1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28 #include <time.h>
29 #include <errno.h>
30
usleep(unsigned long usec)31 int usleep(unsigned long usec)
32 {
33 struct timespec ts;
34
35 ts.tv_sec = usec/1000000UL;
36
37 #ifdef __arm__
38 /* avoid divisions and modulos on the ARM */
39 ts.tv_nsec = (usec - ts.tv_sec*1000000UL)*1000;
40 #else
41 ts.tv_nsec = (usec % 1000000UL) * 1000UL;
42 #endif
43
44 for (;;)
45 {
46 if ( nanosleep( &ts, &ts ) == 0 )
47 return 0;
48
49 // We try again if the nanosleep failure is EINTR.
50 // The other possible failures are EINVAL (which we should pass through),
51 // and ENOSYS, which doesn't happen.
52 if ( errno != EINTR )
53 return -1;
54 }
55 }
56