2 * Copyright (c) 1998 Daniel Eischen <eischen@vigrid.com>.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by Daniel Eischen.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY DANIEL EISCHEN AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * $FreeBSD: src/lib/libc_r/uthread/uthread_priority_queue.c,v 1.5.2.3 2002/10/22 14:44:03 fjoe Exp $
33 * $DragonFly: src/lib/libc_r/uthread/uthread_priority_queue.c,v 1.2 2003/06/17 04:26:48 dillon Exp $
36 #include <sys/queue.h>
39 #include "pthread_private.h"
42 static void pq_insert_prio_list(pq_queue_t *pq, int prio);
44 #if defined(_PTHREADS_INVARIANTS)
46 static int _pq_active = 0;
48 #define _PQ_IN_SCHEDQ (PTHREAD_FLAGS_IN_PRIOQ | PTHREAD_FLAGS_IN_WAITQ | PTHREAD_FLAGS_IN_WORKQ)
50 #define _PQ_SET_ACTIVE() _pq_active = 1
51 #define _PQ_CLEAR_ACTIVE() _pq_active = 0
52 #define _PQ_ASSERT_ACTIVE(msg) do { \
53 if (_pq_active == 0) \
56 #define _PQ_ASSERT_INACTIVE(msg) do { \
57 if (_pq_active != 0) \
60 #define _PQ_ASSERT_IN_WAITQ(thrd, msg) do { \
61 if (((thrd)->flags & PTHREAD_FLAGS_IN_WAITQ) == 0) \
64 #define _PQ_ASSERT_IN_PRIOQ(thrd, msg) do { \
65 if (((thrd)->flags & PTHREAD_FLAGS_IN_PRIOQ) == 0) \
68 #define _PQ_ASSERT_NOT_QUEUED(thrd, msg) do { \
69 if (((thrd)->flags & _PQ_IN_SCHEDQ) != 0) \
72 #define _PQ_ASSERT_PROTECTED(msg) \
73 PTHREAD_ASSERT((_thread_kern_in_sched != 0) || \
74 ((_get_curthread())->sig_defer_count > 0) ||\
75 (_sig_in_handler != 0), msg);
79 #define _PQ_SET_ACTIVE()
80 #define _PQ_CLEAR_ACTIVE()
81 #define _PQ_ASSERT_ACTIVE(msg)
82 #define _PQ_ASSERT_INACTIVE(msg)
83 #define _PQ_ASSERT_IN_WAITQ(thrd, msg)
84 #define _PQ_ASSERT_IN_PRIOQ(thrd, msg)
85 #define _PQ_ASSERT_NOT_QUEUED(thrd, msg)
86 #define _PQ_ASSERT_PROTECTED(msg)
91 _pq_alloc(pq_queue_t *pq, int minprio, int maxprio)
94 int prioslots = maxprio - minprio + 1;
99 /* Create the priority queue with (maxprio - minprio + 1) slots: */
100 else if ((pq->pq_lists =
101 (pq_list_t *) malloc(sizeof(pq_list_t) * prioslots)) == NULL)
105 /* Remember the queue size: */
106 pq->pq_size = prioslots;
113 _pq_init(pq_queue_t *pq)
117 if ((pq == NULL) || (pq->pq_lists == NULL))
121 /* Initialize the queue for each priority slot: */
122 for (i = 0; i < pq->pq_size; i++) {
123 TAILQ_INIT(&pq->pq_lists[i].pl_head);
124 pq->pq_lists[i].pl_prio = i;
125 pq->pq_lists[i].pl_queued = 0;
128 /* Initialize the priority queue: */
129 TAILQ_INIT(&pq->pq_queue);
136 _pq_remove(pq_queue_t *pq, pthread_t pthread)
138 int prio = pthread->active_priority;
141 * Make some assertions when debugging is enabled:
143 _PQ_ASSERT_INACTIVE("_pq_remove: pq_active");
145 _PQ_ASSERT_IN_PRIOQ(pthread, "_pq_remove: Not in priority queue");
146 _PQ_ASSERT_PROTECTED("_pq_remove: prioq not protected!");
149 * Remove this thread from priority list. Note that if
150 * the priority list becomes empty, it is not removed
151 * from the priority queue because another thread may be
152 * added to the priority list (resulting in a needless
153 * removal/insertion). Priority lists are only removed
154 * from the priority queue when _pq_first is called.
156 TAILQ_REMOVE(&pq->pq_lists[prio].pl_head, pthread, pqe);
158 /* This thread is now longer in the priority queue. */
159 pthread->flags &= ~PTHREAD_FLAGS_IN_PRIOQ;
166 _pq_insert_head(pq_queue_t *pq, pthread_t pthread)
171 * Don't insert suspended threads into the priority queue.
172 * The caller is responsible for setting the threads state.
174 if ((pthread->flags & PTHREAD_FLAGS_SUSPENDED) != 0) {
175 /* Make sure the threads state is suspended. */
176 if (pthread->state != PS_SUSPENDED)
177 PTHREAD_SET_STATE(pthread, PS_SUSPENDED);
180 * Make some assertions when debugging is enabled:
182 _PQ_ASSERT_INACTIVE("_pq_insert_head: pq_active");
184 _PQ_ASSERT_NOT_QUEUED(pthread,
185 "_pq_insert_head: Already in priority queue");
186 _PQ_ASSERT_PROTECTED("_pq_insert_head: prioq not protected!");
188 prio = pthread->active_priority;
189 TAILQ_INSERT_HEAD(&pq->pq_lists[prio].pl_head, pthread, pqe);
190 if (pq->pq_lists[prio].pl_queued == 0)
191 /* Insert the list into the priority queue: */
192 pq_insert_prio_list(pq, prio);
194 /* Mark this thread as being in the priority queue. */
195 pthread->flags |= PTHREAD_FLAGS_IN_PRIOQ;
203 _pq_insert_tail(pq_queue_t *pq, pthread_t pthread)
208 * Don't insert suspended threads into the priority queue.
