use NULL as flag for evaluation of query, ensure we pass non-NULL for reply_block...
[oweals/gnunet.git] / src / util / mq.c
index 4ba6c5ff8c255ab4e2e089263bc6de34d6badef6..bd7ad7c4728ecdb131d649ae805a20c39b07d3de 100644 (file)
@@ -58,7 +58,7 @@ struct GNUNET_MQ_Envelope
   /**
    * Called after the message was sent irrevocably.
    */
-  GNUNET_MQ_NotifyCallback sent_cb;
+  GNUNET_SCHEDULER_TaskCallback sent_cb;
 
   /**
    * Closure for @e send_cb
@@ -127,6 +127,11 @@ struct GNUNET_MQ_Handle
    */
   void *error_handler_cls;
 
+  /**
+   * Task to asynchronously run #impl_send_continue().
+   */
+  struct GNUNET_SCHEDULER_Task *send_task;
+
   /**
    * Linked list of messages pending to be sent
    */
@@ -144,23 +149,11 @@ struct GNUNET_MQ_Handle
    */
   struct GNUNET_MQ_Envelope *current_envelope;
 
-  /**
-   * GNUNET_YES if the sent notification was called 
-   * for the current envelope.
-   */
-  int send_notification_called;
-
   /**
    * Map of associations, lazily allocated
    */
   struct GNUNET_CONTAINER_MultiHashMap32 *assoc_map;
 
-  /**
-   * Task scheduled during #GNUNET_MQ_impl_send_continue
-   * or #GNUNET_MQ_impl_send_in_flight
-   */
-  struct GNUNET_SCHEDULER_Task *send_task;
-
   /**
    * Functions to call on queue destruction; kept in a DLL.
    */
@@ -196,9 +189,15 @@ struct GNUNET_MQ_Handle
   unsigned int queue_length;
 
   /**
-   * GNUNET_YES if GNUNET_MQ_impl_evacuate was called.
+   * #GNUNET_YES if GNUNET_MQ_impl_evacuate was called.
+   * FIXME: is this dead?
    */
   int evacuate_called;
+
+  /**
+   * #GNUNET_YES if GNUNET_MQ_impl_send_in_flight() was called.
+   */
+  int in_flight;
 };
 
 
@@ -220,34 +219,6 @@ struct ServerClientSocketState
 };
 
 
-/**
- * Implementation-specific state for connection to
- * service (MQ for clients).
- */
-struct ClientConnectionState
-{
-  /**
-   * Did we call receive alread alreadyy?
-   */
-  int receive_active;
-
-  /**
-   * Do we also want to receive?
-   */
-  int receive_requested;
-
-  /**
-   * Connection to the service.
-   */
-  struct GNUNET_CLIENT_Connection *connection;
-
-  /**
-   * Active transmission request (or NULL).
-   */
-  struct GNUNET_CLIENT_TransmitHandle *th;
-};
-
-
 /**
  * Call the message message handler that was registered
  * for the type of the given message in the given message queue.
@@ -364,7 +335,11 @@ GNUNET_MQ_discard (struct GNUNET_MQ_Envelope *ev)
 unsigned int
 GNUNET_MQ_get_length (struct GNUNET_MQ_Handle *mq)
 {
-  return mq->queue_length;
+  if (GNUNET_YES != mq->in_flight)
+  {
+    return mq->queue_length;
+  }
+  return mq->queue_length - 1;
 }
 
 
@@ -385,7 +360,8 @@ GNUNET_MQ_send (struct GNUNET_MQ_Handle *mq,
   mq->queue_length++;
   ev->parent_queue = mq;
   /* is the implementation busy? queue it! */
-  if (NULL != mq->current_envelope)
+  if ( (NULL != mq->current_envelope) ||
+       (NULL != mq->send_task) )
   {
     GNUNET_CONTAINER_DLL_insert_tail (mq->envelope_head,
                                       mq->envelope_tail,
@@ -427,35 +403,6 @@ GNUNET_MQ_send_copy (struct GNUNET_MQ_Handle *mq,
 }
 
