s3: Avoid a thundering herd in g_lock_unlock
[Samba.git] / lib / util / mutex.h
blobbf845906f2ab5900c853663d0a71c84da6c33602
1 #ifndef _MUTEX_H_
2 #define _MUTEX_H_
3 /*
4 Unix SMB/CIFS implementation.
5 Samba mutex functions
6 Copyright (C) Andrew Tridgell 2003
7 Copyright (C) James J Myers 2003
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>.
23 /**
24 * @file
25 * @brief Mutex operations
28 struct mutex_ops;
30 /* To add a new read/write lock, add it to enum rwlock_id
32 enum rwlock_id { RWLOCK_SMBD, /* global smbd lock */
34 RWLOCK_MAX /* this MUST be kept last */
37 #define MUTEX_LOCK_BY_ID(mutex_index) smb_mutex_lock_by_id(mutex_index, #mutex_index)
38 #define MUTEX_UNLOCK_BY_ID(mutex_index) smb_mutex_unlock_by_id(mutex_index, #mutex_index)
39 #define MUTEX_INIT(mutex, name) smb_mutex_init(mutex, #name)
40 #define MUTEX_DESTROY(mutex, name) smb_mutex_destroy(mutex, #name)
41 #define MUTEX_LOCK(mutex, name) smb_mutex_lock(mutex, #name)
42 #define MUTEX_UNLOCK(mutex, name) smb_mutex_unlock(mutex, #name)
44 #define RWLOCK_INIT(rwlock, name) smb_rwlock_init(rwlock, #name)
45 #define RWLOCK_DESTROY(rwlock, name) smb_rwlock_destroy(rwlock, #name)
46 #define RWLOCK_LOCK_WRITE(rwlock, name) smb_rwlock_lock_write(rwlock, #name)
47 #define RWLOCK_LOCK_READ(rwlock, name) smb_rwlock_lock_read(rwlock, #name)
48 #define RWLOCK_UNLOCK(rwlock, name) smb_rwlock_unlock(rwlock, #name)
52 /* this null typedef ensures we get the types right and avoids the
53 pitfalls of void* */
54 typedef struct smb_mutex {
55 void *mutex;
56 } smb_mutex_t;
57 typedef struct {
58 void *rwlock;
59 } smb_rwlock_t;
61 /* the mutex model operations structure - contains function pointers to
62 the model-specific implementations of each operation */
63 struct mutex_ops {
64 int (*mutex_init)(smb_mutex_t *mutex, const char *name);
65 int (*mutex_lock)(smb_mutex_t *mutex, const char *name);
66 int (*mutex_unlock)(smb_mutex_t *mutex, const char *name);
67 int (*mutex_destroy)(smb_mutex_t *mutex, const char *name);
68 int (*rwlock_init)(smb_rwlock_t *rwlock, const char *name);
69 int (*rwlock_lock_write)(smb_rwlock_t *rwlock, const char *name);
70 int (*rwlock_lock_read)(smb_rwlock_t *rwlock, const char *name);
71 int (*rwlock_unlock)(smb_rwlock_t *rwlock, const char *name);
72 int (*rwlock_destroy)(smb_rwlock_t *rwlock, const char *name);
75 #endif /* endif _MUTEX_H_ */