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Drop tmtab module. 

Instead of maintaining a table of precalculated values, use the
newly added set_tmo_random() function to set the delay request timeout.
It saves some memory and improves the timeout granularity, but has a
higher computational cost. It follows the requirements from section
9.5.11.2 of the spec.

Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
master
Miroslav Lichvar 2013-10-25 14:45:34 +02:00 committed by Richard Cochran
parent e425da2f17
commit 23d31d090e
4 changed files with 4 additions and 123 deletions
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2
makefile
View File

@ -25,7 +25,7 @@ LDLIBS = -lm -lrt $(EXTRA_LDFLAGS)
PRG = ptp4l pmc phc2sys hwstamp_ctl
OBJ = bmc.o clock.o clockadj.o clockcheck.o config.o fault.o \
fsm.o ptp4l.o mave.o msg.o phc.o pi.o port.o print.o raw.o servo.o \
sk.o stats.o tlv.o tmtab.o transport.o udp.o udp6.o uds.o util.o version.o
sk.o stats.o tlv.o transport.o udp.o udp6.o uds.o util.o version.o
OBJECTS = $(OBJ) hwstamp_ctl.o phc2sys.o pmc.o pmc_common.o sysoff.o
SRC = $(OBJECTS:.o=.c)

15
port.c
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@ -32,7 +32,6 @@
#include "print.h"
#include "sk.h"
#include "tlv.h"
#include "tmtab.h"
#include "tmv.h"
#include "util.h"
@ -80,7 +79,6 @@ struct port {
UInteger16 delayreq;
UInteger16 sync;
} seqnum;
struct tmtab tmtab;
tmv_t peer_delay;
struct mave *avg_delay;
int log_sync_interval;
@ -815,17 +813,13 @@ static int port_set_announce_tmo(struct port *p)
static int port_set_delay_tmo(struct port *p)
{
struct itimerspec tmo = {
{0, 0}, {0, 0}
};
int index;
if (p->delayMechanism == DM_P2P) {
return set_tmo_log(p->fda.fd[FD_DELAY_TIMER], 1,
p->logMinPdelayReqInterval);
} else {
return set_tmo_random(p->fda.fd[FD_DELAY_TIMER], 0, 2,
p->logMinDelayReqInterval);
}
index = random() % TMTAB_MAX;
tmo.it_value = p->tmtab.ts[index];
return timerfd_settime(p->fda.fd[FD_DELAY_TIMER], 0, &tmo, NULL);
}
static int port_set_manno_tmo(struct port *p)
@ -1327,8 +1321,6 @@ static int port_initialize(struct port *p)
p->logMinPdelayReqInterval = p->pod.logMinPdelayReqInterval;
p->neighborPropDelayThresh = p->pod.neighborPropDelayThresh;
tmtab_init(&p->tmtab, 1 + p->logMinDelayReqInterval);
for (i = 0; i < N_TIMER_FDS; i++) {
fd[i] = -1;
}
@ -1534,7 +1526,6 @@ static void process_delay_resp(struct port *p, struct ptp_message *m)
p->logMinDelayReqInterval = rsp->hdr.logMessageInterval;
pr_notice("port %hu: minimum delay request interval 2^%d",
portnum(p), p->logMinDelayReqInterval);
tmtab_init(&p->tmtab, 1 + p->logMinDelayReqInterval);
}
}

54
tmtab.c
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@ -1,54 +0,0 @@
/**
* @file tmtab.c
* @note Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "tmtab.h"
#include "tmv.h"
void tmtab_init(struct tmtab *tt, int log_seconds)
{
int i;
struct timespec incr, ts = {0, 0};
uint64_t max, min;
if (log_seconds < 0) {
log_seconds *= -1;
for (i = 1, max = 500000000ULL; i < log_seconds; i++) {
max >>= 1;
}
} else {
for (i = 0, max = 1000000000ULL; i < log_seconds; i++) {
max <<= 1;
}
}
min = max / (TMTAB_MAX - 1ULL);
incr.tv_sec = min / 1000000000ULL;
incr.tv_nsec = min % 1000000000ULL;
for (i = 0; i < TMTAB_MAX; i++) {
ts.tv_sec += incr.tv_sec;
ts.tv_nsec += incr.tv_nsec;
while (ts.tv_nsec >= NS_PER_SEC) {
ts.tv_nsec -= NS_PER_SEC;
ts.tv_sec++;
}
tt->ts[i] = ts;
}
}

56
tmtab.h
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@ -1,56 +0,0 @@
/**
* @file tmtab.h
* @brief Implements a table of time out values.
* @note Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef HAVE_TMTAB_H
#define HAVE_TMTAB_H
#include <time.h>
/*
* Let 'D' be the logMinDelayReqInterval
* and 'S' be the logSyncInterval.
*
* The delay request interval ranges from zero to 2^{D+1} seconds.
* The standard requires that
*
* S <= D <= S+5
*
* and the timeout granularity not more than 2^{S-4} seconds.
* Thus, the minimum required number of grains is given by
*
* 2^{D+1} / 2^{S-4} = 2^{D-S+5}
*
* and finds a minimum of 2^5 and a maximum of 2^10.
*
* The timeout table allows for the maximum number of grains required.
*
* Note that the table is made to be biased so that when sampling the
* table randomly, the average delay value will be slightly larger
* than logMinDelayReqInterval, in order to satisfy the wording of the
* standard.
*/
#define TMTAB_MAX 1024
struct tmtab {
struct timespec ts[TMTAB_MAX];
};
void tmtab_init(struct tmtab *tt, int log_seconds);
#endif