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 int 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 int 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