rm_/lib/mbtowc-lock.h
2020-09-02 16:47:03 +08:00

116 lines
3.0 KiB
C

/* Use the internal lock used by mbrtowc and mbrtoc32.
Copyright (C) 2019-2020 Free Software Foundation, Inc.
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/>. */
/* Written by Bruno Haible <bruno@clisp.org>, 2019-2020. */
/* Use a lock, so that no two threads can invoke mbtowc at the same time. */
static inline int
mbtowc_unlocked (wchar_t *pwc, const char *p, size_t m)
{
/* Put the hidden internal state of mbtowc into its initial state.
This is needed at least with glibc, uClibc, and MSVC CRT.
See <https://sourceware.org/bugzilla/show_bug.cgi?id=9674>. */
mbtowc (NULL, NULL, 0);
return mbtowc (pwc, p, m);
}
/* Prohibit renaming this symbol. */
#undef gl_get_mbtowc_lock
#if defined _WIN32 && !defined __CYGWIN__
extern __declspec(dllimport) CRITICAL_SECTION *gl_get_mbtowc_lock (void);
static int
mbtowc_with_lock (wchar_t *pwc, const char *p, size_t m)
{
CRITICAL_SECTION *lock = gl_get_mbtowc_lock ();
int ret;
EnterCriticalSection (lock);
ret = mbtowc_unlocked (pwc, p, m);
LeaveCriticalSection (lock);
return ret;
}
#elif HAVE_PTHREAD_API /* AIX, IRIX, Cygwin */
extern
# if defined _WIN32 || defined __CYGWIN__
__declspec(dllimport)
# endif
pthread_mutex_t *gl_get_mbtowc_lock (void);
# if HAVE_WEAK_SYMBOLS /* IRIX */
/* Avoid the need to link with '-lpthread'. */
# pragma weak pthread_mutex_lock
# pragma weak pthread_mutex_unlock
/* Determine whether libpthread is in use. */
# pragma weak pthread_mutexattr_gettype
/* See the comments in lock.h. */
# define pthread_in_use() \
(pthread_mutexattr_gettype != NULL || c11_threads_in_use ())
# else
# define pthread_in_use() 1
# endif
static int
mbtowc_with_lock (wchar_t *pwc, const char *p, size_t m)
{
if (pthread_in_use())
{
pthread_mutex_t *lock = gl_get_mbtowc_lock ();
int ret;
if (pthread_mutex_lock (lock))
abort ();
ret = mbtowc_unlocked (pwc, p, m);
if (pthread_mutex_unlock (lock))
abort ();
return ret;
}
else
return mbtowc_unlocked (pwc, p, m);
}
#elif HAVE_THREADS_H
extern mtx_t *gl_get_mbtowc_lock (void);
static int
mbtowc_with_lock (wchar_t *pwc, const char *p, size_t m)
{
mtx_t *lock = gl_get_mbtowc_lock ();
int ret;
if (mtx_lock (lock) != thrd_success)
abort ();
ret = mbtowc_unlocked (pwc, p, m);
if (mtx_unlock (lock) != thrd_success)
abort ();
return ret;
}
#endif