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Diffstat (limited to 'lib/pthread-cond.c')
| -rw-r--r-- | lib/pthread-cond.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/lib/pthread-cond.c b/lib/pthread-cond.c new file mode 100644 index 0000000..06608f3 --- /dev/null +++ b/lib/pthread-cond.c @@ -0,0 +1,199 @@ +/* POSIX condition variables. + Copyright (C) 2010-2022 Free Software Foundation, Inc. + + 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/>. */ + +/* Written by Paul Eggert, 2010, and Bruno Haible <bruno@clisp.org>, 2019. */ + +#include <config.h> + +/* Specification. */ +#include <pthread.h> + +#if (defined _WIN32 && ! defined __CYGWIN__) && USE_WINDOWS_THREADS +# include "windows-thread.h" +#else +# include <errno.h> +# include <limits.h> +# include <sys/time.h> +# include <time.h> +#endif + +#if ((defined _WIN32 && ! defined __CYGWIN__) && USE_WINDOWS_THREADS) || !HAVE_PTHREAD_H + +int +pthread_condattr_init (pthread_condattr_t *attr) +{ + *attr = 0; + return 0; +} + +int +pthread_condattr_destroy (_GL_UNUSED pthread_condattr_t *attr) +{ + return 0; +} + +#endif + +#if (defined _WIN32 && ! defined __CYGWIN__) && USE_WINDOWS_THREADS +/* Use Windows threads. */ + +int +pthread_cond_init (pthread_cond_t *cond, + _GL_UNUSED const pthread_condattr_t *attr) +{ + return glwthread_cond_init (cond); +} + +int +pthread_cond_wait (pthread_cond_t *cond, pthread_mutex_t *mutex) +{ + return glwthread_cond_wait (cond, mutex, + (int (*) (void *)) pthread_mutex_lock, + (int (*) (void *)) pthread_mutex_unlock); +} + +int +pthread_cond_timedwait (pthread_cond_t *cond, pthread_mutex_t *mutex, + const struct timespec *abstime) +{ + return glwthread_cond_timedwait (cond, mutex, + (int (*) (void *)) pthread_mutex_lock, + (int (*) (void *)) pthread_mutex_unlock, + abstime); +} + +int +pthread_cond_signal (pthread_cond_t *cond) +{ + return glwthread_cond_signal (cond); +} + +int +pthread_cond_broadcast (pthread_cond_t *cond) +{ + return glwthread_cond_broadcast (cond); +} + +int +pthread_cond_destroy (pthread_cond_t *cond) +{ + return glwthread_cond_destroy (cond); +} + +#elif HAVE_PTHREAD_H +/* Provide workarounds for POSIX threads. */ + +#else +/* Provide a dummy implementation for single-threaded applications. */ + +int +pthread_cond_init (_GL_UNUSED pthread_cond_t *cond, + _GL_UNUSED const pthread_condattr_t *attr) +{ + /* COND is never seriously used. */ + return 0; +} + +int +pthread_cond_wait (_GL_UNUSED pthread_cond_t *cond, + _GL_UNUSED pthread_mutex_t *mutex) +{ + /* No other thread can signal this condition variable. + Wait endlessly. */ + for (;;) + { + struct timespec duration; + + duration.tv_sec = 86400; + duration.tv_nsec = 0; + nanosleep (&duration, NULL); + } +} + +int +pthread_cond_timedwait (_GL_UNUSED pthread_cond_t *cond, + _GL_UNUSED pthread_mutex_t *mutex, + const struct timespec *abstime) +{ + /* No other thread can signal this condition variable. + Wait until ABSTIME is reached. */ + for (;;) + { + struct timeval currtime; + unsigned long remaining; + struct timespec duration; + + gettimeofday (&currtime, NULL); + + if (currtime.tv_sec > abstime->tv_sec) + remaining = 0; + else + { + unsigned long seconds = abstime->tv_sec - currtime.tv_sec; + remaining = seconds * 1000000000; + if (remaining / 1000000000 != seconds) /* overflow? */ + remaining = ULONG_MAX; + else + { + long nanoseconds = + abstime->tv_nsec - currtime.tv_usec * 1000; + if (nanoseconds >= 0) + { + remaining += nanoseconds; + if (remaining < nanoseconds) /* overflow? */ + remaining = ULONG_MAX; + } + else + { + if (remaining >= - nanoseconds) + remaining -= (- nanoseconds); + else + remaining = 0; + } + } + } + if (remaining == 0) + return ETIMEDOUT; + + /* Sleep up to REMAINING ns. */ + duration.tv_sec = remaining / 1000000000; + duration.tv_nsec = remaining % 1000000000; + nanosleep (&duration, NULL); + } +} + +int +pthread_cond_signal (_GL_UNUSED pthread_cond_t *cond) +{ + /* No threads can currently be blocked on COND. */ + return 0; +} + +int +pthread_cond_broadcast (_GL_UNUSED pthread_cond_t *cond) +{ + /* No threads can currently be blocked on COND. */ + return 0; +} + +int +pthread_cond_destroy (_GL_UNUSED pthread_cond_t *cond) +{ + /* COND is never seriously used. */ + return 0; +} + +#endif |