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37 #define DEBUG_SUBSYSTEM S_LNET
39 #include <libcfs/libcfs.h>
48 * To initialize the wait queue
51 * waitq: pointer to the wait_queue_head_t structure
60 void init_waitqueue_head(wait_queue_head_t *waitq)
62 waitq->magic = CFS_WAITQ_MAGIC;
64 INIT_LIST_HEAD(&(waitq->waiters));
65 spin_lock_init(&(waitq->guard));
69 * init_waitqueue_entry_current
70 * To initialize the wake link node
73 * link: pointer to the wait_queue_t structure
82 void init_waitqueue_entry_current(wait_queue_t *link)
84 struct task_struct * task = current;
85 PTASK_SLOT slot = NULL;
88 /* should bugchk here */
93 slot = CONTAINING_RECORD(task, TASK_SLOT, task);
94 cfs_assert(slot->Magic == TASKSLT_MAGIC);
96 memset(link, 0, sizeof(wait_queue_t));
98 link->magic = CFS_WAITLINK_MAGIC;
101 link->event = &(slot->Event);
102 link->hits = &(slot->hits);
104 atomic_inc(&slot->count);
106 INIT_LIST_HEAD(&(link->waitq[0].link));
107 INIT_LIST_HEAD(&(link->waitq[1].link));
109 link->waitq[0].waitl = link->waitq[1].waitl = link;
115 * To finilize the wake link node
118 * link: pointer to the wait_queue_t structure
127 void cfs_waitlink_fini(wait_queue_t *link)
129 struct task_struct * task = current;
130 PTASK_SLOT slot = NULL;
133 /* should bugchk here */
134 cfs_enter_debugger();
138 slot = CONTAINING_RECORD(task, TASK_SLOT, task);
139 cfs_assert(slot->Magic == TASKSLT_MAGIC);
140 cfs_assert(link->magic == CFS_WAITLINK_MAGIC);
141 cfs_assert(link->waitq[0].waitq == NULL);
142 cfs_assert(link->waitq[1].waitq == NULL);
144 atomic_dec(&slot->count);
149 * cfs_waitq_add_internal
150 * To queue the wait link node to the wait queue
153 * waitq: pointer to the wait_queue_head_t structure
154 * link: pointer to the wait_queue_t structure
155 * int: queue no (Normal or Forward waitq)
164 void cfs_waitq_add_internal(wait_queue_head_t *waitq,
168 LASSERT(waitq != NULL);
169 LASSERT(link != NULL);
170 LASSERT(waitq->magic == CFS_WAITQ_MAGIC);
171 LASSERT(link->magic == CFS_WAITLINK_MAGIC);
172 LASSERT(waitqid < CFS_WAITQ_CHANNELS);
174 spin_lock(&(waitq->guard));
175 LASSERT(link->waitq[waitqid].waitq == NULL);
176 link->waitq[waitqid].waitq = waitq;
177 if (link->flags & CFS_WAITQ_EXCLUSIVE) {
178 list_add_tail(&link->waitq[waitqid].link, &waitq->waiters);
180 list_add(&link->waitq[waitqid].link, &waitq->waiters);
182 spin_unlock(&(waitq->guard));
186 * To queue the wait link node to the wait queue
189 * waitq: pointer to the wait_queue_head_t structure
190 * link: pointer to the wait_queue_t structure
199 void add_wait_queue(wait_queue_head_t *waitq,
202 cfs_waitq_add_internal(waitq, link, CFS_WAITQ_CHAN_NORMAL);
206 * add_wait_queue_exclusive
207 * To set the wait link node to exclusive mode
208 * and queue it to the wait queue
211 * waitq: pointer to the wait_queue_head_t structure
212 * link: pointer to the cfs_wait_link structure
221 void add_wait_queue_exclusive( wait_queue_head_t *waitq,
224 LASSERT(waitq != NULL);
225 LASSERT(link != NULL);
226 LASSERT(waitq->magic == CFS_WAITQ_MAGIC);
227 LASSERT(link->magic == CFS_WAITLINK_MAGIC);
229 link->flags |= CFS_WAITQ_EXCLUSIVE;
230 add_wait_queue(waitq, link);
235 * To remove the wait link node from the waitq
238 * waitq: pointer to the cfs_ waitq_t structure
239 * link: pointer to the wait_queue_t structure
248 void remove_wait_queue( wait_queue_head_t *waitq,
253 LASSERT(waitq != NULL);
254 LASSERT(link != NULL);
256 LASSERT(waitq->magic == CFS_WAITQ_MAGIC);
257 LASSERT(link->magic == CFS_WAITLINK_MAGIC);
259 spin_lock(&(waitq->guard));
261 for (i=0; i < CFS_WAITQ_CHANNELS; i++) {
262 if (link->waitq[i].waitq == waitq)
266 if (i < CFS_WAITQ_CHANNELS) {
267 link->waitq[i].waitq = NULL;
268 list_del_init(&link->waitq[i].link);
270 cfs_enter_debugger();
273 spin_unlock(&(waitq->guard));
278 * Is the waitq active (not empty) ?
