ecc017d24cf39de63fee8731befce2e9459fd32e
[linux-2.6.git] / include / linux / workqueue.h
1 /*
2  * workqueue.h --- work queue handling for Linux.
3  */
4
5 #ifndef _LINUX_WORKQUEUE_H
6 #define _LINUX_WORKQUEUE_H
7
8 #include <linux/timer.h>
9 #include <linux/linkage.h>
10 #include <linux/bitops.h>
11
12 struct workqueue_struct;
13
14 typedef void (*work_func_t)(void *data);
15
16 struct work_struct {
17         /* the first word is the work queue pointer and the pending flag
18          * rolled into one */
19         unsigned long management;
20 #define WORK_STRUCT_PENDING 0           /* T if work item pending execution */
21 #define WORK_STRUCT_FLAG_MASK (3UL)
22 #define WORK_STRUCT_WQ_DATA_MASK (~WORK_STRUCT_FLAG_MASK)
23         struct list_head entry;
24         work_func_t func;
25         void *data;
26 };
27
28 struct delayed_work {
29         struct work_struct work;
30         struct timer_list timer;
31 };
32
33 struct execute_work {
34         struct work_struct work;
35 };
36
37 #define __WORK_INITIALIZER(n, f, d) {                           \
38         .entry  = { &(n).entry, &(n).entry },                   \
39         .func = (f),                                            \
40         .data = (d),                                            \
41         }
42
43 #define __DELAYED_WORK_INITIALIZER(n, f, d) {                   \
44         .work = __WORK_INITIALIZER((n).work, (f), (d)),         \
45         .timer = TIMER_INITIALIZER(NULL, 0, 0),                 \
46         }
47
48 #define DECLARE_WORK(n, f, d)                                   \
49         struct work_struct n = __WORK_INITIALIZER(n, f, d)
50
51 #define DECLARE_DELAYED_WORK(n, f, d)                           \
52         struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, d)
53
54 /*
55  * initialize a work item's function and data pointers
56  */
57 #define PREPARE_WORK(_work, _func, _data)                       \
58         do {                                                    \
59                 (_work)->func = (_func);                        \
60                 (_work)->data = (_data);                        \
61         } while (0)
62
63 #define PREPARE_DELAYED_WORK(_work, _func, _data)               \
64         PREPARE_WORK(&(_work)->work, (_func), (_data))
65
66 /*
67  * initialize all of a work item in one go
68  */
69 #define INIT_WORK(_work, _func, _data)                          \
70         do {                                                    \
71                 INIT_LIST_HEAD(&(_work)->entry);                \
72                 (_work)->management = 0;                        \
73                 PREPARE_WORK((_work), (_func), (_data));        \
74         } while (0)
75
76 #define INIT_DELAYED_WORK(_work, _func, _data)          \
77         do {                                                    \
78                 INIT_WORK(&(_work)->work, (_func), (_data));    \
79                 init_timer(&(_work)->timer);                    \
80         } while (0)
81
82 /**
83  * work_pending - Find out whether a work item is currently pending
84  * @work: The work item in question
85  */
86 #define work_pending(work) \
87         test_bit(WORK_STRUCT_PENDING, &(work)->management)
88
89 /**
90  * delayed_work_pending - Find out whether a delayable work item is currently
91  * pending
92  * @work: The work item in question
93  */
94 #define delayed_work_pending(work) \
95         test_bit(WORK_STRUCT_PENDING, &(work)->work.management)
96
97
98 extern struct workqueue_struct *__create_workqueue(const char *name,
99                                                     int singlethread);
100 #define create_workqueue(name) __create_workqueue((name), 0)
101 #define create_singlethread_workqueue(name) __create_workqueue((name), 1)
102
103 extern void destroy_workqueue(struct workqueue_struct *wq);
104
105 extern int FASTCALL(queue_work(struct workqueue_struct *wq, struct work_struct *work));
106 extern int FASTCALL(queue_delayed_work(struct workqueue_struct *wq, struct delayed_work *work, unsigned long delay));
107 extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
108         struct delayed_work *work, unsigned long delay);
109 extern void FASTCALL(flush_workqueue(struct workqueue_struct *wq));
110
111 extern int FASTCALL(schedule_work(struct work_struct *work));
112 extern int FASTCALL(schedule_delayed_work(struct delayed_work *work, unsigned long delay));
113
114 extern int schedule_delayed_work_on(int cpu, struct delayed_work *work, unsigned long delay);
115 extern int schedule_on_each_cpu(work_func_t func, void *info);
116 extern void flush_scheduled_work(void);
117 extern int current_is_keventd(void);
118 extern int keventd_up(void);
119
120 extern void init_workqueues(void);
121 void cancel_rearming_delayed_work(struct delayed_work *work);
122 void cancel_rearming_delayed_workqueue(struct workqueue_struct *,
123                                        struct delayed_work *);
124 int execute_in_process_context(work_func_t fn, void *, struct execute_work *);
125
126 /*
127  * Kill off a pending schedule_delayed_work().  Note that the work callback
128  * function may still be running on return from cancel_delayed_work().  Run
129  * flush_scheduled_work() to wait on it.
130  */
131 static inline int cancel_delayed_work(struct delayed_work *work)
132 {
133         int ret;
134
135         ret = del_timer_sync(&work->timer);
136         if (ret)
137                 clear_bit(WORK_STRUCT_PENDING, &work->work.management);
138         return ret;
139 }
140
141 #endif