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 static inline unsigned int work_static(struct work_struct *work)
 100 {
 101         return *work_data_bits(work) & (1 << WORK_STRUCT_STATIC);
 102 }
 103 #else
 104 static inline void __init_work(struct work_struct *work, int onstack) { }
 105 static inline void destroy_work_on_stack(struct work_struct *work) { }
 106 static inline unsigned int work_static(struct work_struct *work) { return 0; }
 107 #endif
 108
 109 /*
 110  * initialize all of a work item in one go
 111  *
 112  * NOTE! No point in using "atomic_long_set()": using a direct
 113  * assignment of the work data initializer allows the compiler
 114  * to generate better code.
 115  */
 116 #ifdef CONFIG_LOCKDEP
 117 #define __INIT_WORK(_work, _func, _onstack)                             \
 118         do {                                                            \
 119                 static struct lock_class_key __key;                     \
 120                                                                         \
 121                 __init_work((_work), _onstack);                         \
 122                 (_work)->data = (atomic_long_t) WORK_DATA_INIT();       \
 123                 lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0);\
 124                 INIT_LIST_HEAD(&(_work)->entry);                        \
 125                 PREPARE_WORK((_work), (_func));                         \
 126         } while (0)
 127 #else
 128 #define __INIT_WORK(_work, _func, _onstack)                             \
 129         do {                                                            \
 130                 __init_work((_work), _onstack);                         \
 131                 (_work)->data = (atomic_long_t) WORK_DATA_INIT();       \
 132                 INIT_LIST_HEAD(&(_work)->entry);                        \
 133                 PREPARE_WORK((_work), (_func));                         \
 134         } while (0)
 135 #endif
 136
 137 #define INIT_WORK(_work, _func)                                 \
 138         do {                                                    \
 139                 __INIT_WORK((_work), (_func), 0);               \
 140         } while (0)
 141
 142 #define INIT_WORK_ON_STACK(_work, _func)                        \
 143         do {                                                    \
 144                 __INIT_WORK((_work), (_func), 1);               \
 145         } while (0)
 146
 147 #define INIT_DELAYED_WORK(_work, _func)                         \
 148         do {                                                    \
 149                 INIT_WORK(&(_work)->work, (_func));             \
 150                 init_timer(&(_work)->timer);                    \
 151         } while (0)
 152
 153 #define INIT_DELAYED_WORK_ON_STACK(_work, _func)                \
 154         do {                                                    \
 155                 INIT_WORK_ON_STACK(&(_work)->work, (_func));    \
 156                 init_timer_on_stack(&(_work)->timer);           \
 157         } while (0)
 158
 159 #define INIT_DELAYED_WORK_DEFERRABLE(_work, _func)              \
 160         do {                                                    \
 161                 INIT_WORK(&(_work)->work, (_func));             \
 162                 init_timer_deferrable(&(_work)->timer);         \
 163         } while (0)
 164
 165 /**
 166  * work_pending - Find out whether a work item is currently pending
 167  * @work: The work item in question
 168  */
 169 #define work_pending(work) \
 170         test_bit(WORK_STRUCT_PENDING, work_data_bits(work))
 171
 172 /**
 173  * delayed_work_pending - Find out whether a delayable work item is currently
 174  * pending
 175  * @work: The work item in question
 176  */
 177 #define delayed_work_pending(w) \
 178         work_pending(&(w)->work)
 179
 180 /**
 181  * work_clear_pending - for internal use only, mark a work item as not pending
 182  * @work: The work item in question
 183  */
 184 #define work_clear_pending(work) \
 185         clear_bit(WORK_STRUCT_PENDING, work_data_bits(work))
 186
 187
 188 extern struct workqueue_struct *
 189 __create_workqueue_key(const char *name, int singlethread, int freezeable,
 190                        struct lock_class_key *key, const char *lock_name);
 191
 192 #ifdef CONFIG_LOCKDEP
 193 #define __create_workqueue(name, singlethread, freezeable)      \
 194 ({                                                              \
