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_STATIC  1           /* static initializer (debugobjects) */
  29 #define WORK_STRUCT_FLAG_MASK (3UL)
  30 #define WORK_STRUCT_WQ_DATA_MASK (~WORK_STRUCT_FLAG_MASK)
  31         struct list_head entry;
  32         work_func_t func;
  33 #ifdef CONFIG_LOCKDEP
  34         struct lockdep_map lockdep_map;
  35 #endif
  36 };
  37
  38 #define WORK_DATA_INIT()        ATOMIC_LONG_INIT(0)
  39 #define WORK_DATA_STATIC_INIT() ATOMIC_LONG_INIT(2)
  40
  41 struct delayed_work {
  42         struct work_struct work;
  43         struct timer_list timer;
  44 };
  45
  46 static inline struct delayed_work *to_delayed_work(struct work_struct *work)
  47 {
  48         return container_of(work, struct delayed_work, work);
  49 }
  50
  51 struct execute_work {
  52         struct work_struct work;
  53 };
  54
  55 #ifdef CONFIG_LOCKDEP
  56 /*
  57  * NB: because we have to copy the lockdep_map, setting _key
  58  * here is required, otherwise it could get initialised to the
  59  * copy of the lockdep_map!
  60  */
  61 #define __WORK_INIT_LOCKDEP_MAP(n, k) \
  62         .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
  63 #else
  64 #define __WORK_INIT_LOCKDEP_MAP(n, k)
  65 #endif
  66
  67 #define __WORK_INITIALIZER(n, f) {                              \
  68         .data = WORK_DATA_STATIC_INIT(),                        \
  69         .entry  = { &(n).entry, &(n).entry },                   \
  70         .func = (f),                                            \
  71         __WORK_INIT_LOCKDEP_MAP(#n, &(n))                       \
  72         }
  73
  74 #define __DELAYED_WORK_INITIALIZER(n, f) {                      \
  75         .work = __WORK_INITIALIZER((n).work, (f)),              \
  76         .timer = TIMER_INITIALIZER(NULL, 0, 0),                 \
  77         }
  78
  79 #define DECLARE_WORK(n, f)                                      \
  80         struct work_struct n = __WORK_INITIALIZER(n, f)
  81
  82 #define DECLARE_DELAYED_WORK(n, f)                              \
  83         struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f)
  84
  85 /*
  86  * initialize a work item's function pointer
  87  */
  88 #define PREPARE_WORK(_work, _func)                              \
  89         do {                                                    \
  90                 (_work)->func = (_func);                        \
  91         } while (0)
  92
  93 #define PREPARE_DELAYED_WORK(_work, _func)                      \
  94         PREPARE_WORK(&(_work)->work, (_func))
  95
  96 #ifdef CONFIG_DEBUG_OBJECTS_WORK
  97 extern void __init_work(struct work_struct *work, int onstack);
  98 extern void destroy_work_on_stack(struct work_struct *work);
  99 #else
 100 static inline void __init_work(struct work_struct *work, int onstack) { }
 101 static inline void destroy_work_on_stack(struct work_struct *work) { }
 102 #endif
 103
 104 /*
 105  * initialize all of a work item in one go
 106  *
 107  * NOTE! No point in using "atomic_long_set()": using a direct
 108  * assignment of the work data initializer allows the compiler
 109  * to generate better code.
 110  */
 111 #ifdef CONFIG_LOCKDEP
 112 #define __INIT_WORK(_work, _func, _onstack)                             \
 113         do {                                                            \
 114                 static struct lock_class_key __key;                     \
 115                                                                         \
 116                 __init_work((_work), _onstack);                         \
 117                 (_work)->data = (atomic_long_t) WORK_DATA_INIT();       \
 118                 lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0);\
 119                 INIT_LIST_HEAD(&(_work)->entry);                        \
 120                 PREPARE_WORK((_work), (_func));                         \
 121         } while (0)
 122 #else
 123 #define __INIT_WORK(_work, _func, _onstack)                             \
 124         do {                                                            \
 125                 __init_work((_work), _onstack);                         \
 126                 (_work)->data = (atomic_long_t) WORK_DATA_INIT();       \
 127                 INIT_LIST_HEAD(&(_work)->entry);                        \
 128                 PREPARE_WORK((_work), (_func));                         \
 129         } while (0)
 130 #endif
 131
 132 #define INIT_WORK(_work, _func)                                 \
 133         do {                                                    \
 134                 __INIT_WORK((_work), (_func), 0);               \
 135         } while (0)
 136
 137 #define INIT_WORK_ON_STACK(_work, _func)                        \
 138         do {                                                    \
 139                 __INIT_WORK((_work), (_func), 1);               \
 140         } while (0)
 141
 142 #define INIT_DELAYED_WORK(_work, _func)                         \
 143         do {                                                    \
 144                 INIT_WORK(&(_work)->work, (_func));             \
 145                 init_timer(&(_work)->timer);                    \
 146         } while (0)
 147
 148 #define INIT_DELAYED_WORK_ON_STACK(_work, _func)                \
 149         do {                                                    \
 150                 INIT_WORK_ON_STACK(&(_work)->work, (_func));    \
 151                 init_timer_on_stack(&(_work)->timer);           \
 152         } while (0)
 153
 154 #define INIT_DELAYED_WORK_DEFERRABLE(_work, _func)              \
 155         do {                                                    \
 156                 INIT_WORK(&(_work)->work, (_func));             \
 157                 init_timer_deferrable(&(_work)->timer);         \
