2 This file is part of GNUnet.
3 (C) 2012 Christian Grothoff (and other contributing authors)
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6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
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11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @author Florian Dold
24 * @brief general purpose request queue
27 #include "gnunet_util_lib.h"
29 #define LOG(kind,...) GNUNET_log_from (kind, "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 * usually points to the end of the containing GNUNET_MQ_Envelope
50 struct GNUNET_MessageHeader *mh;
53 * Queue the message is queued in, NULL if message is not queued.
55 struct GNUNET_MQ_Handle *parent_queue;
58 * Called after the message was sent irrevocably.
60 GNUNET_MQ_NotifyCallback sent_cb;
70 * Handle to a message queue.
72 struct GNUNET_MQ_Handle
75 * Handlers array, or NULL if the queue should not receive messages
77 const struct GNUNET_MQ_MessageHandler *handlers;
80 * Closure for the handler callbacks,
81 * as well as for the error handler.
86 * Actual implementation of message sending,
87 * called when a message is added
89 GNUNET_MQ_SendImpl send_impl;
92 * Implementation-dependent queue destruction function
94 GNUNET_MQ_DestroyImpl destroy_impl;
97 * Implementation-specific state
102 * Callback will be called when an error occurs.
104 GNUNET_MQ_ErrorHandler error_handler;
107 * Linked list of messages pending to be sent
109 struct GNUNET_MQ_Envelope *envelope_head;
112 * Linked list of messages pending to be sent
114 struct GNUNET_MQ_Envelope *envelope_tail;
117 * Message that is currently scheduled to be
118 * sent. Not the head of the message queue, as the implementation
119 * needs to know if sending has been already scheduled or not.
121 struct GNUNET_MQ_Envelope *current_envelope;
124 * Has the current envelope been commited?
125 * Either GNUNET_YES or GNUNET_NO.
130 * Map of associations, lazily allocated
132 struct GNUNET_CONTAINER_MultiHashMap32 *assoc_map;
135 * Next id that should be used for the assoc_map,
136 * initialized lazily to a random value together with
145 struct ServerClientSocketState
147 struct GNUNET_SERVER_Client *client;
148 struct GNUNET_SERVER_TransmitHandle* th;
152 struct ClientConnectionState
155 * Did we call receive alread alreadyy?
160 * Do we also want to receive?
162 int receive_requested;
163 struct GNUNET_CLIENT_Connection *connection;
164 struct GNUNET_CLIENT_TransmitHandle *th;
169 * Call the message message handler that was registered
170 * for the type of the given message in the given message queue.
172 * This function is indended to be used for the implementation
175 * @param mq message queue with the handlers
176 * @param mh message to dispatch
179 GNUNET_MQ_inject_message (struct GNUNET_MQ_Handle *mq, const struct GNUNET_MessageHeader *mh)
181 const struct GNUNET_MQ_MessageHandler *handler;
182 int handled = GNUNET_NO;
184 handler = mq->handlers;
187 for (; NULL != handler->cb; handler++)
189 if (handler->type == ntohs (mh->type))
191 handler->cb (mq->handlers_cls, mh);
192 handled = GNUNET_YES;
196 if (GNUNET_NO == handled)
197 LOG (GNUNET_ERROR_TYPE_WARNING, "no handler for message of type %d\n", ntohs (mh->type));
202 * Call the error handler of a message queue with the given
203 * error code. If there is no error handler, log a warning.
205 * This function is intended to be used by the implementation
208 * @param mq message queue
209 * @param error the error type
212 GNUNET_MQ_inject_error (struct GNUNET_MQ_Handle *mq,
213 enum GNUNET_MQ_Error error)
215 if (NULL == mq->error_handler)
217 /* FIXME: log what kind of error occured */
218 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "mq: got error, but no handler installed\n");
221 mq->error_handler (mq->handlers_cls, error);
226 GNUNET_MQ_discard (struct GNUNET_MQ_Envelope *mqm)
228 GNUNET_assert (NULL == mqm->parent_queue);
234 * Send a message with the give message queue.
235 * May only be called once per message.
237 * @param mq message queue
238 * @param ev the envelope with the message to send.
241 GNUNET_MQ_send (struct GNUNET_MQ_Handle *mq, struct GNUNET_MQ_Envelope *ev)
243 GNUNET_assert (NULL != mq);
244 GNUNET_assert (NULL == ev->parent_queue);
246 /* is the implementation busy? queue it! */
247 if (NULL != mq->current_envelope)
249 GNUNET_CONTAINER_DLL_insert_tail (mq->envelope_head, mq->envelope_tail, ev);
252 mq->current_envelope = ev;
253 mq->send_impl (mq, ev->mh, mq->impl_state);
258 * Call the send implementation for the next queued message,
260 * Only useful for implementing message queues,
261 * results in undefined behavior if not used carefully.
