Add a time out table for delay requests.
We can pre-compute a table of suitable values in order to simplify the run time random delay selection. Signed-off-by: Richard Cochran <richardcochran@gmail.com>master
parent
2fd7a1c18f
commit
1d6737b75c
2
makefile
2
makefile
|
@ -25,7 +25,7 @@ LDFLAGS =
|
||||||
LDLIBS = -lm -lrt
|
LDLIBS = -lm -lrt
|
||||||
PRG = linuxptp
|
PRG = linuxptp
|
||||||
OBJ = bmc.o clock.o fsm.o linuxptp.o msg.o phc.o pi.o port.o print.o \
|
OBJ = bmc.o clock.o fsm.o linuxptp.o msg.o phc.o pi.o port.o print.o \
|
||||||
servo.o transport.o udp.o util.o
|
servo.o tmtab.o transport.o udp.o util.o
|
||||||
|
|
||||||
SRC = $(OBJ:.o=.c)
|
SRC = $(OBJ:.o=.c)
|
||||||
DEPEND = $(OBJ:.o=.d)
|
DEPEND = $(OBJ:.o=.d)
|
||||||
|
|
|
@ -0,0 +1,54 @@
|
||||||
|
/**
|
||||||
|
* @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;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
|
@ -0,0 +1,56 @@
|
||||||
|
/**
|
||||||
|
* @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
|
Loading…
Reference in New Issue