bird/lib/timer.c
Ondrej Zajicek (work) 863ecfc785 The MRT protocol
The new MRT protocol is responsible for periodic RIB table dumps in the
MRT format (RFC 6396). Also the existing code for BGP4MP MRT dumps is
refactored and splitted between BGP to MRT protocols, will be more
integrated into MRT in the future.

Example:

protocol mrt {
        table "*";
        filename "%N_%F_%T.mrt";
        period 60;
}

It is partially based on the old MRT code from Pavel Tvrdik.
2018-11-20 17:45:35 +01:00

376 lines
7.8 KiB
C

/*
* BIRD -- Timers
*
* (c) 2013--2017 Ondrej Zajicek <santiago@crfreenet.org>
* (c) 2013--2017 CZ.NIC z.s.p.o.
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
/**
* DOC: Timers
*
* Timers are resources which represent a wish of a module to call a function at
* the specified time. The timer code does not guarantee exact timing, only that
* a timer function will not be called before the requested time.
*
* In BIRD, time is represented by values of the &btime type which is signed
* 64-bit integer interpreted as a relative number of microseconds since some
* fixed time point in past. The current time can be obtained by current_time()
* function with reasonable accuracy and is monotonic. There is also a current
* 'wall-clock' real time obtainable by current_real_time() reported by OS.
*
* Each timer is described by a &timer structure containing a pointer to the
* handler function (@hook), data private to this function (@data), time the
* function should be called at (@expires, 0 for inactive timers), for the other
* fields see |timer.h|.
*/
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include "nest/bird.h"
#include "lib/heap.h"
#include "lib/resource.h"
#include "lib/timer.h"
struct timeloop main_timeloop;
#ifdef USE_PTHREADS
#include <pthread.h>
/* Data accessed and modified from proto/bfd/io.c */
pthread_key_t current_time_key;
static inline struct timeloop *
timeloop_current(void)
{
return pthread_getspecific(current_time_key);
}
static inline void
timeloop_init_current(void)
{
pthread_key_create(&current_time_key, NULL);
pthread_setspecific(current_time_key, &main_timeloop);
}
void wakeup_kick_current(void);
#else
/* Just use main timelooop */
static inline struct timeloop * timeloop_current(void) { return &main_timeloop; }
static inline void timeloop_init_current(void) { }
#endif
btime
current_time(void)
{
return timeloop_current()->last_time;
}
btime
current_real_time(void)
{
struct timeloop *loop = timeloop_current();
if (!loop->real_time)
times_update_real_time(loop);
return loop->real_time;
}
#define TIMER_LESS(a,b) ((a)->expires < (b)->expires)
#define TIMER_SWAP(heap,a,b,t) (t = heap[a], heap[a] = heap[b], heap[b] = t, \
heap[a]->index = (a), heap[b]->index = (b))
static void
tm_free(resource *r)
{
timer *t = (void *) r;
tm_stop(t);
}
static void
tm_dump(resource *r)
{
timer *t = (void *) r;
debug("(code %p, data %p, ", t->hook, t->data);
if (t->randomize)
debug("rand %d, ", t->randomize);
if (t->recurrent)
debug("recur %d, ", t->recurrent);
if (t->expires)
debug("expires in %d ms)\n", (t->expires - current_time()) TO_MS);
else
debug("inactive)\n");
}
static struct resclass tm_class = {
"Timer",
sizeof(timer),
tm_free,
tm_dump,
NULL,
NULL
};
timer *
tm_new(pool *p)
{
timer *t = ralloc(p, &tm_class);
t->index = -1;
return t;
}
void
tm_set(timer *t, btime when)
{
struct timeloop *loop = timeloop_current();
uint tc = timers_count(loop);
if (!t->expires)
{
t->index = ++tc;
t->expires = when;
BUFFER_PUSH(loop->timers) = t;
HEAP_INSERT(loop->timers.data, tc, timer *, TIMER_LESS, TIMER_SWAP);
}
else if (t->expires < when)
{
t->expires = when;
HEAP_INCREASE(loop->timers.data, tc, timer *, TIMER_LESS, TIMER_SWAP, t->index);
}
else if (t->expires > when)
{
t->expires = when;
HEAP_DECREASE(loop->timers.data, tc, timer *, TIMER_LESS, TIMER_SWAP, t->index);
}
#ifdef CONFIG_BFD
/* Hack to notify BFD loops */
