minix3/net/inet/clock.c

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2020-02-21 00:59:27 +05:30
/*
clock.c
Copyright 1995 Philip Homburg
*/
#include "inet.h"
#include "proto.h"
#include "generic/assert.h"
#include "generic/buf.h"
#include "generic/clock.h"
THIS_FILE
int clck_call_expire;
static clock_t curr_time;
static clock_t prev_time;
static minix_timer_t *timer_chain;
static time_t next_timeout;
static void clck_fast_release(minix_timer_t *timer);
static void set_timer(void);
void clck_init()
{
clck_call_expire= 0;
curr_time= 0;
prev_time= 0;
next_timeout= 0;
timer_chain= 0;
}
time_t get_time()
{
if (!curr_time)
{
if (getticks(&curr_time) != OK)
ip_panic(("can't read clock"));
assert(curr_time >= prev_time);
}
return curr_time;
}
void set_time (tim)
clock_t tim;
{
if (!curr_time && tim >= prev_time)
{
/* Some code assumes that no time elapses while it is
* running.
*/
curr_time= tim;
}
else if (!curr_time)
{
DBLOCK(0x20, printf("set_time: new time %lu < prev_time %lu\n",
tim, prev_time));
}
}
void reset_time()
{
prev_time= curr_time;
curr_time= 0;
}
void clck_timer(timer, timeout, func, fd)
minix_timer_t *timer;
time_t timeout;
timer_func_t func;
int fd;
{
minix_timer_t *timer_index;
if (timer->tim_active)
clck_fast_release(timer);
assert(!timer->tim_active);
timer->tim_next= 0;
timer->tim_func= func;
timer->tim_ref= fd;
timer->tim_time= timeout;
timer->tim_active= 1;
if (!timer_chain)
timer_chain= timer;
else if (timeout < timer_chain->tim_time)
{
timer->tim_next= timer_chain;
timer_chain= timer;
}
else
{
timer_index= timer_chain;
while (timer_index->tim_next &&
timer_index->tim_next->tim_time < timeout)
timer_index= timer_index->tim_next;
timer->tim_next= timer_index->tim_next;
timer_index->tim_next= timer;
}
if (next_timeout == 0 || timer_chain->tim_time < next_timeout)
set_timer();
}
void clck_tick (mess)
message *mess;
{
next_timeout= 0;
set_timer();
}
static void clck_fast_release (timer)
minix_timer_t *timer;
{
minix_timer_t *timer_index;
if (!timer->tim_active)
return;
if (timer == timer_chain)
timer_chain= timer_chain->tim_next;
else
{
timer_index= timer_chain;
while (timer_index && timer_index->tim_next != timer)
timer_index= timer_index->tim_next;
assert(timer_index);
timer_index->tim_next= timer->tim_next;
}
timer->tim_active= 0;
}
static void set_timer()
{
time_t new_time;
time_t now;
if (!timer_chain)
return;
now= get_time();
new_time= timer_chain->tim_time;
if (new_time <= now)
{
clck_call_expire= 1;
return;
}
if (next_timeout == 0 || new_time < next_timeout)
{
next_timeout= new_time;
new_time -= now;
if (sys_setalarm(new_time, 0) != OK)
ip_panic(("can't set timer"));
}
}
void clck_untimer (timer)
minix_timer_t *timer;
{
clck_fast_release (timer);
set_timer();
}
void clck_expire_timers()
{
time_t now;
minix_timer_t *timer_index;
clck_call_expire= 0;
if (timer_chain == NULL)
return;
now= get_time();
while (timer_chain && timer_chain->tim_time<=now)
{
assert(timer_chain->tim_active);
timer_chain->tim_active= 0;
timer_index= timer_chain;
timer_chain= timer_chain->tim_next;
(*timer_index->tim_func)(timer_index->tim_ref, timer_index);
}
set_timer();
}
/*
* $PchId: clock.c,v 1.10 2005/06/28 14:23:40 philip Exp $
*/