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
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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 * Map of associations, lazily allocated
126 struct GNUNET_CONTAINER_MultiHashMap32 *assoc_map;
129 * Task scheduled during #GNUNET_MQ_impl_send_continue.
131 GNUNET_SCHEDULER_TaskIdentifier continue_task;
134 * Next id that should be used for the assoc_map,
135 * initialized lazily to a random value together with
144 struct ServerClientSocketState
146 struct GNUNET_SERVER_Client *client;
147 struct GNUNET_SERVER_TransmitHandle* th;
151 struct ClientConnectionState
154 * Did we call receive alread alreadyy?
159 * Do we also want to receive?
161 int receive_requested;
162 struct GNUNET_CLIENT_Connection *connection;
163 struct GNUNET_CLIENT_TransmitHandle *th;
168 * Call the message message handler that was registered
169 * for the type of the given message in the given message queue.
171 * This function is indended to be used for the implementation
174 * @param mq message queue with the handlers
175 * @param mh message to dispatch
178 GNUNET_MQ_inject_message (struct GNUNET_MQ_Handle *mq, const struct GNUNET_MessageHeader *mh)
180 const struct GNUNET_MQ_MessageHandler *handler;
181 int handled = GNUNET_NO;
183 handler = mq->handlers;
186 for (; NULL != handler->cb; handler++)
188 if (handler->type == ntohs (mh->type))
190 handler->cb (mq->handlers_cls, mh);
191 handled = GNUNET_YES;
195 if (GNUNET_NO == handled)
196 LOG (GNUNET_ERROR_TYPE_WARNING, "no handler for message of type %d\n", ntohs (mh->type));
201 * Call the error handler of a message queue with the given
202 * error code. If there is no error handler, log a warning.
204 * This function is intended to be used by the implementation
207 * @param mq message queue
208 * @param error the error type
211 GNUNET_MQ_inject_error (struct GNUNET_MQ_Handle *mq,
212 enum GNUNET_MQ_Error error)
214 if (NULL == mq->error_handler)
216 /* FIXME: log what kind of error occured */
217 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "mq: got error, but no handler installed\n");
220 mq->error_handler (mq->handlers_cls, error);
225 GNUNET_MQ_discard (struct GNUNET_MQ_Envelope *mqm)
227 GNUNET_assert (NULL == mqm->parent_queue);
233 * Send a message with the give message queue.
234 * May only be called once per message.
236 * @param mq message queue
237 * @param ev the envelope with the message to send.
240 GNUNET_MQ_send (struct GNUNET_MQ_Handle *mq, struct GNUNET_MQ_Envelope *ev)
242 GNUNET_assert (NULL != mq);
243 GNUNET_assert (NULL == ev->parent_queue);
245 /* is the implementation busy? queue it! */
246 if (NULL != mq->current_envelope)
248 GNUNET_CONTAINER_DLL_insert_tail (mq->envelope_head, mq->envelope_tail, ev);
251 mq->current_envelope = ev;
252 mq->send_impl (mq, ev->mh, mq->impl_state);
257 * Task run to call the send implementation for the next queued
258 * message, if any. Only useful for implementing message queues,
259 * results in undefined behavior if not used carefully.
261 * @param cls message queue to send the next message with
262 * @param tc scheduler context
265 impl_send_continue (void *cls,
266 const struct GNUNET_SCHEDULER_TaskContext *tc)
268 struct GNUNET_MQ_Handle *mq = cls;
269 struct GNUNET_MQ_Envelope *current_envelope;
271 if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
274 mq->continue_task = GNUNET_SCHEDULER_NO_TASK;
275 /* call is only valid if we're actually currently sending
277 current_envelope = mq->current_envelope;
278 GNUNET_assert (NULL != current_envelope);
279 if (NULL == mq->envelope_head)
281 mq->current_envelope = NULL;
285 mq->current_envelope = mq->envelope_head;
286 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
288 mq->current_envelope);
289 mq->send_impl (mq, mq->current_envelope->mh, mq->impl_state);
291 if (NULL != current_envelope->sent_cb)
292 current_envelope->sent_cb (current_envelope->sent_cls);
293 GNUNET_free (current_envelope);
298 * Call the send implementation for the next queued message,
300 * Only useful for implementing message queues,
301 * results in undefined behavior if not used carefully.