263 * @param mq message queue to send the next message with
266 GNUNET_MQ_impl_send_continue (struct GNUNET_MQ_Handle *mq)
268 /* call is only valid if we're actually currently sending
270 GNUNET_assert (NULL != mq);
271 GNUNET_assert (NULL != mq->current_envelope);
272 GNUNET_assert (GNUNET_YES == mq->commited);
273 mq->commited = GNUNET_NO;
274 GNUNET_free (mq->current_envelope);
275 if (NULL == mq->envelope_head)
277 mq->current_envelope = NULL;
281 GNUNET_assert (NULL != mq->envelope_tail);
282 GNUNET_assert (NULL != mq->envelope_head);
283 mq->current_envelope = mq->envelope_head;
284 GNUNET_CONTAINER_DLL_remove (mq->envelope_head, mq->envelope_tail,
285 mq->current_envelope);
286 mq->send_impl (mq, mq->current_envelope->mh, mq->impl_state);
291 * Create a message queue for the specified handlers.
293 * @param send function the implements sending messages
294 * @param destroy function that implements destroying the queue
295 * @param cancel function that implements canceling a message
296 * @param impl_state for the queue, passed to 'send' and 'destroy'
297 * @param handlers array of message handlers
298 * @param error_handler handler for read and write errors
299 * @param cls closure for message handlers and error handler
300 * @return a new message queue
302 struct GNUNET_MQ_Handle *
303 GNUNET_MQ_queue_for_callbacks (GNUNET_MQ_SendImpl send,
304 GNUNET_MQ_DestroyImpl destroy,
305 GNUNET_MQ_CancelImpl cancel,
307 const struct GNUNET_MQ_MessageHandler *handlers,
308 GNUNET_MQ_ErrorHandler error_handler,
311 struct GNUNET_MQ_Handle *mq;
313 mq = GNUNET_new (struct GNUNET_MQ_Handle);
314 mq->send_impl = send;
315 mq->destroy_impl = destroy;
316 mq->handlers = handlers;
317 mq->handlers_cls = cls;
318 mq->impl_state = impl_state;
325 * Get the message that should currently be sent.
326 * Fails if there is no current message.
327 * Only useful for implementing message queues,
328 * results in undefined behavior if not used carefully.
330 * @param mq message queue with the current message
331 * @return message to send, never NULL
333 const struct GNUNET_MessageHeader *
334 GNUNET_MQ_impl_current (struct GNUNET_MQ_Handle *mq)
336 if (NULL == mq->current_envelope)
338 if (NULL == mq->current_envelope->mh)
340 return mq->current_envelope->mh;
345 * Get the implementation state associated with the
348 * While the GNUNET_MQ_Impl* callbacks receive the
349 * implementation state, continuations that are scheduled
350 * by the implementation function often only have one closure
351 * argument, with this function it is possible to get at the
352 * implementation state when only passing the GNUNET_MQ_Handle
355 * @param mq message queue with the current message
356 * @return message to send, never NULL
359 GNUNET_MQ_impl_state (struct GNUNET_MQ_Handle *mq)
361 return mq->impl_state;
367 * Mark the current message as irrevocably sent, but do not
368 * proceed with sending the next message.
369 * Will call the appropriate GNUNET_MQ_NotifyCallback, if any.
371 * @param mq message queue
374 GNUNET_MQ_impl_send_commit (struct GNUNET_MQ_Handle *mq)
376 GNUNET_assert (NULL != mq->current_envelope);
377 GNUNET_assert (GNUNET_NO == mq->commited);
378 mq->commited = GNUNET_YES;
379 if (NULL != mq->current_envelope->sent_cb)
380 mq->current_envelope->sent_cb (mq->current_envelope->sent_cls);
384 struct GNUNET_MQ_Envelope *
385 GNUNET_MQ_msg_ (struct GNUNET_MessageHeader **mhp, uint16_t size, uint16_t type)
387 struct GNUNET_MQ_Envelope *mqm;
389 mqm = GNUNET_malloc (sizeof *mqm + size);
390 mqm->mh = (struct GNUNET_MessageHeader *) &mqm[1];
391 mqm->mh->size = htons (size);
392 mqm->mh->type = htons (type);
400 * Implementation of the GNUNET_MQ_msg_nested_mh macro.
402 * @param mhp pointer to the message header pointer that will be changed to allocate at
403 * the newly allocated space for the message.