 
-/**
- * Task run to call the send notification for the next queued
- * message, if any.  Only useful for implementing message queues,
- * results in undefined behavior if not used carefully.
- *
- * @param cls message queue to send the next message with
- */
-static void
-impl_send_in_flight (void *cls)
-{
-  struct GNUNET_MQ_Handle *mq = cls;
-  struct GNUNET_MQ_Envelope *current_envelope;
-
-  mq->send_task = NULL;
-  /* call is only valid if we're actually currently sending
-   * a message */
-  current_envelope = mq->current_envelope;
-  GNUNET_assert (NULL != current_envelope);
-  /* can't call cancel from now on anymore */
-  current_envelope->parent_queue = NULL;
-  if ( (GNUNET_NO == mq->send_notification_called) &&
-       (NULL != current_envelope->sent_cb) )
-  {
-    current_envelope->sent_cb (current_envelope->sent_cls);
-  }
-  mq->send_notification_called = GNUNET_YES;
-}
-
-
 /**
  * Task run to call the send implementation for the next queued
  * message, if any.  Only useful for implementing message queues,
@@ -467,32 +414,19 @@ static void
 impl_send_continue (void *cls)
 {
   struct GNUNET_MQ_Handle *mq = cls;
-  struct GNUNET_MQ_Envelope *current_envelope;
 
   mq->send_task = NULL;
   /* call is only valid if we're actually currently sending
    * a message */
-  current_envelope = mq->current_envelope;
-  GNUNET_assert (NULL != current_envelope);
-  impl_send_in_flight (mq);
-  GNUNET_assert (0 < mq->queue_length);
-  mq->queue_length--;
   if (NULL == mq->envelope_head)
-  {
-    mq->current_envelope = NULL;
-  }
-  else
-  {
-    mq->current_envelope = mq->envelope_head;
-    GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
-                                 mq->envelope_tail,
-                                 mq->current_envelope);
-    mq->send_notification_called = GNUNET_NO;
-    mq->send_impl (mq,
-                  mq->current_envelope->mh,
-                  mq->impl_state);
-  }
-  GNUNET_free (current_envelope);
+    return;
+  mq->current_envelope = mq->envelope_head;
+  GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
+                              mq->envelope_tail,
+                              mq->current_envelope);
+  mq->send_impl (mq,
+                mq->current_envelope->mh,
+                mq->impl_state);
 }
 
 
@@ -506,22 +440,33 @@ impl_send_continue (void *cls)
 void
 GNUNET_MQ_impl_send_continue (struct GNUNET_MQ_Handle *mq)
 {
-  /* maybe #GNUNET_MQ_impl_send_in_flight was called? */
-  if (NULL != mq->send_task)
+  struct GNUNET_MQ_Envelope *current_envelope;
+  GNUNET_SCHEDULER_TaskCallback cb;
+
+  GNUNET_assert (0 < mq->queue_length);
+  mq->queue_length--;
+  mq->in_flight = GNUNET_NO;
+  current_envelope = mq->current_envelope;
+  current_envelope->parent_queue = NULL;
+  mq->current_envelope = NULL;
+  GNUNET_assert (NULL == mq->send_task);
+  mq->send_task = GNUNET_SCHEDULER_add_now (&impl_send_continue,
+                                           mq);
+  if (NULL != (cb = current_envelope->sent_cb))
   {
-    GNUNET_SCHEDULER_cancel (mq->send_task);
+    current_envelope->sent_cb = NULL;
+    cb (current_envelope->sent_cls);
   }
-  mq->send_task = GNUNET_SCHEDULER_add_now (&impl_send_continue,
-                                            mq);
+  GNUNET_free (current_envelope);
 }
 
 
 /**
  * Call the send notification for the current message, but do not
- * try to send the next message until #gnunet_mq_impl_send_continue
+ * try to send the next message until #GNUNET_MQ_impl_send_continue
  * is called.
  *
- * only useful for implementing message queues, results in undefined
+ * Only useful for implementing message queues, results in undefined
  * behavior if not used carefully.
  *
  * @param mq message queue to send the next message with
@@ -529,9 +474,21 @@ GNUNET_MQ_impl_send_continue (struct GNUNET_MQ_Handle *mq)
 void
 GNUNET_MQ_impl_send_in_flight (struct GNUNET_MQ_Handle *mq)
 {
-  GNUNET_assert (NULL == mq->send_task);
-  mq->send_task = GNUNET_SCHEDULER_add_now (&impl_send_in_flight,
-                                            mq);
+  struct GNUNET_MQ_Envelope *current_envelope;
+  GNUNET_SCHEDULER_TaskCallback cb;
+
+  mq->in_flight = GNUNET_YES;
+  /* call is only valid if we're actually currently sending
+   * a message */
+  current_envelope = mq->current_envelope;
+  GNUNET_assert (NULL != current_envelope);
+  /* can't call cancel from now on anymore */
+  current_envelope->parent_queue = NULL;
+  if (NULL != (cb = current_envelope->sent_cb))
+  {
+    current_envelope->sent_cb = NULL;
+    cb (current_envelope->sent_cls);
+  }
 }
 
 
@@ -794,175 +751,6 @@ GNUNET_MQ_queue_for_server_client (struct GNUNET_SERVER_Client *client)
 }
 