303 * @param mq message queue to send the next message with
306 GNUNET_MQ_impl_send_continue (struct GNUNET_MQ_Handle *mq)
308 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == mq->continue_task);
309 mq->continue_task = GNUNET_SCHEDULER_add_now (&impl_send_continue,
315 * Create a message queue for the specified handlers.
317 * @param send function the implements sending messages
318 * @param destroy function that implements destroying the queue
319 * @param cancel function that implements canceling a message
320 * @param impl_state for the queue, passed to 'send' and 'destroy'
321 * @param handlers array of message handlers
322 * @param error_handler handler for read and write errors
323 * @param cls closure for message handlers and error handler
324 * @return a new message queue
326 struct GNUNET_MQ_Handle *
327 GNUNET_MQ_queue_for_callbacks (GNUNET_MQ_SendImpl send,
328 GNUNET_MQ_DestroyImpl destroy,
329 GNUNET_MQ_CancelImpl cancel,
331 const struct GNUNET_MQ_MessageHandler *handlers,
332 GNUNET_MQ_ErrorHandler error_handler,
335 struct GNUNET_MQ_Handle *mq;
337 mq = GNUNET_new (struct GNUNET_MQ_Handle);
338 mq->send_impl = send;
339 mq->destroy_impl = destroy;
340 mq->handlers = handlers;
341 mq->handlers_cls = cls;
342 mq->impl_state = impl_state;
349 * Get the message that should currently be sent.
350 * Fails if there is no current message.
351 * Only useful for implementing message queues,
352 * results in undefined behavior if not used carefully.
354 * @param mq message queue with the current message
355 * @return message to send, never NULL
357 const struct GNUNET_MessageHeader *
358 GNUNET_MQ_impl_current (struct GNUNET_MQ_Handle *mq)
360 if (NULL == mq->current_envelope)
362 if (NULL == mq->current_envelope->mh)
364 return mq->current_envelope->mh;
369 * Get the implementation state associated with the
372 * While the GNUNET_MQ_Impl* callbacks receive the
373 * implementation state, continuations that are scheduled
374 * by the implementation function often only have one closure
375 * argument, with this function it is possible to get at the
376 * implementation state when only passing the GNUNET_MQ_Handle
379 * @param mq message queue with the current message
380 * @return message to send, never NULL
383 GNUNET_MQ_impl_state (struct GNUNET_MQ_Handle *mq)
385 return mq->impl_state;
389 struct GNUNET_MQ_Envelope *
390 GNUNET_MQ_msg_ (struct GNUNET_MessageHeader **mhp, uint16_t size, uint16_t type)
392 struct GNUNET_MQ_Envelope *mqm;
394 mqm = GNUNET_malloc (sizeof *mqm + size);
395 mqm->mh = (struct GNUNET_MessageHeader *) &mqm[1];
396 mqm->mh->size = htons (size);
397 mqm->mh->type = htons (type);
405 * Implementation of the GNUNET_MQ_msg_nested_mh macro.
407 * @param mhp pointer to the message header pointer that will be changed to allocate at
408 * the newly allocated space for the message.
409 * @param base_size size of the data before the nested message
410 * @param type type of the message in the envelope
411 * @param nested_mh the message to append to the message after base_size
413 struct GNUNET_MQ_Envelope *
414 GNUNET_MQ_msg_nested_mh_ (struct GNUNET_MessageHeader **mhp, uint16_t base_size, uint16_t type,
415 const struct GNUNET_MessageHeader *nested_mh)
417 struct GNUNET_MQ_Envelope *mqm;
420 if (NULL == nested_mh)
421 return GNUNET_MQ_msg_ (mhp, base_size, type);
423 size = base_size + ntohs (nested_mh->size);
425 /* check for uint16_t overflow */
426 if (size < base_size)
429 mqm = GNUNET_MQ_msg_ (mhp, size, type);
430 memcpy ((char *) mqm->mh + base_size, nested_mh, ntohs (nested_mh->size));
437 * Transmit a queued message to the session's client.
