convert monitor API to use MQ

2 files changed, 111 insertions, 184 deletions

diff --git a/src/arm/arm_monitor_api.c b/src/arm/arm_monitor_api.c
index 19a2f4eb9..6d4129928 100644
--- a/src/arm/arm_monitor_api.c
+++ b/src/arm/arm_monitor_api.c
@@ -42,22 +42,17 @@ struct GNUNET_ARM_MonitorHandle
   /**
    * Our control connection to the ARM service.
    */
-  struct GNUNET_CLIENT_Connection *monitor;
+  struct GNUNET_MQ_Handle *mq;
 
   /**
    * The configuration that we are using.
    */
-  struct GNUNET_CONFIGURATION_Handle *cfg;
-
-  /**
-   * Handle for our current transmission request.
-   */
-  struct GNUNET_CLIENT_TransmitHandle *cth;
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
 
   /**
    * ID of the reconnect task (if any).
    */
-  struct GNUNET_SCHEDULER_Task * reconnect_task;
+  struct GNUNET_SCHEDULER_Task *reconnect_task;
 
   /**
    * Current delay we use for re-trying to connect to core.
@@ -65,32 +60,24 @@ struct GNUNET_ARM_MonitorHandle
   struct GNUNET_TIME_Relative retry_backoff;
 
   /**
-   * Are we currently disconnected and hence unable to send?
-   */
-  unsigned char currently_down;
-
-  /**
    * Callback to invoke on status updates.
    */
   GNUNET_ARM_ServiceStatusCallback service_status;
 
   /**
-   * Closure for service_status.
+   * Closure for @e service_status.
    */
-  void *cls;
+  void *service_status_cls;
 
-  /**
-   * ID of a task to run if we fail to get a reply to the init message in time.
-   */
-  struct GNUNET_SCHEDULER_Task * init_timeout_task_id;
 };
 
 
-static void
-monitor_notify_handler (void *cls,
-                        const struct GNUNET_MessageHeader *msg);
-
-
+/**
+ * Connect to the ARM service for monitoring.
+ *
+ * @param h handle to connect
+ * @return #GNUNET_OK on success
+ */
 static int
 reconnect_arm_monitor (struct GNUNET_ARM_MonitorHandle *h);
 
@@ -98,7 +85,7 @@ reconnect_arm_monitor (struct GNUNET_ARM_MonitorHandle *h);
 /**
  * Task scheduled to try to re-connect to arm.
  *
- * @param cls the 'struct GNUNET_ARM_MonitorHandle'
+ * @param cls the `struct GNUNET_ARM_MonitorHandle`
  */
 static void
 reconnect_arm_monitor_task (void *cls)
@@ -108,7 +95,7 @@ reconnect_arm_monitor_task (void *cls)
   h->reconnect_task = NULL;
   LOG (GNUNET_ERROR_TYPE_DEBUG,
        "Connecting to ARM service for monitoring after delay\n");
-  reconnect_arm_monitor (h);
+  GNUNET_break (GNUNET_OK == reconnect_arm_monitor (h));
 }
 
 
@@ -121,118 +108,123 @@ reconnect_arm_monitor_task (void *cls)
 static void
 reconnect_arm_monitor_later (struct GNUNET_ARM_MonitorHandle *h)
 {
-  if (NULL != h->cth)
+  if (NULL != h->mq)
   {
-    GNUNET_CLIENT_notify_transmit_ready_cancel (h->cth);
-    h->cth = NULL;
+    GNUNET_MQ_destroy (h->mq);
+    h->mq = NULL;
   }
+  GNUNET_assert (NULL == h->reconnect_task);
+  h->reconnect_task
+    = GNUNET_SCHEDULER_add_delayed (h->retry_backoff,
+                                    &reconnect_arm_monitor_task, h);
+  h->retry_backoff = GNUNET_TIME_STD_BACKOFF (h->retry_backoff);
+}
 
-  if (NULL != h->monitor)
-  {
-    GNUNET_CLIENT_disconnect (h->monitor);
-    h->monitor = NULL;
-  }
 
