Ensure a tls key is only generated once - wrap create & destroy in a mutex.
[Samba/gebeck_regimport.git] / lib / util / smb_threads.h
blob945e93803a39ec4ce49ff8eac15af99bff5358b7
1 /*
2 Unix SMB/CIFS implementation.
3 SMB thread interface functions.
4 Copyright (C) Jeremy Allison, 2009.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #ifndef _smb_threads_h_
21 #define _smb_threads_h_
23 enum smb_thread_lock_type {
24 SMB_THREAD_LOCK = 1,
25 SMB_THREAD_UNLOCK
28 struct smb_thread_functions {
29 /* Mutex and tls functions. */
30 int (*create_mutex)(const char *lockname,
31 void **pplock,
32 const char *location);
33 void (*destroy_mutex)(void *plock,
34 const char *location);
35 int (*lock_mutex)(void *plock, enum smb_thread_lock_type lock_type,
36 const char *location);
38 /* Thread local storage. */
39 int (*create_tls_once)(const char *keyname,
40 void **ppkey,
41 const char *location);
42 void (*destroy_tls_once)(void **pkey,
43 const char *location);
44 int (*set_tls)(void *pkey, const void *pval, const char *location);
45 void *(*get_tls)(void *pkey, const char *location);
48 extern const struct smb_thread_functions *global_tfp;
50 /* Define the pthread version of the functions. */
52 #define SMB_THREADS_DEF_PTHREAD_IMPLEMENTATION(tf) \
54 static int smb_create_mutex_pthread(const char *lockname, void **pplock, const char *location) \
55 { \
56 pthread_mutex_t *pmut = (pthread_mutex_t *)malloc(sizeof(pthread_mutex_t)); \
57 if (!pmut) { \
58 return ENOMEM; \
59 } \
60 pthread_mutex_init(pmut, NULL); \
61 *pplock = (void *)pmut; \
62 return 0; \
63 } \
65 static void smb_destroy_mutex_pthread(void *plock, const char *location) \
66 { \
67 pthread_mutex_destroy((pthread_mutex_t *)plock); \
68 free(plock); \
69 } \
71 static int smb_lock_pthread(void *plock, enum smb_thread_lock_type lock_type, const char *location) \
72 { \
73 if (lock_type == SMB_THREAD_UNLOCK) { \
74 return pthread_mutex_unlock((pthread_mutex_t *)plock); \
75 } else { \
76 return pthread_mutex_lock((pthread_mutex_t *)plock); \
77 } \
78 } \
80 static pthread_mutex_t create_tls_mutex = PTHREAD_MUTEX_INITIALIZER; \
82 static int smb_create_tls_once_pthread(const char *keyname, void **ppkey, const char *location) \
83 { \
84 int ret; \
85 pthread_key_t *pkey; \
86 ret = pthread_mutex_lock(&create_tls_mutex); \
87 if (ret) { \
88 return ret; \
89 } \
90 if (*ppkey) { \
91 pthread_mutex_unlock(&create_tls_mutex); \
92 return 0; \
93 } \
94 pkey = (pthread_key_t *)malloc(sizeof(pthread_key_t)); \
95 if (!pkey) { \
96 pthread_mutex_unlock(&create_tls_mutex); \
97 return ENOMEM; \
98 } \
99 ret = pthread_key_create(pkey, NULL); \
100 if (ret) { \
101 free(pkey); \
102 pthread_mutex_unlock(&create_tls_mutex); \
103 return ret; \
105 *ppkey = (void *)pkey; \
106 pthread_mutex_unlock(&create_tls_mutex); \
107 return 0; \
110 static void smb_destroy_tls_once_pthread(void **ppkey, const char *location) \
112 pthread_mutex_lock(&create_tls_mutex); \
113 if (*ppkey) { \
114 pthread_key_delete(*(pthread_key_t *)ppkey); \
115 free(*ppkey); \
116 *ppkey = NULL; \
118 pthread_mutex_unlock(&create_tls_mutex); \
121 static int smb_set_tls_pthread(void *pkey, const void *pval, const char *location) \
123 return pthread_setspecific(*(pthread_key_t *)pkey, pval); \
126 static void *smb_get_tls_pthread(void *pkey, const char *location) \
128 return pthread_getspecific(*(pthread_key_t *)pkey); \
131 static const struct smb_thread_functions (tf) = { \
132 smb_create_mutex_pthread, \
133 smb_destroy_mutex_pthread, \
134 smb_lock_pthread, \
135 smb_create_tls_once_pthread, \
136 smb_destroy_tls_once_pthread, \
137 smb_set_tls_pthread, \
138 smb_get_tls_pthread }
140 #endif