NetBSD/usr.sbin/xntp/xntpd/ntp_timer.c

559 lines
14 KiB
C

/* $NetBSD: ntp_timer.c,v 1.4 1998/08/12 14:11:54 christos Exp $ */
/*
* ntp_timer.c - event timer support routines
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/time.h>
#include <signal.h>
#include <sys/signal.h>
#include "ntpd.h"
#include "ntp_stdlib.h"
/*
* These routines provide support for the event timer. The timer is
* implemented by an interrupt routine which sets a flag once every
* 2**EVENT_TIMEOUT seconds (currently 4), and a timer routine which
* is called when the mainline code gets around to seeing the flag.
* The timer routine dispatches the clock adjustment code if its time
* has come, then searches the timer queue for expiries which are
* dispatched to the transmit procedure. Finally, we call the hourly
* procedure to do cleanup and print a message.
*/
/*
* Alarm flag. The mainline code imports this.
*/
volatile int alarm_flag;
/*
* adjust and hourly counters
*/
static u_long adjust_timer;
static u_long hourly_timer;
/*
* Imported from the leap module. The leap timer.
*/
extern u_long leap_timer;
/*
* Statistics counter for the interested.
*/
volatile u_long alarm_overflow;
#define HOUR (60*60)
/*
* Current_time holds the number of seconds since we started, in
* increments of 2**EVENT_TIMEOUT seconds. The timer queue is the
* hash into which we sort timer entries.
*/
u_long current_time;
struct event timerqueue[TIMER_NSLOTS];
/*
* Stats. Number of overflows and number of calls to transmit().
*/
u_long timer_timereset;
u_long timer_overflows;
u_long timer_xmtcalls;
#ifndef SYS_WINNT
static RETSIGTYPE alarming P((int));
#else
void PASCAL alarming P((UINT,UINT,DWORD,DWORD,DWORD));
#endif /* SYS_WINNT */
#if defined(VMS)
static int vmstimer[2]; /* time for next timer AST */
static int vmsinc[2]; /* timer increment */
#endif /* VMS */
/*
* init_timer - initialize the timer data structures
*/
void
init_timer()
{
register int i;
#if !defined(VMS)
# ifndef SYS_WINNT
#ifndef HAVE_TIMER_SETTIME
struct itimerval itimer;
#else
static timer_t xntpd_timerid; /* should be global if we ever want to kill
timer without rebooting ... */
struct itimerspec itimer;
#endif
# else /* SYS_WINNT */
TIMECAPS tc;
HANDLE hToken;
TOKEN_PRIVILEGES tkp;
UINT wTimerRes, wTimerID;
extern HANDLE hMutex;
# endif /* SYS_WINNT */
#endif /* VMS */
/*
* Initialize...
*/
alarm_flag = 0;
alarm_overflow = 0;
adjust_timer = 1;
hourly_timer = HOUR;
current_time = 0;
timer_overflows = 0;
timer_xmtcalls = 0;
timer_timereset = 0;
for (i = 0; i < TIMER_NSLOTS; i++) {
/*
* Queue pointers should point at themselves. Event
* times must be set to 0 since this is used to
* detect the queue end.
*/
timerqueue[i].next = &timerqueue[i];
timerqueue[i].prev = &timerqueue[i];
timerqueue[i].event_time = 0;
}
#ifndef SYS_WINNT
/*
* Set up the alarm interrupt. The first comes 2**EVENT_TIMEOUT
* seconds from now and they continue on every 2**EVENT_TIMEOUT
* seconds.
