cf24c20de9e48e43a4712722196aad8555207d8c
[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 #include <linux/lockdep.h>
12 #include <asm/atomic.h>
13
14 struct workqueue_struct;
15
16 struct work_struct;
17 typedef void (*work_func_t)(struct work_struct *work);
18
19 /*
20  * The first word is the work queue pointer and the flags rolled into
21  * one
22  */
23 #define work_data_bits(work) ((unsigned long *)(&(work)->data))
24
25 struct work_struct {
26         atomic_long_t data;
27 #define WORK_STRUCT_PENDING 0           /* T if work item pending execution */
28 #define WORK_STRUCT_FLAG_MASK (3UL)
29 #define WORK_STRUCT_WQ_DATA_MASK (~WORK_STRUCT_FLAG_MASK)
30         struct list_head entry;
31         work_func_t func;
32 #ifdef CONFIG_LOCKDEP
33         struct lockdep_map lockdep_map;
34 #endif
35 };
36
37 #define WORK_DATA_INIT()        ATOMIC_LONG_INIT(0)
38
39 struct delayed_work {
40         struct work_struct work;
41         struct timer_list timer;
42 };
43
44 static inline struct delayed_work *to_delayed_work(struct work_struct *work)
45 {
46         return container_of(work, struct delayed_work, work);
47 }
48
49 struct execute_work {
50         struct work_struct work;
51 };
52
53 #ifdef CONFIG_LOCKDEP
54 /*
55  * NB: because we have to copy the lockdep_map, setting _key
56  * here is required, otherwise it could get initialised to the
57  * copy of the lockdep_map!
58  */
59 #define __WORK_INIT_LOCKDEP_MAP(n, k) \
60         .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
61 #else
62 #define __WORK_INIT_LOCKDEP_MAP(n, k)
63 #endif
64
65 #define __WORK_INITIALIZER(n, f) {                              \
66         .data = WORK_DATA_INIT(),                               \
67         .entry  = { &(n).entry, &(n).entry },                   \
68         .func = (f),                                            \
69         __WORK_INIT_LOCKDEP_MAP(#n, &(n))                       \
70         }
71
72 #define __DELAYED_WORK_INITIALIZER(n, f) {                      \
73         .work = __WORK_INITIALIZER((n).work, (f)),              \
74         .timer = TIMER_INITIALIZER(NULL, 0, 0),                 \
75         }
76
77 #define DECLARE_WORK(n, f)                                      \
78         struct work_struct n = __WORK_INITIALIZER(n, f)
79
80 #define DECLARE_DELAYED_WORK(n, f)                              \
81         struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f)
82
83 /*
84  * initialize a work item's function pointer
85  */
86 #define PREPARE_WORK(_work, _func)                              \
87         do {                                                    \
88                 (_work)->func = (_func);                        \
89         } while (0)
90
91 #define PREPARE_DELAYED_WORK(_work, _func)                      \
92         PREPARE_WORK(&(_work)->work, (_func))
93
94 /*
95  * initialize all of a work item in one go
96  *
97  * NOTE! No point in using "atomic_long_set()": using a direct
98  * assignment of the work data initializer allows the compiler
99  * to generate better code.
100  */
101 #ifdef CONFIG_LOCKDEP
102 #define INIT_WORK(_work, _func)                                         \
103         do {                                                            \
104                 static struct lock_class_key __key;                     \
105                                                                         \
106                 (_work)->data = (atomic_long_t) WORK_DATA_INIT();       \
107                 lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0);\
108                 INIT_LIST_HEAD(&(_work)->entry);                        \
109                 PREPARE_WORK((_work), (_func));                         \
110         } while (0)
111 #else
112 #define INIT_WORK(_work, _func)                                         \
113         do {                                                            \
114                 (_work)->data = (atomic_long_t) WORK_DATA_INIT();       \
115                 INIT_LIST_HEAD(&(_work)->entry);                        \
116                 PREPARE_WORK((_work), (_func));                         \
117         } while (0)
118 #endif
119
120 #define INIT_DELAYED_WORK(_work, _func)                         \
121         do {                                                    \
122                 INIT_WORK(&(_work)->work, (_func));             \
123                 init_timer(&(_work)->timer);                    \
124         } while (0)
125
126 #define INIT_DELAYED_WORK_ON_STACK(_work, _func)                \
127         do {                                                    \
128                 INIT_WORK(&(_work)->work, (_func));             \
129                 init_timer_on_stack(&(_work)->timer);           \
130         } while (0)
131
132 #define INIT_DELAYED_WORK_DEFERRABLE(_work, _func)                      \
133         do {                                                    \
134                 INIT_WORK(&(_work)->work, (_func));             \
135                 init_timer_deferrable(&(_work)->timer);         \
136         } while (0)
137
138 #define INIT_DELAYED_WORK_ON_STACK(_work, _func)                \
139         do {                                                    \
140                 INIT_WORK(&(_work)->work, (_func));             \
141                 init_timer_on_stack(&(_work)->timer);           \
142         } while (0)
143
144 /**
145  * work_pending - Find out whether a work item is currently pending
146  * @work: The work item in question
