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rtems/cpukit/include/machine/_kernel_time.h
rrs c6d8589bb0 Synchronize kernel <sys/time.h> with FreeBSD 
Integrate parts of this commit:

This commit brings in a new refactored TCP stack
called Rack. Rack includes the following features: - A different SACK
processing scheme (the old sack structures are not used). - RACK (Recent
acknowledgment) where counting dup-acks is no longer done instead time
is used to knwo when to retransmit. (see the I-D) - TLP (Tail Loss
Probe) where we will probe for tail-losses to attempt to try not to take
a retransmit time-out. (see the I-D) - Burst mitigation using TCPHTPS -
PRR (partial rate reduction) see the RFC.

Once built into your kernel, you can select this stack by either
socket option with the name of the stack is "rack" or by setting
the global sysctl so the default is rack.

Note that any connection that does not support SACK will be kicked
back to the "default" base  FreeBSD stack (currently known as "default").

To build this into your kernel you will need to enable in your
kernel:
   makeoptions WITH_EXTRA_TCP_STACKS=1
   options TCPHPTS

Sponsored by:	Netflix Inc.
Differential Revision:		https://reviews.freebsd.org/D15525
2019-11-18 07:16:30 +01:00

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/*-
* Copyright (c) 2016 embedded brains GmbH
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if !defined(_SYS_TIME_H_) || !defined(_KERNEL)
#error "must be included via <sys/time.h> in kernel space"
#endif
#include <machine/_timecounter.h>
/* Operations on timespecs */
#ifndef timespecclear
#define timespecclear(tvp) ((tvp)->tv_sec = (tvp)->tv_nsec = 0)
#endif
#ifndef timespecisset
#define timespecisset(tvp) ((tvp)->tv_sec || (tvp)->tv_nsec)
#endif
#ifndef timespeccmp
#define timespeccmp(tvp, uvp, cmp) \
(((tvp)->tv_sec == (uvp)->tv_sec) ? \
((tvp)->tv_nsec cmp (uvp)->tv_nsec) : \
((tvp)->tv_sec cmp (uvp)->tv_sec))
#endif
#ifndef timespecadd
#define timespecadd(tsp, usp, vsp) \
do { \
(vsp)->tv_sec = (tsp)->tv_sec + (usp)->tv_sec; \
(vsp)->tv_nsec = (tsp)->tv_nsec + (usp)->tv_nsec; \
if ((vsp)->tv_nsec >= 1000000000L) { \
(vsp)->tv_sec++; \
(vsp)->tv_nsec -= 1000000000L; \
} \
} while (0)
#endif
#ifndef timespecsub
#define timespecsub(tsp, usp, vsp) \
do { \
(vsp)->tv_sec = (tsp)->tv_sec - (usp)->tv_sec; \
(vsp)->tv_nsec = (tsp)->tv_nsec - (usp)->tv_nsec; \
if ((vsp)->tv_nsec < 0) { \
(vsp)->tv_sec--; \
(vsp)->tv_nsec += 1000000000L; \
} \
} while (0)
#endif
/*
* Simple macros to convert ticks to milliseconds
* or microseconds and vice-versa. The answer
* will always be at least 1. Note the return
* value is a uint32_t however we step up the
* operations to 64 bit to avoid any overflow/underflow
* problems.
*/
#define TICKS_2_MSEC(t) max(1, (uint32_t)(hz == 1000) ? \
(t) : (((uint64_t)(t) * (uint64_t)1000)/(uint64_t)hz))
#define TICKS_2_USEC(t) max(1, (uint32_t)(hz == 1000) ? \
((t) * 1000) : (((uint64_t)(t) * (uint64_t)1000000)/(uint64_t)hz))
#define MSEC_2_TICKS(m) max(1, (uint32_t)((hz == 1000) ? \
(m) : ((uint64_t)(m) * (uint64_t)hz)/(uint64_t)1000))
#define USEC_2_TICKS(u) max(1, (uint32_t)((hz == 1000) ? \
((u) / 1000) : ((uint64_t)(u) * (uint64_t)hz)/(uint64_t)1000000))
/* Operations on timevals. */
#define timevalclear(tvp) ((tvp)->tv_sec = (tvp)->tv_usec = 0)
#define timevalisset(tvp) ((tvp)->tv_sec || (tvp)->tv_usec)
