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sched/wait: Clean up wait.h details a bit
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Since we are changing wait.h profoundly, use the opportunity to:

 - add a sentence to explain what this file is about
 - remove whitespace noise
 - prettify weird looking line break fixup attempts
 - standardize type definition and initialization sequences
 - use consistent style details

No code is changed.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-O8dIie5swnctqpupakatvqyq@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Ingo Molnar committed Oct 4, 2013
1 parent c2eb505 commit fb869b6
Showing 1 changed file with 60 additions and 64 deletions.
124 changes: 60 additions & 64 deletions include/linux/wait.h
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Original file line number Diff line number Diff line change
@@ -1,7 +1,8 @@
#ifndef _LINUX_WAIT_H
#define _LINUX_WAIT_H


/*
* Linux wait queue related types and methods
*/
#include <linux/list.h>
#include <linux/stddef.h>
#include <linux/spinlock.h>
Expand All @@ -13,27 +14,27 @@ typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, v
int default_wake_function(wait_queue_t *wait, unsigned mode, int flags, void *key);

struct __wait_queue {
unsigned int flags;
unsigned int flags;
#define WQ_FLAG_EXCLUSIVE 0x01
void *private;
wait_queue_func_t func;
struct list_head task_list;
void *private;
wait_queue_func_t func;
struct list_head task_list;
};

struct wait_bit_key {
void *flags;
int bit_nr;
#define WAIT_ATOMIC_T_BIT_NR -1
void *flags;
int bit_nr;
#define WAIT_ATOMIC_T_BIT_NR -1
};

struct wait_bit_queue {
struct wait_bit_key key;
wait_queue_t wait;
struct wait_bit_key key;
wait_queue_t wait;
};

struct __wait_queue_head {
spinlock_t lock;
struct list_head task_list;
spinlock_t lock;
struct list_head task_list;
};
typedef struct __wait_queue_head wait_queue_head_t;

Expand Down Expand Up @@ -84,17 +85,17 @@ extern void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct

static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
{
q->flags = 0;
q->private = p;
q->func = default_wake_function;
q->flags = 0;
q->private = p;
q->func = default_wake_function;
}

static inline void init_waitqueue_func_entry(wait_queue_t *q,
wait_queue_func_t func)
static inline void
init_waitqueue_func_entry(wait_queue_t *q, wait_queue_func_t func)
{
q->flags = 0;
q->private = NULL;
q->func = func;
q->flags = 0;
q->private = NULL;
q->func = func;
}

static inline int waitqueue_active(wait_queue_head_t *q)
Expand All @@ -114,8 +115,8 @@ static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new)
/*
* Used for wake-one threads:
*/
static inline void __add_wait_queue_exclusive(wait_queue_head_t *q,
wait_queue_t *wait)
static inline void
__add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait)
{
wait->flags |= WQ_FLAG_EXCLUSIVE;
__add_wait_queue(q, wait);
Expand All @@ -127,23 +128,22 @@ static inline void __add_wait_queue_tail(wait_queue_head_t *head,
list_add_tail(&new->task_list, &head->task_list);
}

static inline void __add_wait_queue_tail_exclusive(wait_queue_head_t *q,
wait_queue_t *wait)
static inline void
__add_wait_queue_tail_exclusive(wait_queue_head_t *q, wait_queue_t *wait)
{
wait->flags |= WQ_FLAG_EXCLUSIVE;
__add_wait_queue_tail(q, wait);
}

static inline void __remove_wait_queue(wait_queue_head_t *head,
wait_queue_t *old)
static inline void
__remove_wait_queue(wait_queue_head_t *head, wait_queue_t *old)
{
list_del(&old->task_list);
}

void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key);
void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr,
void *key);
void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr);
void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr);
void __wake_up_bit(wait_queue_head_t *, void *, int);
Expand All @@ -170,21 +170,21 @@ wait_queue_head_t *bit_waitqueue(void *, int);
/*
* Wakeup macros to be used to report events to the targets.
*/
#define wake_up_poll(x, m) \
#define wake_up_poll(x, m) \
__wake_up(x, TASK_NORMAL, 1, (void *) (m))
#define wake_up_locked_poll(x, m) \
#define wake_up_locked_poll(x, m) \
__wake_up_locked_key((x), TASK_NORMAL, (void *) (m))
#define wake_up_interruptible_poll(x, m) \
#define wake_up_interruptible_poll(x, m) \
__wake_up(x, TASK_INTERRUPTIBLE, 1, (void *) (m))
#define wake_up_interruptible_sync_poll(x, m) \
__wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (m))

#define ___wait_cond_timeout(condition) \
({ \
bool __cond = (condition); \
if (__cond && !__ret) \
__ret = 1; \
__cond || !__ret; \
bool __cond = (condition); \
if (__cond && !__ret) \
__ret = 1; \
__cond || !__ret; \
})

#define ___wait_signal_pending(state) \
Expand All @@ -209,8 +209,8 @@ wait_queue_head_t *bit_waitqueue(void *, int);
if (___wait_signal_pending(state)) { \
__ret = -ERESTARTSYS; \
if (exclusive) { \
abort_exclusive_wait(&wq, &__wait, \
state, NULL); \
abort_exclusive_wait(&wq, &__wait, \
state, NULL); \
goto __out; \
} \
break; \
Expand All @@ -222,7 +222,7 @@ wait_queue_head_t *bit_waitqueue(void *, int);
__out: __ret; \
})

