2 * Copyright (c) 2016, JANET(UK)
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of JANET(UK) nor the names of its 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
25 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
26 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
27 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
29 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
31 * OF THE POSSIBILITY OF SUCH DAMAGE.
42 static int tr_mq_msg_destructor(void *object)
44 TR_MQ_MSG *msg=talloc_get_type_abort(object, TR_MQ_MSG);
45 if ( (msg->p!=NULL) && (msg->p_free!=NULL))
50 TR_MQ_MSG *tr_mq_msg_new(TALLOC_CTX *mem_ctx, const char *message, TR_MQ_PRIORITY prio)
52 TR_MQ_MSG *msg=talloc(mem_ctx, TR_MQ_MSG);
56 msg->message=talloc_strdup(msg, message);
57 if (msg->message==NULL) {
62 talloc_set_destructor((void *)msg, tr_mq_msg_destructor);
67 void tr_mq_msg_free(TR_MQ_MSG *msg)
73 TR_MQ_PRIORITY tr_mq_msg_get_prio(TR_MQ_MSG *msg)
78 const char *tr_mq_msg_get_message(TR_MQ_MSG *msg)
83 void *tr_mq_msg_get_payload(TR_MQ_MSG *msg)
88 /* call with a pointer to the payload and a function to free it later */
89 void tr_mq_msg_set_payload(TR_MQ_MSG *msg, void *p, void (*p_free)(void *))
96 static TR_MQ_MSG *tr_mq_msg_get_next(TR_MQ_MSG *msg)
101 static void tr_mq_msg_set_next(TR_MQ_MSG *msg, TR_MQ_MSG *next)
107 TR_MQ *tr_mq_new(TALLOC_CTX *mem_ctx)
109 TR_MQ *mq=talloc(mem_ctx, TR_MQ);
111 pthread_mutex_init(&(mq->mutex), 0);
112 pthread_cond_init(&(mq->have_msg_cond), 0);
115 mq->last_hi_prio=NULL;
120 void tr_mq_free(TR_MQ *mq)
123 tr_mq_lock(mq); /* don't pull the rug out from under someone */
128 int tr_mq_lock(TR_MQ *mq)
130 return pthread_mutex_lock(&(mq->mutex));
133 int tr_mq_unlock(TR_MQ *mq)
135 return pthread_mutex_unlock(&(mq->mutex));
138 static TR_MQ_MSG *tr_mq_get_head(TR_MQ *mq)
143 static void tr_mq_set_head(TR_MQ *mq, TR_MQ_MSG *msg)
148 static TR_MQ_MSG *tr_mq_get_tail(TR_MQ *mq)
153 static void tr_mq_set_tail(TR_MQ *mq, TR_MQ_MSG *msg)
158 void tr_mq_set_notify_cb(TR_MQ *mq, TR_MQ_NOTIFY_FN cb, void *arg)
161 mq->notify_cb_arg=arg;
164 void tr_mq_clear(TR_MQ *mq)
170 m=tr_mq_get_head(mq);
172 n=tr_mq_msg_get_next(m);
176 tr_mq_set_head(mq, NULL);
177 tr_mq_set_tail(mq, NULL);
181 static int tr_mq_empty(TR_MQ *mq)
183 return tr_mq_get_head(mq)==NULL;
186 /* puts msg in mq's talloc context */
187 static void tr_mq_append(TR_MQ *mq, TR_MQ_MSG *msg)
189 if (tr_mq_get_head(mq)==NULL) {
190 tr_mq_set_head(mq, msg);
191 tr_mq_set_tail(mq, msg);
193 tr_mq_msg_set_next(tr_mq_get_tail(mq), msg); /* add to list */
194 tr_mq_set_tail(mq, msg); /* update tail of list */
196 talloc_steal(mq, msg);
199 static void tr_mq_append_high_prio(TR_MQ *mq, TR_MQ_MSG *new)
201 if (tr_mq_get_head(mq)==NULL) {
202 tr_mq_set_head(mq, new);
203 tr_mq_set_tail(mq, new);
204 } else if (mq->last_hi_prio==NULL) {
205 tr_mq_msg_set_next(new, tr_mq_get_head(mq)); /* add to front of list */
206 tr_mq_set_head(mq, new); /* update head of list */
208 tr_mq_msg_set_next(new, tr_mq_msg_get_next(mq->last_hi_prio));
209 tr_mq_msg_set_next(mq->last_hi_prio, new); /* add to end of hi prio msgs */
211 mq->last_hi_prio=new; /* in any case, this is now the last high priority msg */
212 talloc_steal(mq,new);
215 #define DEBUG_TR_MQ 0
217 static void tr_mq_print(TR_MQ *mq)
219 TR_MQ_MSG *m=mq->head;
222 tr_debug("tr_mq_print: mq contents:");
225 tr_debug("tr_mq_print: Entry %02d: %-15s (prio %d)",
226 ii, tr_mq_msg_get_message(m), tr_mq_msg_get_prio(m));
227 m=tr_mq_msg_get_next(m);
231 void tr_mq_add(TR_MQ *mq, TR_MQ_MSG *msg)
234 TR_MQ_NOTIFY_FN notify_cb=NULL;
235 void *notify_cb_arg=NULL;
239 was_empty=tr_mq_empty(mq);
240 switch (tr_mq_msg_get_prio(msg)) {
241 case TR_MQ_PRIO_HIGH:
242 tr_mq_append_high_prio(mq, msg);
245 tr_mq_append(mq, msg);
248 /* before releasing the mutex, get notify_cb data out of mq */
249 notify_cb=mq->notify_cb;
250 notify_cb_arg=mq->notify_cb_arg;
256 /* Before releasing the lock, signal any waiting threads that there's now
257 * something in the queue. Used for blocking tr_mq_pop() call. */
260 pthread_cond_broadcast(&(mq->have_msg_cond));
264 /* see if we need to tell someone we became non-empty */
265 if (was_empty && (notify_cb!=NULL))
266 notify_cb(mq, notify_cb_arg);
269 /* Caller must free msg via tr_mq_msg_free, waiting up to maxwait seconds (0 for non-blocking).
270 * Not guaranteed to wait if an error occurs - immediately returns without a message. */
271 TR_MQ_MSG *tr_mq_pop(TR_MQ *mq, time_t maxwait)
273 TR_MQ_MSG *popped=NULL;
275 struct timespec expiration={0};
278 if ((tr_mq_get_head(mq)==NULL) && (maxwait>0)) {
279 /* No msgs yet, and blocking was requested */
280 if (0!=clock_gettime(CLOCK_REALTIME, &expiration)) {
281 tr_notice("tr_mq_pop: error reading realtime clock.");
284 expiration.tv_sec+=maxwait;
286 while ((wait_err==0) && (NULL==tr_mq_get_head(mq)))
287 wait_err=pthread_cond_timedwait(&(mq->have_msg_cond),
291 if ((wait_err!=0) && (wait_err!=ETIMEDOUT)) {
292 tr_notice("tr_mq_pop: error waiting for message.");
295 /* if it timed out, ok to go ahead and check once more for a message, so no special exit */
298 if (tr_mq_get_head(mq)!=NULL) {
299 popped=tr_mq_get_head(mq);
300 tr_mq_set_head(mq, tr_mq_msg_get_next(popped)); /* popped is the old head */
302 if (popped==mq->last_hi_prio)
303 mq->last_hi_prio=NULL;
305 if (tr_mq_get_head(mq)==NULL)
306 tr_mq_set_tail(mq, NULL); /* just popped the last element */
310 tr_mq_msg_set_next(popped, NULL); /* disconnect from list */