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22 * @author Florian Dold
24 * @brief general purpose request queue
27 #include "gnunet_util_lib.h"
29 #define LOG(kind,...) GNUNET_log_from (kind, "util-mq",__VA_ARGS__)
32 struct GNUNET_MQ_Envelope
35 * Messages are stored in a linked list.
36 * Each queue has its own list of envelopes.
38 struct GNUNET_MQ_Envelope *next;
41 * Messages are stored in a linked list
42 * Each queue has its own list of envelopes.
44 struct GNUNET_MQ_Envelope *prev;
47 * Actual allocated message header.
48 * The GNUNET_MQ_Envelope header is allocated at
49 * the end of the message.
51 struct GNUNET_MessageHeader *mh;
54 * Queue the message is queued in, NULL if message is not queued.
56 struct GNUNET_MQ_Handle *parent_queue;
59 * Called after the message was sent irrevocably.
61 GNUNET_SCHEDULER_TaskCallback sent_cb;
64 * Closure for @e sent_cb
69 * Flags that were set for this envelope by
70 * #GNUNET_MQ_env_set_options(). Only valid if
71 * @e have_custom_options is set.
76 * Additional options buffer set for this envelope by
77 * #GNUNET_MQ_env_set_options(). Only valid if
78 * @e have_custom_options is set.
83 * Did the application call #GNUNET_MQ_env_set_options()?
85 int have_custom_options;
90 * Handle to a message queue.
92 struct GNUNET_MQ_Handle
95 * Handlers array, or NULL if the queue should not receive messages
97 struct GNUNET_MQ_MessageHandler *handlers;
100 * Actual implementation of message sending,
101 * called when a message is added
103 GNUNET_MQ_SendImpl send_impl;
106 * Implementation-dependent queue destruction function
108 GNUNET_MQ_DestroyImpl destroy_impl;
111 * Implementation-dependent send cancel function
113 GNUNET_MQ_CancelImpl cancel_impl;
116 * Implementation-specific state
121 * Callback will be called when an error occurs.
123 GNUNET_MQ_ErrorHandler error_handler;
126 * Closure for the error handler.
128 void *error_handler_cls;
131 * Task to asynchronously run #impl_send_continue().
133 struct GNUNET_SCHEDULER_Task *send_task;
136 * Linked list of messages pending to be sent
138 struct GNUNET_MQ_Envelope *envelope_head;
141 * Linked list of messages pending to be sent
143 struct GNUNET_MQ_Envelope *envelope_tail;
146 * Message that is currently scheduled to be
147 * sent. Not the head of the message queue, as the implementation
148 * needs to know if sending has been already scheduled or not.
150 struct GNUNET_MQ_Envelope *current_envelope;
153 * Map of associations, lazily allocated
155 struct GNUNET_CONTAINER_MultiHashMap32 *assoc_map;
158 * Functions to call on queue destruction; kept in a DLL.
160 struct GNUNET_MQ_DestroyNotificationHandle *dnh_head;
163 * Functions to call on queue destruction; kept in a DLL.
165 struct GNUNET_MQ_DestroyNotificationHandle *dnh_tail;
168 * Additional options buffer set for this queue by
169 * #GNUNET_MQ_set_options(). Default is 0.
171 const void *default_extra;
174 * Flags that were set for this queue by
175 * #GNUNET_MQ_set_options(). Default is 0.
177 uint64_t default_flags;
180 * Next id that should be used for the @e assoc_map,
181 * initialized lazily to a random value together with
187 * Number of entries we have in the envelope-DLL.
189 unsigned int queue_length;
192 * #GNUNET_YES if GNUNET_MQ_impl_evacuate was called.
193 * FIXME: is this dead?
198 * #GNUNET_YES if GNUNET_MQ_impl_send_in_flight() was called.
205 * Call the message message handler that was registered
206 * for the type of the given message in the given message queue.