*/
# if !defined(VMS)
#if defined(HAVE_TIMER_CREATE) && defined(HAVE_TIMER_SETTIME)
if (timer_create (CLOCK_REALTIME, NULL, &xntpd_timerid) ==
#ifdef SYS_VXWORKS
ERROR
#else
-1
#endif
)
{
fprintf (stderr, "timer create FAILED\n");
exit (0);
}
(void) signal_no_reset(SIGALRM, alarming);
itimer.it_interval.tv_sec = itimer.it_value.tv_sec = (1<<EVENT_TIMEOUT);
itimer.it_interval.tv_nsec = itimer.it_value.tv_nsec = 0;
timer_settime(xntpd_timerid, 0 /*!TIMER_ABSTIME*/, &itimer, NULL);
#else
(void) signal_no_reset(SIGALRM, alarming);
itimer.it_interval.tv_sec = itimer.it_value.tv_sec = (1<<EVENT_TIMEOUT);
itimer.it_interval.tv_usec = itimer.it_value.tv_usec = 0;
setitimer(ITIMER_REAL, &itimer, (struct itimerval *)0);
#endif
# else /* VMS */
vmsinc[0] = 10000000; /* 1 sec */
vmsinc[1] = 0;
lib$emul(&(1<<EVENT_TIMEOUT), &vmsinc, &0, &vmsinc);
sys$gettim(&vmstimer); /* that's "now" as abstime */
lib$addx(&vmsinc, &vmstimer, &vmstimer);
sys$setimr(0, &vmstimer, alarming, alarming, 0);
# endif /* VMS */
#else /* SYS_WINNT */
_tzset();
/*
* Get privileges needed for fiddling with the clock
*/
/* get the current process token handle */
if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, &hToken)) {
msyslog(LOG_ERR, "OpenProcessToken failed: %m");
exit(1);
}
/* get the LUID for system-time privilege. */
LookupPrivilegeValue(NULL, SE_SYSTEMTIME_NAME, &tkp.Privileges[0].Luid);
tkp.PrivilegeCount = 1; /* one privilege to set */
tkp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
/* get set-time privilege for this process. */
AdjustTokenPrivileges(hToken, FALSE, &tkp, 0, (PTOKEN_PRIVILEGES) NULL, 0);
/* cannot test return value of AdjustTokenPrivileges. */
if (GetLastError() != ERROR_SUCCESS)
msyslog(LOG_ERR, "AdjustTokenPrivileges failed: %m");
/*
* Set up timer interrupts for every 2**EVENT_TIMEOUT seconds
* Under Windows/NT, expiry of timer interval leads to invocation
* of a callback function (on a different thread) rather than
* generating an alarm signal
*/
/* determine max and min resolution supported */
if(timeGetDevCaps(&tc, sizeof(TIMECAPS)) != TIMERR_NOERROR) {
msyslog(LOG_ERR, "timeGetDevCaps failed: %m");
exit(1);
}
wTimerRes = min(max(tc.wPeriodMin, TARGET_RESOLUTION), tc.wPeriodMax);
/* establish the minimum timer resolution that we'll use */
timeBeginPeriod(wTimerRes);
hMutex = CreateMutex(
NULL, /* no security attributes */
FALSE, /* initially not owned */
"MutexForNTP"); /* name of mutex */
if (hMutex == NULL) {
msyslog(LOG_ERR, "cannot create a mutex: %m\n");
exit(1);
}
/* start the timer event */
wTimerID = timeSetEvent(
(1<<EVENT_TIMEOUT) * 1000, /* Delay in ms */
wTimerRes, /* Resolution */
(LPTIMECALLBACK) alarming, /* Callback function */
(DWORD) 0, /* User data */
TIME_PERIODIC); /* Event type (periodic) */
if (wTimerID == 0) {
msyslog(LOG_ERR, "timeSetEvent failed: %m");
exit(1);
}
#endif /* SYS_WINNT */
}
#ifdef TIMERQUEUE_DEBUG
/* Timer queue sanity checking routines */
static void EV_ASSERT(struct event *ev, char *m)
{
if ( ! ev )
{ msyslog(LOG_ERR, "%s is NULL, aborting!",m); abort(); }
}
static void EV_LINKCHK(struct event *ev, char *m)
{
if ( ! ev )
{ msyslog(LOG_ERR, "%s is NULL, aborting!",m); abort(); }
if ( ! ev->next )
{ msyslog(LOG_ERR, "%s->next is NULL, aborting!",m); abort(); }
if ( ! ev->prev )
{ msyslog(LOG_ERR, "%s->prev is NULL, aborting!",m); abort(); }
if ( ev->next->prev != ev )
{ msyslog(LOG_ERR, "%s->next->prev != self, aborting!",m); abort(); }
if ( ev->prev->next != ev )
{ msyslog(LOG_ERR, "%s->prev->next != self, aborting!",m); abort(); }
}
#else /* TIMERQUEUE_DEBUG */
# define EV_ASSERT() {}
# define EV_LINKCHK() {}
#endif /* TIMERQUEUE_DEBUG */
/*
* timer - dispatch anyone who needs to be
*/
void
timer()
{
register struct event *ev;
register struct event *tq;
#ifdef SYS_WINNT
extern HANDLE hMutex;
#endif
current_time += (1<<EVENT_TIMEOUT);
/*
* Adjustment timeout first
*/
if (adjust_timer <= current_time) {
adjust_timer += 1;
adj_host_clock();
}
#ifdef SYS_WINNT
if (!ReleaseMutex(hMutex)) {
msyslog(LOG_ERR, "alarming cannot release mutex: %m\n");
exit(1);
}
#endif /* SYS_WINNT */
/*
* Leap timer next.
