Context *fc;
size_t size;
uint64_t bits;
-
+
GNUNET_STATISTICS_update (stats,
- _("# messages fragmented"),
- 1, GNUNET_NO);
+ _("# messages fragmented"),
+ 1,
+ GNUNET_NO);
GNUNET_assert (mtu >= 1024 + sizeof (struct FragmentHeader));
- size = ntohs (msg->size);
+ size = ntohs (msg->size);
GNUNET_STATISTICS_update (stats,
- _("# total size of fragmented messages"),
- size, GNUNET_NO);
+ _("# total size of fragmented messages"),
+ size, GNUNET_NO);
GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
fc = GNUNET_malloc (sizeof (struct GNUNET_FRAGMENT_Context) + size);
fc->stats = stats;
fc->mtu = mtu;
fc->tracker = tracker;
- fc->delay = delay;
- fc->msg = (const struct GNUNET_MessageHeader*)&fc[1];
+ 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;
- fc->fragment_id = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
- UINT32_MAX);
+ fc->fragment_id =
+ GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
+ UINT32_MAX);
memcpy (&fc[1], msg, size);
- bits = (size + mtu - sizeof (struct FragmentHeader) - 1) / (mtu - sizeof (struct FragmentHeader));
+ bits =
+ (size + mtu - sizeof (struct FragmentHeader) - 1) / (mtu -
+ sizeof (struct
+ FragmentHeader));
GNUNET_assert (bits <= 64);
if (bits == 64)
- fc->acks_mask = UINT64_MAX; /* set all 64 bit */
+ fc->acks_mask = UINT64_MAX; /* set all 64 bit */
else
- fc->acks_mask = (1LL << bits) - 1; /* set lowest 'bits' bit */
+ fc->acks_mask = (1LL << bits) - 1; /* set lowest 'bits' bit */
fc->acks = fc->acks_mask;
- fc->task = GNUNET_SCHEDULER_add_now (&transmit_next,
- fc);
+ fc->task = GNUNET_SCHEDULER_add_now (&transmit_next, fc);
return fc;
}
{
GNUNET_assert (fc->proc_busy == GNUNET_YES);
fc->proc_busy = GNUNET_NO;
- GNUNET_assert (fc->task == GNUNET_SCHEDULER_NO_TASK);
- fc->task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining (fc->delay_until),
- &transmit_next,
- fc);
+ GNUNET_assert (fc->task == NULL);
+ fc->task =
+ GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining
+ (fc->delay_until), &transmit_next, fc);
}
*
* @param fc fragmentation context
* @param msg acknowledgement message we received
- * @return GNUNET_OK if this ack completes the work of the 'fc'
+ * @return #GNUNET_OK if this ack completes the work of the 'fc'
* (all fragments have been received);
- * GNUNET_NO if more messages are pending
- * GNUNET_SYSERR if this ack is not valid for this fc
+ * #GNUNET_NO if more messages are pending
+ * #GNUNET_SYSERR if this ack is not valid for this fc
*/
-int
+int
GNUNET_FRAGMENT_process_ack (struct GNUNET_FRAGMENT_Context *fc,
- const struct GNUNET_MessageHeader *msg)
+ const struct GNUNET_MessageHeader *msg)
{
const struct FragmentAcknowledgement *fa;
uint64_t abits;
struct GNUNET_TIME_Relative ndelay;
-
- if (sizeof (struct FragmentAcknowledgement) !=
- ntohs (msg->size))
- {
- GNUNET_break_op (0);
- return GNUNET_SYSERR;
- }
+ unsigned int ack_cnt;
+ unsigned int snd_cnt;
+ unsigned int i;
+
+ if (sizeof (struct FragmentAcknowledgement) != ntohs (msg->size))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
fa = (const struct FragmentAcknowledgement *) msg;
if (ntohl (fa->fragment_id) != fc->fragment_id)
- return GNUNET_SYSERR; /* not our ACK */
+ return GNUNET_SYSERR; /* not our ACK */
abits = GNUNET_ntohll (fa->bits);