 
-/**
- * Type of a function to call when we receive a message
- * from the service.
- *
- * @param cls closure
- * @param msg message received, NULL on timeout or fatal error
- */
-static void
-handle_client_message (void *cls,
-                       const struct GNUNET_MessageHeader *msg)
-{
-  struct GNUNET_MQ_Handle *mq = cls;
-  struct ClientConnectionState *state;
-
-  state = mq->impl_state;
-  if (NULL == msg)
-  {
-    GNUNET_MQ_inject_error (mq, GNUNET_MQ_ERROR_READ);
-    return;
-  }
-  GNUNET_CLIENT_receive (state->connection,
-                        &handle_client_message,
-                        mq,
-                         GNUNET_TIME_UNIT_FOREVER_REL);
-  GNUNET_MQ_inject_message (mq, msg);
-}
-
-
-/**
- * Transmit a queued message to the session's client.
- *
- * @param cls consensus session
- * @param size number of bytes available in @a buf
- * @param buf where the callee should write the message
- * @return number of bytes written to buf
- */
-static size_t
-connection_client_transmit_queued (void *cls,
-                                   size_t size,
-                                   void *buf)
-{
-  struct GNUNET_MQ_Handle *mq = cls;
-  const struct GNUNET_MessageHeader *msg;
-  struct ClientConnectionState *state = mq->impl_state;
-  size_t msg_size;
-
-  GNUNET_assert (NULL != mq);
-  state->th = NULL;
-  msg = GNUNET_MQ_impl_current (mq);
-
-  if (NULL == buf)
-  {
-    GNUNET_MQ_inject_error (mq, GNUNET_MQ_ERROR_READ);
-    return 0;
-  }
-
-  if ( (GNUNET_YES == state->receive_requested) &&
-       (GNUNET_NO == state->receive_active) )
-  {
-    state->receive_active = GNUNET_YES;
-    GNUNET_CLIENT_receive (state->connection,
-                          &handle_client_message,
-                          mq,
-                           GNUNET_TIME_UNIT_FOREVER_REL);
-  }
-
-  msg_size = ntohs (msg->size);
-  GNUNET_assert (size >= msg_size);
-  GNUNET_memcpy (buf, msg, msg_size);
-  state->th = NULL;
-
-  GNUNET_MQ_impl_send_continue (mq);
-
-  return msg_size;
-}
-
-
-static void
-connection_client_destroy_impl (struct GNUNET_MQ_Handle *mq,
-                                void *impl_state)
-{
-  struct ClientConnectionState *state = impl_state;
-
-  if (NULL != state->th)
-  {
-    GNUNET_CLIENT_notify_transmit_ready_cancel (state->th);
-    state->th = NULL;
-  }
-  GNUNET_CLIENT_disconnect (state->connection);
-  GNUNET_free (impl_state);
-}
-
-
-static void
-connection_client_send_impl (struct GNUNET_MQ_Handle *mq,
-                             const struct GNUNET_MessageHeader *msg,
-                             void *impl_state)
-{
-  struct ClientConnectionState *state = impl_state;
-
-  GNUNET_assert (NULL != state);
-  GNUNET_assert (NULL == state->th);
-  state->th =
-      GNUNET_CLIENT_notify_transmit_ready (state->connection,
-                                          ntohs (msg->size),
-                                           GNUNET_TIME_UNIT_FOREVER_REL,
-                                           GNUNET_NO,
-                                           &connection_client_transmit_queued,
-                                           mq);
-  GNUNET_assert (NULL != state->th);
-}
-
-
-static void
-connection_client_cancel_impl (struct GNUNET_MQ_Handle *mq,
-                               void *impl_state)
-{
-  struct ClientConnectionState *state = impl_state;
-
-  if (NULL != state->th)
-  {
-    GNUNET_CLIENT_notify_transmit_ready_cancel (state->th);
-    state->th = NULL;
-  }
-  else if (NULL != mq->send_task)
-  {
-    GNUNET_SCHEDULER_cancel (mq->send_task);
-    mq->send_task = NULL;
-  }
-  else
-    GNUNET_assert (0);
-}
-
-
-struct GNUNET_MQ_Handle *
-GNUNET_MQ_queue_for_connection_client (struct GNUNET_CLIENT_Connection *connection,
-                                       const struct GNUNET_MQ_MessageHandler *handlers,
-                                       GNUNET_MQ_ErrorHandler error_handler,
-                                       void *error_handler_cls)
-{
-  struct GNUNET_MQ_Handle *mq;
-  struct ClientConnectionState *state;
-  unsigned int i;
-
-  mq = GNUNET_new (struct GNUNET_MQ_Handle);
-  if (NULL != handlers)
-  {
-    for (i=0;NULL != handlers[i].cb; i++) ;
-    mq->handlers = GNUNET_new_array (i + 1,
-                                    struct GNUNET_MQ_MessageHandler);
-    GNUNET_memcpy (mq->handlers,
-                   handlers,
-                   i * sizeof (struct GNUNET_MQ_MessageHandler));
-  }
-  mq->error_handler = error_handler;
-  mq->error_handler_cls = error_handler_cls;
-  state = GNUNET_new (struct ClientConnectionState);
-  state->connection = connection;
-  mq->impl_state = state;
-  mq->send_impl = &connection_client_send_impl;
-  mq->destroy_impl = &connection_client_destroy_impl;
-  mq->cancel_impl = &connection_client_cancel_impl;
-  if (NULL != handlers)
-    state->receive_requested = GNUNET_YES;
-
-  return mq;
-}
-
-
 /**
  * Associate the assoc_data in mq with a unique request id.
  *
@@ -1023,12 +811,13 @@ GNUNET_MQ_assoc_remove (struct GNUNET_MQ_Handle *mq,
  * @param cb_cls closure for the callback
  */
 void
-GNUNET_MQ_notify_sent (struct GNUNET_MQ_Envelope *mqm,
-                       GNUNET_MQ_NotifyCallback cb,
+GNUNET_MQ_notify_sent (struct GNUNET_MQ_Envelope *ev,
+                       GNUNET_SCHEDULER_TaskCallback cb,
                        void *cb_cls)
 {
-  mqm->sent_cb = cb;
-  mqm->sent_cls = cb_cls;
+  GNUNET_assert (NULL == ev->sent_cb);
+  ev->sent_cb = cb;
+  ev->sent_cls = cb_cls;
 }
 