*/
if (leap_timer != 0 && leap_timer <= current_time)
leap_process();
/*
* Now dispatch any peers whose event timer has expired.
*/
/* Added mutex to prevent race condition among threads under Windows NT */
#ifdef SYS_WINNT
WaitForSingleObject(m_hListMutex,INFINITE);
#endif /* SYS_WINNT */
#ifdef TIMERQUEUE_DEBUG
{
int i;
int j;
for (i = 0; i < TIMER_NSLOTS; ++i)
{
struct event *qh;
qh = ev = &timerqueue[i];
if (qh->event_time != 0) {
msyslog(LOG_ERR, "timerqueue[%d].event_time is %d instead of 0!",
i, timerqueue[i].event_time);
abort();
}
j = 0;
do
{
if (ev->prev->next != ev) {
msyslog(LOG_ERR, "timerqueue[%d]: #%d: ev->prev->next != ev",
i, j);
abort();
}
if (ev->next->prev != ev) {
msyslog(LOG_ERR, "timerqueue[%d]: #%d: ev->next->prev != ev",
i, j);
abort();
}
++j;
ev = ev->next;
}
while (qh != ev);
}
}
#endif /* TIMERQUEUE_DEBUG */
tq = &timerqueue[TIMER_SLOT(current_time)];
if (tq) {
ev = tq->next;
while (ev
&& ev->event_time != 0
&& ev->event_time < (current_time + (1<<EVENT_TIMEOUT))) {
tq->next = ev->next;
tq->next->prev = tq;
ev->prev = ev->next = 0;
timer_xmtcalls++;
ev->event_handler(ev->peer);
ev = tq->next;
}
if (!ev) {
msyslog(LOG_ERR, "timer: ev was NIL!");
abort();
}
} else {
msyslog(LOG_ERR, "timer: tq was NIL!");
abort();
}
/* Added mutex to prevent race condition among threads under Windows NT */
#ifdef SYS_WINNT
ReleaseMutex(m_hListMutex);
#endif /* SYS_WINNT */
/*
* Finally, call the hourly routine
*/
if (hourly_timer <= current_time) {
hourly_timer += HOUR;
hourly_stats();
}
}
#ifndef SYS_WINNT
/*
* alarming - tell the world we've been alarmed
*/
static RETSIGTYPE
alarming(sig)
int sig;
{
extern int initializing; /* from main line code */
#if !defined(VMS)
if (initializing)
return;
if (alarm_flag)
alarm_overflow++;
else
alarm_flag++;
#else /* VMS AST routine */
if (!initializing) {
if (alarm_flag) alarm_overflow++;
else alarm_flag = 1; /* increment is no good */
}
lib$addx(&vmsinc,&vmstimer,&vmstimer);
sys$setimr(0,&vmstimer,alarming,alarming,0);
#endif /* VMS */
}
#else /* SYS_WINNT */
/*
* alarming for WinNT - invoke the timer() routine after grabbing the mutex
*/
void PASCAL alarming (UINT wTimerID, UINT msg,
DWORD dwUser, DWORD dw1, DWORD dw2)
{
extern int debug;
static int initializing2 = 1;
extern HANDLE hMutex;
DWORD dwWaitResult;
extern HANDLE TimerThreadHandle;
static DWORD threadID;
#ifdef DEBUG
SYSTEMTIME st;
#endif
/*
* set the priority for timer() thread to be higher than the main thread
*/
if (initializing2) {
TimerThreadHandle = GetCurrentThread();
if (!SetThreadPriority(TimerThreadHandle, (DWORD) THREAD_PRIORITY_HIGHEST))
msyslog(LOG_ERR, "SetThreadPriority failed: %m");
threadID = GetCurrentThreadId();
initializing2 = 0;
}
#ifdef DEBUG
if (debug > 9) {
GetSystemTime(&st);
printf("thread %u (timer callback): time %02u:%02u:%02u:%03u\n",
threadID, st.wHour, st.wMinute, st.wSecond, st.wMilliseconds);
