• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // -*- C++ -*-
2 //===----------------------------------------------------------------------===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #ifndef _LIBCPP_SUPPORT_IBM_NANOSLEEP_H
11 #define _LIBCPP_SUPPORT_IBM_NANOSLEEP_H
12 
13 #include <unistd.h>
14 
nanosleep(const struct timespec * req,struct timespec * rem)15 inline int nanosleep(const struct timespec* req, struct timespec* rem)
16 {
17    // The nanosleep() function is not available on z/OS. Therefore, we will call
18    // sleep() to sleep for whole seconds and usleep() to sleep for any remaining
19    // fraction of a second. Any remaining nanoseconds will round up to the next
20    // microsecond.
21 
22    useconds_t __micro_sec = (rem->tv_nsec + 999) / 1000;
23    if (__micro_sec > 999999)
24    {
25      ++rem->tv_sec;
26      __micro_sec -= 1000000;
27    }
28    while (rem->tv_sec)
29       rem->tv_sec = sleep(rem->tv_sec);
30    if (__micro_sec) {
31      rem->tv_nsec = __micro_sec * 1000;
32      return usleep(__micro_sec);
33    }
34    rem->tv_nsec = 0;
35    return 0;
36 }
37 
38 #endif // _LIBCPP_SUPPORT_IBM_NANOSLEEP_H
39