2 This file is part of GNUnet.
3 (C) 2012 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
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.
10 GNUnet is distributed in the hope that it will be useful, but
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 mq->continue_task = GNUNET_SCHEDULER_NO_TASK;
272 /* call is only valid if we're actually currently sending
274 current_envelope = mq->current_envelope;
275 GNUNET_assert (NULL != current_envelope);
276 if (NULL == mq->envelope_head)
278 mq->current_envelope = NULL;
282 mq->current_envelope = mq->envelope_head;
283 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
285 mq->current_envelope);
286 mq->send_impl (mq, mq->current_envelope->mh, mq->impl_state);
288 if (NULL != current_envelope->sent_cb)
289 current_envelope->sent_cb (current_envelope->sent_cls);
290 GNUNET_free (current_envelope);
295 * Call the send implementation for the next queued message,
297 * Only useful for implementing message queues,
298 * results in undefined behavior if not used carefully.
300 * @param mq message queue to send the next message with
303 GNUNET_MQ_impl_send_continue (struct GNUNET_MQ_Handle *mq)
305 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == mq->continue_task);
306 mq->continue_task = GNUNET_SCHEDULER_add_now (&impl_send_continue,
312 * Create a message queue for the specified handlers.
314 * @param send function the implements sending messages
315 * @param destroy function that implements destroying the queue
316 * @param cancel function that implements canceling a message
317 * @param impl_state for the queue, passed to 'send' and 'destroy'
318 * @param handlers array of message handlers
319 * @param error_handler handler for read and write errors
320 * @param cls closure for message handlers and error handler
321 * @return a new message queue
323 struct GNUNET_MQ_Handle *
324 GNUNET_MQ_queue_for_callbacks (GNUNET_MQ_SendImpl send,
325 GNUNET_MQ_DestroyImpl destroy,
326 GNUNET_MQ_CancelImpl cancel,
328 const struct GNUNET_MQ_MessageHandler *handlers,
329 GNUNET_MQ_ErrorHandler error_handler,
332 struct GNUNET_MQ_Handle *mq;
334 mq = GNUNET_new (struct GNUNET_MQ_Handle);
335 mq->send_impl = send;
336 mq->destroy_impl = destroy;
337 mq->handlers = handlers;
338 mq->handlers_cls = cls;
339 mq->impl_state = impl_state;
346 * Get the message that should currently be sent.
347 * Fails if there is no current message.
348 * Only useful for implementing message queues,
349 * results in undefined behavior if not used carefully.
351 * @param mq message queue with the current message
352 * @return message to send, never NULL
354 const struct GNUNET_MessageHeader *
355 GNUNET_MQ_impl_current (struct GNUNET_MQ_Handle *mq)
357 if (NULL == mq->current_envelope)
359 if (NULL == mq->current_envelope->mh)
361 return mq->current_envelope->mh;
366 * Get the implementation state associated with the
369 * While the GNUNET_MQ_Impl* callbacks receive the
370 * implementation state, continuations that are scheduled
371 * by the implementation function often only have one closure
372 * argument, with this function it is possible to get at the
373 * implementation state when only passing the GNUNET_MQ_Handle
376 * @param mq message queue with the current message
377 * @return message to send, never NULL
380 GNUNET_MQ_impl_state (struct GNUNET_MQ_Handle *mq)
382 return mq->impl_state;
386 struct GNUNET_MQ_Envelope *
387 GNUNET_MQ_msg_ (struct GNUNET_MessageHeader **mhp, uint16_t size, uint16_t type)
389 struct GNUNET_MQ_Envelope *mqm;
391 mqm = GNUNET_malloc (sizeof *mqm + size);
392 mqm->mh = (struct GNUNET_MessageHeader *) &mqm[1];
393 mqm->mh->size = htons (size);
394 mqm->mh->type = htons (type);
402 * Implementation of the GNUNET_MQ_msg_nested_mh macro.
404 * @param mhp pointer to the message header pointer that will be changed to allocate at
405 * the newly allocated space for the message.
