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comparison lisp/oobr/tree-x/usleep.c @ 0:376386a54a3c r19-14

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Import from CVS: tag r19-14
author cvs
date Mon, 13 Aug 2007 08:45:50 +0200
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-1:000000000000 0:376386a54a3c
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