-fix
[oweals/gnunet.git] / src / lockmanager / lockmanager_api.c
index b25904d7bed69e29e668059e775f5dcf994f7d39..99f5ab50370e420efd3a377e629d2d6ec590df6d 100644 (file)
  * @author Sree Harsha Totakura
  */
 
+/**
+ * To be fixed:
+ *  Should the handle be freed when the connection to service is lost?
+ *  Should cancel_request have a call back (else simultaneous calls break)
+ */
+
 #include "platform.h"
 #include "gnunet_common.h"
 #include "gnunet_container_lib.h"
 
 #define TIMEOUT TIME_REL_MINS(3)
 
+
+/**
+ * The message queue
+ */
+struct MessageQueue
+{
+  /**
+   * The next pointer for doubly linked list
+   */
+  struct MessageQueue *next;
+
+  /**
+   * The prev pointer for doubly linked list
+   */
+  struct MessageQueue *prev;
+  
+  /**
+   * The LOCKMANAGER Message
+   */
+  struct GNUNET_LOCKMANAGER_Message *msg;
+};
+
+
 /**
  * Handler for the lockmanager service
  */
@@ -52,10 +81,25 @@ struct GNUNET_LOCKMANAGER_Handle
    */
   struct GNUNET_CLIENT_Connection *conn;
 
+  /**
+   * The transmit handle for transmissions using conn
+   */
+  struct GNUNET_CLIENT_TransmitHandle *transmit_handle;
+
   /**
    * Hashmap handle
    */
   struct GNUNET_CONTAINER_MultiHashMap *hashmap;
+
+  /**
+   * Double linked list head for message queue
+   */
+  struct MessageQueue *mq_head;
+
+  /**
+   * Double linked list tail for message queue
+   */
+  struct MessageQueue *mq_tail;
 };
 
 
@@ -79,11 +123,6 @@ struct GNUNET_LOCKMANAGER_LockingRequest
    */
   void *status_cb_cls;
 
-  /**
-   * The pending transmit handle for the ACQUIRE message
-   */
-  struct GNUNET_CLIENT_TransmitHandle *transmit_handle;
-
   /**
    * The locking domain of this request
    */
@@ -123,6 +162,86 @@ struct LockingRequestMatch
 };
 
 
+/**
+ * Transmit notify for sending message to server
+ *
+ * @param cls the lockmanager handle
+ * @param size number of bytes available in buf
+ * @param buf where the callee should write the message
+ * @return number of bytes written to buf
+ */
+static size_t 
+transmit_notify (void *cls, size_t size, void *buf)
+{
+  struct GNUNET_LOCKMANAGER_Handle *handle = cls;
+  struct MessageQueue *queue_entity;
+  uint16_t msg_size;
+
+  handle->transmit_handle = NULL;
+  if ((0 == size) || (NULL == buf))
+  {
+    /* FIXME: Timed out -- requeue? */
+    return 0;
+  }
+  queue_entity = handle->mq_head;
+  GNUNET_assert (NULL != queue_entity);
+  msg_size = ntohs (queue_entity->msg->header.size);
+  GNUNET_assert (size >= msg_size);
+  memcpy (buf, queue_entity->msg, msg_size);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Message of size %u sent\n", msg_size);
+  GNUNET_free (queue_entity->msg);
+  GNUNET_CONTAINER_DLL_remove (handle->mq_head,
+                               handle->mq_tail,
+                               queue_entity);
+  GNUNET_free (queue_entity);
+  queue_entity = handle->mq_head;
+  if (NULL != queue_entity)
+  {
+    handle->transmit_handle =
+      GNUNET_CLIENT_notify_transmit_ready (handle->conn,
+                                           ntohs
+                                           (queue_entity->msg->header.size),
+                                           TIMEOUT,
+                                           GNUNET_YES,
+                                           &transmit_notify,
+                                           handle);
+  }
+  return msg_size;
+}
+
+
+/**
+ * Queues a message into handle's send message queue
+ *
+ * @param handle the lockmanager handle whose queue will be used
+ * @param msg the message to be queued
+ */
+static void
+queue_message (struct GNUNET_LOCKMANAGER_Handle *handle,
+               struct GNUNET_LOCKMANAGER_Message *msg)
+{
+  struct MessageQueue *queue_entity;
+
+  GNUNET_assert (NULL != msg);
+  queue_entity = GNUNET_malloc (sizeof (struct MessageQueue));
+  queue_entity->msg = msg;
+  GNUNET_CONTAINER_DLL_insert_tail (handle->mq_head,
+                                    handle->mq_tail,
+                                    queue_entity);
+  if (NULL == handle->transmit_handle)
+  {
+    handle->transmit_handle =
+      GNUNET_CLIENT_notify_transmit_ready (handle->conn,
+                                           ntohs (msg->header.size),
+                                           TIMEOUT,
+                                           GNUNET_YES,
+                                           &transmit_notify,
+                                           handle);
+  }
+}
+
+
 /**
  * Get the key for the given lock in the 'lock_map'.
  *
@@ -290,6 +409,10 @@ handle_replies (void *cls,
                                            handle);
     return;
   }
+  GNUNET_CLIENT_receive (handle->conn,
+                         &handle_replies,
+                         handle,
+                         GNUNET_TIME_UNIT_FOREVER_REL);
   if (GNUNET_MESSAGE_TYPE_LOCKMANAGER_SUCCESS != ntohs(msg->type))
   {
     GNUNET_break (0);
@@ -337,35 +460,6 @@ handle_replies (void *cls,
 }
 