208 * This function is indended to be used for the implementation
211 * @param mq message queue with the handlers
212 * @param mh message to dispatch
215 GNUNET_MQ_inject_message (struct GNUNET_MQ_Handle *mq,
216 const struct GNUNET_MessageHeader *mh)
218 const struct GNUNET_MQ_MessageHandler *handler;
219 int handled = GNUNET_NO;
220 uint16_t msize = ntohs (mh->size);
221 uint16_t mtype = ntohs (mh->type);
223 LOG (GNUNET_ERROR_TYPE_DEBUG,
224 "Received message of type %u and size %u\n",
227 if (NULL == mq->handlers)
229 for (handler = mq->handlers; NULL != handler->cb; handler++)
231 if (handler->type == mtype)
233 handled = GNUNET_YES;
234 if ( (handler->expected_size > msize) ||
235 ( (handler->expected_size != msize) &&
236 (NULL == handler->mv) ) )
238 /* Too small, or not an exact size and
239 no 'mv' handler to check rest */
240 LOG (GNUNET_ERROR_TYPE_ERROR,
241 "Received malformed message of type %u\n",
242 (unsigned int) handler->type);
243 GNUNET_MQ_inject_error (mq,
244 GNUNET_MQ_ERROR_MALFORMED);
247 if ( (NULL == handler->mv) ||
249 handler->mv (handler->cls, mh)) )
251 /* message well-formed, pass to handler */
252 handler->cb (handler->cls, mh);
256 /* Message rejected by check routine */
257 LOG (GNUNET_ERROR_TYPE_ERROR,
258 "Received malformed message of type %u\n",
259 (unsigned int) handler->type);
260 GNUNET_MQ_inject_error (mq,
261 GNUNET_MQ_ERROR_MALFORMED);
267 if (GNUNET_NO == handled)
268 LOG (GNUNET_ERROR_TYPE_INFO,
269 "No handler for message of type %u and size %u\n",
275 * Call the error handler of a message queue with the given
276 * error code. If there is no error handler, log a warning.
278 * This function is intended to be used by the implementation
281 * @param mq message queue
282 * @param error the error type
285 GNUNET_MQ_inject_error (struct GNUNET_MQ_Handle *mq,
286 enum GNUNET_MQ_Error error)
288 if (NULL == mq->error_handler)
290 LOG (GNUNET_ERROR_TYPE_WARNING,
291 "Got error %d, but no handler installed\n",
295 mq->error_handler (mq->error_handler_cls,
301 * Discard the message queue message, free all
302 * allocated resources. Must be called in the event
303 * that a message is created but should not actually be sent.
305 * @param mqm the message to discard
308 GNUNET_MQ_discard (struct GNUNET_MQ_Envelope *ev)
310 GNUNET_assert (NULL == ev->parent_queue);
316 * Obtain the current length of the message queue.
318 * @param mq queue to inspect
319 * @return number of queued, non-transmitted messages
322 GNUNET_MQ_get_length (struct GNUNET_MQ_Handle *mq)
324 if (GNUNET_YES != mq->in_flight)
326 return mq->queue_length;
328 return mq->queue_length - 1;
333 * Send a message with the given message queue.
334 * May only be called once per message.
336 * @param mq message queue
337 * @param ev the envelope with the message to send.
340 GNUNET_MQ_send (struct GNUNET_MQ_Handle *mq,
341 struct GNUNET_MQ_Envelope *ev)
343 GNUNET_assert (NULL != mq);
344 GNUNET_assert (NULL == ev->parent_queue);
347 GNUNET_break (mq->queue_length < 10000); /* This would seem like a bug... */
348 ev->parent_queue = mq;
349 /* is the implementation busy? queue it! */
350 if ( (NULL != mq->current_envelope) ||
351 (NULL != mq->send_task) )
353 GNUNET_CONTAINER_DLL_insert_tail (mq->envelope_head,
358 GNUNET_assert (NULL == mq->envelope_head);
359 mq->current_envelope = ev;
361 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
362 "mq: sending message of type %u, queue empty\n", ntohs(ev->mh->type));
371 * Remove the first envelope that has not yet been sent from the message
372 * queue and return it.
374 * @param mq queue to remove envelope from
375 * @return NULL if queue is empty (or has no envelope that is not under transmission)
377 struct GNUNET_MQ_Envelope *
378 GNUNET_MQ_unsent_head (struct GNUNET_MQ_Handle *mq)
380 struct GNUNET_MQ_Envelope *env;
382 env = mq->envelope_head;
383 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
387 env->parent_queue = NULL;
393 * Function to copy an envelope. The envelope must not yet
394 * be in any queue or have any options or callbacks set.
