xref: /minix3/minix/lib/libc/sys/adjtime.c (revision 433d6423c39e34ec4b79c950597bb2d236f886be)
1*433d6423SLionel Sambuc #include <sys/cdefs.h>
2*433d6423SLionel Sambuc #include <lib.h>
3*433d6423SLionel Sambuc #include "namespace.h"
4*433d6423SLionel Sambuc 
5*433d6423SLionel Sambuc #include <string.h>
6*433d6423SLionel Sambuc #include <sys/time.h>
7*433d6423SLionel Sambuc #include <time.h>
8*433d6423SLionel Sambuc 
9*433d6423SLionel Sambuc #ifdef __weak_alias
10*433d6423SLionel Sambuc __weak_alias(adjtime, __adjtime50);
11*433d6423SLionel Sambuc #endif
12*433d6423SLionel Sambuc 
adjtime(const struct timeval * delta,struct timeval * olddelta)13*433d6423SLionel Sambuc int adjtime(const struct timeval *delta, struct timeval *olddelta)
14*433d6423SLionel Sambuc {
15*433d6423SLionel Sambuc   message m;
16*433d6423SLionel Sambuc 
17*433d6423SLionel Sambuc   memset(&m, 0, sizeof(m));
18*433d6423SLionel Sambuc   m.m_lc_pm_time.clk_id = CLOCK_REALTIME;
19*433d6423SLionel Sambuc   m.m_lc_pm_time.now = 0; /* use adjtime() method to slowly adjust the clock. */
20*433d6423SLionel Sambuc   m.m_lc_pm_time.sec = delta->tv_sec;
21*433d6423SLionel Sambuc   m.m_lc_pm_time.nsec = delta->tv_usec * 1000; /* convert usec to nsec */
22*433d6423SLionel Sambuc 
23*433d6423SLionel Sambuc   if (_syscall(PM_PROC_NR, PM_CLOCK_SETTIME, &m) < 0)
24*433d6423SLionel Sambuc   	return -1;
25*433d6423SLionel Sambuc 
26*433d6423SLionel Sambuc   if (olddelta != NULL) {
27*433d6423SLionel Sambuc 	/* the kernel returns immediately and the adjustment happens in the
28*433d6423SLionel Sambuc 	 * background. Also, any currently running adjustment is stopped by
29*433d6423SLionel Sambuc 	 * another call to adjtime(2), so the only values possible on Minix
30*433d6423SLionel Sambuc 	 * for olddelta are those of delta.
31*433d6423SLionel Sambuc 	 */
32*433d6423SLionel Sambuc 	olddelta->tv_sec = delta->tv_sec;
33*433d6423SLionel Sambuc 	olddelta->tv_usec = delta->tv_usec;
34*433d6423SLionel Sambuc   }
35*433d6423SLionel Sambuc 
36*433d6423SLionel Sambuc   return 0;
37*433d6423SLionel Sambuc }
38*433d6423SLionel Sambuc 
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