 
@@ -1165,7 +954,7 @@ GNUNET_MQ_send_cancel (struct GNUNET_MQ_Envelope *ev)
 
   GNUNET_assert (NULL != mq);
   GNUNET_assert (NULL != mq->cancel_impl);
-  
+
   mq->evacuate_called = GNUNET_NO;
 
   if (mq->current_envelope == ev)
@@ -1187,7 +976,6 @@ GNUNET_MQ_send_cancel (struct GNUNET_MQ_Envelope *ev)
       GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
                                    mq->envelope_tail,
                                    mq->current_envelope);
-      mq->send_notification_called = GNUNET_NO;
       mq->send_impl (mq,
                     mq->current_envelope->mh,
                     mq->impl_state);
@@ -1352,4 +1140,50 @@ GNUNET_MQ_destroy_notify_cancel (struct GNUNET_MQ_DestroyNotificationHandle *dnh
 }
 
 
+/**
+ * Insert @a env into the envelope DLL starting at @a env_head
+ * Note that @a env must not be in any MQ while this function
+ * is used with DLLs defined outside of the MQ module.  This
+ * is just in case some application needs to also manage a
+ * FIFO of envelopes independent of MQ itself and wants to
+ * re-use the pointers internal to @a env.  Use with caution.
+ *
+ * @param[in|out] env_head of envelope DLL
+ * @param[in|out] env_tail tail of envelope DLL
+ * @param[in|out] env element to insert at the tail
+ */
+void
+GNUNET_MQ_dll_insert_tail (struct GNUNET_MQ_Envelope **env_head,
+                           struct GNUNET_MQ_Envelope **env_tail,
+                           struct GNUNET_MQ_Envelope *env)
+{
+  GNUNET_CONTAINER_DLL_insert_tail (*env_head,
+                                    *env_tail,
+                                    env);
+}
+
+
+/**
+ * Remove @a env from the envelope DLL starting at @a env_head.
+ * Note that @a env must not be in any MQ while this function
+ * is used with DLLs defined outside of the MQ module. This
+ * is just in case some application needs to also manage a
+ * FIFO of envelopes independent of MQ itself and wants to
+ * re-use the pointers internal to @a env.  Use with caution.
+ *
+ * @param[in|out] env_head of envelope DLL
+ * @param[in|out] env_tail tail of envelope DLL
+ * @param[in|out] env element to remove from the DLL
+ */
+void
+GNUNET_MQ_dll_remove (struct GNUNET_MQ_Envelope **env_head,
+                      struct GNUNET_MQ_Envelope **env_tail,
+                      struct GNUNET_MQ_Envelope *env)
+{
+  GNUNET_CONTAINER_DLL_remove (*env_head,
+                               *env_tail,
+                               env);
+}
+
+
 /* end of mq.c */