439 * @param cls consensus session
440 * @param size number of bytes available in buf
441 * @param buf where the callee should write the message
442 * @return number of bytes written to buf
445 transmit_queued (void *cls, size_t size,
448 struct GNUNET_MQ_Handle *mq = cls;
449 struct ServerClientSocketState *state = GNUNET_MQ_impl_state (mq);
450 const struct GNUNET_MessageHeader *msg = GNUNET_MQ_impl_current (mq);
453 GNUNET_assert (NULL != buf);
455 msg_size = ntohs (msg->size);
456 GNUNET_assert (size >= msg_size);
457 memcpy (buf, msg, msg_size);
460 GNUNET_MQ_impl_send_continue (mq);
467 server_client_destroy_impl (struct GNUNET_MQ_Handle *mq,
470 struct ServerClientSocketState *state = impl_state;
472 if (NULL != state->th)
474 GNUNET_SERVER_notify_transmit_ready_cancel (state->th);
478 GNUNET_assert (NULL != mq);
479 GNUNET_assert (NULL != state);
480 GNUNET_SERVER_client_drop (state->client);
486 server_client_send_impl (struct GNUNET_MQ_Handle *mq,
487 const struct GNUNET_MessageHeader *msg, void *impl_state)
489 struct ServerClientSocketState *state = impl_state;
491 GNUNET_assert (NULL != mq);
492 GNUNET_assert (NULL != state);
494 GNUNET_SERVER_notify_transmit_ready (state->client, ntohs (msg->size),
495 GNUNET_TIME_UNIT_FOREVER_REL,
496 &transmit_queued, mq);
500 struct GNUNET_MQ_Handle *
501 GNUNET_MQ_queue_for_server_client (struct GNUNET_SERVER_Client *client)
503 struct GNUNET_MQ_Handle *mq;
504 struct ServerClientSocketState *scss;
506 mq = GNUNET_new (struct GNUNET_MQ_Handle);
507 scss = GNUNET_new (struct ServerClientSocketState);
508 mq->impl_state = scss;
509 scss->client = client;
510 GNUNET_SERVER_client_keep (client);
511 mq->send_impl = server_client_send_impl;
512 mq->destroy_impl = server_client_destroy_impl;
518 * Type of a function to call when we receive a message
522 * @param msg message received, NULL on timeout or fatal error
525 handle_client_message (void *cls,
526 const struct GNUNET_MessageHeader *msg)
528 struct GNUNET_MQ_Handle *mq = cls;
529 struct ClientConnectionState *state;
531 state = mq->impl_state;
535 GNUNET_MQ_inject_error (mq, GNUNET_MQ_ERROR_READ);
539 GNUNET_CLIENT_receive (state->connection, handle_client_message, mq,
540 GNUNET_TIME_UNIT_FOREVER_REL);
542 GNUNET_MQ_inject_message (mq, msg);
547 * Transmit a queued message to the session's client.
549 * @param cls consensus session
550 * @param size number of bytes available in @a buf
551 * @param buf where the callee should write the message
552 * @return number of bytes written to buf
555 connection_client_transmit_queued (void *cls,
559 struct GNUNET_MQ_Handle *mq = cls;
560 const struct GNUNET_MessageHeader *msg;
561 struct ClientConnectionState *state = mq->impl_state;
564 GNUNET_assert (NULL != mq);
565 msg = GNUNET_MQ_impl_current (mq);
569 GNUNET_MQ_inject_error (mq, GNUNET_MQ_ERROR_READ);
573 if ( (GNUNET_YES == state->receive_requested) &&
574 (GNUNET_NO == state->receive_active) )
576 state->receive_active = GNUNET_YES;
577 GNUNET_CLIENT_receive (state->connection, handle_client_message, mq,
578 GNUNET_TIME_UNIT_FOREVER_REL);
582 msg_size = ntohs (msg->size);
583 GNUNET_assert (size >= msg_size);
584 memcpy (buf, msg, msg_size);
587 GNUNET_MQ_impl_send_continue (mq);
594 connection_client_destroy_impl (struct GNUNET_MQ_Handle *mq, void *impl_state)
596 GNUNET_free (impl_state);
601 connection_client_send_impl (struct GNUNET_MQ_Handle *mq,
602 const struct GNUNET_MessageHeader *msg, void *impl_state)
604 struct ClientConnectionState *state = impl_state;
606 GNUNET_assert (NULL != state);