#define __wait_event(wq, condition) \
#define __wait_event(wq, condition) \
(void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
schedule())

Expand All @@ -238,9 +238,9 @@ __out: __ret; \
* wake_up() has to be called after changing any variable that could
* change the result of the wait condition.
*/
#define wait_event(wq, condition) \
#define wait_event(wq, condition) \
do { \
if (condition) \
if (condition) \
break; \
__wait_event(wq, condition); \
} while (0)
Expand Down Expand Up @@ -270,7 +270,7 @@ do { \
#define wait_event_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
if (!(condition)) \
if (!(condition)) \
__ret = __wait_event_timeout(wq, condition, timeout); \
__ret; \
})
Expand Down Expand Up @@ -329,7 +329,7 @@ do { \
({ \
long __ret = timeout; \
if (!(condition)) \
__ret = __wait_event_interruptible_timeout(wq, \
__ret = __wait_event_interruptible_timeout(wq, \
condition, timeout); \
__ret; \
})
Expand Down Expand Up @@ -569,7 +569,6 @@ do { \
? 0 : __wait_event_interruptible_locked(wq, condition, 1, 1))



#define __wait_event_killable(wq, condition) \
___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule())

Expand Down Expand Up @@ -663,7 +662,7 @@ do { \


#define __wait_event_interruptible_lock_irq(wq, condition, lock, cmd) \
___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \
___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \
spin_unlock_irq(&lock); \
cmd; \
schedule(); \
Expand Down Expand Up @@ -698,7 +697,7 @@ do { \
({ \
int __ret = 0; \
if (!(condition)) \
__ret = __wait_event_interruptible_lock_irq(wq, \
__ret = __wait_event_interruptible_lock_irq(wq, \
condition, lock, cmd); \
__ret; \
})
Expand Down Expand Up @@ -734,18 +733,18 @@ do { \
__ret; \
})

#define __wait_event_interruptible_lock_irq_timeout(wq, condition, \
lock, timeout) \
#define __wait_event_interruptible_lock_irq_timeout(wq, condition, \
lock, timeout) \
___wait_event(wq, ___wait_cond_timeout(condition), \
TASK_INTERRUPTIBLE, 0, ret, \
TASK_INTERRUPTIBLE, 0, ret, \
spin_unlock_irq(&lock); \
__ret = schedule_timeout(__ret); \
spin_lock_irq(&lock));

/**
* wait_event_interruptible_lock_irq_timeout - sleep until a condition gets true or a timeout elapses.
* The condition is checked under the lock. This is expected
* to be called with the lock taken.
* wait_event_interruptible_lock_irq_timeout - sleep until a condition gets
* true or a timeout elapses. The condition is checked under
* the lock. This is expected to be called with the lock taken.
* @wq: the waitqueue to wait on
* @condition: a C expression for the event to wait for
* @lock: a locked spinlock_t, which will be released before schedule()
Expand Down Expand Up @@ -783,20 +782,17 @@ do { \
* We plan to remove these interfaces.
*/
extern void sleep_on(wait_queue_head_t *q);
extern long sleep_on_timeout(wait_queue_head_t *q,
signed long timeout);
extern long sleep_on_timeout(wait_queue_head_t *q, signed long timeout);
extern void interruptible_sleep_on(wait_queue_head_t *q);
extern long interruptible_sleep_on_timeout(wait_queue_head_t *q,
signed long timeout);
extern long interruptible_sleep_on_timeout(wait_queue_head_t *q, signed long timeout);

/*
* Waitqueues which are removed from the waitqueue_head at wakeup time
*/
void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state);
void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state);
void finish_wait(wait_queue_head_t *q, wait_queue_t *wait);
void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait,
unsigned int mode, void *key);
void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, unsigned int mode, void *key);
int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);

Expand Down Expand Up @@ -842,8 +838,8 @@ int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
* One uses wait_on_bit() where one is waiting for the bit to clear,
* but has no intention of setting it.
*/
static inline int wait_on_bit(void *word, int bit,
int (*action)(void *), unsigned mode)
static inline int
wait_on_bit(void *word, int bit, int (*action)(void *), unsigned mode)
{
if (!test_bit(bit, word))
return 0;
Expand All @@ -866,8 +862,8 @@ static inline int wait_on_bit(void *word, int bit,
* One uses wait_on_bit_lock() where one is waiting for the bit to
* clear with the intention of setting it, and when done, clearing it.
*/
static inline int wait_on_bit_lock(void *word, int bit,
int (*action)(void *), unsigned mode)
static inline int
wait_on_bit_lock(void *word, int bit, int (*action)(void *), unsigned mode)
{
if (!test_and_set_bit(bit, word))
return 0;
Expand All @@ -891,5 +887,5 @@ int wait_on_atomic_t(atomic_t *val, int (*action)(atomic_t *), unsigned mode)
return 0;
return out_of_line_wait_on_atomic_t(val, action, mode);
}
#endif

#endif /* _LINUX_WAIT_H */

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