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1 | #ifndef _URCU_TLS_COMPAT_H |
2 | #define _URCU_TLS_COMPAT_H | |
3 | ||
4 | /* | |
5 | * urcu/tls-compat.h | |
6 | * | |
7 | * Userspace RCU library - Thread-Local Storage Compatibility Header | |
8 | * | |
9 | * Copyright 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
10 | * | |
11 | * This library is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU Lesser General Public | |
13 | * License as published by the Free Software Foundation; either | |
14 | * version 2.1 of the License, or (at your option) any later version. | |
15 | * | |
16 | * This library is distributed in the hope that it will be useful, | |
17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
19 | * Lesser General Public License for more details. | |
20 | * | |
21 | * You should have received a copy of the GNU Lesser General Public | |
22 | * License along with this library; if not, write to the Free Software | |
23 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
24 | */ | |
25 | ||
26 | #include <stdlib.h> | |
27 | #include <urcu/config.h> | |
28 | #include <urcu/compiler.h> | |
29 | #include <urcu/arch.h> | |
30 | ||
31 | #ifdef __cplusplus | |
32 | extern "C" { | |
33 | #endif | |
34 | ||
35 | #ifdef CONFIG_RCU_TLS /* Based on ax_tls.m4 */ | |
36 | ||
37 | # define DECLARE_URCU_TLS(type, name) \ | |
3db1417f | 38 | CONFIG_RCU_TLS type name |
4d0d66bb MD |
39 | |
40 | # define DEFINE_URCU_TLS(type, name) \ | |
3db1417f | 41 | CONFIG_RCU_TLS type name |
4d0d66bb | 42 | |
3db1417f | 43 | # define URCU_TLS(name) (name) |
4d0d66bb MD |
44 | |
45 | #else /* #ifndef CONFIG_RCU_TLS */ | |
46 | ||
47 | # include <pthread.h> | |
48 | ||
49 | struct urcu_tls { | |
50 | pthread_key_t key; | |
51 | pthread_mutex_t init_mutex; | |
52 | int init_done; | |
53 | }; | |
54 | ||
55 | # define DECLARE_URCU_TLS(type, name) \ | |
56 | type *__tls_access_ ## name(void) | |
57 | ||
58 | /* | |
59 | * Note: we don't free memory at process exit, since it will be dealt | |
60 | * with by the OS. | |
61 | */ | |
62 | # define DEFINE_URCU_TLS(type, name) \ | |
63 | type *__tls_access_ ## name(void) \ | |
64 | { \ | |
65 | static struct urcu_tls __tls_ ## name = { \ | |
66 | .init_mutex = PTHREAD_MUTEX_INITIALIZER,\ | |
67 | .init_done = 0, \ | |
68 | }; \ | |
69 | void *__tls_p; \ | |
70 | if (!__tls_ ## name.init_done) { \ | |
71 | /* Mutex to protect concurrent init */ \ | |
72 | pthread_mutex_lock(&__tls_ ## name.init_mutex); \ | |
73 | if (!__tls_ ## name.init_done) { \ | |
74 | (void) pthread_key_create(&__tls_ ## name.key, \ | |
75 | free); \ | |
76 | cmm_smp_wmb(); /* create key before write init_done */ \ | |
77 | __tls_ ## name.init_done = 1; \ | |
78 | } \ | |
79 | pthread_mutex_unlock(&__tls_ ## name.init_mutex); \ | |
80 | } \ | |
81 | cmm_smp_rmb(); /* read init_done before getting key */ \ | |
82 | __tls_p = pthread_getspecific(__tls_ ## name.key); \ | |
83 | if (caa_unlikely(__tls_p == NULL)) { \ | |
84 | __tls_p = calloc(1, sizeof(type)); \ | |
85 | (void) pthread_setspecific(__tls_ ## name.key, \ | |
86 | __tls_p); \ | |
87 | } \ | |
88 | return __tls_p; \ | |
89 | } | |
90 | ||
91 | # define URCU_TLS(name) (*__tls_access_ ## name()) | |
92 | ||
93 | #endif /* #else #ifndef CONFIG_RCU_TLS */ | |
94 | ||
95 | #ifdef __cplusplus | |
96 | } | |
97 | #endif | |
98 | ||
99 | #endif /* _URCU_TLS_COMPAT_H */ |