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Diffstat (limited to 'lib/pthread-mutex.c')
| -rw-r--r-- | lib/pthread-mutex.c | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/lib/pthread-mutex.c b/lib/pthread-mutex.c new file mode 100644 index 0000000..5af75b5 --- /dev/null +++ b/lib/pthread-mutex.c @@ -0,0 +1,258 @@ +/* POSIX mutexes (locks). + 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-timedmutex.h" +# include "windows-timedrecmutex.h" +#else +# include <stdlib.h> +#endif + +#if ((defined _WIN32 && ! defined __CYGWIN__) && USE_WINDOWS_THREADS) || !HAVE_PTHREAD_H + +int +pthread_mutexattr_init (pthread_mutexattr_t *attr) +{ + *attr = (PTHREAD_MUTEX_STALLED << 2) | PTHREAD_MUTEX_DEFAULT; + return 0; +} + +int +pthread_mutexattr_gettype (const pthread_mutexattr_t *attr, int *typep) +{ + *typep = *attr & (PTHREAD_MUTEX_DEFAULT | PTHREAD_MUTEX_NORMAL + | PTHREAD_MUTEX_ERRORCHECK | PTHREAD_MUTEX_RECURSIVE); + return 0; +} + +int +pthread_mutexattr_settype (pthread_mutexattr_t *attr, int type) +{ + if (!(type == PTHREAD_MUTEX_DEFAULT + || type == PTHREAD_MUTEX_NORMAL + || type == PTHREAD_MUTEX_ERRORCHECK + || type == PTHREAD_MUTEX_RECURSIVE)) + return EINVAL; + *attr ^= (*attr ^ type) + & (PTHREAD_MUTEX_DEFAULT | PTHREAD_MUTEX_NORMAL + | PTHREAD_MUTEX_ERRORCHECK | PTHREAD_MUTEX_RECURSIVE); + return 0; +} + +int +pthread_mutexattr_getrobust (const pthread_mutexattr_t *attr, int *robustp) +{ + *robustp = (*attr >> 2) & (PTHREAD_MUTEX_STALLED | PTHREAD_MUTEX_ROBUST); + return 0; +} + +int +pthread_mutexattr_setrobust (pthread_mutexattr_t *attr, int robust) +{ + if (!(robust == PTHREAD_MUTEX_STALLED || robust == PTHREAD_MUTEX_ROBUST)) + return EINVAL; + *attr ^= (*attr ^ (robust << 2)) + & ((PTHREAD_MUTEX_STALLED | PTHREAD_MUTEX_ROBUST) << 2); + return 0; +} + +int +pthread_mutexattr_destroy (_GL_UNUSED pthread_mutexattr_t *attr) +{ + return 0; +} + +#elif PTHREAD_MUTEXATTR_ROBUST_UNIMPLEMENTED + +int +pthread_mutexattr_getrobust (const pthread_mutexattr_t *attr, int *robustp) +{ + *robustp = PTHREAD_MUTEX_STALLED; + return 0; +} + +int +pthread_mutexattr_setrobust (pthread_mutexattr_t *attr, int robust) +{ + if (!(robust == PTHREAD_MUTEX_STALLED || robust == PTHREAD_MUTEX_ROBUST)) + return EINVAL; + if (!(robust == PTHREAD_MUTEX_STALLED)) + return ENOTSUP; + return 0; +} + +#endif + +#if (defined _WIN32 && ! defined __CYGWIN__) && USE_WINDOWS_THREADS +/* Use Windows threads. */ + +int +pthread_mutex_init (pthread_mutex_t *mutex, const pthread_mutexattr_t *attr) +{ + /* This implementation does not support PTHREAD_MUTEX_ERRORCHECK + and ignores the 'robust' attribute. */ + if (attr != NULL + && (*attr & (PTHREAD_MUTEX_DEFAULT | PTHREAD_MUTEX_NORMAL + | PTHREAD_MUTEX_ERRORCHECK | PTHREAD_MUTEX_RECURSIVE)) + == PTHREAD_MUTEX_RECURSIVE) + { + mutex->type = 2; + return glwthread_timedrecmutex_init (&mutex->u.u_timedrecmutex); + } + else + { + mutex->type = 1; + return glwthread_timedmutex_init (&mutex->u.u_timedmutex); + } +} + +int +pthread_mutex_lock (pthread_mutex_t *mutex) +{ + switch (mutex->type) + { + case 1: + return glwthread_timedmutex_lock (&mutex->u.u_timedmutex); + case 2: + return glwthread_timedrecmutex_lock (&mutex->u.u_timedrecmutex); + default: + abort (); + } +} + +int +pthread_mutex_trylock (pthread_mutex_t *mutex) +{ + switch (mutex->type) + { + case 1: + return glwthread_timedmutex_trylock (&mutex->u.u_timedmutex); + case 2: + return glwthread_timedrecmutex_trylock (&mutex->u.u_timedrecmutex); + default: + abort (); + } +} + +int +pthread_mutex_timedlock (pthread_mutex_t *mutex, const struct timespec *abstime) +{ + switch (mutex->type) + { + case 1: + return glwthread_timedmutex_timedlock (&mutex->u.u_timedmutex, abstime); + case 2: + return glwthread_timedrecmutex_timedlock (&mutex->u.u_timedrecmutex, + abstime); + default: + abort (); + } +} + +int +pthread_mutex_unlock (pthread_mutex_t *mutex) +{ + switch (mutex->type) + { + case 1: + return glwthread_timedmutex_unlock (&mutex->u.u_timedmutex); + case 2: + return glwthread_timedrecmutex_unlock (&mutex->u.u_timedrecmutex); + default: + abort (); + } +} + +int +pthread_mutex_destroy (pthread_mutex_t *mutex) +{ + switch (mutex->type) + { + case 1: + return glwthread_timedmutex_destroy (&mutex->u.u_timedmutex); + case 2: + return glwthread_timedrecmutex_destroy (&mutex->u.u_timedrecmutex); + default: + abort (); + } +} + +#elif HAVE_PTHREAD_H +/* Provide workarounds for POSIX threads. */ + +/* pthread_mutex_timedlock is defined by the 'pthread_mutex_timedlock' + module. */ + +#else +/* Provide a dummy implementation for single-threaded applications. */ + +int +pthread_mutex_init (_GL_UNUSED pthread_mutex_t *mutex, + _GL_UNUSED const pthread_mutexattr_t *attr) +{ + /* MUTEX is never seriously used. */ + return 0; +} + +int +pthread_mutex_lock (_GL_UNUSED pthread_mutex_t *mutex) +{ + /* There is only one thread, so it always gets the lock. This + implementation does not support PTHREAD_MUTEX_ERRORCHECK. */ + return 0; +} + +int +pthread_mutex_trylock (_GL_UNUSED pthread_mutex_t *mutex) +{ + /* There is only one thread, so it always gets the lock. This + implementation does not support PTHREAD_MUTEX_ERRORCHECK. */ + return 0; +} + +int +pthread_mutex_timedlock (_GL_UNUSED pthread_mutex_t *mutex, + _GL_UNUSED const struct timespec *abstime) +{ + /* There is only one thread, so it always gets the lock. This + implementation does not support PTHREAD_MUTEX_ERRORCHECK. */ + return 0; +} + +int +pthread_mutex_unlock (_GL_UNUSED pthread_mutex_t *mutex) +{ + /* There is only one thread, so it always unlocks successfully. + This implementation does not support robust mutexes or + PTHREAD_MUTEX_ERRORCHECK. */ + return 0; +} + +int +pthread_mutex_destroy (_GL_UNUSED pthread_mutex_t *mutex) +{ + /* MUTEX is never seriously used. */ + return 0; +} + +#endif |