1  /* Threads compatibility routines for libgcc2 and libobjc.  */
       2  /* Compile this one with gcc.  */
       3  /* Copyright (C) 2019-2023 Free Software Foundation, Inc.
       4  
       5  This file is part of GCC.
       6  
       7  GCC is free software; you can redistribute it and/or modify it under
       8  the terms of the GNU General Public License as published by the Free
       9  Software Foundation; either version 3, or (at your option) any later
      10  version.
      11  
      12  GCC is distributed in the hope that it will be useful, but WITHOUT ANY
      13  WARRANTY; without even the implied warranty of MERCHANTABILITY or
      14  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
      15  for more details.
      16  
      17  Under Section 7 of GPL version 3, you are granted additional
      18  permissions described in the GCC Runtime Library Exception, version
      19  3.1, as published by the Free Software Foundation.
      20  
      21  You should have received a copy of the GNU General Public License and
      22  a copy of the GCC Runtime Library Exception along with this program;
      23  see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      24  <http://www.gnu.org/licenses/>.  */
      25  
      26  /* AMD GCN does not support dynamic creation of threads.  There may be many
      27     hardware threads, but they're all created simultaneously at launch time.
      28  
      29     This implementation is intended to provide mutexes for libgfortran, etc.
      30     It is not intended to provide a TLS implementation at this time,
      31     although that may be added later if needed.
      32  
      33     __gthread_active_p returns "1" to ensure that mutexes are used, and that
      34     programs attempting to use emutls will fail with the appropriate abort.
      35     It is expected that the TLS tests will fail.  */
      36  
      37  #ifndef GCC_GTHR_GCN_H
      38  #define GCC_GTHR_GCN_H
      39  
      40  #define __GTHREADS 1
      41  
      42  #ifdef __cplusplus
      43  extern "C" {
      44  #endif
      45  
      46  #ifdef _LIBOBJC
      47  #error "Objective C is not supported on AMD GCN"
      48  #else
      49  
      50  static inline int
      51  __gthread_active_p (void)
      52  {
      53    return 1;
      54  }
      55  
      56  typedef int __gthread_key_t;
      57  typedef int __gthread_once_t;
      58  typedef int __gthread_mutex_t;
      59  typedef int __gthread_recursive_mutex_t;
      60  
      61  #define __GTHREAD_ONCE_INIT 0
      62  #define __GTHREAD_MUTEX_INIT 0
      63  #define __GTHREAD_RECURSIVE_MUTEX_INIT 0
      64  
      65  static inline int
      66  __gthread_once (__gthread_once_t *__once __attribute__((unused)),
      67  		void (*__func) (void) __attribute__((unused)))
      68  {
      69    return 0;
      70  }
      71  
      72  static inline int
      73  __gthread_key_create (__gthread_key_t *__key __attribute__((unused)),
      74  		      void (*__dtor) (void *) __attribute__((unused)))
      75  {
      76    /* Operation is not supported.  */
      77    return -1;
      78  }
      79  
      80  static inline int
      81  __gthread_key_delete (__gthread_key_t __key __attribute__ ((__unused__)))
      82  {
      83    /* Operation is not supported.  */
      84    return -1;
      85  }
      86  
      87  static inline void *
      88  __gthread_getspecific (__gthread_key_t __key __attribute__((unused)))
      89  {
      90    return NULL;
      91  }
      92  
      93  static inline int
      94  __gthread_setspecific (__gthread_key_t __key __attribute__((unused)),
      95  		       const void *__ptr __attribute__((unused)))
      96  {
      97    /* Operation is not supported.  */
      98    return -1;
      99  }
     100  
     101  static inline int
     102  __gthread_mutex_destroy (__gthread_mutex_t *__mutex __attribute__((unused)))
     103  {
     104    return 0;
     105  }
     106  
     107  static inline int
     108  __gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t *__mutex __attribute__((unused)))
     109  {
     110    return 0;
     111  }
     112  
     113  
     114  static inline int
     115  __gthread_mutex_lock (__gthread_mutex_t *__mutex)
     116  {
     117    while (__sync_lock_test_and_set (__mutex, 1))
     118      asm volatile ("s_sleep\t1" ::: "memory");
     119  
     120    return 0;
     121  }
     122  
     123  static inline int
     124  __gthread_mutex_trylock (__gthread_mutex_t *__mutex)
     125  {
     126    return __sync_lock_test_and_set (__mutex, 1);
     127  }
     128  
     129  static inline int
     130  __gthread_mutex_unlock (__gthread_mutex_t *__mutex)
     131  {
     132    __sync_lock_release (__mutex);
     133  
     134    return 0;
     135  }
     136  
     137  static inline int
     138  __gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *__mutex __attribute__((unused)))
     139  {
     140    /* Operation is not supported.  */
     141    return -1;
     142  }
     143  
     144  static inline int
     145  __gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *__mutex __attribute__((unused)))
     146  {
     147    /* Operation is not supported.  */
     148    return -1;
     149  }
     150  
     151  static inline int
     152  __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *__mutex __attribute__((unused)))
     153  {
     154    /* Operation is not supported.  */
     155    return -1;
     156  }
     157  #endif /* _LIBOBJC */
     158  
     159  #ifdef __cplusplus
     160  }
     161  #endif
     162  
     163  #endif /* ! GCC_GTHR_GCN_H */