1#ifndef _LINUX_WAIT_H 2#define _LINUX_WAIT_H 3 4#define WNOHANG 0x00000001 5#define WUNTRACED 0x00000002 6#define WSTOPPED WUNTRACED 7#define WEXITED 0x00000004 8#define WCONTINUED 0x00000008 9#define WNOWAIT 0x01000000 /* Don't reap, just poll status. */ 10 11#define __WNOTHREAD 0x20000000 /* Don't wait on children of other threads in this group */ 12#define __WALL 0x40000000 /* Wait on all children, regardless of type */ 13#define __WCLONE 0x80000000 /* Wait only on non-SIGCHLD children */ 14 15/* First argument to waitid: */ 16#define P_ALL 0 17#define P_PID 1 18#define P_PGID 2 19 20#ifdef __KERNEL__ 21 22#include <linux/list.h> 23#include <linux/stddef.h> 24#include <linux/spinlock.h> 25#include <asm/system.h> 26#include <asm/current.h> 27 28typedef struct __wait_queue wait_queue_t; 29typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int sync, void *key); 30int default_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); 31 32struct __wait_queue { 33 unsigned int flags; 34#define WQ_FLAG_EXCLUSIVE 0x01 35 void *private; 36 wait_queue_func_t func; 37 struct list_head task_list; 38}; 39 40struct wait_bit_key { 41 void *flags; 42 int bit_nr; 43}; 44 45struct wait_bit_queue { 46 struct wait_bit_key key; 47 wait_queue_t wait; 48}; 49 50struct __wait_queue_head { 51 spinlock_t lock; 52 struct list_head task_list; 53}; 54typedef struct __wait_queue_head wait_queue_head_t; 55 56struct task_struct; 57 58/* 59 * Macros for declaration and initialisaton of the datatypes 60 */ 61 62#define __WAITQUEUE_INITIALIZER(name, tsk) { \ 63 .private = tsk, \ 64 .func = default_wake_function, \ 65 .task_list = { NULL, NULL } } 66 67#define DECLARE_WAITQUEUE(name, tsk) \ 68 wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk) 69 70#define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \ 71 .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ 72 .task_list = { &(name).task_list, &(name).task_list } } 73 74#define DECLARE_WAIT_QUEUE_HEAD(name) \ 75 wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name) 76 77#define __WAIT_BIT_KEY_INITIALIZER(word, bit) \ 78 { .flags = word, .bit_nr = bit, } 79 80extern void init_waitqueue_head(wait_queue_head_t *q); 81 82#ifdef CONFIG_LOCKDEP 83# define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \ 84 ({ init_waitqueue_head(&name); name; }) 85# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \ 86 wait_queue_head_t name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) 87#else 88# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name) 89#endif 90 91static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p) 92{ 93 q->flags = 0; 94 q->private = p; 95 q->func = default_wake_function; 96} 97 98static inline void init_waitqueue_func_entry(wait_queue_t *q, 99 wait_queue_func_t func) 100{ 101 q->flags = 0; 102 q->private = NULL; 103 q->func = func; 104} 105 106static inline int waitqueue_active(wait_queue_head_t *q) 107{ 108 return !list_empty(&q->task_list); 109} 110 111/* 112 * Used to distinguish between sync and async io wait context: 113 * sync i/o typically specifies a NULL wait queue entry or a wait 114 * queue entry bound to a task (current task) to wake up. 115 * aio specifies a wait queue entry with an async notification 116 * callback routine, not associated with any task. 117 */ 118#define is_sync_wait(wait) (!