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-rw-r--r--include/linux/wait.h393
1 files changed, 163 insertions, 230 deletions
diff --git a/include/linux/wait.h b/include/linux/wait.h
index a67fc163559..eaa00b10aba 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -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>
@@ -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;
@@ -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)
@@ -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);
@@ -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);
@@ -170,27 +170,64 @@ 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_event(wq, condition) \
-do { \
- DEFINE_WAIT(__wait); \
+#define ___wait_cond_timeout(condition) \
+({ \
+ bool __cond = (condition); \
+ if (__cond && !__ret) \
+ __ret = 1; \
+ __cond || !__ret; \
+})
+
+#define ___wait_is_interruptible(state) \
+ (!__builtin_constant_p(state) || \
+ state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE) \
+
+#define ___wait_event(wq, condition, state, exclusive, ret, cmd) \
+({ \
+ __label__ __out; \
+ wait_queue_t __wait; \
+ long __ret = ret; \
+ \
+ INIT_LIST_HEAD(&__wait.task_list); \
+ if (exclusive) \
+ __wait.flags = WQ_FLAG_EXCLUSIVE; \
+ else \
+ __wait.flags = 0; \
\
for (;;) { \
- prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
+ long __int = prepare_to_wait_event(&wq, &__wait, state);\
+ \
if (condition) \
break; \
- schedule(); \
+ \
+ if (___wait_is_interruptible(state) && __int) { \
+ __ret = __int; \
+ if (exclusive) { \
+ abort_exclusive_wait(&wq, &__wait, \
+ state, NULL); \
+ goto __out; \
+ } \
+ break; \
+ } \
+ \
+ cmd; \
} \
finish_wait(&wq, &__wait); \
-} while (0)
+__out: __ret; \
+})
+
+#define __wait_event(wq, condition) \
+ (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
+ schedule())
/**
* wait_event - sleep until a condition gets true
@@ -204,29 +241,17 @@ do { \
* 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)
-#define __wait_event_timeout(wq, condition, ret) \
-do { \
- DEFINE_WAIT(__wait); \
- \
- for (;;) { \
- prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
- if (condition) \
- break; \
- ret = schedule_timeout(ret); \
- if (!ret) \
- break; \
- } \
- if (!ret && (condition)) \
- ret = 1; \
- finish_wait(&wq, &__wait); \
-} while (0)
+#define __wait_event_timeout(wq, condition, timeout) \
+ ___wait_event(wq, ___wait_cond_timeout(condition), \
+ TASK_UNINTERRUPTIBLE, 0, timeout, \
+ __ret = schedule_timeout(__ret))
/**
* wait_event_timeout - sleep until a condition gets true or a timeout elapses
@@ -248,29 +273,40 @@ do { \
#define wait_event_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
- if (!(condition)) \
- __wait_event_timeout(wq, condition, __ret); \
+ if (!___wait_cond_timeout(condition)) \
+ __ret = __wait_event_timeout(wq, condition, timeout); \
__ret; \
})
-#define __wait_event_interruptible(wq, condition, ret) \
+#define __wait_event_cmd(wq, condition, cmd1, cmd2) \
+ (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
+ cmd1; schedule(); cmd2)
+
+/**
+ * wait_event_cmd - sleep until a condition gets true
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ * cmd1: the command will be executed before sleep
+ * cmd2: the command will be executed after sleep
+ *
+ * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
+ * @condition evaluates to true. The @condition is checked each time
+ * the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ */
+#define wait_event_cmd(wq, condition, cmd1, cmd2) \
do { \
- DEFINE_WAIT(__wait); \
- \
- for (;;) { \
- prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
- if (condition) \
- break; \
- if (!signal_pending(current)) { \
