projects/linux·blob 0221872a · refs

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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
12struct workqueue_struct;
13
14struct work_struct;
15typedef void (*work_func_t)(struct work_struct *work);
16
17struct work_struct {
18 /* the first word is the work queue pointer and the flags rolled into
19 * one */
20 unsigned long management;
21#define WORK_STRUCT_PENDING 0 /* T if work item pending execution */
22#define WORK_STRUCT_NOAUTOREL 1 /* F if work item automatically released on exec */
23#define WORK_STRUCT_FLAG_MASK (3UL)
24#define WORK_STRUCT_WQ_DATA_MASK (~WORK_STRUCT_FLAG_MASK)
25 struct list_head entry;
26 work_func_t func;
27};
28
29struct delayed_work {
30 struct work_struct work;
31 struct timer_list timer;
32};
33
34struct execute_work {
35 struct work_struct work;
36};
37
38#define __WORK_INITIALIZER(n, f) { \
39 .management = 0, \
40 .entry = { &(n).entry, &(n).entry }, \
41 .func = (f), \
42 }
43
44#define __WORK_INITIALIZER_NAR(n, f) { \
45 .management = (1 << WORK_STRUCT_NOAUTOREL), \
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 __DELAYED_WORK_INITIALIZER_NAR(n, f) { \
56 .work = __WORK_INITIALIZER_NAR((n).work, (f)), \
57 .timer = TIMER_INITIALIZER(NULL, 0, 0), \
58 }
59
60#define DECLARE_WORK(n, f) \
61 struct work_struct n = __WORK_INITIALIZER(n, f)
62
63#define DECLARE_WORK_NAR(n, f) \
64 struct work_struct n = __WORK_INITIALIZER_NAR(n, f)
65
66#define DECLARE_DELAYED_WORK(n, f) \
67 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f)
68
69#define DECLARE_DELAYED_WORK_NAR(n, f) \
70 struct dwork_struct n = __DELAYED_WORK_INITIALIZER_NAR(n, f)
71
72/*
73 * initialize a work item's function pointer
74 */
75#define PREPARE_WORK(_work, _func) \
76 do { \
77 (_work)->func = (_func); \
78 } while (0)
79
80#define PREPARE_DELAYED_WORK(_work, _func) \
81 PREPARE_WORK(&(_work)->work, (_func))
82
83/*
84 * initialize all of a work item in one go
85 */
86#define INIT_WORK(_work, _func) \
87 do { \
88 (_work)->management = 0; \
89 INIT_LIST_HEAD(&(_work)->entry); \
90 PREPARE_WORK((_work), (_func)); \
91 } while (0)
92
93#define INIT_WORK_NAR(_work, _func) \
94 do { \
95 (_work)->management = (1 << WORK_STRUCT_NOAUTOREL); \
96 INIT_LIST_HEAD(&(_work)->entry); \
97 PREPARE_WORK((_work), (_func)); \
98 } while (0)
99
100#define INIT_DELAYED_WORK(_work, _func) \
101 do { \
102 INIT_WORK(&(_work)->work, (_func)); \
103 init_timer(&(_work)->timer); \
104 } while (0)
105
106#define INIT_DELAYED_WORK_NAR(_work, _func) \
107 do { \
108 INIT_WORK_NAR(&(_work)->work, (_func)); \
109 init_timer(&(_work)->timer); \
110 } while (0)
111
112/**
113 * work_pending - Find out whether a work item is currently pending
114 * @work: The work item in question
115 */
116#define work_pending(work) \
117 test_bit(WORK_STRUCT_PENDING, &(work)->management)
118
119/**
120 * delayed_work_pending - Find out whether a delayable work item is currently
121 * pending
122 * @work: The work item in question
123 */
124#define delayed_work_pending(w) \
125 work_pending(&(w)->work)
126
127/**
128 * work_release - Release a work item under execution
129 * @work: The work item to release
130 *
131 * This is used to release a work item that has been initialised with automatic
132 * release mode disabled (WORK_STRUCT_NOAUTOREL is set). This gives the work
133 * function the opportunity to grab auxiliary data from the container of the
134 * work_struct before clearing the pending bit as the work_struct may be
135 * subject to deallocation the moment the pending bit is cleared.
136 *
137 * In such a case, this should be called in the work function after it has
138 * fetched any data it may require from the containter of the work_struct.
139 * After this function has been called, the work_struct may be scheduled for
140 * further execution or it may be deallocated unless other precautions are
141 * taken.
142 *
143 * This should also be used to release a delayed work item.
144 */
145#define work_release(work) \
146 clear_bit(WORK_STRUCT_PENDING, &(work)->management)
147
148
149extern struct workqueue_struct *__create_workqueue(const char *name,
150 int singlethread,
151 int freezeable);
152#define create_workqueue(name) __create_workqueue((name), 0, 0)
153#define create_freezeable_workqueue(name) __create_workqueue((name), 0, 1)
154#define create_singlethread_workqueue(name) __create_workqueue((name), 1, 0)
155
156extern void destroy_workqueue(struct workqueue_struct *wq);
157
158extern int FASTCALL(queue_work(struct workqueue_struct *wq, struct work_struct *work));
159extern int FASTCALL(queue_delayed_work(struct workqueue_struct *wq, struct delayed_work *work, unsigned long delay));
160extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
161 struct delayed_work *work, unsigned long delay);
162extern void FASTCALL(flush_workqueue(struct workqueue_struct *wq));
163
164extern int FASTCALL(schedule_work(struct work_struct *work));
165extern int FASTCALL(run_scheduled_work(struct work_struct *work));
166extern int FASTCALL(schedule_delayed_work(struct delayed_work *work, unsigned long delay));
167
168extern int schedule_delayed_work_on(int cpu, struct delayed_work *work, unsigned long delay);
169extern int schedule_on_each_cpu(work_func_t func);
170extern void flush_scheduled_work(void);
171extern int current_is_keventd(void);
172extern int keventd_up(void);
173
174extern void init_workqueues(void);
175void cancel_rearming_delayed_work(struct delayed_work *work);
176void cancel_rearming_delayed_workqueue(struct workqueue_struct *,
177 struct delayed_work *);
178int execute_in_process_context(work_func_t fn, struct execute_work *);
179
180/*
181 * Kill off a pending schedule_delayed_work(). Note that the work callback
182 * function may still be running on return from cancel_delayed_work(). Run
183 * flush_scheduled_work() to wait on it.
184 */
185static inline int cancel_delayed_work(struct delayed_work *work)
186{
187 int ret;
188
189 ret = del_timer_sync(&work->timer);
190 if (ret)
191 clear_bit(WORK_STRUCT_PENDING, &work->work.management);
192 return ret;
193}
194
195#endif