fflush(stdout);
}
#endif
dwWaitResult = WaitForSingleObject(
hMutex, /* handle of mutex */
5000L); /* five-second time-out interval */
switch (dwWaitResult) {
case WAIT_OBJECT_0:
/* The thread got mutex ownership. */
/* the mutex is released in the timer() routine */
timer();
break;
default:
/* Cannot get mutex ownership due to time-out. */
msyslog(LOG_ERR, "alarming error with mutex: %m\n");
exit(1);
}
UNREFERENCED_PARAMETER(dw1);
UNREFERENCED_PARAMETER(dw2);
UNREFERENCED_PARAMETER(dwUser);
UNREFERENCED_PARAMETER(msg);
UNREFERENCED_PARAMETER(wTimerID);
}
#endif /* SYS_WINNT */
/*
* timer_clr_stats - clear timer module stat counters
*/
void
timer_clr_stats()
{
timer_overflows = 0;
timer_xmtcalls = 0;
timer_timereset = current_time;
}
#ifdef TIMERQUEUE_DEBUG
/* macro versions of these routines are available in include/ntp.h */
# ifdef SYS_WINNT /* WindowsNT apparently needs mutex locking around here */
# define WINNT_WAIT() WaitForSingleObject(m_hListMutex,INFINITE)
# define WINNT_RELS() ReleaseMutex(m_hListMutex)
# else
# define WINNT_WAIT() {}
# define WINNT_RELS() {}
# endif
/*
* TIMER_ENQUEUE() puts stuff on the timer queue. It takes as
* arguments (ea), an array of event slots, and (iev), the event
* to be inserted. This one searches the hash bucket from the
* end, and is about optimum for the timing requirements of
* NTP peers.
*/
void TIMER_ENQUEUE(struct event *ea, struct event *iev)
{
register struct event *ev;
EV_LINKCHK( ea, "TIMER_ENQUEUE(): ea" );
EV_ASSERT( iev, "TIMER_ENQUEUE(): iev" );
WINNT_WAIT();
ev = (ea)[TIMER_SLOT((iev)->event_time)].prev;
EV_LINKCHK( ev, "TIMER_ENQUEUE(): ev" );
while (ev->event_time > (iev)->event_time) {
ev = ev->prev;
EV_LINKCHK( ev, "TIMER_ENQUEUE(): ev" );
}
(iev)->prev = ev;
(iev)->next = ev->next;
(ev)->next->prev = (iev);
(ev)->next = (iev);
WINNT_RELS();
}
/*
* TIMER_INSERT() also puts stuff on the timer queue, but searches the
* bucket from the top. This is better for things that do very short
* time outs, like clock support.
*/
void TIMER_INSERT(struct event *ea, struct event *iev)
{
register struct event *ev;
EV_LINKCHK( ea, "TIMER_INSERT(): ea" );
EV_ASSERT( iev, "TIMER_INSERT(): iev" );
WINNT_WAIT();
ev = (ea)[TIMER_SLOT((iev)->event_time)].next;
EV_LINKCHK( ev, "TIMER_INSERT(): ev" );
while (ev->event_time != 0 &&
ev->event_time < (iev)->event_time) {
ev = ev->next;
EV_LINKCHK( ev, "TIMER_INSERT(): ev" );
}
(iev)->next = ev;
(iev)->prev = ev->prev;
(ev)->prev->next = (iev);
(ev)->prev = (iev);
WINNT_RELS();
}
/*
* Remove an event from the queue.
*/
void TIMER_DEQUEUE(struct event *ev)
{
EV_ASSERT( ev, "TIMER_DEQUEUE(): ev" );
WINNT_WAIT();
if ((ev)->next != 0) {
EV_LINKCHK( ev, "TIMER_DEQUEUE(): ev" );
(ev)->next->prev = (ev)->prev;
(ev)->prev->next = (ev)->next;
(ev)->next = (ev)->prev = 0;
}
WINNT_RELS();
}
#endif /* TIMERQUEUE_DEBUG */