406 * @param base_size size of the data before the nested message
407 * @param type type of the message in the envelope
408 * @param nested_mh the message to append to the message after base_size
410 struct GNUNET_MQ_Envelope *
411 GNUNET_MQ_msg_nested_mh_ (struct GNUNET_MessageHeader **mhp, uint16_t base_size, uint16_t type,
412 const struct GNUNET_MessageHeader *nested_mh)
414 struct GNUNET_MQ_Envelope *mqm;
417 if (NULL == nested_mh)
418 return GNUNET_MQ_msg_ (mhp, base_size, type);
420 size = base_size + ntohs (nested_mh->size);
422 /* check for uint16_t overflow */
423 if (size < base_size)
426 mqm = GNUNET_MQ_msg_ (mhp, size, type);
427 memcpy ((char *) mqm->mh + base_size, nested_mh, ntohs (nested_mh->size));
434 * Transmit a queued message to the session's client.
436 * @param cls consensus session
437 * @param size number of bytes available in buf
438 * @param buf where the callee should write the message
439 * @return number of bytes written to buf
442 transmit_queued (void *cls, size_t size,
445 struct GNUNET_MQ_Handle *mq = cls;
446 struct ServerClientSocketState *state = GNUNET_MQ_impl_state (mq);
447 const struct GNUNET_MessageHeader *msg = GNUNET_MQ_impl_current (mq);
450 GNUNET_assert (NULL != buf);
452 msg_size = ntohs (msg->size);
453 GNUNET_assert (size >= msg_size);
454 memcpy (buf, msg, msg_size);
457 GNUNET_MQ_impl_send_continue (mq);
464 server_client_destroy_impl (struct GNUNET_MQ_Handle *mq,
467 struct ServerClientSocketState *state = impl_state;
469 GNUNET_assert (NULL != mq);
470 GNUNET_assert (NULL != state);
471 GNUNET_SERVER_client_drop (state->client);
477 server_client_send_impl (struct GNUNET_MQ_Handle *mq,
478 const struct GNUNET_MessageHeader *msg, void *impl_state)
480 struct ServerClientSocketState *state = impl_state;
482 GNUNET_assert (NULL != mq);
483 GNUNET_assert (NULL != state);
485 GNUNET_SERVER_notify_transmit_ready (state->client, ntohs (msg->size),
486 GNUNET_TIME_UNIT_FOREVER_REL,
487 &transmit_queued, mq);
491 struct GNUNET_MQ_Handle *
492 GNUNET_MQ_queue_for_server_client (struct GNUNET_SERVER_Client *client)
494 struct GNUNET_MQ_Handle *mq;
495 struct ServerClientSocketState *scss;
497 mq = GNUNET_new (struct GNUNET_MQ_Handle);
498 scss = GNUNET_new (struct ServerClientSocketState);
499 mq->impl_state = scss;
500 scss->client = client;
501 GNUNET_SERVER_client_keep (client);
502 mq->send_impl = server_client_send_impl;
503 mq->destroy_impl = server_client_destroy_impl;
509 * Type of a function to call when we receive a message
513 * @param msg message received, NULL on timeout or fatal error
516 handle_client_message (void *cls,
517 const struct GNUNET_MessageHeader *msg)
519 struct GNUNET_MQ_Handle *mq = cls;
520 struct ClientConnectionState *state;
522 state = mq->impl_state;
526 GNUNET_MQ_inject_error (mq, GNUNET_MQ_ERROR_READ);
530 GNUNET_CLIENT_receive (state->connection, handle_client_message, mq,
531 GNUNET_TIME_UNIT_FOREVER_REL);
533 GNUNET_MQ_inject_message (mq, msg);
538 * Transmit a queued message to the session's client.