(wait) || ((wait)->private)) 119 120extern void FASTCALL(add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait)); 121extern void FASTCALL(add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait)); 122extern void FASTCALL(remove_wait_queue(wait_queue_head_t *q, wait_queue_t * wait)); 123 124static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new) 125{ 126 list_add(&new->task_list, &head->task_list); 127} 128 129/* 130 * Used for wake-one threads: 131 */ 132static inline void __add_wait_queue_tail(wait_queue_head_t *head, 133 wait_queue_t *new) 134{ 135 list_add_tail(&new->task_list, &head->task_list); 136} 137 138static inline void __remove_wait_queue(wait_queue_head_t *head, 139 wait_queue_t *old) 140{ 141 list_del(&old->task_list); 142} 143 144void FASTCALL(__wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key)); 145extern void FASTCALL(__wake_up_locked(wait_queue_head_t *q, unsigned int mode)); 146extern void FASTCALL(__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr)); 147void FASTCALL(__wake_up_bit(wait_queue_head_t *, void *, int)); 148int FASTCALL(__wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned)); 149int FASTCALL(__wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned)); 150void FASTCALL(wake_up_bit(void *, int)); 151int FASTCALL(out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned)); 152int FASTCALL(out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned)); 153wait_queue_head_t *FASTCALL(bit_waitqueue(void *, int)); 154 155#define wake_up(x) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 1, NULL) 156#define wake_up_nr(x, nr) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, nr, NULL) 157#define wake_up_all(x) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 0, NULL) 158#define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL) 159#define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL) 160#define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL) 161#define wake_up_locked(x) __wake_up_locked((x), TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE) 162#define wake_up_interruptible_sync(x) __wake_up_sync((x),TASK_INTERRUPTIBLE, 1) 163 164#define __wait_event(wq, condition) \ 165do { \ 166 DEFINE_WAIT(__wait); \ 167 \ 168 for (;;) { \ 169 prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \ 170 if (condition) \ 171 break; \ 172 schedule(); \ 173 } \ 174 finish_wait(&wq, &__wait); \ 175} while (0) 176 177/** 178 * wait_event - sleep until a condition gets true 179 * @wq: the waitqueue to wait on 180 * @condition: a C expression for the event to wait for 181 * 182 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the 183 * @condition evaluates to true. The @condition is checked each time 184 * the waitqueue @wq is woken up. 185 * 186 * wake_up() has to be called after changing any variable that could 187 * change the result of the wait condition. 188 */ 189#define wait_event(wq, condition) \ 190do { \ 191 if (condition) \ 192 break; \ 193 __wait_event(wq, condition); \ 194} while (0) 195 196#define __wait_event_timeout(wq, condition, ret) \ 197do { \ 198 DEFINE_WAIT(__wait); \ 199 \ 200 for (;;) { \ 201 prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \ 202 if (condition) \ 203 break; \ 204 ret = schedule_timeout(ret); \ 205 if (!ret) \ 206 break; \ 207 } \ 208 finish_wait(&wq, &__wait); \ 209} while (0) 210 211/** 212 * wait_event_timeout - sleep until a condition gets true or a timeout elapses 213 * @wq: the waitqueue to wait on 214 * @condition: a C expression for the event to wait for 215 * @timeout: timeout, in jiffies 216 * 217 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the 218 * @condition evaluates to true. The @condition is checked each time 219 * the waitqueue @wq is woken up. 220 * 221 * wake_up() has to be called after changing any variable that could 222 * change the result of the wait condition. 223 * 224 * The function returns 0 if the @timeout elapsed, and the remaining 225 * jiffies if the condition evaluated to true before the timeout elapsed. 226 */ 227#define wait_event_timeout(wq, condition, timeout) \ 228({ \ 229 long __ret = timeout; \ 230 if (!