-  if (NULL != h->init_timeout_task_id)
+/**
+ * Check notification messages received from ARM is well-formed.
+ *
+ * @param cls our `struct GNUNET_ARM_MonitorHandle`
+ * @param msg the message received from the arm service
+ * @return #GNUNET_OK if the message is well-formed
+ */
+static int
+check_monitor_notify (void *cls,
+                       const struct GNUNET_ARM_StatusMessage *res)
+{
+  size_t sl = ntohs (res->header.size) - sizeof (struct GNUNET_ARM_StatusMessage);
+  const char *name = (const char *) &res[1];
+
+  if ( (0 == sl) ||
+       ('\0' != name[sl-1]) )
   {
-    GNUNET_SCHEDULER_cancel (h->init_timeout_task_id);
-    h->init_timeout_task_id = NULL;
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
   }
-
-  GNUNET_assert (NULL == h->reconnect_task);
-  h->reconnect_task =
-      GNUNET_SCHEDULER_add_delayed (h->retry_backoff, &reconnect_arm_monitor_task, h);
-
-  h->retry_backoff = GNUNET_TIME_STD_BACKOFF (h->retry_backoff);
+  return GNUNET_OK;
 }
 
 
 /**
- * Init message timed out. Disconnect and try again.
+ * Handler for notification messages received from ARM.
  *
- * @param cls arm monitor handle
+ * @param cls our `struct GNUNET_ARM_MonitorHandle`
+ * @param msg the message received from the arm service
  */
 static void
-init_timeout_task (void *cls)
+handle_monitor_notify (void *cls,
+                       const struct GNUNET_ARM_StatusMessage *res)
 {
   struct GNUNET_ARM_MonitorHandle *h = cls;
+  enum GNUNET_ARM_ServiceStatus status;
 
+  status = (enum GNUNET_ARM_ServiceStatus) ntohl (res->status);
   LOG (GNUNET_ERROR_TYPE_DEBUG,
-       "Init message timed out\n");
-  h->init_timeout_task_id = NULL;
-  reconnect_arm_monitor_later (h);
+       "Received notification from ARM for service `%s' with status %d\n",
+       (const char *) &res[1],
+       (int) status);
+  if (NULL != h->service_status)
+    h->service_status (h->service_status_cls,
+                       (const char *) &res[1],
+                       status);
 }
 
 
 /**
- * Transmit the monitoring initialization message to the arm service.
+ * Generic error handler, called with the appropriate error code and
+ * the same closure specified at the creation of the message queue.
+ * Not every message queue implementation supports an error handler.
  *
- * @param cls closure with the 'struct GNUNET_ARM_MonitorHandle'
- * @param size number of bytes available in buf
- * @param buf where the callee should write the message
- * @return number of bytes written to buf
+ * @param cls closure with the `struct GNUNET_ARM_MonitorHandle *`
+ * @param error error code
  */
-static size_t
-transmit_monitoring_init_message (void *cls, size_t size, void *buf)
+static void
+mq_error_handler (void *cls,
+                  enum GNUNET_MQ_Error error)
 {
   struct GNUNET_ARM_MonitorHandle *h = cls;
-  struct GNUNET_MessageHeader *msg;
-  uint16_t msize;
 
-  GNUNET_assert (NULL == h->reconnect_task);
-  GNUNET_assert (NULL == h->init_timeout_task_id);
-  h->cth = NULL;
-  if (NULL == buf)
-  {
-    LOG (GNUNET_ERROR_TYPE_DEBUG,
-         "Transmission failed, initiating reconnect\n");
-    reconnect_arm_monitor_later (h);
-    return 0;
-  }
-  msize = sizeof (struct GNUNET_MessageHeader);
-  if (size < msize)
-  {
-    LOG (GNUNET_ERROR_TYPE_DEBUG,
-        "Request is too big (%u < %u), not sending it\n", size, msize);
-    h->cth = GNUNET_CLIENT_notify_transmit_ready (h->monitor, msize,
-        GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_NO,
-        transmit_monitoring_init_message, h);
-    return 0;
-  }
-
-  msg = buf;
-  msg->size = htons (msize);
-  msg->type = htons (GNUNET_MESSAGE_TYPE_ARM_MONITOR);
-  LOG (GNUNET_ERROR_TYPE_DEBUG,
-       "Transmitting ARM monitoring init message with %u bytes to arm.\n",
-       (unsigned int) msize);
-
-  h->init_timeout_task_id = GNUNET_SCHEDULER_add_delayed (
-      INIT_TIMEOUT, init_timeout_task, h);
-  GNUNET_CLIENT_receive (h->monitor, &monitor_notify_handler, h,
-                         GNUNET_TIME_UNIT_FOREVER_REL);
-  return msize;
+  reconnect_arm_monitor_later (h);
 }
 