396 * @param env envelope to copy
397 * @return copy of @a env
399 struct GNUNET_MQ_Envelope *
400 GNUNET_MQ_env_copy (struct GNUNET_MQ_Envelope *env)
402 GNUNET_assert (NULL == env->next);
403 GNUNET_assert (NULL == env->parent_queue);
404 GNUNET_assert (NULL == env->sent_cb);
405 GNUNET_assert (GNUNET_NO == env->have_custom_options);
406 return GNUNET_MQ_msg_copy (env->mh);
411 * Send a copy of a message with the given message queue.
412 * Can be called repeatedly on the same envelope.
414 * @param mq message queue
415 * @param ev the envelope with the message to send.
418 GNUNET_MQ_send_copy (struct GNUNET_MQ_Handle *mq,
419 const struct GNUNET_MQ_Envelope *ev)
421 struct GNUNET_MQ_Envelope *env;
424 msize = ntohs (ev->mh->size);
425 env = GNUNET_malloc (sizeof (struct GNUNET_MQ_Envelope) +
427 env->mh = (struct GNUNET_MessageHeader *) &env[1];
428 env->sent_cb = ev->sent_cb;
429 env->sent_cls = ev->sent_cls;
430 GNUNET_memcpy (&env[1],
439 * Task run to call the send implementation for the next queued
440 * message, if any. Only useful for implementing message queues,
441 * results in undefined behavior if not used carefully.
443 * @param cls message queue to send the next message with
446 impl_send_continue (void *cls)
448 struct GNUNET_MQ_Handle *mq = cls;
450 mq->send_task = NULL;
451 /* call is only valid if we're actually currently sending
453 if (NULL == mq->envelope_head)
455 mq->current_envelope = mq->envelope_head;
456 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
458 mq->current_envelope);
460 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
461 "mq: sending message of type %u from queue\n", ntohs(mq->current_envelope->mh->type));
464 mq->current_envelope->mh,
470 * Call the send implementation for the next queued message, if any.
471 * Only useful for implementing message queues, results in undefined
472 * behavior if not used carefully.
474 * @param mq message queue to send the next message with
477 GNUNET_MQ_impl_send_continue (struct GNUNET_MQ_Handle *mq)
479 struct GNUNET_MQ_Envelope *current_envelope;
480 GNUNET_SCHEDULER_TaskCallback cb;
482 GNUNET_assert (0 < mq->queue_length);
484 mq->in_flight = GNUNET_NO;
485 current_envelope = mq->current_envelope;
486 current_envelope->parent_queue = NULL;
487 mq->current_envelope = NULL;
488 GNUNET_assert (NULL == mq->send_task);
489 mq->send_task = GNUNET_SCHEDULER_add_now (&impl_send_continue,
491 if (NULL != (cb = current_envelope->sent_cb))
493 current_envelope->sent_cb = NULL;
494 cb (current_envelope->sent_cls);
496 GNUNET_free (current_envelope);
501 * Call the send notification for the current message, but do not
502 * try to send the next message until #GNUNET_MQ_impl_send_continue
505 * Only useful for implementing message queues, results in undefined
506 * behavior if not used carefully.
508 * @param mq message queue to send the next message with
511 GNUNET_MQ_impl_send_in_flight (struct GNUNET_MQ_Handle *mq)
513 struct GNUNET_MQ_Envelope *current_envelope;
514 GNUNET_SCHEDULER_TaskCallback cb;
516 mq->in_flight = GNUNET_YES;
517 /* call is only valid if we're actually currently sending
519 current_envelope = mq->current_envelope;
520 GNUNET_assert (NULL != current_envelope);
521 /* can't call cancel from now on anymore */
522 current_envelope->parent_queue = NULL;
523 if (NULL != (cb = current_envelope->sent_cb))
525 current_envelope->sent_cb = NULL;
526 cb (current_envelope->sent_cls);
532 * Create a message queue for the specified handlers.
