diff options
Diffstat (limited to 'nptl')
-rw-r--r-- | nptl/Makefile | 2 | ||||
-rw-r--r-- | nptl/Versions | 1 | ||||
-rw-r--r-- | nptl/call_once.c | 31 | ||||
-rw-r--r-- | nptl/threads.h | 11 |
4 files changed, 44 insertions, 1 deletions
diff --git a/nptl/Makefile b/nptl/Makefile index 4b889ab04e..d55d24b09a 100644 --- a/nptl/Makefile +++ b/nptl/Makefile @@ -143,7 +143,7 @@ libpthread-routines = nptl-init nptlfreeres vars events version pt-interp \ pthread_setattr_default_np pthread_getattr_default_np \ thrd_create thrd_detach thrd_exit thrd_join \ mtx_destroy mtx_init mtx_lock mtx_timedlock \ - mtx_trylock mtx_unlock + mtx_trylock mtx_unlock call_once # pthread_setuid pthread_seteuid pthread_setreuid \ # pthread_setresuid \ # pthread_setgid pthread_setegid pthread_setregid \ diff --git a/nptl/Versions b/nptl/Versions index ca1be37354..0fdba18c74 100644 --- a/nptl/Versions +++ b/nptl/Versions @@ -273,6 +273,7 @@ libpthread { GLIBC_2.28 { thrd_create; thrd_detach; thrd_exit; thrd_join; mtx_init; mtx_lock; mtx_timedlock; mtx_trylock; mtx_unlock; mtx_destroy; + call_once; } GLIBC_PRIVATE { diff --git a/nptl/call_once.c b/nptl/call_once.c new file mode 100644 index 0000000000..5bc88cbbed --- /dev/null +++ b/nptl/call_once.c @@ -0,0 +1,31 @@ +/* C11 threads call once implementation. + Copyright (C) 2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library 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. + + The GNU C Library 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 the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <stdalign.h> + +#include "thrd_priv.h" + +void +call_once (once_flag *flag, void (*func)(void)) +{ + _Static_assert (sizeof (once_flag) == sizeof (pthread_once_t), + "sizeof (once_flag) != sizeof (pthread_once_t)"); + _Static_assert (alignof (once_flag) == alignof (pthread_once_t), + "alignof (once_flag) != alignof (pthread_once_t)"); + __pthread_once (&flag->__data, func); +} diff --git a/nptl/threads.h b/nptl/threads.h index 13d0075ea9..32f7cf8f75 100644 --- a/nptl/threads.h +++ b/nptl/threads.h @@ -48,6 +48,12 @@ enum mtx_timed = 2 }; +typedef struct +{ + int __data __ONCE_ALIGNMENT; +} once_flag; +#define ONCE_FLAG_INIT { 0 } + typedef union { char __size[__SIZEOF_PTHREAD_MUTEX_T]; @@ -129,6 +135,11 @@ extern int mtx_unlock (mtx_t *__mutex); /* Destroy the mutex object pointed by __MUTEX. */ extern void mtx_destroy (mtx_t *__mutex); + +/* Call function __FUNC exactly once, even if invoked from several threads. + All calls must be made with the same __FLAGS object. */ +extern void call_once (once_flag *__flag, void (*__func)(void)); + __END_DECLS #endif /* _THREADS_H */ |