WebSVN – Kolibri OS – Diff – /drivers/include/linux/mutex.h


/*
 * Mutexes: blocking mutual exclusion locks
 *
 * started by Ingo Molnar:
 *
 *  Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar 
 *
 * This file contains the main data structure and API definitions.
 */
#ifndef __LINUX_MUTEX_H
#define __LINUX_MUTEX_H
 
#include 
#include 
#include 
#include 
#include 
#include 
 
/*
 * Simple, straightforward mutexes with strict semantics:
 *
 * - only one task can hold the mutex at a time
 * - only the owner can unlock the mutex
 * - multiple unlocks are not permitted
 * - recursive locking is not permitted
 * - a mutex object must be initialized via the API
 * - a mutex object must not be initialized via memset or copying
 * - task may not exit with mutex held
 * - memory areas where held locks reside must not be freed
 * - held mutexes must not be reinitialized
 * - mutexes may not be used in hardware or software interrupt
 *   contexts such as tasklets and timers
 *
 * These semantics are fully enforced when DEBUG_MUTEXES is
 * enabled. Furthermore, besides enforcing the above rules, the mutex
 * debugging code also implements a number of additional features
 * that make lock debugging easier and faster:
 *
 * - uses symbolic names of mutexes, whenever they are printed in debug output
 * - point-of-acquire tracking, symbolic lookup of function names
 * - list of all locks held in the system, printout of them
 * - owner tracking
 * - detects self-recursing locks and prints out all relevant info
 * - detects multi-task circular deadlocks and prints out all affected
 *   locks and tasks (and only those tasks)
 */
struct mutex {
	/* 1: unlocked, 0: locked, negative: locked, possible waiters */
	struct list_head	wait_list;
    atomic_t            count;
};
 
/*
 * This is the control structure for tasks blocked on mutex,
 * which resides on the blocked task's kernel stack:
 */
struct mutex_waiter {
	struct list_head	list;
    int                *task;
};
 
 
#define __MUTEX_INITIALIZER(lockname) \
                { .wait_list = LIST_HEAD_INIT(lockname.wait_list), \
                  .count = ATOMIC_INIT(1) \
                }
 
#define DEFINE_MUTEX(mutexname) \
        struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
 
void __attribute__ ((fastcall)) __attribute__ ((dllimport))
     mutex_init(struct mutex*)__asm__("MutexInit");
void __attribute__ ((fastcall)) __attribute__ ((dllimport))
     mutex_lock(struct mutex*)__asm__("MutexLock");
void __attribute__ ((fastcall)) __attribute__ ((dllimport))
     mutex_unlock(struct mutex*)__asm__("MutexUnlock");
 
static inline int mutex_lock_interruptible(struct mutex *lock)
{
    mutex_lock(lock);
    return 0;
}
 
# define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock)
 
 
/**
 * mutex_is_locked - is the mutex locked
 * @lock: the mutex to be queried
 *
 * Returns 1 if the mutex is locked, 0 if unlocked.
 */
static inline int mutex_is_locked(struct mutex *lock)
{
	return atomic_read(&lock->count) != 1;
}
 
static inline int mutex_trylock(struct mutex *lock)
{
    if (likely(atomic_cmpxchg(&lock->count, 1, 0) == 1))
        return 1;
    return 0;
}
 
static inline void mutex_destroy(struct mutex *lock)
{
 
};
 