 158         } while (0)
 159
 160 /**
 161  * work_pending - Find out whether a work item is currently pending
 162  * @work: The work item in question
 163  */
 164 #define work_pending(work) \
 165         test_bit(WORK_STRUCT_PENDING, work_data_bits(work))
 166
 167 /**
 168  * delayed_work_pending - Find out whether a delayable work item is currently
 169  * pending
 170  * @work: The work item in question
 171  */
 172 #define delayed_work_pending(w) \
 173         work_pending(&(w)->work)
 174
 175 /**
 176  * work_clear_pending - for internal use only, mark a work item as not pending
 177  * @work: The work item in question
 178  */
 179 #define work_clear_pending(work) \
 180         clear_bit(WORK_STRUCT_PENDING, work_data_bits(work))
 181
 182
 183 extern struct workqueue_struct *
 184 __create_workqueue_key(const char *name, int singlethread,
 185                        int freezeable, int rt, struct lock_class_key *key,
 186                        const char *lock_name);
 187
 188 #ifdef CONFIG_LOCKDEP
 189 #define __create_workqueue(name, singlethread, freezeable, rt)  \
 190 ({                                                              \
 191         static struct lock_class_key __key;                     \
 192         const char *__lock_name;                                \
 193                                                                 \
 194         if (__builtin_constant_p(name))                         \
 195                 __lock_name = (name);                           \
 196         else                                                    \
 197                 __lock_name = #name;                            \
 198                                                                 \
 199         __create_workqueue_key((name), (singlethread),          \
 200                                (freezeable), (rt), &__key,      \
 201                                __lock_name);                    \
 202 })
 203 #else
 204 #define __create_workqueue(name, singlethread, freezeable, rt)  \
 205         __create_workqueue_key((name), (singlethread), (freezeable), (rt), \
 206                                NULL, NULL)
 207 #endif
 208
 209 #define create_workqueue(name) __create_workqueue((name), 0, 0, 0)
 210 #define create_rt_workqueue(name) __create_workqueue((name), 0, 0, 1)
 211 #define create_freezeable_workqueue(name) __create_workqueue((name), 1, 1, 0)
 212 #define create_singlethread_workqueue(name) __create_workqueue((name), 1, 0, 0)
 213
 214 extern void destroy_workqueue(struct workqueue_struct *wq);
 215
 216 extern int queue_work(struct workqueue_struct *wq, struct work_struct *work);
 217 extern int queue_work_on(int cpu, struct workqueue_struct *wq,
 218                         struct work_struct *work);
 219 extern int queue_delayed_work(struct workqueue_struct *wq,
 220                         struct delayed_work *work, unsigned long delay);
 221 extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 222                         struct delayed_work *work, unsigned long delay);
 223
 224 extern void flush_workqueue(struct workqueue_struct *wq);
 225 extern void flush_scheduled_work(void);
 226 extern void flush_delayed_work(struct delayed_work *work);
 227
 228 extern int schedule_work(struct work_struct *work);
 229 extern int schedule_work_on(int cpu, struct work_struct *work);
 230 extern int schedule_delayed_work(struct delayed_work *work, unsigned long delay);
 231 extern int schedule_delayed_work_on(int cpu, struct delayed_work *work,
 232                                         unsigned long delay);
 233 extern int schedule_on_each_cpu(work_func_t func);
 234 extern int current_is_keventd(void);
 235 extern int keventd_up(void);
 236
 237 extern void init_workqueues(void);
 238 int execute_in_process_context(work_func_t fn, struct execute_work *);
 239
 240 extern int flush_work(struct work_struct *work);
 241
 242 extern int cancel_work_sync(struct work_struct *work);
 243
 244 /*
 245  * Kill off a pending schedule_delayed_work().  Note that the work callback
 246  * function may still be running on return from cancel_delayed_work(), unless
 247  * it returns 1 and the work doesn't re-arm itself. Run flush_workqueue() or
 248  * cancel_work_sync() to wait on it.
 249  */
 250 static inline int cancel_delayed_work(struct delayed_work *work)
 251 {
 252         int ret;
 253
 254         ret = del_timer_sync(&work->timer);
 255         if (ret)
 256                 work_clear_pending(&work->work);
 257         return ret;
 258 }
 259
 260 /*
 261  * Like above, but uses del_timer() instead of del_timer_sync(). This means,
 262  * if it returns 0 the timer function may be running and the queueing is in
 263  * progress.
 264  */
 265 static inline int __cancel_delayed_work(struct delayed_work *work)
 266 {
 267         int ret;
 268
 269         ret = del_timer(&work->timer);
 270         if (ret)
 271                 work_clear_pending(&work->work);
 272         return ret;
 273 }
 274
 275 extern int cancel_delayed_work_sync(struct delayed_work *work);
 276
 277 /* Obsolete. use cancel_delayed_work_sync() */
 278 static inline
 279 void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq,
 280                                         struct delayed_work *work)
 281 {
 282         cancel_delayed_work_sync(work);
 283 }
 284
 285 /* Obsolete. use cancel_delayed_work_sync() */
 286 static inline
 287 void cancel_rearming_delayed_work(struct delayed_work *work)
 288 {
 289         cancel_delayed_work_sync(work);
 290 }
 291
 292 #ifndef CONFIG_SMP
 293 static inline long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
 294 {
 295         return fn(arg);
 296 }
 297 #else
 298 long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg);
 299 #endif /* CONFIG_SMP */
 300 #endif