540 * @param cls consensus session
541 * @param size number of bytes available in @a buf
542 * @param buf where the callee should write the message
543 * @return number of bytes written to buf
546 connection_client_transmit_queued (void *cls,
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);
585 connection_client_destroy_impl (struct GNUNET_MQ_Handle *mq, void *impl_state)
587 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_CLIENT_notify_transmit_ready (state->connection, ntohs (msg->size),
601 GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_NO,
602 &connection_client_transmit_queued, mq);
603 GNUNET_assert (NULL != state->th);
607 struct GNUNET_MQ_Handle *
608 GNUNET_MQ_queue_for_connection_client (struct GNUNET_CLIENT_Connection *connection,
609 const struct GNUNET_MQ_MessageHandler *handlers,
610 GNUNET_MQ_ErrorHandler error_handler,
613 struct GNUNET_MQ_Handle *mq;
614 struct ClientConnectionState *state;
616 GNUNET_assert (NULL != connection);
618 mq = GNUNET_new (struct GNUNET_MQ_Handle);
619 mq->handlers = handlers;
620 mq->error_handler = error_handler;
621 mq->handlers_cls = cls;
622 state = GNUNET_new (struct ClientConnectionState);
623 state->connection = connection;
624 mq->impl_state = state;
625 mq->send_impl = connection_client_send_impl;
626 mq->destroy_impl = connection_client_destroy_impl;
627 if (NULL != handlers)
628 state->receive_requested = GNUNET_YES;
635 GNUNET_MQ_replace_handlers (struct GNUNET_MQ_Handle *mq,
636 const struct GNUNET_MQ_MessageHandler *new_handlers,
639 /* FIXME: notify implementation? */
640 /* FIXME: what about NULL handlers? abort receive? */
641 mq->handlers = new_handlers;
642 mq->handlers_cls = cls;
647 * Associate the assoc_data in mq with a unique request id.
649 * @param mq message queue, id will be unique for the queue
650 * @param assoc_data to associate
653 GNUNET_MQ_assoc_add (struct GNUNET_MQ_Handle *mq,
658 if (NULL == mq->assoc_map)
660 mq->assoc_map = GNUNET_CONTAINER_multihashmap32_create (8);
664 GNUNET_CONTAINER_multihashmap32_put (mq->assoc_map, id, assoc_data,
665 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
671 GNUNET_MQ_assoc_get (struct GNUNET_MQ_Handle *mq, uint32_t request_id)
673 if (NULL == mq->assoc_map)
675 return GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map, request_id);
680 GNUNET_MQ_assoc_remove (struct GNUNET_MQ_Handle *mq, uint32_t request_id)
684 if (NULL == mq->assoc_map)
686 val = GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map, request_id);
687 GNUNET_CONTAINER_multihashmap32_remove_all (mq->assoc_map, request_id);
693 GNUNET_MQ_notify_sent (struct GNUNET_MQ_Envelope *mqm,
694 GNUNET_MQ_NotifyCallback cb,
703 GNUNET_MQ_destroy (struct GNUNET_MQ_Handle *mq)
705 if (NULL != mq->destroy_impl)
707 mq->destroy_impl (mq, mq->impl_state);
709 if (GNUNET_SCHEDULER_NO_TASK != mq->continue_task)
711 GNUNET_SCHEDULER_cancel (mq->continue_task);
712 mq->continue_task = GNUNET_SCHEDULER_NO_TASK;
714 while (NULL != mq->envelope_head)
716 struct GNUNET_MQ_Envelope *ev;
717 ev = mq->envelope_head;
718 GNUNET_CONTAINER_DLL_remove (mq->envelope_head, mq->envelope_tail, ev);
719 GNUNET_MQ_discard (ev);
722 if (NULL != mq->current_envelope)
724 GNUNET_MQ_discard (mq->current_envelope);
725 mq->current_envelope = NULL;
728 if (NULL != mq->assoc_map)
730 GNUNET_CONTAINER_multihashmap32_destroy (mq->assoc_map);
731 mq->assoc_map = NULL;
738 struct GNUNET_MessageHeader *
739 GNUNET_MQ_extract_nested_mh_ (const struct GNUNET_MessageHeader *mh, uint16_t base_size)
742 uint16_t nested_size;
743 struct GNUNET_MessageHeader *nested_msg;
745 whole_size = ntohs (mh->size);
746 GNUNET_assert (whole_size >= base_size);
748 nested_size = whole_size - base_size;
750 if (0 == nested_size)
753 if (nested_size < sizeof (struct GNUNET_MessageHeader))
759 nested_msg = (struct GNUNET_MessageHeader *) ((char *) mh + base_size);
761 if (ntohs (nested_msg->size) != nested_size)
764 nested_msg->size = htons (nested_size);