534 * @param send function the implements sending messages
535 * @param destroy function that implements destroying the queue
536 * @param cancel function that implements canceling a message
537 * @param impl_state for the queue, passed to 'send' and 'destroy'
538 * @param handlers array of message handlers
539 * @param error_handler handler for read and write errors
540 * @param error_handler_cls closure for @a error_handler
541 * @return a new message queue
543 struct GNUNET_MQ_Handle *
544 GNUNET_MQ_queue_for_callbacks (GNUNET_MQ_SendImpl send,
545 GNUNET_MQ_DestroyImpl destroy,
546 GNUNET_MQ_CancelImpl cancel,
548 const struct GNUNET_MQ_MessageHandler *handlers,
549 GNUNET_MQ_ErrorHandler error_handler,
550 void *error_handler_cls)
552 struct GNUNET_MQ_Handle *mq;
554 mq = GNUNET_new (struct GNUNET_MQ_Handle);
555 mq->send_impl = send;
556 mq->destroy_impl = destroy;
557 mq->cancel_impl = cancel;
558 mq->handlers = GNUNET_MQ_copy_handlers (handlers);
559 mq->error_handler = error_handler;
560 mq->error_handler_cls = error_handler_cls;
561 mq->impl_state = impl_state;
568 * Change the closure argument in all of the `handlers` of the
571 * @param mq to modify
572 * @param handlers_cls new closure to use
575 GNUNET_MQ_set_handlers_closure (struct GNUNET_MQ_Handle *mq,
580 if (NULL == mq->handlers)
582 for (i=0;NULL != mq->handlers[i].cb; i++)
583 mq->handlers[i].cls = handlers_cls;
588 * Get the message that should currently be sent.
589 * Fails if there is no current message.
590 * Only useful for implementing message queues,
591 * results in undefined behavior if not used carefully.
593 * @param mq message queue with the current message
594 * @return message to send, never NULL
596 const struct GNUNET_MessageHeader *
597 GNUNET_MQ_impl_current (struct GNUNET_MQ_Handle *mq)
599 GNUNET_assert (NULL != mq->current_envelope);
600 GNUNET_assert (NULL != mq->current_envelope->mh);
601 return mq->current_envelope->mh;
606 * Get the implementation state associated with the
609 * While the GNUNET_MQ_Impl* callbacks receive the
610 * implementation state, continuations that are scheduled
611 * by the implementation function often only have one closure
612 * argument, with this function it is possible to get at the
613 * implementation state when only passing the GNUNET_MQ_Handle
616 * @param mq message queue with the current message
617 * @return message to send, never NULL
620 GNUNET_MQ_impl_state (struct GNUNET_MQ_Handle *mq)
622 return mq->impl_state;
626 struct GNUNET_MQ_Envelope *
627 GNUNET_MQ_msg_ (struct GNUNET_MessageHeader **mhp,
631 struct GNUNET_MQ_Envelope *ev;
633 ev = GNUNET_malloc (size + sizeof (struct GNUNET_MQ_Envelope));
634 ev->mh = (struct GNUNET_MessageHeader *) &ev[1];
635 ev->mh->size = htons (size);
636 ev->mh->type = htons (type);
644 * Create a new envelope by copying an existing message.
646 * @param hdr header of the message to copy
647 * @return envelope containing @a hdr
649 struct GNUNET_MQ_Envelope *
650 GNUNET_MQ_msg_copy (const struct GNUNET_MessageHeader *hdr)
652 struct GNUNET_MQ_Envelope *mqm;
653 uint16_t size = ntohs (hdr->size);
655 mqm = GNUNET_malloc (sizeof (*mqm) + size);
656 mqm->mh = (struct GNUNET_MessageHeader *) &mqm[1];
657 GNUNET_memcpy (mqm->mh,
665 * Implementation of the #GNUNET_MQ_msg_nested_mh macro.
667 * @param mhp pointer to the message header pointer that will be changed to allocate at
668 * the newly allocated space for the message.
