|
163
|
1 /*
|
|
|
2 * NAME:
|
|
|
3 * usleep -- This is the precision timer for Test Set
|
|
|
4 * Automation. It uses the select(2) system
|
|
|
5 * call to delay for the desired number of
|
|
|
6 * micro-seconds. This call returns ZERO
|
|
|
7 * (which is usually ignored) on successful
|
|
|
8 * completion, -1 otherwise.
|
|
|
9 *
|
|
|
10 * ALGORITHM:
|
|
|
11 * 1) We range check the passed in microseconds and log a
|
|
|
12 * warning message if appropriate. We then return without
|
|
|
13 * delay, flagging an error.
|
|
|
14 * 2) Load the Seconds and micro-seconds portion of the
|
|
|
15 * interval timer structure.
|
|
|
16 * 3) Call select(2) with no file descriptors set, just the
|
|
|
17 * timer, this results in either delaying the proper
|
|
|
18 * ammount of time or being interupted early by a signal.
|
|
|
19 *
|
|
|
20 * HISTORY:
|
|
|
21 * Added when the need for a subsecond timer was evident.
|
|
|
22 *
|
|
|
23 * AUTHOR:
|
|
|
24 * Michael J. Dyer <mike@sherlock.med.ge.com>
|
|
|
25 */
|
|
|
26
|
|
|
27 #ifndef HAVE_USLEEP
|
|
|
28 #include <unistd.h>
|
|
|
29 #include <stdlib.h>
|
|
|
30 #include <stdio.h>
|
|
|
31 #include <errno.h>
|
|
|
32 #include <time.h>
|
|
|
33 #include <sys/time.h>
|
|
|
34 #include <sys/param.h>
|
|
|
35 #include <sys/types.h>
|
|
|
36
|
|
|
37 int usleep( unsigned long int microSeconds )
|
|
|
38 {
|
|
|
39 unsigned int Seconds, uSec;
|
|
|
40 int nfds, readfds, writefds, exceptfds;
|
|
|
41 struct timeval Timer;
|
|
|
42
|
|
|
43 nfds = readfds = writefds = exceptfds = 0;
|
|
|
44
|
|
|
45 if( (microSeconds == (unsigned long) 0)
|
|
|
46 || microSeconds > (unsigned long) 4000000 )
|
|
|
47 {
|
|
|
48 errno = ERANGE; /* value out of range */
|
|
|
49 perror( "usleep time out of range ( 0 -> 4000000 ) " );
|
|
|
50 return -1;
|
|
|
51 }
|
|
|
52
|
|
|
53 Seconds = microSeconds / (unsigned long) 1000000;
|
|
|
54 uSec = microSeconds % (unsigned long) 1000000;
|
|
|
55
|
|
|
56 Timer.tv_sec = Seconds;
|
|
|
57 Timer.tv_usec = uSec;
|
|
|
58
|
|
|
59 if( select( nfds, &readfds, &writefds, &exceptfds, &Timer ) < 0 )
|
|
|
60 {
|
|
|
61 perror( "usleep (select) failed" );
|
|
|
62 return -1;
|
|
|
63 }
|
|
|
64
|
|
|
65 return 0;
|
|
|
66 }
|
|
|
67 #else
|
|
|
68 /* this is to avoid a "object file has no symbol" error/warning.
|
|
|
69 */
|
|
|
70 static int local_junk;
|
|
|
71 #endif
|