- if (GNUNET_YES == fc->wack)
+ 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->ack_delay.rel_value_us =
+ (ndelay.rel_value_us / fc->num_transmissions + 3 * fc->ack_delay.rel_value_us) / 4;
+ /* calculate ratio msg sent vs. msg acked */
+ ack_cnt = 0;
+ snd_cnt = 0;
+ for (i=0;i<64;i++)
{
- /* 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 + 3 * fc->delay.rel_value) / 4;
+ if (1 == (fc->acks_mask & (1ULL << i)))
+ {
+ snd_cnt++;
+ if (0 == (abits & (1ULL << i)))
+ ack_cnt++;
+ }
}
- GNUNET_STATISTICS_update (fc->stats,
- _("# fragment acknowledgements received"),
- 1,
- GNUNET_NO);
- if (abits != (fc->acks & abits))
+ if (0 == ack_cnt)
{
- /* ID collission or message reordering, count! This should be rare! */
- GNUNET_STATISTICS_update (fc->stats,
- _("# bits removed from fragmentation ACKs"),
- 1, GNUNET_NO);
+ /* 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 */
+ fc->msg_delay.rel_value_us = ((fc->msg_delay.rel_value_us * ack_cnt) / snd_cnt);
+ }
+ else if (snd_cnt == ack_cnt)
+ {
+ fc->msg_delay.rel_value_us =
+ (ndelay.rel_value_us / fc->num_transmissions + 3 * fc->msg_delay.rel_value_us) / 5;
+ }
+ fc->num_transmissions = 0;
+ fc->msg_delay = GNUNET_TIME_relative_min (fc->msg_delay,
+ GNUNET_TIME_UNIT_SECONDS);
+ fc->ack_delay = GNUNET_TIME_relative_min (fc->ack_delay,
+ GNUNET_TIME_UNIT_SECONDS);
+ }
+ GNUNET_STATISTICS_update (fc->stats,
+ _("# fragment acknowledgements received"),
+ 1,
+ GNUNET_NO);
+ if (abits != (fc->acks & abits))
+ {
+ /* ID collission or message reordering, count! This should be rare! */
+ GNUNET_STATISTICS_update (fc->stats,
+ _("# bits removed from fragmentation ACKs"), 1,
+ GNUNET_NO);
+ }
fc->acks = abits & fc->acks_mask;
if (0 != fc->acks)
+ {
+ /* more to transmit, do so right now (if tracker permits...) */
+ if (fc->task != NULL)
+ {
+ /* schedule next transmission now, no point in waiting... */
+ GNUNET_SCHEDULER_cancel (fc->task);
+ fc->task = GNUNET_SCHEDULER_add_now (&transmit_next, fc);
+ }
+ else
{
- /* more to transmit, do so right now (if tracker permits...) */
- if (fc->task != GNUNET_SCHEDULER_NO_TASK)
- {
- /* schedule next transmission now, no point in waiting... */
- GNUNET_SCHEDULER_cancel (fc->task);
- fc->task = GNUNET_SCHEDULER_add_now (&transmit_next,
- fc);
- }
- else
- {
- /* only case where there is no task should be if we're waiting
- for the right to transmit again (proc_busy set to YES) */
- GNUNET_assert (GNUNET_YES == fc->proc_busy);
- }
- return GNUNET_NO;
+ /* only case where there is no task should be if we're waiting
+ * for the right to transmit again (proc_busy set to YES) */
+ GNUNET_assert (GNUNET_YES == fc->proc_busy);
}
+ return GNUNET_NO;
+ }
/* all done */
GNUNET_STATISTICS_update (fc->stats,
- _("# fragmentation transmissions completed"),
- 1,
- GNUNET_NO);
- if (fc->task != GNUNET_SCHEDULER_NO_TASK)
- {
- GNUNET_SCHEDULER_cancel (fc->task);
- fc->task = GNUNET_SCHEDULER_NO_TASK;
- }
+ _("# fragmentation transmissions completed"),
+ 1,
+ GNUNET_NO);
+ if (NULL != fc->task)
+ {
+ GNUNET_SCHEDULER_cancel (fc->task);
+ fc->task = NULL;
+ }
return GNUNET_OK;
}
* 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)
+ if (fc->task != NULL)
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;
}
/* end of fragmentation.c */
-