5c89ac6e7f559c08273659e2bf65f278e7d04ca7
[linux-3.10.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 #include <asm/atomic.h>
12
13 struct workqueue_struct;
14
15 struct work_struct;
16 typedef void (*work_func_t)(struct work_struct *work);
17
18 /*
19  * The first word is the work queue pointer and the flags rolled into
20  * one
21  */
22 #define work_data_bits(work) ((unsigned long *)(&(work)->data))
23
24 struct work_struct {
25         atomic_long_t data;
26 #define WORK_STRUCT_PENDING 0           /* T if work item pending execution */
27 #define WORK_STRUCT_FLAG_MASK (3UL)
28 #define WORK_STRUCT_WQ_DATA_MASK (~WORK_STRUCT_FLAG_MASK)
29         struct list_head entry;
30         work_func_t func;
31 };
32
33 #define WORK_DATA_INIT()        ATOMIC_LONG_INIT(0)
34
35 struct delayed_work {
36         struct work_struct work;
37         struct timer_list timer;
38 };
39
40 struct execute_work {
41         struct work_struct work;
42 };
43
44 #define __WORK_INITIALIZER(n, f) {                              \
45         .data = WORK_DATA_INIT(),                               \
46         .entry  = { &(n).entry, &(n).entry },                   \
47         .func = (f),                                            \
48         }
49
50 #define __DELAYED_WORK_INITIALIZER(n, f) {                      \
51         .work = __WORK_INITIALIZER((n).work, (f)),              \
52         .timer = TIMER_INITIALIZER(NULL, 0, 0),                 \
53         }
54
55 #define DECLARE_WORK(n, f)                                      \
56         struct work_struct n = __WORK_INITIALIZER(n, f)
57
58 #define DECLARE_DELAYED_WORK(n, f)                              \
59         struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f)
60
61 /*
62  * initialize a work item's function pointer
63  */
64 #define PREPARE_WORK(_work, _func)                              \
65         do {                                                    \
66                 (_work)->func = (_func);                        \
67         } while (0)
68
69 #define PREPARE_DELAYED_WORK(_work, _func)                      \
70         PREPARE_WORK(&(_work)->work, (_func))
71
72 /*
73  * initialize all of a work item in one go
74  *
75  * NOTE! No point in using "atomic_long_set()": useing a direct
76  * assignment of the work data initializer allows the compiler
77  * to generate better code.
78  */
79 #define INIT_WORK(_work, _func)                                         \
80         do {                                                            \
81                 (_work)->data = (atomic_long_t) WORK_DATA_INIT();       \
82                 INIT_LIST_HEAD(&(_work)->entry);                        \
83                 PREPARE_WORK((_work), (_func));                         \
84         } while (0)
85
86 #define INIT_DELAYED_WORK(_work, _func)                         \
87         do {                                                    \
88                 INIT_WORK(&(_work)->work, (_func));             \
89                 init_timer(&(_work)->timer);                    \
90         } while (0)
91
92 #define INIT_DELAYED_WORK_DEFERRABLE(_work, _func)                      \
93         do {                                                    \
94                 INIT_WORK(&(_work)->work, (_func));             \
95                 init_timer_deferrable(&(_work)->timer);         \
96         } while (0)
97
98 /**
99  * work_pending - Find out whether a work item is currently pending
100  * @work: The work item in question
101  */
102 #define work_pending(work) \
103         test_bit(WORK_STRUCT_PENDING, work_data_bits(work))
104
105 /**
106  * delayed_work_pending - Find out whether a delayable work item is currently
107  * pending
108  * @work: The work item in question
109  */
110 #define delayed_work_pending(w) \
111         work_pending(&(w)->work)
112
113 /**
114  * work_clear_pending - for internal use only, mark a work item as not pending
115  * @work: The work item in question
116  */
117 #define work_clear_pending(work) \
118         clear_bit(WORK_STRUCT_PENDING, work_data_bits(work))
119
120
121 extern struct workqueue_struct *__create_workqueue(const char *name,
122                                                     int singlethread,
123                                                     int freezeable);
124 #define create_workqueue(name) __create_workqueue((name), 0, 0)
125 #define create_freezeable_workqueue(name) __create_workqueue((name), 1, 1)
126 #define create_singlethread_workqueue(name) __create_workqueue((name), 1, 0)
127
128 extern void destroy_workqueue(struct workqueue_struct *wq);
129
130 extern int FASTCALL(queue_work(struct workqueue_struct *wq, struct work_struct *work));
131 extern int FASTCALL(queue_delayed_work(struct workqueue_struct *wq,
132                         struct delayed_work *work, unsigned long delay));
133 extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
134                         struct delayed_work *work, unsigned long delay);
135
136 extern void FASTCALL(flush_workqueue(struct workqueue_struct *wq));
137 extern void flush_scheduled_work(void);
138
139 extern int FASTCALL(schedule_work(struct work_struct *work));
140 extern int FASTCALL(schedule_delayed_work(struct delayed_work *work,
141                                         unsigned long delay));
142 extern int schedule_delayed_work_on(int cpu, struct delayed_work *work,
143                                         unsigned long delay);
144 extern int schedule_on_each_cpu(work_func_t func);
145 extern int current_is_keventd(void);
146 extern int keventd_up(void);
147
148 extern void init_workqueues(void);
149 int execute_in_process_context(work_func_t fn, struct execute_work *);
150
151 extern void cancel_work_sync(struct work_struct *work);
152
153 /*
154  * Kill off a pending schedule_delayed_work().  Note that the work callback
155  * function may still be running on return from cancel_delayed_work(), unless
156  * it returns 1 and the work doesn't re-arm itself. Run flush_workqueue() or
157  * cancel_work_sync() to wait on it.
158  */
159 static inline int cancel_delayed_work(struct delayed_work *work)
160 {
161         int ret;
162
163         ret = del_timer_sync(&work->timer);
164         if (ret)
165                 work_clear_pending(&work->work);
166         return ret;
167 }
168
169 extern void cancel_delayed_work_sync(struct delayed_work *work);
170
171 /* Obsolete. use cancel_delayed_work_sync() */
172 static inline
173 void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq,
174                                         struct delayed_work *work)
175 {
176         cancel_delayed_work_sync(work);
177 }
178
179 /* Obsolete. use cancel_delayed_work_sync() */
180 static inline
181 void cancel_rearming_delayed_work(struct delayed_work *work)
182 {
183         cancel_delayed_work_sync(work);
184 }
185
186 #endif