404 * @param base_size size of the data before the nested message
405 * @param type type of the message in the envelope
406 * @param nested_mh the message to append to the message after base_size
408 struct GNUNET_MQ_Envelope *
409 GNUNET_MQ_msg_nested_mh_ (struct GNUNET_MessageHeader **mhp, uint16_t base_size, uint16_t type,
410 const struct GNUNET_MessageHeader *nested_mh)
412 struct GNUNET_MQ_Envelope *mqm;
415 if (NULL == nested_mh)
416 return GNUNET_MQ_msg_ (mhp, base_size, type);
418 size = base_size + ntohs (nested_mh->size);
420 /* check for uint16_t overflow */
421 if (size < base_size)
424 mqm = GNUNET_MQ_msg_ (mhp, size, type);
425 memcpy ((char *) mqm->mh + base_size, nested_mh, ntohs (nested_mh->size));
432 * Transmit a queued message to the session's client.
434 * @param cls consensus session
435 * @param size number of bytes available in buf
436 * @param buf where the callee should write the message
437 * @return number of bytes written to buf
440 transmit_queued (void *cls, size_t size,
443 struct GNUNET_MQ_Handle *mq = cls;
444 struct ServerClientSocketState *state = GNUNET_MQ_impl_state (mq);
445 const struct GNUNET_MessageHeader *msg = GNUNET_MQ_impl_current (mq);
448 GNUNET_assert (NULL != buf);
450 msg_size = ntohs (msg->size);
451 GNUNET_assert (size >= msg_size);
452 memcpy (buf, msg, msg_size);
455 GNUNET_MQ_impl_send_continue (mq);
463 server_client_destroy_impl (struct GNUNET_MQ_Handle *mq,
466 struct ServerClientSocketState *state = impl_state;
468 GNUNET_assert (NULL != mq);
469 GNUNET_assert (NULL != state);
470 GNUNET_SERVER_client_drop (state->client);
475 server_client_send_impl (struct GNUNET_MQ_Handle *mq,
476 const struct GNUNET_MessageHeader *msg, void *impl_state)
478 struct ServerClientSocketState *state = impl_state;
480 GNUNET_assert (NULL != mq);
481 GNUNET_assert (NULL != state);
483 GNUNET_MQ_impl_send_commit (mq);
486 GNUNET_SERVER_notify_transmit_ready (state->client, ntohs (msg->size),
487 GNUNET_TIME_UNIT_FOREVER_REL,
488 &transmit_queued, mq);
492 struct GNUNET_MQ_Handle *
493 GNUNET_MQ_queue_for_server_client (struct GNUNET_SERVER_Client *client)
495 struct GNUNET_MQ_Handle *mq;
496 struct ServerClientSocketState *scss;
498 mq = GNUNET_new (struct GNUNET_MQ_Handle);
499 scss = GNUNET_new (struct ServerClientSocketState);
500 mq->impl_state = scss;
501 scss->client = client;
502 GNUNET_SERVER_client_keep (client);
503 mq->send_impl = server_client_send_impl;
504 mq->destroy_impl = server_client_destroy_impl;
510 * Type of a function to call when we receive a message
514 * @param msg message received, NULL on timeout or fatal error
517 handle_client_message (void *cls,
518 const struct GNUNET_MessageHeader *msg)
520 struct GNUNET_MQ_Handle *mq = cls;
521 struct ClientConnectionState *state;
523 state = mq->impl_state;
527 GNUNET_MQ_inject_error (mq, GNUNET_MQ_ERROR_READ);
531 GNUNET_CLIENT_receive (state->connection, handle_client_message, mq,
532 GNUNET_TIME_UNIT_FOREVER_REL);
534 GNUNET_MQ_inject_message (mq, msg);
539 * Transmit a queued message to the session's client.
