1 /* Threads compatibility routines for libgcc2 and libobjc.  */
2 /* Compile this one with gcc.  */
3 /* Copyright (C) 2019-2021 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 */
164