669 * @param base_size size of the data before the nested message
670 * @param type type of the message in the envelope
671 * @param nested_mh the message to append to the message after base_size
673 struct GNUNET_MQ_Envelope *
674 GNUNET_MQ_msg_nested_mh_ (struct GNUNET_MessageHeader **mhp,
677 const struct GNUNET_MessageHeader *nested_mh)
679 struct GNUNET_MQ_Envelope *mqm;
682 if (NULL == nested_mh)
683 return GNUNET_MQ_msg_ (mhp, base_size, type);
685 size = base_size + ntohs (nested_mh->size);
687 /* check for uint16_t overflow */
688 if (size < base_size)
691 mqm = GNUNET_MQ_msg_ (mhp, size, type);
692 GNUNET_memcpy ((char *) mqm->mh + base_size,
694 ntohs (nested_mh->size));
701 * Associate the assoc_data in mq with a unique request id.
703 * @param mq message queue, id will be unique for the queue
704 * @param assoc_data to associate
707 GNUNET_MQ_assoc_add (struct GNUNET_MQ_Handle *mq,
712 if (NULL == mq->assoc_map)
714 mq->assoc_map = GNUNET_CONTAINER_multihashmap32_create (8);
718 GNUNET_assert (GNUNET_OK ==
719 GNUNET_CONTAINER_multihashmap32_put (mq->assoc_map,
722 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
728 * Get the data associated with a @a request_id in a queue
730 * @param mq the message queue with the association
731 * @param request_id the request id we are interested in
732 * @return the associated data
735 GNUNET_MQ_assoc_get (struct GNUNET_MQ_Handle *mq,
738 if (NULL == mq->assoc_map)
740 return GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map,
746 * Remove the association for a @a request_id
748 * @param mq the message queue with the association
749 * @param request_id the request id we want to remove
750 * @return the associated data
753 GNUNET_MQ_assoc_remove (struct GNUNET_MQ_Handle *mq,
758 if (NULL == mq->assoc_map)
760 val = GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map,
762 GNUNET_CONTAINER_multihashmap32_remove_all (mq->assoc_map,
769 * Call a callback once the envelope has been sent, that is,
770 * sending it can not be canceled anymore.
771 * There can be only one notify sent callback per envelope.
773 * @param ev message to call the notify callback for
774 * @param cb the notify callback
775 * @param cb_cls closure for the callback
778 GNUNET_MQ_notify_sent (struct GNUNET_MQ_Envelope *ev,
779 GNUNET_SCHEDULER_TaskCallback cb,
782 GNUNET_assert (NULL == ev->sent_cb);
784 ev->sent_cls = cb_cls;
789 * Handle we return for callbacks registered to be
790 * notified when #GNUNET_MQ_destroy() is called on a queue.
792 struct GNUNET_MQ_DestroyNotificationHandle
797 struct GNUNET_MQ_DestroyNotificationHandle *prev;
802 struct GNUNET_MQ_DestroyNotificationHandle *next;
805 * Queue to notify about.
807 struct GNUNET_MQ_Handle *mq;
812 GNUNET_SCHEDULER_TaskCallback cb;
822 * Destroy the message queue.
824 * @param mq message queue to destroy
827 GNUNET_MQ_destroy (struct GNUNET_MQ_Handle *mq)
829 struct GNUNET_MQ_DestroyNotificationHandle *dnh;
831 if (NULL != mq->destroy_impl)
833 mq->destroy_impl (mq, mq->impl_state);
835 if (NULL != mq->send_task)
837 GNUNET_SCHEDULER_cancel (mq->send_task);
838 mq->send_task = NULL;
840 while (NULL != mq->envelope_head)
842 struct GNUNET_MQ_Envelope *ev;
844 ev = mq->envelope_head;
845 ev->parent_queue = NULL;
846 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
849 GNUNET_assert (0 < mq->queue_length);
851 GNUNET_MQ_discard (ev);
853 if (NULL != mq->current_envelope)
855 /* we can only discard envelopes that
857 mq->current_envelope->parent_queue = NULL;
858 GNUNET_MQ_discard (mq->current_envelope);
859 mq->current_envelope = NULL;
860 GNUNET_assert (0 < mq->queue_length);
863 GNUNET_assert (0 == mq->queue_length);
