/* ISO C11 Standard: 7.26 - Thread support library  <threads.h>.

   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/>.  */

#ifndef _THREADS_H

#define _THREADS_H	1

#include <features.h>

#include <time.h>

__BEGIN_DECLS

#include <bits/pthreadtypes-arch.h>

#include <bits/types/struct_timespec.h>

#ifndef __cplusplus

# define thread_local _Thread_local

#endif

#define TSS_DTOR_ITERATIONS 4

typedef unsigned int tss_t;

typedef void (*tss_dtor_t) (void*);

typedef unsigned long int 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 struct

{

  int __data __ONCE_ALIGNMENT;

} once_flag;

#define ONCE_FLAG_INIT { 0 }

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.  */

extern int thrd_sleep (const struct timespec *__time_point,

		       struct timespec *__remaining);

/* 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.  */

extern int mtx_timedlock (mtx_t *__restrict __mutex,

			  const struct timespec *__restrict __time_point);

/* 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.  */

extern int cnd_timedwait (cnd_t *__restrict __cond,

			  mtx_t *__restrict __mutex,

			  const struct timespec *__restrict __time_point);

/* 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 */