if ((loop != &main_timeloop) && (t->index == 1))
wakeup_kick_current();
#endif
}
void
tm_start(timer *t, btime after)
{
tm_set(t, current_time() + MAX(after, 0));
}
void
tm_stop(timer *t)
{
if (!t->expires)
return;
struct timeloop *loop = timeloop_current();
uint tc = timers_count(loop);
HEAP_DELETE(loop->timers.data, tc, timer *, TIMER_LESS, TIMER_SWAP, t->index);
BUFFER_POP(loop->timers);
t->index = -1;
t->expires = 0;
}
void
timers_init(struct timeloop *loop, pool *p)
{
times_init(loop);
BUFFER_INIT(loop->timers, p, 4);
BUFFER_PUSH(loop->timers) = NULL;
}
void io_log_event(void *hook, void *data);
void
timers_fire(struct timeloop *loop)
{
btime base_time;
timer *t;
times_update(loop);
base_time = loop->last_time;
while (t = timers_first(loop))
{
if (t->expires > base_time)
return;
if (t->recurrent)
{
btime when = t->expires + t->recurrent;
if (when <= loop->last_time)
when = loop->last_time + t->recurrent;
if (t->randomize)
when += random() % (t->randomize + 1);
tm_set(t, when);
}
else
tm_stop(t);
/* This is ugly hack, we want to log just timers executed from the main I/O loop */
if (loop == &main_timeloop)
io_log_event(t->hook, t->data);
t->hook(t);
}
}
void
timer_init(void)
{
timers_init(&main_timeloop, &root_pool);
timeloop_init_current();
}
/**
* tm_parse_time - parse a date and time
* @x: time string
*
* tm_parse_time() takes a textual representation of a date and time
* (yyyy-mm-dd[ hh:mm:ss[.sss]]) and converts it to the corresponding value of
* type &btime.
*/
btime
tm_parse_time(char *x)
{
struct tm tm;
int usec, n1, n2, n3, r;
r = sscanf(x, "%d-%d-%d%n %d:%d:%d%n.%d%n",
&tm.tm_year, &tm.tm_mon, &tm.tm_mday, &n1,
&tm.tm_hour, &tm.tm_min, &tm.tm_sec, &n2,
&usec, &n3);
if ((r == 3) && !x[n1])
tm.tm_hour = tm.tm_min = tm.tm_sec = usec = 0;
else if ((r == 6) && !x[n2])
usec = 0;
else if ((r == 7) && !x[n3])
{
/* Convert subsecond digits to proper precision */
int digits = n3 - n2 - 1;
if ((usec < 0) || (usec > 999999) || (digits < 1) || (digits > 6))
return 0;
while (digits++ < 6)
usec *= 10;
}
else
return 0;
tm.tm_mon--;
tm.tm_year -= 1900;
s64 ts = mktime(&tm);
if ((ts == (s64) (time_t) -1) || (ts < 0) || (ts > ((s64) 1 << 40)))
return 0;
return ts S + usec;
}
/**
* tm_format_time - convert date and time to textual representation
* @x: destination buffer of size %TM_DATETIME_BUFFER_SIZE
* @fmt: specification of resulting textual representation of the time
* @t: time
*
* This function formats the given relative time value @t to a textual
* date/time representation (dd-mm-yyyy hh:mm:ss) in real time.
*/
void
tm_format_time(char *x, struct timeformat *fmt, btime t)
{
btime dt = current_time() - t;
btime rt = current_real_time() - dt;
int v1 = !fmt->limit || (dt < fmt->limit);
if (!tm_format_real_time(x, TM_DATETIME_BUFFER_SIZE, v1 ? fmt->fmt1 : fmt->fmt2, rt))
strcpy(x, "<error>");
}
/* Replace %f in format string with usec scaled to requested precision */
static int
strfusec(char *buf, int size, const char *fmt, uint usec)
{
char *str = buf;
int parity = 0;
while (*fmt)
{
if (!size)
return 0;
if ((fmt[0] == '%') && (!parity) &&
((fmt[1] == 'f') || (fmt[1] >= '1') && (fmt[1] <= '6') && (fmt[2] == 'f')))
{
int digits = (fmt[1] == 'f') ? 6 : (fmt[1] - '0');
uint d = digits, u = usec;
/* Convert microseconds to requested precision */
while (d++ < 6)
u /= 10;
int num = bsnprintf(str, size, "%0*u", digits, u);
if (num < 0)
return 0;
fmt += (fmt[1] == 'f') ? 2 : 3;
ADVANCE(str, size, num);
}
else
{
/* Handle '%%' expression */
parity = (*fmt == '%') ? !parity : 0;
*str++ = *fmt++;
size--;
}
}
if (!size)
return 0;
*str = 0;
return str - buf;
}
int
tm_format_real_time(char *x, size_t max, const char *fmt, btime t)
{
s64 t1 = t TO_S;
s64 t2 = t - t1 S;
time_t ts = t1;
struct tm tm;
if (!localtime_r(&ts, &tm))
return 0;
byte tbuf[TM_DATETIME_BUFFER_SIZE];
if (!strfusec(tbuf, max, fmt, t2))
return 0;
if (!strftime(x, max, tbuf, &tm))
return 0;
return 1;
}