LXR linux/include/linux/rtmutex.h

   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 <mingo@redhat.com>
   7 *  Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
   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/plist.h>
  17#include <linux/spinlock_types.h>
  18
  19/**
  20 * The rt_mutex structure
  21 *
  22 * @wait_lock:  spinlock to protect the structure
  23 * @wait_list:  pilist head to enqueue waiters in priority order
  24 * @owner:      the mutex owner
  25 */
  26struct rt_mutex {
  27        spinlock_t              wait_lock;
  28        struct plist_head       wait_list;
  29        struct task_struct      *owner;
  30#ifdef CONFIG_DEBUG_RT_MUTEXES
  31        int                     save_state;
  32        const char              *name, *file;
  33        int                     line;
  34        void                    *magic;
  35#endif
  36};
  37
  38struct rt_mutex_waiter;
  39struct hrtimer_sleeper;
  40
  41#ifdef CONFIG_DEBUG_RT_MUTEXES
  42 extern int rt_mutex_debug_check_no_locks_freed(const void *from,
  43                                                unsigned long len);
  44 extern void rt_mutex_debug_check_no_locks_held(struct task_struct *task);
  45#else
  46 static inline int rt_mutex_debug_check_no_locks_freed(const void *from,
  47                                                       unsigned long len)
  48 {
  49        return 0;
  50 }
  51# define rt_mutex_debug_check_no_locks_held(task)       do { } while (0)
  52#endif
  53
  54#ifdef CONFIG_DEBUG_RT_MUTEXES
  55# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
  56        , .name = #mutexname, .file = __FILE__, .line = __LINE__
  57# define rt_mutex_init(mutex)                   __rt_mutex_init(mutex, __func__)
  58 extern void rt_mutex_debug_task_free(struct task_struct *tsk);
  59#else
  60# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname)
  61# define rt_mutex_init(mutex)                   __rt_mutex_init(mutex, NULL)
  62# define rt_mutex_debug_task_free(t)                    do { } while (0)
  63#endif
  64
  65#define __RT_MUTEX_INITIALIZER(mutexname) \
  66        { .wait_lock = __SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
  67        , .wait_list = PLIST_HEAD_INIT(mutexname.wait_list, mutexname.wait_lock) \
  68        , .owner = NULL \
  69        __DEBUG_RT_MUTEX_INITIALIZER(mutexname)}
  70
  71#define DEFINE_RT_MUTEX(mutexname) \
  72        struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname)
  73
  74/**
  75 * rt_mutex_is_locked - is the mutex locked
  76 * @lock: the mutex to be queried
  77 *
  78 * Returns 1 if the mutex is locked, 0 if unlocked.
  79 */
  80static inline int rt_mutex_is_locked(struct rt_mutex *lock)
  81{
  82        return lock->owner != NULL;
  83}
  84
  85extern void __rt_mutex_init(struct rt_mutex *lock, const char *name);
  86extern void rt_mutex_destroy(struct rt_mutex *lock);
  87
  88extern void rt_mutex_lock(struct rt_mutex *lock);
  89extern int rt_mutex_lock_interruptible(struct rt_mutex *lock,
  90                                                int detect_deadlock);
  91extern int rt_mutex_timed_lock(struct rt_mutex *lock,
  92                                        struct hrtimer_sleeper *timeout,
  93                                        int detect_deadlock);
  94
  95extern int rt_mutex_trylock(struct rt_mutex *lock);
  96
  97extern void rt_mutex_unlock(struct rt_mutex *lock);
  98
  99#ifdef CONFIG_RT_MUTEXES
 100# define INIT_RT_MUTEXES(tsk)                                           \
 101        .pi_waiters     = PLIST_HEAD_INIT(tsk.pi_waiters, tsk.pi_lock), \
 102        INIT_RT_MUTEX_DEBUG(tsk)
 103#else
 104# define INIT_RT_MUTEXES(tsk)
 105#endif
 106
 107#endif
 108