(condition)) \ 231 __wait_event_timeout(wq, condition, __ret); \ 232 __ret; \ 233}) 234 235#define __wait_event_interruptible(wq, condition, ret) \ 236do { \ 237 DEFINE_WAIT(__wait); \ 238 \ 239 for (;;) { \ 240 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ 241 if (condition) \ 242 break; \ 243 if (!signal_pending(current)) { \ 244 schedule(); \ 245 continue; \ 246 } \ 247 ret = -ERESTARTSYS; \ 248 break; \ 249 } \ 250 finish_wait(&wq, &__wait); \ 251} while (0) 252 253/** 254 * wait_event_interruptible - sleep until a condition gets true 255 * @wq: the waitqueue to wait on 256 * @condition: a C expression for the event to wait for 257 * 258 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 259 * @condition evaluates to true or a signal is received. 260 * The @condition is checked each time the waitqueue @wq is woken up. 261 * 262 * wake_up() has to be called after changing any variable that could 263 * change the result of the wait condition. 264 * 265 * The function will return -ERESTARTSYS if it was interrupted by a 266 * signal and 0 if @condition evaluated to true. 267 */ 268#define wait_event_interruptible(wq, condition) \ 269({ \ 270 int __ret = 0; \ 271 if (!(condition)) \ 272 __wait_event_interruptible(wq, condition, __ret); \ 273 __ret; \ 274}) 275 276#define __wait_event_interruptible_timeout(wq, condition, ret) \ 277do { \ 278 DEFINE_WAIT(__wait); \ 279 \ 280 for (;;) { \ 281 prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ 282 if (condition) \ 283 break; \ 284 if (!signal_pending(current)) { \ 285 ret = schedule_timeout(ret); \ 286 if (!ret) \ 287 break; \ 288 continue; \ 289 } \ 290 ret = -ERESTARTSYS; \ 291 break; \ 292 } \ 293 finish_wait(&wq, &__wait); \ 294} while (0) 295 296/** 297 * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses 298 * @wq: the waitqueue to wait on 299 * @condition: a C expression for the event to wait for 300 * @timeout: timeout, in jiffies 301 * 302 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 303 * @condition evaluates to true or a signal is received. 304 * The @condition is checked each time the waitqueue @wq is woken up. 305 * 306 * wake_up() has to be called after changing any variable that could 307 * change the result of the wait condition. 308 * 309 * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it 310 * was interrupted by a signal, and the remaining jiffies otherwise 311 * if the condition evaluated to true before the timeout elapsed. 312 */ 313#define wait_event_interruptible_timeout(wq, condition, timeout) \ 314({ \ 315 long __ret = timeout; \ 316 if (!(condition)) \ 317 __wait_event_interruptible_timeout(wq, condition, __ret); \ 318 __ret; \ 319}) 320 321#define __wait_event_interruptible_exclusive(wq, condition, ret) \ 322do { \ 323 DEFINE_WAIT(__wait); \ 324 \ 325 for (;;) { \ 326 prepare_to_wait_exclusive(&wq, &__wait, \ 327 TASK_INTERRUPTIBLE); \ 328 if (condition) \ 329 break; \ 330 if (!signal_pending(current)) { \ 331 schedule(); \ 332 continue; \ 333 } \ 334 ret = -ERESTARTSYS; \ 335 break; \ 336 } \ 337 finish_wait(&wq, &__wait); \ 338} while (0) 339 340#define wait_event_interruptible_exclusive(wq, condition) \ 341({ \ 342 int __ret = 0; \ 343 if (!(condition)) \ 344 __wait_event_interruptible_exclusive(wq, condition, __ret);\ 345 __ret; \ 346}) 347 348/* 349 * Must be called with the spinlock in the wait_queue_head_t held. 350 */ 351static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q, 352 wait_queue_t * wait) 353{ 354 wait->flags |= WQ_FLAG_EXCLUSIVE; 355 __add_wait_queue_tail(q, wait); 356} 357 358/* 359 * Must be called with the spinlock in the wait_queue_head_t held. 360 */ 361static inline void remove_wait_queue_locked(wait_queue_head_t *q, 362 wait_queue_t * wait) 363{ 364 __remove_wait_queue(q, wait); 365} 366 367/* 368 * These are the old interfaces to sleep waiting for an event. 