- schedule(); \
- continue; \
- } \
- ret = -ERESTARTSYS; \
+ if (condition) \
break; \
- } \
- finish_wait(&wq, &__wait); \
+ __wait_event_cmd(wq, condition, cmd1, cmd2); \
} while (0)
+#define __wait_event_interruptible(wq, condition) \
+ ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \
+ schedule())
+
/**
* wait_event_interruptible - sleep until a condition gets true
* @wq: the waitqueue to wait on
@@ -290,31 +326,14 @@ do { \
({ \
int __ret = 0; \
if (!(condition)) \
- __wait_event_interruptible(wq, condition, __ret); \
+ __ret = __wait_event_interruptible(wq, condition); \
__ret; \
})
-#define __wait_event_interruptible_timeout(wq, condition, ret) \
-do { \
- DEFINE_WAIT(__wait); \
- \
- for (;;) { \
- prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
- if (condition) \
- break; \
- if (!signal_pending(current)) { \
- ret = schedule_timeout(ret); \
- if (!ret) \
- break; \
- continue; \
- } \
- ret = -ERESTARTSYS; \
- break; \
- } \
- if (!ret && (condition)) \
- ret = 1; \
- finish_wait(&wq, &__wait); \
-} while (0)
+#define __wait_event_interruptible_timeout(wq, condition, timeout) \
+ ___wait_event(wq, ___wait_cond_timeout(condition), \
+ TASK_INTERRUPTIBLE, 0, timeout, \
+ __ret = schedule_timeout(__ret))
/**
* wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
@@ -337,15 +356,15 @@ do { \
#define wait_event_interruptible_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
- if (!(condition)) \
- __wait_event_interruptible_timeout(wq, condition, __ret); \
+ if (!___wait_cond_timeout(condition)) \
+ __ret = __wait_event_interruptible_timeout(wq, \
+ condition, timeout); \
__ret; \
})
#define __wait_event_hrtimeout(wq, condition, timeout, state) \
({ \
int __ret = 0; \
- DEFINE_WAIT(__wait); \
struct hrtimer_sleeper __t; \
\
hrtimer_init_on_stack(&__t.timer, CLOCK_MONOTONIC, \
@@ -356,25 +375,15 @@ do { \
current->timer_slack_ns, \
HRTIMER_MODE_REL); \
\
- for (;;) { \
- prepare_to_wait(&wq, &__wait, state); \
- if (condition) \
- break; \
- if (state == TASK_INTERRUPTIBLE && \
- signal_pending(current)) { \
- __ret = -ERESTARTSYS; \
- break; \
- } \
+ __ret = ___wait_event(wq, condition, state, 0, 0, \
if (!__t.task) { \
__ret = -ETIME; \
break; \
} \
- schedule(); \
- } \
+ schedule()); \
\
hrtimer_cancel(&__t.timer); \
destroy_hrtimer_on_stack(&__t.timer); \
- finish_wait(&wq, &__wait); \
__ret; \
})
@@ -428,33 +437,15 @@ do { \
__ret; \
})
-#define __wait_event_interruptible_exclusive(wq, condition, ret) \
-do { \
- DEFINE_WAIT(__wait); \
- \
- for (;;) { \
- prepare_to_wait_exclusive(&wq, &__wait, \
- TASK_INTERRUPTIBLE); \
- if (condition) { \
- finish_wait(&wq, &__wait); \
- break; \
- } \
- if (!signal_pending(current)) { \
- schedule(); \
- continue; \
- } \
- ret = -ERESTARTSYS; \
- abort_exclusive_wait(&wq, &__wait, \
- TASK_INTERRUPTIBLE, NULL); \
- break; \
- } \
-} while (0)
+#define __wait_event_interruptible_exclusive(wq, condition) \
+ ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \
+ schedule())
#define wait_event_interruptible_exclusive(wq, condition) \
({ \
int __ret = 0; \
if (!(condition)) \
- __wait_event_interruptible_exclusive(wq, condition, __ret);\
+ __ret = __wait_event_interruptible_exclusive(wq, condition);\
__ret; \
})
@@ -606,24 +597,8 @@ do { \
? 0 : __wait_event_interruptible_locked(wq, condition, 1, 1))
-
-#define __wait_event_killable(wq, condition, ret) \
-do { \
- DEFINE_WAIT(__wait); \
- \
- for (;;) { \
- prepare_to_wait(&wq, &__wait, TASK_KILLABLE); \
- if (condition) \
- break; \
- if (!fatal_signal_pending(current)) { \
- schedule(); \
- continue; \
- } \
- ret = -ERESTARTSYS; \
- break; \
- } \
- finish_wait(&wq, &__wait); \
-} while (0)
