From 4682deeb62247d34de87f8e777f99e2d337fd377 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=B6rg=20Frings-F=C3=BCrst?= Date: Sun, 20 Oct 2024 15:21:43 +0200 Subject: New upstream version 1.3 --- lib/glthread/once.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 lib/glthread/once.c (limited to 'lib/glthread/once.c') diff --git a/lib/glthread/once.c b/lib/glthread/once.c new file mode 100644 index 00000000..869ba3ba --- /dev/null +++ b/lib/glthread/once.c @@ -0,0 +1,80 @@ +/* Once-only initialization in multithreaded situations. + Copyright (C) 2005-2024 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 . */ + +/* Written by Bruno Haible , 2005. + Based on GCC's gthr-posix.h, gthr-posix95.h. */ + +#include + +#include "glthread/once.h" + +/* ========================================================================= */ + +#if USE_ISOC_THREADS || USE_ISOC_AND_POSIX_THREADS + +#endif + +/* ========================================================================= */ + +#if USE_POSIX_THREADS + +static const pthread_once_t fresh_once = PTHREAD_ONCE_INIT; + +int +glthread_once_singlethreaded (pthread_once_t *once_control) +{ + /* We don't know whether pthread_once_t is an integer type, a floating-point + type, a pointer type, or a structure type. */ + char *firstbyte = (char *)once_control; + if (*firstbyte == *(const char *)&fresh_once) + { + /* First time use of once_control. Invert the first byte. */ + *firstbyte = ~ *(const char *)&fresh_once; + return 1; + } + else + return 0; +} + +# if !(PTHREAD_IN_USE_DETECTION_HARD || USE_POSIX_THREADS_WEAK) + +int +glthread_once_multithreaded (pthread_once_t *once_control, + void (*init_function) (void)) +{ + int err = pthread_once (once_control, init_function); + if (err == ENOSYS) + { + /* This happens on FreeBSD 11: The pthread_once function in libc returns + ENOSYS. */ + if (glthread_once_singlethreaded (once_control)) + init_function (); + return 0; + } + return err; +} + +# endif + +#endif + +/* ========================================================================= */ + +#if USE_WINDOWS_THREADS + +#endif + +/* ========================================================================= */ -- cgit v1.2.3