/* ISO C11 Standard: 7.26 - Thread support library <threads.h>. Copyright (C) 2018-2021 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 <https://www.gnu.org/licenses/>. */ #ifndef _THREADS_H #define _THREADS_H 1 #include <features.h> #include <time.h> __BEGIN_DECLS #include <bits/thread-shared-types.h> #include <bits/types/struct_timespec.h> #ifndef __cplusplus # define thread_local _Thread_local #endif #define TSS_DTOR_ITERATIONS 4 typedef __tss_t tss_t; typedef void (*tss_dtor_t) (void*); typedef __thrd_t thrd_t; typedef int (*thrd_start_t) (void*); /* Exit and error codes. */ enum { thrd_success = 0, thrd_busy = 1, thrd_error = 2, thrd_nomem = 3, thrd_timedout = 4 }; /* Mutex types. */ enum { mtx_plain = 0, mtx_recursive = 1, mtx_timed = 2 }; typedef __once_flag once_flag; #define ONCE_FLAG_INIT __ONCE_FLAG_INIT typedef union { char __size[__SIZEOF_PTHREAD_MUTEX_T]; long int __align __LOCK_ALIGNMENT; } mtx_t; typedef union { char __size[__SIZEOF_PTHREAD_COND_T]; __extension__ long long int __align __LOCK_ALIGNMENT; } cnd_t; /* Threads functions. */ /* Create a new thread executing the function __FUNC. Arguments for __FUNC are passed through __ARG. If succesful, __THR is set to new thread identifier. */ extern int thrd_create (thrd_t *__thr, thrd_start_t __func, void *__arg); /* Check if __LHS and __RHS point to the same thread. */ extern int thrd_equal (thrd_t __lhs, thrd_t __rhs); /* Return current thread identifier. */ extern thrd_t thrd_current (void); /* Block current thread execution for at least the time pointed by __TIME_POINT. The current thread may resume if receives a signal. In that case, if __REMAINING is not NULL, the remaining time is stored in the object pointed by it. */ #ifndef __USE_TIME_BITS64 extern int thrd_sleep (const struct timespec *__time_point, struct timespec *__remaining); #else # ifdef __REDIRECT extern int __REDIRECT (thrd_sleep, (const struct timespec *__time_point, struct timespec *__remaining), __thrd_sleep64); # else # define thrd_sleep __thrd_sleep64 # endif #endif /* Terminate current thread execution, cleaning up any thread local storage and freeing resources. Returns the value specified in __RES. */ extern void thrd_exit (int __res) __attribute__ ((__noreturn__)); /* Detach the thread identified by __THR from the current environment (it does not allow join or wait for it). */ extern int thrd_detach (thrd_t __thr); /* Block current thread until execution of __THR is complete. In case that __RES is not NULL, will store the return value of __THR when exiting. */ extern int thrd_join (thrd_t __thr, int *__res); /* Stop current thread execution and call the scheduler to decide which thread should execute next. The current thread may be selected by the scheduler to keep running. */ extern void thrd_yield (void); #ifdef __USE_EXTERN_INLINES /* Optimizations. */ __extern_inline int thrd_equal (thrd_t __thread1, thrd_t __thread2) { return __thread1 == __thread2; } #endif /* Mutex functions. */ /* Creates a new mutex object with type __TYPE. If successful the new object is pointed by __MUTEX. */ extern int mtx_init (mtx_t *__mutex, int __type); /* Block the current thread until the mutex pointed to by __MUTEX is unlocked. In that case current thread will not be blocked. */ extern int mtx_lock (mtx_t *__mutex); /* Block the current thread until the mutex pointed by __MUTEX is unlocked or time pointed by __TIME_POINT is reached. In case the mutex is unlock, the current thread will not be blocked. */ #ifndef __USE_TIME_BITS64 extern int mtx_timedlock (mtx_t *__restrict __mutex, const struct timespec *__restrict __time_point); #else # ifdef __REDIRECT extern int __REDIRECT (mtx_timedlock, (mtx_t *__restrict __mutex, const struct timespec *__restrict __time_point), __mtx_timedlock64); # else # define mtx_timedlock __mtx_timedlock64 # endif #endif /* Try to lock the mutex pointed by __MUTEX without blocking. If the mutex is free the current threads takes control of it, otherwise it returns immediately. */ extern int mtx_trylock (mtx_t *__mutex); /* Unlock the mutex pointed by __MUTEX. It may potentially awake other threads waiting on this mutex. */ 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)); /* Condition variable functions. */ /* Initialize new condition variable pointed by __COND. */ extern int cnd_init (cnd_t *__cond); /* Unblock one thread that currently waits on condition variable pointed by __COND. */ extern int cnd_signal (cnd_t *__cond); /* Unblock all threads currently waiting on condition variable pointed by __COND. */ extern int cnd_broadcast (cnd_t *__cond); /* Block current thread on the condition variable pointed by __COND. */ extern int cnd_wait (cnd_t *__cond, mtx_t *__mutex); /* Block current thread on the condition variable until condition variable pointed by __COND is signaled or time pointed by __TIME_POINT is reached. */ #ifndef __USE_TIME_BITS64 extern int cnd_timedwait (cnd_t *__restrict __cond, mtx_t *__restrict __mutex, const struct timespec *__restrict __time_point); #else # ifdef __REDIRECT extern int __REDIRECT (cnd_timedwait, (cnd_t *__restrict __cond, mtx_t *__restrict __mutex, const struct timespec *__restrict __time_point), __cnd_timedwait64); # else # define cnd_timedwait __cnd_timedwait64 # endif #endif /* Destroy condition variable pointed by __cond and free all of its resources. */ extern void cnd_destroy (cnd_t *__COND); /* Thread specific storage functions. */ /* Create new thread-specific storage key and stores it in the object pointed by __TSS_ID. If __DESTRUCTOR is not NULL, the function will be called when the thread terminates. */ extern int tss_create (tss_t *__tss_id, tss_dtor_t __destructor); /* Return the value held in thread-specific storage for the current thread identified by __TSS_ID. */ extern void *tss_get (tss_t __tss_id); /* Sets the value of the thread-specific storage identified by __TSS_ID for the current thread to __VAL. */ extern int tss_set (tss_t __tss_id, void *__val); /* Destroys the thread-specific storage identified by __TSS_ID. The destructor is not called until thrd_exit is called. */ extern void tss_delete (tss_t __tss_id); __END_DECLS #endif /* _THREADS_H */