209 * The caller is responsible for setting the threads state.
211 if ((pthread->flags & PTHREAD_FLAGS_SUSPENDED) != 0) {
212 /* Make sure the threads state is suspended. */
213 if (pthread->state != PS_SUSPENDED)
214 PTHREAD_SET_STATE(pthread, PS_SUSPENDED);
217 * Make some assertions when debugging is enabled:
219 _PQ_ASSERT_INACTIVE("_pq_insert_tail: pq_active");
221 _PQ_ASSERT_NOT_QUEUED(pthread,
222 "_pq_insert_tail: Already in priority queue");
223 _PQ_ASSERT_PROTECTED("_pq_insert_tail: prioq not protected!");
225 prio = pthread->active_priority;
226 TAILQ_INSERT_TAIL(&pq->pq_lists[prio].pl_head, pthread, pqe);
227 if (pq->pq_lists[prio].pl_queued == 0)
228 /* Insert the list into the priority queue: */
229 pq_insert_prio_list(pq, prio);
231 /* Mark this thread as being in the priority queue. */
232 pthread->flags |= PTHREAD_FLAGS_IN_PRIOQ;
240 _pq_first(pq_queue_t *pq)
243 pthread_t pthread = NULL;
246 * Make some assertions when debugging is enabled:
248 _PQ_ASSERT_INACTIVE("_pq_first: pq_active");
250 _PQ_ASSERT_PROTECTED("_pq_first: prioq not protected!");
252 while (((pql = TAILQ_FIRST(&pq->pq_queue)) != NULL) &&
254 if ((pthread = TAILQ_FIRST(&pql->pl_head)) == NULL) {
256 * The priority list is empty; remove the list
259 TAILQ_REMOVE(&pq->pq_queue, pql, pl_link);
261 /* Mark the list as not being in the queue: */
263 } else if ((pthread->flags & PTHREAD_FLAGS_SUSPENDED) != 0) {
265 * This thread is suspended; remove it from the
266 * list and ensure its state is suspended.
268 TAILQ_REMOVE(&pql->pl_head, pthread, pqe);
269 PTHREAD_SET_STATE(pthread, PS_SUSPENDED);
271 /* This thread is now longer in the priority queue. */
272 pthread->flags &= ~PTHREAD_FLAGS_IN_PRIOQ;
283 pq_insert_prio_list(pq_queue_t *pq, int prio)
288 * Make some assertions when debugging is enabled:
290 _PQ_ASSERT_ACTIVE("pq_insert_prio_list: pq_active");
291 _PQ_ASSERT_PROTECTED("_pq_insert_prio_list: prioq not protected!");
294 * The priority queue is in descending priority order. Start at
295 * the beginning of the queue and find the list before which the
296 * new list should be inserted.
298 pql = TAILQ_FIRST(&pq->pq_queue);
299 while ((pql != NULL) && (pql->pl_prio > prio))
300 pql = TAILQ_NEXT(pql, pl_link);
302 /* Insert the list: */
304 TAILQ_INSERT_TAIL(&pq->pq_queue, &pq->pq_lists[prio], pl_link);
306 TAILQ_INSERT_BEFORE(pql, &pq->pq_lists[prio], pl_link);
308 /* Mark this list as being in the queue: */
309 pq->pq_lists[prio].pl_queued = 1;
313 _waitq_insert(pthread_t pthread)
318 * Make some assertions when debugging is enabled:
320 _PQ_ASSERT_INACTIVE("_waitq_insert: pq_active");
322 _PQ_ASSERT_NOT_QUEUED(pthread, "_waitq_insert: Already in queue");
324 if (pthread->wakeup_time.tv_sec == -1)
325 TAILQ_INSERT_TAIL(&_waitingq, pthread, pqe);
327 tid = TAILQ_FIRST(&_waitingq);
328 while ((tid != NULL) && (tid->wakeup_time.tv_sec != -1) &&
329 ((tid->wakeup_time.tv_sec < pthread->wakeup_time.tv_sec) ||
330 ((tid->wakeup_time.tv_sec == pthread->wakeup_time.tv_sec) &&
331 (tid->wakeup_time.tv_nsec <= pthread->wakeup_time.tv_nsec))))
332 tid = TAILQ_NEXT(tid, pqe);
334 TAILQ_INSERT_TAIL(&_waitingq, pthread, pqe);
336 TAILQ_INSERT_BEFORE(tid, pthread, pqe);
338 pthread->flags |= PTHREAD_FLAGS_IN_WAITQ;
344 _waitq_remove(pthread_t pthread)
347 * Make some assertions when debugging is enabled:
349 _PQ_ASSERT_INACTIVE("_waitq_remove: pq_active");
351 _PQ_ASSERT_IN_WAITQ(pthread, "_waitq_remove: Not in queue");
353 TAILQ_REMOVE(&_waitingq, pthread, pqe);
354 pthread->flags &= ~PTHREAD_FLAGS_IN_WAITQ;
360 _waitq_setactive(void)
362 _PQ_ASSERT_INACTIVE("_waitq_setactive: pq_active");
367 _waitq_clearactive(void)
369 _PQ_ASSERT_ACTIVE("_waitq_clearactive: ! pq_active");