#endif

Subversion Repositories Kolibri OS

(root)/drivers/include/linux/mutex.h – Rev 5056 → 5270

Rev 5056		Rev 5270
1	/*	1	/*
2	* Mutexes: blocking mutual exclusion locks	2	* Mutexes: blocking mutual exclusion locks
3	*	3	*
4	* started by Ingo Molnar:	4	* started by Ingo Molnar:
5	*	5	*
6	* Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar	6	* Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar
7	*	7	*
8	* This file contains the main data structure and API definitions.	8	* This file contains the main data structure and API definitions.
9	*/	9	*/
10	#ifndef __LINUX_MUTEX_H	10	#ifndef __LINUX_MUTEX_H
11	#define __LINUX_MUTEX_H	11	#define __LINUX_MUTEX_H
-		12
12		13	#include
13	#include	14	#include
-		15	#include
-		16	#include
-		17	#include
14	#include	18	#include
15		19
16	/*	20	/*
17	* Simple, straightforward mutexes with strict semantics:	21	* Simple, straightforward mutexes with strict semantics:
18	*	22	*
19	* - only one task can hold the mutex at a time	23	* - only one task can hold the mutex at a time
20	* - only the owner can unlock the mutex	24	* - only the owner can unlock the mutex
21	* - multiple unlocks are not permitted	25	* - multiple unlocks are not permitted
22	* - recursive locking is not permitted	26	* - recursive locking is not permitted
23	* - a mutex object must be initialized via the API	27	* - a mutex object must be initialized via the API
24	* - a mutex object must not be initialized via memset or copying	28	* - a mutex object must not be initialized via memset or copying
25	* - task may not exit with mutex held	29	* - task may not exit with mutex held
26	* - memory areas where held locks reside must not be freed	30	* - memory areas where held locks reside must not be freed
27	* - held mutexes must not be reinitialized	31	* - held mutexes must not be reinitialized
28	* - mutexes may not be used in hardware or software interrupt	32	* - mutexes may not be used in hardware or software interrupt
29	* contexts such as tasklets and timers	33	* contexts such as tasklets and timers
30	*	34	*
31	* These semantics are fully enforced when DEBUG_MUTEXES is	35	* These semantics are fully enforced when DEBUG_MUTEXES is
32	* enabled. Furthermore, besides enforcing the above rules, the mutex	36	* enabled. Furthermore, besides enforcing the above rules, the mutex
33	* debugging code also implements a number of additional features	37	* debugging code also implements a number of additional features
34	* that make lock debugging easier and faster:	38	* that make lock debugging easier and faster:
35	*	39	*
36	* - uses symbolic names of mutexes, whenever they are printed in debug output	40	* - uses symbolic names of mutexes, whenever they are printed in debug output
37	* - point-of-acquire tracking, symbolic lookup of function names	41	* - point-of-acquire tracking, symbolic lookup of function names
38	* - list of all locks held in the system, printout of them	42	* - list of all locks held in the system, printout of them
39	* - owner tracking	43	* - owner tracking
40	* - detects self-recursing locks and prints out all relevant info	44	* - detects self-recursing locks and prints out all relevant info
41	* - detects multi-task circular deadlocks and prints out all affected	45	* - detects multi-task circular deadlocks and prints out all affected
42	* locks and tasks (and only those tasks)	46	* locks and tasks (and only those tasks)
43	*/	47	*/
44	struct mutex {	48	struct mutex {
45	/* 1: unlocked, 0: locked, negative: locked, possible waiters */	49	/* 1: unlocked, 0: locked, negative: locked, possible waiters */
46	struct list_head wait_list;	50	struct list_head wait_list;
47	atomic_t count;	51	atomic_t count;
48	};	52	};
49		53
50	/*	54	/*
51	* This is the control structure for tasks blocked on mutex,	55	* This is the control structure for tasks blocked on mutex,
52	* which resides on the blocked task's kernel stack:	56	* which resides on the blocked task's kernel stack:
53	*/	57	*/
54	struct mutex_waiter {	58	struct mutex_waiter {
55	struct list_head list;	59	struct list_head list;
56	int *task;	60	int *task;
57	};	61	};
58		62
59		63
60	#define __MUTEX_INITIALIZER(lockname) \	64	#define __MUTEX_INITIALIZER(lockname) \
61	{ .wait_list = LIST_HEAD_INIT(lockname.wait_list), \	65	{ .wait_list = LIST_HEAD_INIT(lockname.wait_list), \
62	.count = ATOMIC_INIT(1) \	66	.count = ATOMIC_INIT(1) \
63	}	67	}
64		68
65	#define DEFINE_MUTEX(mutexname) \	69	#define DEFINE_MUTEX(mutexname) \
66	struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)	70	struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
67		71
68	void __attribute__ ((fastcall)) __attribute__ ((dllimport))	72	void __attribute__ ((fastcall)) __attribute__ ((dllimport))
69	mutex_init(struct mutex*)__asm__("MutexInit");	73	mutex_init(struct mutex*)__asm__("MutexInit");
70	void __attribute__ ((fastcall)) __attribute__ ((dllimport))	74	void __attribute__ ((fastcall)) __attribute__ ((dllimport))
71	mutex_lock(struct mutex*)__asm__("MutexLock");	75	mutex_lock(struct mutex*)__asm__("MutexLock");
72	void __attribute__ ((fastcall)) __attribute__ ((dllimport))	76	void __attribute__ ((fastcall)) __attribute__ ((dllimport))
73	mutex_unlock(struct mutex*)__asm__("MutexUnlock");	77	mutex_unlock(struct mutex*)__asm__("MutexUnlock");
74		78
75	static inline int mutex_lock_interruptible(struct mutex *lock)	79	static inline int mutex_lock_interruptible(struct mutex *lock)
76	{	80	{
77	mutex_lock(lock);	81	mutex_lock(lock);
78	return 0;	82	return 0;
79	}	83	}
80		84
81	# define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock)	85	# define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock)
82		86
83		87
84	/**	88	/**
85	* mutex_is_locked - is the mutex locked	89	* mutex_is_locked - is the mutex locked
86	* @lock: the mutex to be queried	90	* @lock: the mutex to be queried
87	*	91	*
88	* Returns 1 if the mutex is locked, 0 if unlocked.	92	* Returns 1 if the mutex is locked, 0 if unlocked.
89	*/	93	*/
90	static inline int mutex_is_locked(struct mutex *lock)	94	static inline int mutex_is_locked(struct mutex *lock)
91	{	95	{
92	return atomic_read(&lock->count) != 1;	96	return atomic_read(&lock->count) != 1;
93	}	97	}
94		98
95	static inline int mutex_trylock(struct mutex *lock)	99	static inline int mutex_trylock(struct mutex *lock)
96	{	100	{
97	if (likely(atomic_cmpxchg(&lock->count, 1, 0) == 1))	101	if (likely(atomic_cmpxchg(&lock->count, 1, 0) == 1))
98	return 1;	102	return 1;
99	return 0;	103	return 0;
100	}	104	}
101		105
102	static inline void mutex_destroy(struct mutex *lock)	106	static inline void mutex_destroy(struct mutex *lock)
103	{	107	{
104		108
105	};	109	};
106		110
107	#endif	111	#endif