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.
44 static int tr_mq_msg_destructor(void *object)
46 TR_MQ_MSG *msg=talloc_get_type_abort(object, TR_MQ_MSG);
47 if ( (msg->p!=NULL) && (msg->p_free!=NULL))
52 TR_MQ_MSG *tr_mq_msg_new(TALLOC_CTX *mem_ctx, const char *message)
54 TR_MQ_MSG *msg=talloc(mem_ctx, TR_MQ_MSG);
57 msg->message=talloc_strdup(msg, message);
58 if (msg->message==NULL) {
63 talloc_set_destructor((void *)msg, tr_mq_msg_destructor);
68 void tr_mq_msg_free(TR_MQ_MSG *msg)
74 const char *tr_mq_msg_get_message(TR_MQ_MSG *msg)
79 void *tr_mq_msg_get_payload(TR_MQ_MSG *msg)
84 /* call with a pointer to the payload and a function to free it later */
85 void tr_mq_msg_set_payload(TR_MQ_MSG *msg, void *p, void (*p_free)(void *))
92 static TR_MQ_MSG *tr_mq_msg_get_next(TR_MQ_MSG *msg)
97 static void tr_mq_msg_set_next(TR_MQ_MSG *msg, TR_MQ_MSG *next)
103 TR_MQ *tr_mq_new(TALLOC_CTX *mem_ctx)
105 TR_MQ *mq=talloc(mem_ctx, TR_MQ);
106 pthread_condattr_t cattr;
109 pthread_mutex_init(&(mq->mutex), 0);
110 pthread_condattr_init(&cattr);
112 pthread_condattr_setclock(&cattr, CLOCK_MONOTONIC); /* use the monotonic clock for timeouts */
113 pthread_cond_init(&(mq->have_msg_cond), &cattr);
114 pthread_condattr_destroy(&cattr);
120 mq->notify_cb_arg=NULL;
125 void tr_mq_free(TR_MQ *mq)
128 tr_mq_lock(mq); /* don't pull the rug out from under someone */
133 int tr_mq_lock(TR_MQ *mq)
135 return pthread_mutex_lock(&(mq->mutex));
138 int tr_mq_unlock(TR_MQ *mq)
140 return pthread_mutex_unlock(&(mq->mutex));
143 static TR_MQ_MSG *tr_mq_get_head(TR_MQ *mq)
148 static void tr_mq_set_head(TR_MQ *mq, TR_MQ_MSG *msg)
153 static TR_MQ_MSG *tr_mq_get_tail(TR_MQ *mq)
158 static void tr_mq_set_tail(TR_MQ *mq, TR_MQ_MSG *msg)
163 void tr_mq_set_notify_cb(TR_MQ *mq, TR_MQ_NOTIFY_FN cb, void *arg)
166 mq->notify_cb_arg=arg;
169 void tr_mq_clear(TR_MQ *mq)
175 m=tr_mq_get_head(mq);
177 n=tr_mq_msg_get_next(m);
181 tr_mq_set_head(mq, NULL);
182 tr_mq_set_tail(mq, NULL);
186 static int tr_mq_empty(TR_MQ *mq)
188 return tr_mq_get_head(mq)==NULL;
191 /* puts msg in mq's talloc context */
192 static void tr_mq_append(TR_MQ *mq, TR_MQ_MSG *msg)
194 if (tr_mq_get_head(mq)==NULL) {
195 tr_mq_set_head(mq, msg);
196 tr_mq_set_tail(mq, msg);
198 tr_mq_msg_set_next(tr_mq_get_tail(mq), msg); /* add to list */
199 tr_mq_set_tail(mq, msg); /* update tail of list */
201 talloc_steal(mq, msg);
204 #define DEBUG_TR_MQ 0
206 static void tr_mq_print(TR_MQ *mq)
208 TR_MQ_MSG *m=mq->head;
211 tr_debug("tr_mq_print: mq contents:");
214 tr_debug("tr_mq_print: Entry %02d: %-15s",
215 ii, tr_mq_msg_get_message(m));
216 m=tr_mq_msg_get_next(m);
220 void tr_mq_add(TR_MQ *mq, TR_MQ_MSG *msg)
223 TR_MQ_NOTIFY_FN notify_cb=NULL;
224 void *notify_cb_arg=NULL;
228 was_empty=tr_mq_empty(mq);
229 tr_mq_append(mq, msg);
231 /* before releasing the mutex, get notify_cb data out of mq */
232 notify_cb=mq->notify_cb;
233 notify_cb_arg=mq->notify_cb_arg;
239 /* Before releasing the lock, signal any waiting threads that there's now
240 * something in the queue. Used for blocking tr_mq_pop() call. */
243 pthread_cond_broadcast(&(mq->have_msg_cond));
247 /* see if we need to tell someone we became non-empty */
248 if (was_empty && (notify_cb!=NULL))
249 notify_cb(mq, notify_cb_arg);
252 /* Compute an absolute time from a desired timeout interval for use with tr_mq_pop().
253 * Fills in *ts and returns 0 on success. */
254 int tr_mq_pop_timeout(time_t seconds, struct timespec *ts)
256 if (0!=clock_gettime(CLOCK_MONOTONIC, ts))
263 /* Retrieves a message from the queue, waiting until absolute
264 * time ts_abort before giving up (using CLOCK_MONOTONIC). If ts_abort
265 * has passed, returns an existing message but will not wait if one is
266 * not already available. If ts_abort is null, no blocking. Not
267 * guaranteed to wait if an error occurs - immediately returns without
268 * a message. Use tr_mq_pop_timeout() to get an absolute time that
269 * is guaranteed compatible with this function.
271 * Caller should free msg via tr_mq_msg_free when done with it. It stays
272 * in the TR_MQ's context, though, so use talloc_steal() if you want to do
273 * something clever with it. */
274 TR_MQ_MSG *tr_mq_pop(TR_MQ *mq, struct timespec *ts_abort)
276 TR_MQ_MSG *popped=NULL;
280 if ((tr_mq_get_head(mq)==NULL) && (ts_abort!=NULL)) {
281 /* No msgs yet, and blocking was requested */
282 while ((wait_err==0) && (NULL==tr_mq_get_head(mq)))
283 wait_err=pthread_cond_timedwait(&(mq->have_msg_cond),
287 if ((wait_err!=0) && (wait_err!=ETIMEDOUT)) {
288 tr_notice("tr_mq_pop: error waiting for message.");
291 /* if it timed out, ok to go ahead and check once more for a message, so no special exit */
294 if (tr_mq_get_head(mq)!=NULL) {
295 popped=tr_mq_get_head(mq);
296 tr_mq_set_head(mq, tr_mq_msg_get_next(popped)); /* popped is the old head */
298 if (tr_mq_get_head(mq)==NULL)
299 tr_mq_set_tail(mq, NULL); /* just popped the last element */
303 tr_mq_msg_set_next(popped, NULL); /* disconnect from list */