 195         static struct lock_class_key __key;                     \
 196         const char *__lock_name;                                \
 197                                                                 \
 198         if (__builtin_constant_p(name))                         \
 199                 __lock_name = (name);                           \
 200         else                                                    \
 201                 __lock_name = #name;                            \
 202                                                                 \
 203         __create_workqueue_key((name), (singlethread),          \
 204                                (freezeable), &__key,            \
 205                                __lock_name);                    \
 206 })
 207 #else
 208 #define __create_workqueue(name, singlethread, freezeable)      \
 209         __create_workqueue_key((name), (singlethread), (freezeable), \
 210                                NULL, NULL)
 211 #endif
 212
 213 #define create_workqueue(name) __create_workqueue((name), 0, 0)
 214 #define create_freezeable_workqueue(name) __create_workqueue((name), 1, 1)
 215 #define create_singlethread_workqueue(name) __create_workqueue((name), 1, 0)
 216
 217 extern void destroy_workqueue(struct workqueue_struct *wq);
 218
 219 extern int queue_work(struct workqueue_struct *wq, struct work_struct *work);
 220 extern int queue_work_on(int cpu, struct workqueue_struct *wq,
 221                         struct work_struct *work);
 222 extern int queue_delayed_work(struct workqueue_struct *wq,
 223                         struct delayed_work *work, unsigned long delay);
 224 extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 225                         struct delayed_work *work, unsigned long delay);
 226
 227 extern void flush_workqueue(struct workqueue_struct *wq);
 228 extern void flush_scheduled_work(void);
 229 extern void flush_delayed_work(struct delayed_work *work);
 230
 231 extern int schedule_work(struct work_struct *work);
 232 extern int schedule_work_on(int cpu, struct work_struct *work);
 233 extern int schedule_delayed_work(struct delayed_work *work, unsigned long delay);
 234 extern int schedule_delayed_work_on(int cpu, struct delayed_work *work,
 235                                         unsigned long delay);
 236 extern int schedule_on_each_cpu(work_func_t func);
 237 extern int current_is_keventd(void);
 238 extern int keventd_up(void);
 239
 240 extern void init_workqueues(void);
 241 int execute_in_process_context(work_func_t fn, struct execute_work *);
 242
 243 extern int flush_work(struct work_struct *work);
 244
 245 extern int cancel_work_sync(struct work_struct *work);
 246
 247 /*
 248  * Kill off a pending schedule_delayed_work().  Note that the work callback
 249  * function may still be running on return from cancel_delayed_work(), unless
 250  * it returns 1 and the work doesn't re-arm itself. Run flush_workqueue() or
 251  * cancel_work_sync() to wait on it.
 252  */
 253 static inline int cancel_delayed_work(struct delayed_work *work)
 254 {
 255         int ret;
 256
 257         ret = del_timer_sync(&work->timer);
 258         if (ret)
 259                 work_clear_pending(&work->work);
 260         return ret;
 261 }
 262
 263 /*
 264  * Like above, but uses del_timer() instead of del_timer_sync(). This means,
 265  * if it returns 0 the timer function may be running and the queueing is in
 266  * progress.
 267  */
 268 static inline int __cancel_delayed_work(struct delayed_work *work)
 269 {
 270         int ret;
 271
 272         ret = del_timer(&work->timer);
 273         if (ret)
 274                 work_clear_pending(&work->work);
 275         return ret;
 276 }
 277
 278 extern int cancel_delayed_work_sync(struct delayed_work *work);
 279
 280 /* Obsolete. use cancel_delayed_work_sync() */
 281 static inline
 282 void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq,
 283                                         struct delayed_work *work)
 284 {
 285         cancel_delayed_work_sync(work);
 286 }
 287
 288 /* Obsolete. use cancel_delayed_work_sync() */
 289 static inline
 290 void cancel_rearming_delayed_work(struct delayed_work *work)
 291 {
 292         cancel_delayed_work_sync(work);
 293 }
 294
 295 #ifndef CONFIG_SMP
 296 static inline long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
 297 {
 298         return fn(arg);
 299 }
 300 #else
 301 long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg);
 302 #endif /* CONFIG_SMP */
 303 #endif