fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / include / linux / wait.h
index ddb0a16..2e079bf 100644 (file)
@@ -19,7 +19,6 @@
 
 #ifdef __KERNEL__
 
-#include <linux/config.h>
 #include <linux/list.h>
 #include <linux/stddef.h>
 #include <linux/spinlock.h>
@@ -33,7 +32,7 @@ int default_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key
 struct __wait_queue {
        unsigned int flags;
 #define WQ_FLAG_EXCLUSIVE      0x01
-       struct task_struct * task;
+       void *private;
        wait_queue_func_t func;
        struct list_head task_list;
 };
@@ -54,13 +53,14 @@ struct __wait_queue_head {
 };
 typedef struct __wait_queue_head wait_queue_head_t;
 
+struct task_struct;
 
 /*
  * Macros for declaration and initialisaton of the datatypes
  */
 
 #define __WAITQUEUE_INITIALIZER(name, tsk) {                           \
-       .task           = tsk,                                          \
+       .private        = tsk,                                          \
        .func           = default_wake_function,                        \
        .task_list      = { NULL, NULL } }
 
@@ -68,7 +68,7 @@ typedef struct __wait_queue_head wait_queue_head_t;
        wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk)
 
 #define __WAIT_QUEUE_HEAD_INITIALIZER(name) {                          \
-       .lock           = SPIN_LOCK_UNLOCKED,                           \
+       .lock           = __SPIN_LOCK_UNLOCKED(name.lock),              \
        .task_list      = { &(name).task_list, &(name).task_list } }
 
 #define DECLARE_WAIT_QUEUE_HEAD(name) \
@@ -77,16 +77,21 @@ typedef struct __wait_queue_head wait_queue_head_t;
 #define __WAIT_BIT_KEY_INITIALIZER(word, bit)                          \
        { .flags = word, .bit_nr = bit, }
 
-static inline void init_waitqueue_head(wait_queue_head_t *q)
-{
-       q->lock = SPIN_LOCK_UNLOCKED;
-       INIT_LIST_HEAD(&q->task_list);
-}
+extern void init_waitqueue_head(wait_queue_head_t *q);
+
+#ifdef CONFIG_LOCKDEP
+# define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \
+       ({ init_waitqueue_head(&name); name; })
+# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \
+       wait_queue_head_t name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
+#else
+# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name)
+#endif
 
 static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
 {
        q->flags = 0;
-       q->task = p;
+       q->private = p;
        q->func = default_wake_function;
 }
 
@@ -94,7 +99,7 @@ static inline void init_waitqueue_func_entry(wait_queue_t *q,
                                        wait_queue_func_t func)
 {
        q->flags = 0;
-       q->task = NULL;
+       q->private = NULL;
        q->func = func;
 }
 
@@ -110,7 +115,7 @@ static inline int waitqueue_active(wait_queue_head_t *q)
  * aio specifies a wait queue entry with an async notification
  * callback routine, not associated with any task.
  */
-#define is_sync_wait(wait)     (!(wait) || ((wait)->task))
+#define is_sync_wait(wait)     (!(wait) || ((wait)->private))
 
 extern void FASTCALL(add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait));
 extern void FASTCALL(add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait));
@@ -169,6 +174,18 @@ do {                                                                       \
        finish_wait(&wq, &__wait);                                      \
 } while (0)
 
+/**
+ * wait_event - sleep until a condition gets true
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ *
+ * 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(wq, condition)                                      \
 do {                                                                   \
        if (condition)                                                  \
@@ -191,6 +208,22 @@ do {                                                                       \
        finish_wait(&wq, &__wait);                                      \
 } while (0)
 
+/**
+ * wait_event_timeout - sleep until a condition gets true or a timeout elapses
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ * @timeout: timeout, in jiffies
+ *
+ * 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.
+ *
+ * The function returns 0 if the @timeout elapsed, and the remaining
+ * jiffies if the condition evaluated to true before the timeout elapsed.
+ */
 #define wait_event_timeout(wq, condition, timeout)                     \
 ({                                                                     \
        long __ret = timeout;                                           \
@@ -217,6 +250,21 @@ do {                                                                       \
        finish_wait(&wq, &__wait);                                      \
 } while (0)
 
+/**
+ * wait_event_interruptible - sleep until a condition gets true
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ *
+ * The process is put to sleep (TASK_INTERRUPTIBLE) until the
+ * @condition evaluates to true or a signal is received.
+ * 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.
+ *
+ * The function will return -ERESTARTSYS if it was interrupted by a
+ * signal and 0 if @condition evaluated to true.
+ */
 #define wait_event_interruptible(wq, condition)                                \
 ({                                                                     \
        int __ret = 0;                                                  \
@@ -245,6 +293,23 @@ do {                                                                       \
        finish_wait(&wq, &__wait);                                      \
 } while (0)
 
+/**
+ * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ * @timeout: timeout, in jiffies
+ *
+ * The process is put to sleep (TASK_INTERRUPTIBLE) until the
+ * @condition evaluates to true or a signal is received.
+ * 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.
+ *
+ * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
+ * was interrupted by a signal, and the remaining jiffies otherwise
+ * if the condition evaluated to true before the timeout elapsed.
+ */
 #define wait_event_interruptible_timeout(wq, condition, timeout)       \
 ({                                                                     \
        long __ret = timeout;                                           \
@@ -304,10 +369,10 @@ static inline void remove_wait_queue_locked(wait_queue_head_t *q,
  * They are racy.  DO NOT use them, use the wait_event* interfaces above.  
  * We plan to remove these interfaces during 2.7.
  */
-extern void FASTCALL(sleep_on(wait_queue_head_t *q));
-extern long FASTCALL(sleep_on_timeout(wait_queue_head_t *q,
+extern void __deprecated FASTCALL(sleep_on(wait_queue_head_t *q));
+extern long __deprecated FASTCALL(sleep_on_timeout(wait_queue_head_t *q,
                                      signed long timeout));
-extern void FASTCALL(interruptible_sleep_on(wait_queue_head_t *q));
+extern void __deprecated FASTCALL(interruptible_sleep_on(wait_queue_head_t *q));
 extern long FASTCALL(interruptible_sleep_on_timeout(wait_queue_head_t *q,
                                                    signed long timeout));
 
@@ -324,18 +389,16 @@ int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
 
 #define DEFINE_WAIT(name)                                              \
        wait_queue_t name = {                                           \
-               .task           = current,                              \
+               .private        = current,                              \
                .func           = autoremove_wake_function,             \
-               .task_list      = {     .next = &(name).task_list,      \
-                                       .prev = &(name).task_list,      \
-                               },                                      \
+               .task_list      = LIST_HEAD_INIT((name).task_list),     \
        }
 
 #define DEFINE_WAIT_BIT(name, word, bit)                               \
        struct wait_bit_queue name = {                                  \
                .key = __WAIT_BIT_KEY_INITIALIZER(word, bit),           \
                .wait   = {                                             \
-                       .task           = current,                      \
+                       .private        = current,                      \
                        .func           = wake_bit_function,            \
                        .task_list      =                               \
                                LIST_HEAD_INIT((name).wait.task_list),  \
@@ -344,7 +407,7 @@ int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
 
 #define init_wait(wait)                                                        \
        do {                                                            \
-               (wait)->task = current;                                 \
+               (wait)->private = current;                              \
                (wait)->func = autoremove_wake_function;                \
                INIT_LIST_HEAD(&(wait)->task_list);                     \
        } while (0)