| /* Pausing execution of the current thread. |
| Copyright (C) 2009-2020 Free Software Foundation, Inc. |
| Written by Eric Blake <ebb9@byu.net>, 2009. |
| |
| This program is free software: you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
| |
| /* This file is _intentionally_ light-weight. Rather than using |
| select or nanosleep, both of which drag in external libraries on |
| some platforms, this merely rounds up to the nearest second if |
| usleep() does not exist. If sub-second resolution is important, |
| then use a more powerful interface to begin with. */ |
| |
| #include <config.h> |
| |
| /* Specification. */ |
| #include <unistd.h> |
| |
| #include <errno.h> |
| |
| #if defined _WIN32 && ! defined __CYGWIN__ |
| # define WIN32_LEAN_AND_MEAN /* avoid including junk */ |
| # include <windows.h> |
| #endif |
| |
| #ifndef HAVE_USLEEP |
| # define HAVE_USLEEP 0 |
| #endif |
| |
| /* Sleep for MICRO microseconds, which can be greater than 1 second. |
| Return -1 and set errno to EINVAL on range error (about 4295 |
| seconds), or 0 on success. Interaction with SIGALARM is |
| unspecified. */ |
| |
| int |
| usleep (useconds_t micro) |
| #undef usleep |
| { |
| #if defined _WIN32 && ! defined __CYGWIN__ |
| unsigned int milliseconds = micro / 1000; |
| if (sizeof milliseconds < sizeof micro && micro / 1000 != milliseconds) |
| { |
| errno = EINVAL; |
| return -1; |
| } |
| if (micro % 1000) |
| milliseconds++; |
| Sleep (milliseconds); |
| return 0; |
| #else |
| unsigned int seconds = micro / 1000000; |
| if (sizeof seconds < sizeof micro && micro / 1000000 != seconds) |
| { |
| errno = EINVAL; |
| return -1; |
| } |
| if (!HAVE_USLEEP && micro % 1000000) |
| seconds++; |
| while ((seconds = sleep (seconds)) != 0); |
| |
| # if !HAVE_USLEEP |
| # define usleep(x) 0 |
| # endif |
| return usleep (micro % 1000000); |
| #endif |
| } |