+#define __wait_event_killable(wq, condition) \
+ ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule())
/**
* wait_event_killable - sleep until a condition gets true
@@ -644,26 +619,17 @@ do { \
({ \
int __ret = 0; \
if (!(condition)) \
- __wait_event_killable(wq, condition, __ret); \
+ __ret = __wait_event_killable(wq, condition); \
__ret; \
})
#define __wait_event_lock_irq(wq, condition, lock, cmd) \
-do { \
- DEFINE_WAIT(__wait); \
- \
- for (;;) { \
- prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
- if (condition) \
- break; \
- spin_unlock_irq(&lock); \
- cmd; \
- schedule(); \
- spin_lock_irq(&lock); \
- } \
- finish_wait(&wq, &__wait); \
-} while (0)
+ (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
+ spin_unlock_irq(&lock); \
+ cmd; \
+ schedule(); \
+ spin_lock_irq(&lock))
/**
* wait_event_lock_irq_cmd - sleep until a condition gets true. The
@@ -723,26 +689,12 @@ do { \
} while (0)
-#define __wait_event_interruptible_lock_irq(wq, condition, \
- lock, ret, cmd) \
-do { \
- DEFINE_WAIT(__wait); \
- \
- for (;;) { \
- prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
- if (condition) \
- break; \
- if (signal_pending(current)) { \
- ret = -ERESTARTSYS; \
- break; \
- } \
- spin_unlock_irq(&lock); \
- cmd; \
- schedule(); \
- spin_lock_irq(&lock); \
- } \
- finish_wait(&wq, &__wait); \
-} while (0)
+#define __wait_event_interruptible_lock_irq(wq, condition, lock, cmd) \
+ ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \
+ spin_unlock_irq(&lock); \
+ cmd; \
+ schedule(); \
+ spin_lock_irq(&lock))
/**
* wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true.
@@ -772,10 +724,9 @@ do { \
#define wait_event_interruptible_lock_irq_cmd(wq, condition, lock, cmd) \
({ \
int __ret = 0; \
- \
if (!(condition)) \
- __wait_event_interruptible_lock_irq(wq, condition, \
- lock, __ret, cmd); \
+ __ret = __wait_event_interruptible_lock_irq(wq, \
+ condition, lock, cmd); \
__ret; \
})
@@ -804,39 +755,24 @@ do { \
#define wait_event_interruptible_lock_irq(wq, condition, lock) \
({ \
int __ret = 0; \
- \
if (!(condition)) \
- __wait_event_interruptible_lock_irq(wq, condition, \
- lock, __ret, ); \
+ __ret = __wait_event_interruptible_lock_irq(wq, \
+ condition, lock,); \
__ret; \
})
#define __wait_event_interruptible_lock_irq_timeout(wq, condition, \
- lock, ret) \
-do { \
- DEFINE_WAIT(__wait); \
- \
- for (;;) { \
- prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
- if (condition) \
- break; \
- if (signal_pending(current)) { \
- ret = -ERESTARTSYS; \
- break; \
- } \
- spin_unlock_irq(&lock); \
- ret = schedule_timeout(ret); \
- spin_lock_irq(&lock); \
- if (!ret) \
- break; \
- } \
- finish_wait(&wq, &__wait); \
-} while (0)
+ lock, timeout) \
+ ___wait_event(wq, ___wait_cond_timeout(condition), \
+ TASK_INTERRUPTIBLE, 0, timeout, \
+ 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()
@@ -860,11 +796,10 @@ do { \
#define wait_event_interruptible_lock_irq_timeout(wq, condition, lock, \
timeout) \
({ \
- int __ret = timeout; \
- \
- if (!(condition)) \
- __wait_event_interruptible_lock_irq_timeout( \
- wq, condition, lock, __ret); \
+ long __ret = timeout; \
+ if (!___wait_cond_timeout(condition)) \
+ __ret = __wait_event_interruptible_lock_irq_timeout( \
+ wq, condition, lock, timeout); \
__ret; \
})
@@ -875,20 +810,18 @@ 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);
+long prepare_to_wait_event(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);
@@ -934,8 +867,8 @@ 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;
@@ -958,8 +891,8 @@ 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;
@@ -983,5 +916,5 @@ 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 */