#define timevalcmp(tvp, uvp, cmp) \
(((tvp)->tv_sec == (uvp)->tv_sec) ? \
((tvp)->tv_usec cmp (uvp)->tv_usec) : \
((tvp)->tv_sec cmp (uvp)->tv_sec))
/* timevaladd and timevalsub are not inlined */
/*
* Kernel to clock driver interface.
*/
void inittodr(time_t base);
void resettodr(void);
#define time_second _Timecounter_Time_second
#define time_uptime _Timecounter_Time_uptime
extern struct timeval boottime;
extern struct bintime tc_tick_bt;
extern sbintime_t tc_tick_sbt;
extern struct bintime tick_bt;
extern sbintime_t tick_sbt;
extern int tc_precexp;
extern int tc_timepercentage;
extern struct bintime bt_timethreshold;
extern struct bintime bt_tickthreshold;
extern sbintime_t sbt_timethreshold;
extern sbintime_t sbt_tickthreshold;
/*
* Functions for looking at our clock: [get]{bin,nano,micro}[up]time()
*
* Functions without the "get" prefix returns the best timestamp
* we can produce in the given format.
*
* "bin" == struct bintime == seconds + 64 bit fraction of seconds.
* "nano" == struct timespec == seconds + nanoseconds.
* "micro" == struct timeval == seconds + microseconds.
*
* Functions containing "up" returns time relative to boot and
* should be used for calculating time intervals.
*
* Functions without "up" returns UTC time.
*
* Functions with the "get" prefix returns a less precise result
* much faster than the functions without "get" prefix and should
* be used where a precision of 1/hz seconds is acceptable or where
* performance is priority. (NB: "precision", _not_ "resolution" !)
*/
#define binuptime(_bt) _Timecounter_Binuptime(_bt)
#define nanouptime(_tsp) _Timecounter_Nanouptime(_tsp)
#define microuptime(_tvp) _Timecounter_Microuptime(_tvp)
static __inline sbintime_t
sbinuptime(void)
{
struct bintime _bt;
binuptime(&_bt);
return (bttosbt(_bt));
}
#define bintime(_bt) _Timecounter_Bintime(_bt)
#define nanotime(_tsp) _Timecounter_Nanotime(_tsp)
#define microtime(_tvp) _Timecounter_Microtime(_tvp)
#define getbinuptime(_bt) _Timecounter_Getbinuptime(_bt)
#define getnanouptime(_tsp) _Timecounter_Getnanouptime(_tsp)
#define getmicrouptime(_tvp) _Timecounter_Getmicrouptime(_tvp)
static __inline sbintime_t
getsbinuptime(void)
{
struct bintime _bt;
getbinuptime(&_bt);
return (bttosbt(_bt));
}
#define getbintime(_bt) _Timecounter_Getbintime(_bt)
#define getnanotime(_tsp) _Timecounter_Getnanotime(_tsp)
#define getmicrotime(_tvp) _Timecounter_Getmicrotime(_tvp)
#define getboottime(_tvp) _Timecounter_Getboottime(_tvp)
#define getboottimebin(_bt) _Timecounter_Getboottimebin(_bt)
/* Other functions */
int itimerdecr(struct itimerval *itp, int usec);
int itimerfix(struct timeval *tv);
int ppsratecheck(struct timeval *, int *, int);
int ratecheck(struct timeval *, const struct timeval *);
void timevaladd(struct timeval *t1, const struct timeval *t2);
void timevalsub(struct timeval *t1, const struct timeval *t2);
int tvtohz(struct timeval *tv);
#define TC_DEFAULTPERC 5
#define BT2FREQ(bt) \
(((uint64_t)0x8000000000000000 + ((bt)->frac >> 2)) / \
((bt)->frac >> 1))
#define SBT2FREQ(sbt) ((SBT_1S + ((sbt) >> 1)) / (sbt))
#define FREQ2BT(freq, bt) \
{ \
(bt)->sec = 0; \
(bt)->frac = ((uint64_t)0x8000000000000000 / (freq)) << 1; \
}
#define TIMESEL(sbt, sbt2) \
(((sbt2) >= sbt_timethreshold) ? \
((*(sbt) = getsbinuptime()), 1) : ((*(sbt) = sbinuptime()), 0))
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