607 GNUNET_assert (NULL == state->th);
609 GNUNET_CLIENT_notify_transmit_ready (state->connection, ntohs (msg->size),
610 GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_NO,
611 &connection_client_transmit_queued, mq);
612 GNUNET_assert (NULL != state->th);
616 struct GNUNET_MQ_Handle *
617 GNUNET_MQ_queue_for_connection_client (struct GNUNET_CLIENT_Connection *connection,
618 const struct GNUNET_MQ_MessageHandler *handlers,
619 GNUNET_MQ_ErrorHandler error_handler,
622 struct GNUNET_MQ_Handle *mq;
623 struct ClientConnectionState *state;
625 GNUNET_assert (NULL != connection);
627 mq = GNUNET_new (struct GNUNET_MQ_Handle);
628 mq->handlers = handlers;
629 mq->error_handler = error_handler;
630 mq->handlers_cls = cls;
631 state = GNUNET_new (struct ClientConnectionState);
632 state->connection = connection;
633 mq->impl_state = state;
634 mq->send_impl = connection_client_send_impl;
635 mq->destroy_impl = connection_client_destroy_impl;
636 if (NULL != handlers)
637 state->receive_requested = GNUNET_YES;
644 GNUNET_MQ_replace_handlers (struct GNUNET_MQ_Handle *mq,
645 const struct GNUNET_MQ_MessageHandler *new_handlers,
648 /* FIXME: notify implementation? */
649 /* FIXME: what about NULL handlers? abort receive? */
650 mq->handlers = new_handlers;
651 mq->handlers_cls = cls;
656 * Associate the assoc_data in mq with a unique request id.
658 * @param mq message queue, id will be unique for the queue
659 * @param assoc_data to associate
662 GNUNET_MQ_assoc_add (struct GNUNET_MQ_Handle *mq,
667 if (NULL == mq->assoc_map)
669 mq->assoc_map = GNUNET_CONTAINER_multihashmap32_create (8);
673 GNUNET_CONTAINER_multihashmap32_put (mq->assoc_map, id, assoc_data,
674 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
680 GNUNET_MQ_assoc_get (struct GNUNET_MQ_Handle *mq, uint32_t request_id)
682 if (NULL == mq->assoc_map)
684 return GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map, request_id);
689 GNUNET_MQ_assoc_remove (struct GNUNET_MQ_Handle *mq, uint32_t request_id)
693 if (NULL == mq->assoc_map)
695 val = GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map, request_id);
696 GNUNET_CONTAINER_multihashmap32_remove_all (mq->assoc_map, request_id);
702 GNUNET_MQ_notify_sent (struct GNUNET_MQ_Envelope *mqm,
703 GNUNET_MQ_NotifyCallback cb,
712 GNUNET_MQ_destroy (struct GNUNET_MQ_Handle *mq)
714 if (NULL != mq->destroy_impl)
716 mq->destroy_impl (mq, mq->impl_state);
718 if (GNUNET_SCHEDULER_NO_TASK != mq->continue_task)
720 GNUNET_SCHEDULER_cancel (mq->continue_task);
721 mq->continue_task = GNUNET_SCHEDULER_NO_TASK;
723 while (NULL != mq->envelope_head)
725 struct GNUNET_MQ_Envelope *ev;
726 ev = mq->envelope_head;
727 GNUNET_CONTAINER_DLL_remove (mq->envelope_head, mq->envelope_tail, ev);
728 GNUNET_MQ_discard (ev);
731 if (NULL != mq->current_envelope)
733 GNUNET_MQ_discard (mq->current_envelope);
734 mq->current_envelope = NULL;
737 if (NULL != mq->assoc_map)
739 GNUNET_CONTAINER_multihashmap32_destroy (mq->assoc_map);
740 mq->assoc_map = NULL;
747 struct GNUNET_MessageHeader *
748 GNUNET_MQ_extract_nested_mh_ (const struct GNUNET_MessageHeader *mh, uint16_t base_size)
751 uint16_t nested_size;
752 struct GNUNET_MessageHeader *nested_msg;
754 whole_size = ntohs (mh->size);
755 GNUNET_assert (whole_size >= base_size);
757 nested_size = whole_size - base_size;
759 if (0 == nested_size)
762 if (nested_size < sizeof (struct GNUNET_MessageHeader))
768 nested_msg = (struct GNUNET_MessageHeader *) ((char *) mh + base_size);
770 if (ntohs (nested_msg->size) != nested_size)
773 nested_msg->size = htons (nested_size);