147  */
148 #define work_pending(work) \
149         test_bit(WORK_STRUCT_PENDING, work_data_bits(work))
150
151 /**
152  * delayed_work_pending - Find out whether a delayable work item is currently
153  * pending
154  * @work: The work item in question
155  */
156 #define delayed_work_pending(w) \
157         work_pending(&(w)->work)
158
159 /**
160  * work_clear_pending - for internal use only, mark a work item as not pending
161  * @work: The work item in question
162  */
163 #define work_clear_pending(work) \
164         clear_bit(WORK_STRUCT_PENDING, work_data_bits(work))
165
166
167 extern struct workqueue_struct *
168 __create_workqueue_key(const char *name, int singlethread,
169                        int freezeable, int rt, struct lock_class_key *key,
170                        const char *lock_name);
171
172 #ifdef CONFIG_LOCKDEP
173 #define __create_workqueue(name, singlethread, freezeable, rt)  \
174 ({                                                              \
175         static struct lock_class_key __key;                     \
176         const char *__lock_name;                                \
177                                                                 \
178         if (__builtin_constant_p(name))                         \
179                 __lock_name = (name);                           \
180         else                                                    \
181                 __lock_name = #name;                            \
182                                                                 \
183         __create_workqueue_key((name), (singlethread),          \
184                                (freezeable), (rt), &__key,      \
185                                __lock_name);                    \
186 })
187 #else
188 #define __create_workqueue(name, singlethread, freezeable, rt)  \
189         __create_workqueue_key((name), (singlethread), (freezeable), (rt), \
190                                NULL, NULL)
191 #endif
192
193 #define create_workqueue(name) __create_workqueue((name), 0, 0, 0)
194 #define create_rt_workqueue(name) __create_workqueue((name), 0, 0, 1)
195 #define create_freezeable_workqueue(name) __create_workqueue((name), 1, 1, 0)
196 #define create_singlethread_workqueue(name) __create_workqueue((name), 1, 0, 0)
197
198 extern void destroy_workqueue(struct workqueue_struct *wq);
199
200 extern int queue_work(struct workqueue_struct *wq, struct work_struct *work);
201 extern int queue_work_on(int cpu, struct workqueue_struct *wq,
202                         struct work_struct *work);
203 extern int queue_delayed_work(struct workqueue_struct *wq,
204                         struct delayed_work *work, unsigned long delay);
205 extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
206                         struct delayed_work *work, unsigned long delay);
207
208 extern void flush_workqueue(struct workqueue_struct *wq);
209 extern void flush_scheduled_work(void);
210 extern void flush_delayed_work(struct delayed_work *work);
211
212 extern int schedule_work(struct work_struct *work);
213 extern int schedule_work_on(int cpu, struct work_struct *work);
214 extern int schedule_delayed_work(struct delayed_work *work, unsigned long delay);
215 extern int schedule_delayed_work_on(int cpu, struct delayed_work *work,
216                                         unsigned long delay);
217 extern int schedule_on_each_cpu(work_func_t func);
218 extern int current_is_keventd(void);
219 extern int keventd_up(void);
220
221 extern void init_workqueues(void);
222 int execute_in_process_context(work_func_t fn, struct execute_work *);
223
224 extern int flush_work(struct work_struct *work);
225
226 extern int cancel_work_sync(struct work_struct *work);
227
228 /*
229  * Kill off a pending schedule_delayed_work().  Note that the work callback
230  * function may still be running on return from cancel_delayed_work(), unless
231  * it returns 1 and the work doesn't re-arm itself. Run flush_workqueue() or
232  * cancel_work_sync() to wait on it.
233  */
234 static inline int cancel_delayed_work(struct delayed_work *work)
235 {
236         int ret;
237
238         ret = del_timer_sync(&work->timer);
239         if (ret)
240                 work_clear_pending(&work->work);
241         return ret;
242 }
243
244 /*
245  * Like above, but uses del_timer() instead of del_timer_sync(). This means,
246  * if it returns 0 the timer function may be running and the queueing is in
247  * progress.
248  */
249 static inline int __cancel_delayed_work(struct delayed_work *work)
250 {
251         int ret;
252
253         ret = del_timer(&work->timer);
254         if (ret)
255                 work_clear_pending(&work->work);
256         return ret;
257 }
258
259 extern int cancel_delayed_work_sync(struct delayed_work *work);
260
261 /* Obsolete. use cancel_delayed_work_sync() */
262 static inline
263 void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq,
264                                         struct delayed_work *work)
265 {
266         cancel_delayed_work_sync(work);
267 }
268
269 /* Obsolete. use cancel_delayed_work_sync() */
270 static inline
271 void cancel_rearming_delayed_work(struct delayed_work *work)
272 {
273         cancel_delayed_work_sync(work);
274 }
275
276 #ifndef CONFIG_SMP
277 static inline long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
278 {
279         return fn(arg);
280 }
281 #else
282 long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg);
283 #endif /* CONFIG_SMP */
284 #endif