2 * Copyright 2000, International Business Machines Corporation and others.
5 * This software has been released under the terms of the IBM Public
6 * License. For details, see the LICENSE file in the top-level source
7 * directory or online at http://www.openafs.org/dl/license10.html
10 /* Elapsed time package */
11 /* See rx_clock.h for calling conventions */
14 #include "afs/param.h"
16 #include <afs/param.h>
18 #include <afsconfig.h>
21 #include <sys/time_impl.h>
29 #include "rx/rx_clock.h"
33 #include "afs/sysincludes.h"
34 #include "afsincludes.h"
36 #include "rx/rx_clock.h"
47 #if !defined(AFS_USE_GETTIMEOFDAY)
48 /*use this package only if gettimeofday is much much costlier than getitime */
52 #if defined(AFS_GFS_ENV)
53 #define STARTVALUE 8000000 /* Ultrix bounds smaller, too small for general use */
55 #define STARTVALUE 100000000 /* Max number of seconds setitimer allows, for some reason */
58 struct clock clock_now; /* The last elapsed time ready by clock_GetTimer */
60 /* This is set to 1 whenever the time is read, and reset to 0 whenever clock_NewTime is called. This is to allow the caller to control the frequency with which the actual time is re-evaluated (an expensive operation) */
61 int clock_haveCurrentTime;
63 int clock_nUpdates; /* The actual number of clock updates */
64 static int clockInitialized = 0;
66 /* Initialize the clock */
70 struct itimerval itimer, otimer;
72 if (!clockInitialized) {
73 itimer.it_value.tv_sec = STARTVALUE;
74 itimer.it_value.tv_usec = 0;
75 itimer.it_interval.tv_sec = 0;
76 itimer.it_interval.tv_usec = 0;
78 if (setitimer(ITIMER_REAL, &itimer, &otimer) != 0) {
79 fprintf(stderr, "clock: could not set interval timer; \
80 aborted(errno=%d)\n", errno);
90 /* Make clock uninitialized. */
98 /* Compute the current time. The timer gets the current total elapsed time since startup, expressed in seconds and microseconds. This call is almost 200 usec on an APC RT */
100 clock_UpdateTime(void)
102 struct itimerval itimer;
103 getitimer(ITIMER_REAL, &itimer);
104 clock_now.sec = STARTVALUE - 1 - itimer.it_value.tv_sec; /* The "-1" makes up for adding 1000000 usec, on the next line */
105 clock_now.usec = 1000000 - itimer.it_value.tv_usec;
106 if (clock_now.usec == 1000000)
107 clock_now.usec = 0, clock_now.sec++;
108 clock_haveCurrentTime = 1;
114 #endif /* AFS_USE_GETTIMEOFDAY */