 
+/**
+ * Connect to the ARM service for monitoring.
+ *
+ * @param h handle to connect
+ * @return #GNUNET_OK on success
+ */
 static int
 reconnect_arm_monitor (struct GNUNET_ARM_MonitorHandle *h)
 {
-  GNUNET_assert (NULL == h->monitor);
-  h->monitor = GNUNET_CLIENT_connect ("arm", h->cfg);
-  if (NULL == h->monitor)
+  GNUNET_MQ_hd_var_size (monitor_notify,
+                         GNUNET_MESSAGE_TYPE_ARM_STATUS,
+                         struct GNUNET_ARM_StatusMessage);
+  struct GNUNET_MQ_MessageHandler handlers[] = {
+    make_monitor_notify_handler (h),
+    GNUNET_MQ_handler_end ()
+  };
+  struct GNUNET_MessageHeader *msg;
+  struct GNUNET_MQ_Envelope *env;
+
+  GNUNET_assert (NULL == h->mq);
+  h->mq = GNUNET_CLIENT_connecT (h->cfg,
+                                 "arm",
+                                 handlers,
+                                 &mq_error_handler,
+                                 h);
+  if (NULL == h->mq)
   {
-    LOG (GNUNET_ERROR_TYPE_DEBUG,
-           "arm_api, GNUNET_CLIENT_connect returned NULL\n");
     if (NULL != h->service_status)
-      h->service_status (h->cls, NULL, GNUNET_ARM_SERVICE_STOPPED);
+      h->service_status (h->service_status_cls,
+                         NULL,
+                         GNUNET_ARM_SERVICE_STOPPED);
     return GNUNET_SYSERR;
   }
-  LOG (GNUNET_ERROR_TYPE_DEBUG,
-         "arm_api, GNUNET_CLIENT_connect returned non-NULL\n");
-  h->cth = GNUNET_CLIENT_notify_transmit_ready (h->monitor,
-      sizeof (struct GNUNET_MessageHeader), GNUNET_TIME_UNIT_FOREVER_REL,
-      GNUNET_NO, &transmit_monitoring_init_message, h);
+  env = GNUNET_MQ_msg (msg,
+                       GNUNET_MESSAGE_TYPE_ARM_MONITOR);
+  GNUNET_MQ_send (h->mq,
+                  env);
   return GNUNET_OK;
 }
 
@@ -245,22 +237,20 @@ reconnect_arm_monitor (struct GNUNET_ARM_MonitorHandle *h)
  *        the ARM service may internally use a different
  *        configuration to determine how to start the service).
  * @param cont callback to invoke on status updates
- * @param cont_cls closure
+ * @param cont_cls closure for @a cont
  * @return context to use for further ARM monitor operations, NULL on error.
  */
 struct GNUNET_ARM_MonitorHandle *
 GNUNET_ARM_monitor (const struct GNUNET_CONFIGURATION_Handle *cfg,
-    GNUNET_ARM_ServiceStatusCallback cont, void *cont_cls)
+                    GNUNET_ARM_ServiceStatusCallback cont,
+                    void *cont_cls)
 {
   struct GNUNET_ARM_MonitorHandle *h;
 
   h = GNUNET_new (struct GNUNET_ARM_MonitorHandle);
-  h->cfg = GNUNET_CONFIGURATION_dup (cfg);
-  h->currently_down = GNUNET_YES;
-  h->reconnect_task = NULL;
-  h->init_timeout_task_id = NULL;
+  h->cfg = cfg;
   h->service_status = cont;
-  h->cls = cont_cls;
+  h->service_status_cls = cont_cls;
   if (GNUNET_OK != reconnect_arm_monitor (h))
   {
     GNUNET_free (h);
@@ -278,86 +268,18 @@ GNUNET_ARM_monitor (const struct GNUNET_CONFIGURATION_Handle *cfg,
 void
 GNUNET_ARM_monitor_disconnect_and_free (struct GNUNET_ARM_MonitorHandle *h)
 {
-  LOG (GNUNET_ERROR_TYPE_DEBUG, "Disconnecting from ARM service\n");
-  if (NULL != h->cth)
+  if (NULL != h->mq)
   {
-    GNUNET_CLIENT_notify_transmit_ready_cancel (h->cth);
-    h->cth = NULL;
-  }
-  if (NULL != h->init_timeout_task_id)
-  {
-    GNUNET_SCHEDULER_cancel (h->init_timeout_task_id);
-    h->init_timeout_task_id = NULL;
-  }
-  if (NULL != h->monitor)
-  {
-    GNUNET_CLIENT_disconnect (h->monitor);
-    h->monitor = NULL;
+    GNUNET_MQ_destroy (h->mq);
+    h->mq = NULL;
   }
   if (NULL != h->reconnect_task)
   {
     GNUNET_SCHEDULER_cancel (h->reconnect_task);
     h->reconnect_task = NULL;
   }
-  GNUNET_CONFIGURATION_destroy (h->cfg);
   GNUNET_free (h);
 }
 