864 while (NULL != (dnh = mq->dnh_head))
866 dnh->cb (dnh->cb_cls);
867 GNUNET_MQ_destroy_notify_cancel (dnh);
869 if (NULL != mq->assoc_map)
871 GNUNET_CONTAINER_multihashmap32_destroy (mq->assoc_map);
872 mq->assoc_map = NULL;
874 GNUNET_free_non_null (mq->handlers);
879 const struct GNUNET_MessageHeader *
880 GNUNET_MQ_extract_nested_mh_ (const struct GNUNET_MessageHeader *mh,
884 uint16_t nested_size;
885 const struct GNUNET_MessageHeader *nested_msg;
887 whole_size = ntohs (mh->size);
888 GNUNET_assert (whole_size >= base_size);
889 nested_size = whole_size - base_size;
890 if (0 == nested_size)
892 if (nested_size < sizeof (struct GNUNET_MessageHeader))
897 nested_msg = (const struct GNUNET_MessageHeader *) ((char *) mh + base_size);
898 if (ntohs (nested_msg->size) != nested_size)
908 * Cancel sending the message. Message must have been sent with
909 * #GNUNET_MQ_send before. May not be called after the notify sent
910 * callback has been called
912 * @param ev queued envelope to cancel
915 GNUNET_MQ_send_cancel (struct GNUNET_MQ_Envelope *ev)
917 struct GNUNET_MQ_Handle *mq = ev->parent_queue;
919 GNUNET_assert (NULL != mq);
920 GNUNET_assert (NULL != mq->cancel_impl);
922 mq->evacuate_called = GNUNET_NO;
924 if (mq->current_envelope == ev)
926 /* complex case, we already started with transmitting
927 the message using the callbacks. */
928 GNUNET_assert (0 < mq->queue_length);
932 /* continue sending the next message, if any */
933 mq->current_envelope = mq->envelope_head;
934 if (NULL != mq->current_envelope)
936 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
938 mq->current_envelope);
940 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
941 "mq: sending canceled message of type %u queue\n", ntohs(ev->mh->type));
944 mq->current_envelope->mh,
950 /* simple case, message is still waiting in the queue */
951 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
954 GNUNET_assert (0 < mq->queue_length);
958 if (GNUNET_YES != mq->evacuate_called)
960 ev->parent_queue = NULL;
969 * Function to obtain the current envelope
970 * from within #GNUNET_MQ_SendImpl implementations.
972 * @param mq message queue to interrogate
973 * @return the current envelope
975 struct GNUNET_MQ_Envelope *
976 GNUNET_MQ_get_current_envelope (struct GNUNET_MQ_Handle *mq)
978 return mq->current_envelope;
983 * Function to obtain the last envelope in the queue.
985 * @param mq message queue to interrogate
986 * @return the last envelope in the queue
988 struct GNUNET_MQ_Envelope *
989 GNUNET_MQ_get_last_envelope (struct GNUNET_MQ_Handle *mq)
991 if (NULL != mq->envelope_tail)
992 return mq->envelope_tail;
994 return mq->current_envelope;
999 * Set application-specific options for this envelope.
1000 * Overrides the options set for the queue with
1001 * #GNUNET_MQ_set_options() for this message only.
1003 * @param env message to set options for
1004 * @param flags flags to use (meaning is queue-specific)
1005 * @param extra additional buffer for further data (also queue-specific)
1008 GNUNET_MQ_env_set_options (struct GNUNET_MQ_Envelope *env,
1014 env->have_custom_options = GNUNET_YES;
1019 * Get application-specific options for this envelope.
1021 * @param env message to set options for
1022 * @param[out] flags set to flags to use (meaning is queue-specific)
1023 * @return extra additional buffer for further data (also queue-specific)
1026 GNUNET_MQ_env_get_options (struct GNUNET_MQ_Envelope *env,
1029 struct GNUNET_MQ_Handle *mq = env->parent_queue;
1031 if (GNUNET_YES == env->have_custom_options)
1033 *flags = env->flags;
1041 *flags = mq->default_flags;
1042 return mq->default_extra;
1047 * Set application-specific options for this queue.
