hack: try to avoid "buffer full" problem when pushing DL traffic

This is hack-level development. With this commit you can do UDP DL traffic of say 100Mb/s over a 5MHz link with one connected UE and the eNB should not crash because of memory exhaustion. Of course on the receiver side you won't get 100Mb/s and many many lost packets. But the system should not crash. 1Gb/s does not work. So in any case try to remain within some reasonable limits. There is no reason to push more than twice the maximum achievable throughput of the link. This work is based on a patch proposed by Francesco Gringoli.
2018-03-09 10:18:12 +01:00
parent 963805820c
commit 71e7f9713a
4 changed files with 130 additions and 1 deletions
@@ -391,6 +391,103 @@ int itti_send_msg_to_task(task_id_t destination_task_id, instance_t instance, Me
  return 0;
 }

+/* same as itti_send_msg_to_task but returns -1 in case of failure instead of crashing */
+/* TODO: this is a hack - the whole logic needs a proper rework. */
+/* look for HACK_RLC_UM_LIMIT for others places related to the hack. Please do not remove this comment. */
+int itti_try_send_msg_to_task(task_id_t destination_task_id, instance_t instance, MessageDef *message)
+{
+  thread_id_t destination_thread_id;
+  task_id_t origin_task_id;
+  message_list_t *new;
+  uint32_t priority;
+  message_number_t message_number;
+  uint32_t message_id;
+
+  AssertFatal (message != NULL, "Message is NULL!\n");
+  AssertFatal (destination_task_id < itti_desc.task_max, "Destination task id (%d) is out of range (%d)\n", destination_task_id, itti_desc.task_max);
+
+  destination_thread_id = TASK_GET_THREAD_ID(destination_task_id);
+  message->ittiMsgHeader.destinationTaskId = destination_task_id;
+  message->ittiMsgHeader.instance = instance;
+  message->ittiMsgHeader.lte_time.frame = itti_desc.lte_time.frame;
+  message->ittiMsgHeader.lte_time.slot = itti_desc.lte_time.slot;
+  message_id = message->ittiMsgHeader.messageId;
+  AssertFatal (message_id < itti_desc.messages_id_max, "Message id (%d) is out of range (%d)!\n", message_id, itti_desc.messages_id_max);
+
+  origin_task_id = ITTI_MSG_ORIGIN_ID(message);
+
+  priority = itti_get_message_priority (message_id);
+
+  /* Increment the global message number */
+  message_number = itti_increment_message_number ();
+
+  itti_dump_queue_message (origin_task_id, message_number, message, itti_desc.messages_info[message_id].name,
+                           sizeof(MessageHeader) + message->ittiMsgHeader.ittiMsgSize);
+
+  if (destination_task_id != TASK_UNKNOWN) {
+
+    if (itti_desc.threads[destination_thread_id].task_state == TASK_STATE_ENDED) {
+      ITTI_DEBUG(ITTI_DEBUG_ISSUES, " Message %s, number %lu with priority %d can not be sent from %s to queue (%u:%s), ended destination task!\n",
+                 itti_desc.messages_info[message_id].name,
+                 message_number,
+                 priority,
+                 itti_get_task_name(origin_task_id),
+                 destination_task_id,
+                 itti_get_task_name(destination_task_id));
+    } else {
+      /* We cannot send a message if the task is not running */
+      AssertFatal (itti_desc.threads[destination_thread_id].task_state == TASK_STATE_READY,
+                   "Task %s Cannot send message %s (%d) to thread %d, it is not in ready state (%d)!\n",
+                   itti_get_task_name(origin_task_id),
+                   itti_desc.messages_info[message_id].name,
+                   message_id,
+                   destination_thread_id,
+                   itti_desc.threads[destination_thread_id].task_state);
+
+      /* Allocate new list element */
+      new = (message_list_t *) itti_malloc (origin_task_id, destination_task_id, sizeof(struct message_list_s));
+
+      /* Fill in members */
+      new->msg = message;
+      new->message_number = message_number;
+      new->message_priority = priority;
+
+      /* Enqueue message in destination task queue */
+      if (lfds611_queue_enqueue(itti_desc.tasks[destination_task_id].message_queue, new) == 0) {
+        itti_free(origin_task_id, new);
+        return -1;
+      }
+
+      {
+        /* Only use event fd for tasks, subtasks will pool the queue */
+        if (TASK_GET_PARENT_TASK_ID(destination_task_id) == TASK_UNKNOWN) {
+          ssize_t write_ret;
+          eventfd_t sem_counter = 1;
+
+          /* Call to write for an event fd must be of 8 bytes */
+          write_ret = write (itti_desc.threads[destination_thread_id].task_event_fd, &sem_counter, sizeof(sem_counter));
+          AssertFatal (write_ret == sizeof(sem_counter), "Write to task message FD (%d) failed (%d/%d)\n",
+                       destination_thread_id, (int) write_ret, (int) sizeof(sem_counter));
+        }
+      }
+
+      ITTI_DEBUG(ITTI_DEBUG_SEND, " Message %s, number %lu with priority %d successfully sent from %s to queue (%u:%s)\n",
+                 itti_desc.messages_info[message_id].name,
+                 message_number,
+                 priority,
+                 itti_get_task_name(origin_task_id),
+                 destination_task_id,
+                 itti_get_task_name(destination_task_id));
+    }
+  } else {
+    /* This is a debug message to TASK_UNKNOWN, we can release safely release it */
+    int result = itti_free(origin_task_id, message);
+    AssertFatal (result == EXIT_SUCCESS, "Failed to free memory (%d)!\n", result);
+  }
+
+  return 0;
+}
+
 void itti_subscribe_event_fd(task_id_t task_id, int fd)
 {
  thread_id_t thread_id;