369 * They are racy. DO NOT use them, use the wait_event* interfaces above. 370 * We plan to remove these interfaces during 2.7. 371 */ 372extern void FASTCALL(sleep_on(wait_queue_head_t *q)); 373extern long FASTCALL(sleep_on_timeout(wait_queue_head_t *q, 374 signed long timeout)); 375extern void FASTCALL(interruptible_sleep_on(wait_queue_head_t *q)); 376extern long FASTCALL(interruptible_sleep_on_timeout(wait_queue_head_t *q, 377 signed long timeout)); 378 379/* 380 * Waitqueues which are removed from the waitqueue_head at wakeup time 381 */ 382void FASTCALL(prepare_to_wait(wait_queue_head_t *q, 383 wait_queue_t *wait, int state)); 384void FASTCALL(prepare_to_wait_exclusive(wait_queue_head_t *q, 385 wait_queue_t *wait, int state)); 386void FASTCALL(finish_wait(wait_queue_head_t *q, wait_queue_t *wait)); 387int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); 388int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key); 389 390#define DEFINE_WAIT(name) \ 391 wait_queue_t name = { \ 392 .private = current, \ 393 .func = autoremove_wake_function, \ 394 .task_list = LIST_HEAD_INIT((name).task_list), \ 395 } 396 397#define DEFINE_WAIT_BIT(name, word, bit) \ 398 struct wait_bit_queue name = { \ 399 .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \ 400 .wait = { \ 401 .private = current, \ 402 .func = wake_bit_function, \ 403 .task_list = \ 404 LIST_HEAD_INIT((name).wait.task_list), \ 405 }, \ 406 } 407 408#define init_wait(wait) \ 409 do { \ 410 (wait)->private = current; \ 411 (wait)->func = autoremove_wake_function; \ 412 INIT_LIST_HEAD(&(wait)->task_list); \ 413 } while (0) 414 415/** 416 * wait_on_bit - wait for a bit to be cleared 417 * @word: the word being waited on, a kernel virtual address 418 * @bit: the bit of the word being waited on 419 * @action: the function used to sleep, which may take special actions 420 * @mode: the task state to sleep in 421 * 422 * There is a standard hashed waitqueue table for generic use. This 423 * is the part of the hashtable's accessor API that waits on a bit. 424 * For instance, if one were to have waiters on a bitflag, one would 425 * call wait_on_bit() in threads waiting for the bit to clear. 426 * One uses wait_on_bit() where one is waiting for the bit to clear, 427 * but has no intention of setting it. 428 */ 429static inline int wait_on_bit(void *word, int bit, 430 int (*action)(void *), unsigned mode) 431{ 432 if (!test_bit(bit, word)) 433 return 0; 434 return out_of_line_wait_on_bit(word, bit, action, mode); 435} 436 437/** 438 * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it 439 * @word: the word being waited on, a kernel virtual address 440 * @bit: the bit of the word being waited on 441 * @action: the function used to sleep, which may take special actions 442 * @mode: the task state to sleep in 443 * 444 * There is a standard hashed waitqueue table for generic use. This 445 * is the part of the hashtable's accessor API that waits on a bit 446 * when one intends to set it, for instance, trying to lock bitflags. 447 * For instance, if one were to have waiters trying to set bitflag 448 * and waiting for it to clear before setting it, one would call 449 * wait_on_bit() in threads waiting to be able to set the bit. 450 * One uses wait_on_bit_lock() where one is waiting for the bit to 451 * clear with the intention of setting it, and when done, clearing it. 452 */ 453static inline int wait_on_bit_lock(void *word, int bit, 454 int (*action)(void *), unsigned mode) 455{ 456 if (!test_and_set_bit(bit, word)) 457 return 0; 458 return out_of_line_wait_on_bit_lock(word, bit, action, mode); 459} 460 461#endif /* __KERNEL__ */ 462 463#endif 464