 
-/**
- * Handler for notification messages received from ARM.
- *
- * @param cls our "struct GNUNET_ARM_MonitorHandle"
- * @param msg the message received from the arm service
- */
-static void
-monitor_notify_handler (void *cls, const struct GNUNET_MessageHeader *msg)
-{
-  struct GNUNET_ARM_MonitorHandle *h = cls;
-  uint16_t msize;
-  const struct GNUNET_ARM_StatusMessage *res;
-  enum GNUNET_ARM_ServiceStatus status;
-
-  if (NULL == msg)
-  {
-    LOG (GNUNET_ERROR_TYPE_INFO,
-         _("Monitoring client was disconnected from arm service, trying to reconnect.\n"));
-    reconnect_arm_monitor_later (h);
-    return;
-  }
-  msize = ntohs (msg->size);
-  LOG (GNUNET_ERROR_TYPE_DEBUG,
-       "Processing message of type %u and size %u from arm service\n",
-       ntohs (msg->type), msize);
-  switch (ntohs (msg->type))
-  {
-  case GNUNET_MESSAGE_TYPE_ARM_STATUS:
-    if (msize <= sizeof (struct GNUNET_ARM_StatusMessage))
-    {
-      GNUNET_break (0);
-      reconnect_arm_monitor_later (h);
-      return;
-    }
-    if (NULL != h->init_timeout_task_id)
-    {
-      GNUNET_SCHEDULER_cancel (h->init_timeout_task_id);
-      h->init_timeout_task_id = NULL;
-    }
-    res = (const struct GNUNET_ARM_StatusMessage *) msg;
-    LOG (GNUNET_ERROR_TYPE_DEBUG,
-         "Received response from ARM for service `%s': %u\n",
-         (const char *) &res[1], ntohs (msg->type));
-    status = (enum GNUNET_ARM_ServiceStatus) ntohl (res->status);
-    GNUNET_CLIENT_receive (h->monitor, &monitor_notify_handler, h,
-                           GNUNET_TIME_UNIT_FOREVER_REL);
-    if (NULL != h->service_status)
-      h->service_status (h->cls, (const char *) &res[1], status);
-    break;
-  default:
-    reconnect_arm_monitor_later (h);
-    return;
-  }
-}
-
-
 /* end of arm_api.c */
diff --git a/src/arm/gnunet-service-arm.c b/src/arm/gnunet-service-arm.c
index 0ccffa27b..8bc6e9e07 100644
--- a/src/arm/gnunet-service-arm.c
+++ b/src/arm/gnunet-service-arm.c
@@ -989,7 +989,8 @@ handle_stop (void *cls,
  * @param message the actual message
  */
 static void
-handle_list (void *cls, struct GNUNET_SERVER_Client *client,
+handle_list (void *cls,
+             struct GNUNET_SERVER_Client *client,
              const struct GNUNET_MessageHeader *message)
 {
   struct GNUNET_ARM_ListResultMessage *msg;
@@ -1595,7 +1596,8 @@ setup_service (void *cls,
  * @param client identification of the client
  */
 static void
-handle_client_connecting (void *cls, struct GNUNET_SERVER_Client *client)
+handle_client_connecting (void *cls,
+                          struct GNUNET_SERVER_Client *client)
 {
   /* All clients are considered to be of the "monitor" kind
    * (that is, they don't affect ARM shutdown).
@@ -1615,9 +1617,12 @@ handle_client_connecting (void *cls, struct GNUNET_SERVER_Client *client)
  *         #GNUNET_SYSERR to close it (signal serious error)
  */
 static void
-handle_monitor (void *cls, struct GNUNET_SERVER_Client *client,
-             const struct GNUNET_MessageHeader *message)
+handle_monitor (void *cls,
+                struct GNUNET_SERVER_Client *client,
+                const struct GNUNET_MessageHeader *message)
 {
+  /* FIXME: might want to start by letting monitor know about
+     services that are already running */
   /* Removal is handled by the server implementation, internally. */
   if ((NULL != client) && (NULL != notifier))
   {