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Diffstat (limited to 'gnulib-tests/usleep.c')
-rw-r--r-- | gnulib-tests/usleep.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/gnulib-tests/usleep.c b/gnulib-tests/usleep.c new file mode 100644 index 0000000..08a2251 --- /dev/null +++ b/gnulib-tests/usleep.c @@ -0,0 +1,76 @@ +/* Pausing execution of the current thread. + Copyright (C) 2009-2023 Free Software Foundation, Inc. + Written by Eric Blake <ebb9@byu.net>, 2009. + + This file is free software: you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + This file 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 Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser 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 +} |