 
-/**
- * Transmit notify for sending message to server
- *
- * @param cls the message to send
- * @param size number of bytes available in buf
- * @param buf where the callee should write the message
- * @return number of bytes written to buf
- */
-static size_t 
-transmit_notify (void *cls, size_t size, void *buf)
-{
-  struct GNUNET_LOCKMANAGER_Message *msg = cls;
-  uint16_t msg_size;
-
-  if ((0 == size) || (NULL == buf))
-  {
-    /* FIXME: Timed out -- requeue? */
-    return 0;
-  }
-  msg_size = ntohs (msg->header.size);
-  GNUNET_assert (size >= msg_size);
-  memcpy (buf, msg, msg_size);
-  GNUNET_free (msg);
-  LOG (GNUNET_ERROR_TYPE_DEBUG,
-       "Message of size %u sent\n", msg_size);
-  return msg_size;
-}
-
-
 /**
  * Iterator to free hash map entries.
  *
@@ -442,8 +536,9 @@ GNUNET_LOCKMANAGER_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
 void
 GNUNET_LOCKMANAGER_disconnect (struct GNUNET_LOCKMANAGER_Handle *handle)
 {
+  struct MessageQueue *head;
+
   LOG (GNUNET_ERROR_TYPE_DEBUG, "%s()\n", __func__);
-  GNUNET_CLIENT_disconnect (handle->conn);
   if (0 != GNUNET_CONTAINER_multihashmap_size (handle->hashmap))
   {
     LOG (GNUNET_ERROR_TYPE_WARNING,
@@ -454,6 +549,22 @@ GNUNET_LOCKMANAGER_disconnect (struct GNUNET_LOCKMANAGER_Handle *handle)
                                            handle);
   }
   GNUNET_CONTAINER_multihashmap_destroy (handle->hashmap);
+  /* Clear the message queue */
+  if (NULL != handle->transmit_handle)
+  {
+    GNUNET_CLIENT_notify_transmit_ready_cancel (handle->transmit_handle);
+  }
+  head = handle->mq_head;
+  while (NULL != head)
+  {
+    GNUNET_CONTAINER_DLL_remove (handle->mq_head,
+                                 handle->mq_tail,
+                                 head);
+    GNUNET_free (head->msg);
+    GNUNET_free (head);
+    head = handle->mq_head;
+  }
+  GNUNET_CLIENT_disconnect (handle->conn);
   GNUNET_free (handle);
   LOG (GNUNET_ERROR_TYPE_DEBUG, "%s() END\n", __func__);
 }
@@ -513,13 +624,7 @@ GNUNET_LOCKMANAGER_acquire_lock (struct GNUNET_LOCKMANAGER_Handle *handle,
   msg->lock = htonl (lock);
   memcpy (&msg[1], r->domain, domain_name_length);
   LOG (GNUNET_ERROR_TYPE_DEBUG, "Queueing ACQUIRE message\n");
-  r->transmit_handle =
-    GNUNET_CLIENT_notify_transmit_ready (r->handle->conn,
-                                         msg_size,
-                                         TIMEOUT,
-                                         GNUNET_YES,
-                                         &transmit_notify,
-                                         msg);
+  queue_message (handle, msg);
   get_key (r->domain, r->lock, &hash);
   GNUNET_CONTAINER_multihashmap_put (r->handle->hashmap,
                                      &hash,
@@ -560,12 +665,7 @@ GNUNET_LOCKMANAGER_cancel_request (struct GNUNET_LOCKMANAGER_LockingRequest
     msg->header.size = htons (msg_size);
     msg->lock = htonl (request->lock);
     memcpy (&msg[1], request->domain, domain_name_length);
-    GNUNET_CLIENT_notify_transmit_ready (request->handle->conn,
-                                         msg_size,
-                                         TIMEOUT, /* What if this fails */
-                                         GNUNET_NO,
-                                         &transmit_notify,
-                                         msg);
+    queue_message (request->handle, msg);
   }
   get_key (request->domain, request->lock, &hash);
   GNUNET_assert (GNUNET_YES ==