541 * @param cls consensus session
542 * @param size number of bytes available in buf
543 * @param buf where the callee should write the message
544 * @return number of bytes written to buf
547 connection_client_transmit_queued (void *cls, size_t size,
550 struct GNUNET_MQ_Handle *mq = cls;
551 const struct GNUNET_MessageHeader *msg;
552 struct ClientConnectionState *state = mq->impl_state;
555 GNUNET_assert (NULL != mq);
556 msg = GNUNET_MQ_impl_current (mq);
560 GNUNET_MQ_inject_error (mq, GNUNET_MQ_ERROR_READ);
564 if ( (GNUNET_YES == state->receive_requested) &&
565 (GNUNET_NO == state->receive_active) )
567 state->receive_active = GNUNET_YES;
568 GNUNET_CLIENT_receive (state->connection, handle_client_message, mq,
569 GNUNET_TIME_UNIT_FOREVER_REL);
573 msg_size = ntohs (msg->size);
574 GNUNET_assert (size >= msg_size);
575 memcpy (buf, msg, msg_size);
578 GNUNET_MQ_impl_send_continue (mq);
586 connection_client_destroy_impl (struct GNUNET_MQ_Handle *mq, void *impl_state)
588 GNUNET_free (impl_state);
592 connection_client_send_impl (struct GNUNET_MQ_Handle *mq,
593 const struct GNUNET_MessageHeader *msg, void *impl_state)
595 struct ClientConnectionState *state = impl_state;
597 GNUNET_assert (NULL != state);
598 GNUNET_assert (NULL == state->th);
600 GNUNET_MQ_impl_send_commit (mq);
603 GNUNET_CLIENT_notify_transmit_ready (state->connection, ntohs (msg->size),
604 GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_NO,
605 &connection_client_transmit_queued, mq);
609 struct GNUNET_MQ_Handle *
610 GNUNET_MQ_queue_for_connection_client (struct GNUNET_CLIENT_Connection *connection,
611 const struct GNUNET_MQ_MessageHandler *handlers,
612 GNUNET_MQ_ErrorHandler error_handler,
615 struct GNUNET_MQ_Handle *mq;
616 struct ClientConnectionState *state;
618 GNUNET_assert (NULL != connection);
620 mq = GNUNET_new (struct GNUNET_MQ_Handle);
621 mq->handlers = handlers;
622 mq->error_handler = error_handler;
623 mq->handlers_cls = cls;
624 state = GNUNET_new (struct ClientConnectionState);
625 state->connection = connection;
626 mq->impl_state = state;
627 mq->send_impl = connection_client_send_impl;
628 mq->destroy_impl = connection_client_destroy_impl;
629 if (NULL != handlers)
630 state->receive_requested = GNUNET_YES;
637 GNUNET_MQ_replace_handlers (struct GNUNET_MQ_Handle *mq,
638 const struct GNUNET_MQ_MessageHandler *new_handlers,
641 /* FIXME: notify implementation? */
642 /* FIXME: what about NULL handlers? abort receive? */
643 mq->handlers = new_handlers;
644 mq->handlers_cls = cls;
649 * Associate the assoc_data in mq with a unique request id.
651 * @param mq message queue, id will be unique for the queue
652 * @param assoc_data to associate
655 GNUNET_MQ_assoc_add (struct GNUNET_MQ_Handle *mq,
660 if (NULL == mq->assoc_map)
662 mq->assoc_map = GNUNET_CONTAINER_multihashmap32_create (8);
666 GNUNET_CONTAINER_multihashmap32_put (mq->assoc_map, id, assoc_data,
667 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
674 GNUNET_MQ_assoc_get (struct GNUNET_MQ_Handle *mq, uint32_t request_id)
676 if (NULL == mq->assoc_map)
678 return GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map, request_id);
683 GNUNET_MQ_assoc_remove (struct GNUNET_MQ_Handle *mq, uint32_t request_id)
687 if (NULL == mq->assoc_map)
689 val = GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map, request_id);
690 GNUNET_CONTAINER_multihashmap32_remove_all (mq->assoc_map, request_id);
696 GNUNET_MQ_notify_sent (struct GNUNET_MQ_Envelope *mqm,
697 GNUNET_MQ_NotifyCallback cb,
706 GNUNET_MQ_destroy (struct GNUNET_MQ_Handle *mq)
708 if (NULL != mq->destroy_impl)
710 mq->destroy_impl (mq, mq->impl_state);
713 while (NULL != mq->envelope_head)
715 struct GNUNET_MQ_Envelope *ev;
716 ev = mq->envelope_head;
717 GNUNET_CONTAINER_DLL_remove (mq->envelope_head, mq->envelope_tail, ev);
718 GNUNET_MQ_discard (ev);
721 if (NULL != mq->current_envelope)
723 GNUNET_MQ_discard (mq->current_envelope);
724 mq->current_envelope = NULL;
727 if (NULL != mq->assoc_map)
729 GNUNET_CONTAINER_multihashmap32_destroy (mq->assoc_map);
730 mq->assoc_map = NULL;
737 struct GNUNET_MessageHeader *
738 GNUNET_MQ_extract_nested_mh_ (const struct GNUNET_MessageHeader *mh, uint16_t base_size)
741 uint16_t nested_size;
742 struct GNUNET_MessageHeader *nested_msg;
744 whole_size = ntohs (mh->size);
745 GNUNET_assert (whole_size >= base_size);
747 nested_size = whole_size - base_size;
749 if (0 == nested_size)
752 if (nested_size < sizeof (struct GNUNET_MessageHeader))
758 nested_msg = (struct GNUNET_MessageHeader *) ((char *) mh + base_size);
760 if (ntohs (nested_msg->size) != nested_size)
763 nested_msg->size = htons (nested_size);