1049 * @param mq message queue to set options for
1050 * @param flags flags to use (meaning is queue-specific)
1051 * @param extra additional buffer for further data (also queue-specific)
1054 GNUNET_MQ_set_options (struct GNUNET_MQ_Handle *mq,
1058 mq->default_flags = flags;
1059 mq->default_extra = extra;
1064 * Register function to be called whenever @a mq is being
1067 * @param mq message queue to watch
1068 * @param cb function to call on @a mq destruction
1069 * @param cb_cls closure for @a cb
1070 * @return handle for #GNUNET_MQ_destroy_notify_cancel().
1072 struct GNUNET_MQ_DestroyNotificationHandle *
1073 GNUNET_MQ_destroy_notify (struct GNUNET_MQ_Handle *mq,
1074 GNUNET_SCHEDULER_TaskCallback cb,
1077 struct GNUNET_MQ_DestroyNotificationHandle *dnh;
1079 dnh = GNUNET_new (struct GNUNET_MQ_DestroyNotificationHandle);
1082 dnh->cb_cls = cb_cls;
1083 GNUNET_CONTAINER_DLL_insert (mq->dnh_head,
1091 * Cancel registration from #GNUNET_MQ_destroy_notify().
1093 * @param dnh handle for registration to cancel
1096 GNUNET_MQ_destroy_notify_cancel (struct GNUNET_MQ_DestroyNotificationHandle *dnh)
1098 struct GNUNET_MQ_Handle *mq = dnh->mq;
1100 GNUNET_CONTAINER_DLL_remove (mq->dnh_head,
1108 * Insert @a env into the envelope DLL starting at @a env_head
1109 * Note that @a env must not be in any MQ while this function
1110 * is used with DLLs defined outside of the MQ module. This
1111 * is just in case some application needs to also manage a
1112 * FIFO of envelopes independent of MQ itself and wants to
1113 * re-use the pointers internal to @a env. Use with caution.
1115 * @param[in|out] env_head of envelope DLL
1116 * @param[in|out] env_tail tail of envelope DLL
1117 * @param[in|out] env element to insert at the tail
1120 GNUNET_MQ_dll_insert_tail (struct GNUNET_MQ_Envelope **env_head,
1121 struct GNUNET_MQ_Envelope **env_tail,
1122 struct GNUNET_MQ_Envelope *env)
1124 GNUNET_CONTAINER_DLL_insert_tail (*env_head,
1131 * Remove @a env from the envelope DLL starting at @a env_head.
1132 * Note that @a env must not be in any MQ while this function
1133 * is used with DLLs defined outside of the MQ module. This
1134 * is just in case some application needs to also manage a
1135 * FIFO of envelopes independent of MQ itself and wants to
1136 * re-use the pointers internal to @a env. Use with caution.
1138 * @param[in|out] env_head of envelope DLL
1139 * @param[in|out] env_tail tail of envelope DLL
1140 * @param[in|out] env element to remove from the DLL
1143 GNUNET_MQ_dll_remove (struct GNUNET_MQ_Envelope **env_head,
1144 struct GNUNET_MQ_Envelope **env_tail,
1145 struct GNUNET_MQ_Envelope *env)
1147 GNUNET_CONTAINER_DLL_remove (*env_head,
1154 * Copy an array of handlers.
1156 * Useful if the array has been delared in local memory and needs to be
1157 * persisted for future use.
1159 * @param handlers Array of handlers to be copied. Can be NULL (nothing done).
1160 * @return A newly allocated array of handlers.
1161 * Needs to be freed with #GNUNET_free.
1163 struct GNUNET_MQ_MessageHandler *
1164 GNUNET_MQ_copy_handlers (const struct GNUNET_MQ_MessageHandler *handlers)
1166 struct GNUNET_MQ_MessageHandler *copy;
1169 if (NULL == handlers)
1172 count = GNUNET_MQ_count_handlers (handlers);
1173 copy = GNUNET_new_array (count + 1,
1174 struct GNUNET_MQ_MessageHandler);
1175 GNUNET_memcpy (copy,
1177 count * sizeof (struct GNUNET_MQ_MessageHandler));
1183 * Count the handlers in a handler array.
1185 * @param handlers Array of handlers to be counted.
1186 * @return The number of handlers in the array.
1189 GNUNET_MQ_count_handlers (const struct GNUNET_MQ_MessageHandler *handlers)
1193 if (NULL == handlers)
1196 for (i=0; NULL != handlers[i].cb; i++) ;