freebsd-skq/sys/sys/counter.h
glebius 592e0af9a0 Provide counter_ratecheck(), a MP-friendly substitution to ppsratecheck().
When rated event happens at a very quick rate, the ppsratecheck() is not
only racy, but also becomes a performance bottleneck.

Together with:	rrs, jtl
2016-12-09 17:58:34 +00:00

77 lines
2.5 KiB
C

/*-
* Copyright (c) 2012 Gleb Smirnoff <glebius@FreeBSD.org>
* 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.
*
* $FreeBSD$
*/
#ifndef __SYS_COUNTER_H__
#define __SYS_COUNTER_H__
typedef uint64_t *counter_u64_t;
#ifdef _KERNEL
#include <machine/counter.h>
counter_u64_t counter_u64_alloc(int);
void counter_u64_free(counter_u64_t);
void counter_u64_zero(counter_u64_t);
uint64_t counter_u64_fetch(counter_u64_t);
#define COUNTER_ARRAY_ALLOC(a, n, wait) do { \
for (int i = 0; i < (n); i++) \
(a)[i] = counter_u64_alloc(wait); \
} while (0)
#define COUNTER_ARRAY_FREE(a, n) do { \
for (int i = 0; i < (n); i++) \
counter_u64_free((a)[i]); \
} while (0)
#define COUNTER_ARRAY_COPY(a, dstp, n) do { \
for (int i = 0; i < (n); i++) \
((uint64_t *)(dstp))[i] = counter_u64_fetch((a)[i]);\
} while (0)
#define COUNTER_ARRAY_ZERO(a, n) do { \
for (int i = 0; i < (n); i++) \
counter_u64_zero((a)[i]); \
} while (0)
/*
* counter(9) based rate checking.
*/
struct counter_rate {
counter_u64_t cr_rate; /* Events since last second */
volatile int cr_lock; /* Lock to clean the struct */
int cr_ticks; /* Ticks on last clean */
int cr_over; /* Over limit since cr_ticks? */
};
int64_t counter_ratecheck(struct counter_rate *, int64_t);
#endif /* _KERNEL */
#endif /* ! __SYS_COUNTER_H__ */