281 * waitq: pointer to the cfs_ waitq_t structure
284 * Zero: the waitq is empty
285 * Non-Zero: the waitq is active
288 * We always returns TRUE here, the same to Darwin.
291 int waitqueue_active(wait_queue_head_t *waitq)
293 LASSERT(waitq != NULL);
294 LASSERT(waitq->magic == CFS_WAITQ_MAGIC);
301 * To wake up all the non-exclusive tasks plus nr exclusive
305 * waitq: pointer to the wait_queue_head_t structure
306 * nr: number of exclusive tasks to be woken up
316 void wake_up_nr(wait_queue_head_t *waitq, int nr)
319 cfs_waitlink_channel_t * scan;
321 LASSERT(waitq != NULL);
322 LASSERT(waitq->magic == CFS_WAITQ_MAGIC);
324 spin_lock(&waitq->guard);
325 list_for_each_entry(scan, &waitq->waiters,
328 wait_queue_t *waitl = scan->waitl;
330 result = cfs_wake_event(waitl->event);
331 LASSERT( result == FALSE || result == TRUE );
334 atomic_inc(waitl->hits);
337 if ((waitl->flags & CFS_WAITQ_EXCLUSIVE) && --nr == 0)
341 spin_unlock(&waitq->guard);
347 * To wake up all the non-exclusive tasks and 1 exclusive
350 * waitq: pointer to the wait_queue_head_t structure
359 void wake_up(wait_queue_head_t *waitq)
361 wake_up_nr(waitq, 1);
367 * To wake up all the tasks in the waitq
370 * waitq: pointer to the wait_queue_head_t structure
379 void wake_up_all(wait_queue_head_t *waitq)
381 LASSERT(waitq != NULL);
382 LASSERT(waitq->magic ==CFS_WAITQ_MAGIC);
384 wake_up_nr(waitq, 0);
389 * To wait on the link node until it is signaled.
392 * link: pointer to the wait_queue_t structure
401 void waitq_wait(wait_queue_t *link, long state)
403 LASSERT(link != NULL);
404 LASSERT(link->magic == CFS_WAITLINK_MAGIC);
406 if (atomic_read(link->hits) > 0) {
407 atomic_dec(link->hits);
408 LASSERT((__u32)atomic_read(link->hits) < (__u32)0xFFFFFF00);
410 cfs_wait_event_internal(link->event, 0);
416 * To wait the link node to be signaled with a timeout limit
419 * link: pointer to the wait_queue_t structure
420 * timeout: the timeout limitation
423 * Woken up: return the difference of the current time and
428 * What if it happens to be woken up at the just timeout time !?
431 int64_t waitq_timedwait( wait_queue_t *link,
436 if (atomic_read(link->hits) > 0) {
437 atomic_dec(link->hits);
438 LASSERT((__u32)atomic_read(link->hits) < (__u32)0xFFFFFF00);
439 return (int64_t)TRUE;
442 return (int64_t)cfs_wait_event_internal(link->event, timeout);