projects/linux·blob v3.16 · refs

103 lines · 2.9 KiB

1/*
2 * RT Mutexes: blocking mutual exclusion locks with PI support
3 *
4 * started by Ingo Molnar and Thomas Gleixner:
5 *
6 * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <[email protected]>
7 * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <[email protected]>
8 *
9 * This file contains the public data structure and API definitions.
10 */
11
12#ifndef __LINUX_RT_MUTEX_H
13#define __LINUX_RT_MUTEX_H
14
15#include <linux/linkage.h>
16#include <linux/rbtree.h>
17#include <linux/spinlock_types.h>
18
19extern int max_lock_depth; /* for sysctl */
20
21/**
22 * The rt_mutex structure
23 *
24 * @wait_lock: spinlock to protect the structure
25 * @waiters: rbtree root to enqueue waiters in priority order
26 * @waiters_leftmost: top waiter
27 * @owner: the mutex owner
28 */
29struct rt_mutex {
30 raw_spinlock_t wait_lock;
31 struct rb_root waiters;
32 struct rb_node *waiters_leftmost;
33 struct task_struct *owner;
34#ifdef CONFIG_DEBUG_RT_MUTEXES
35 int save_state;
36 const char *name, *file;
37 int line;
38 void *magic;
39#endif
40};
41
42struct rt_mutex_waiter;
43struct hrtimer_sleeper;
44
45#ifdef CONFIG_DEBUG_RT_MUTEXES
46 extern int rt_mutex_debug_check_no_locks_freed(const void *from,
47 unsigned long len);
48 extern void rt_mutex_debug_check_no_locks_held(struct task_struct *task);
49#else
50 static inline int rt_mutex_debug_check_no_locks_freed(const void *from,
51 unsigned long len)
52 {
53 return 0;
54 }
55# define rt_mutex_debug_check_no_locks_held(task) do { } while (0)
56#endif
57
58#ifdef CONFIG_DEBUG_RT_MUTEXES
59# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
60 , .name = #mutexname, .file = __FILE__, .line = __LINE__
61# define rt_mutex_init(mutex) __rt_mutex_init(mutex, __func__)
62 extern void rt_mutex_debug_task_free(struct task_struct *tsk);
63#else
64# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname)
65# define rt_mutex_init(mutex) __rt_mutex_init(mutex, NULL)
66# define rt_mutex_debug_task_free(t) do { } while (0)
67#endif
68
69#define __RT_MUTEX_INITIALIZER(mutexname) \
70 { .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
71 , .waiters = RB_ROOT \
72 , .owner = NULL \
73 __DEBUG_RT_MUTEX_INITIALIZER(mutexname)}
74
75#define DEFINE_RT_MUTEX(mutexname) \
76 struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname)
77
78/**
79 * rt_mutex_is_locked - is the mutex locked
80 * @lock: the mutex to be queried
81 *
82 * Returns 1 if the mutex is locked, 0 if unlocked.
83 */
84static inline int rt_mutex_is_locked(struct rt_mutex *lock)
85{
86 return lock->owner != NULL;
87}
88
89extern void __rt_mutex_init(struct rt_mutex *lock, const char *name);
90extern void rt_mutex_destroy(struct rt_mutex *lock);
91
92extern void rt_mutex_lock(struct rt_mutex *lock);
93extern int rt_mutex_lock_interruptible(struct rt_mutex *lock,
94 int detect_deadlock);
95extern int rt_mutex_timed_lock(struct rt_mutex *lock,
96 struct hrtimer_sleeper *timeout,
97 int detect_deadlock);
98
99extern int rt_mutex_trylock(struct rt_mutex *lock);
100
101extern void rt_mutex_unlock(struct rt_mutex *lock);
102
103#endif