Synnefo » snf-ganeti

digraph "design-2.1-lock-acquire" {

  graph[fontsize=8, fontname="Helvetica"]

  node[fontsize=8, fontname="Helvetica", width="0", height="0"]

  edge[fontsize=8, fontname="Helvetica"]

  /* Actions */

  abort[label="Abort\n(couldn't acquire)"]

  acquire[label="Acquire lock"]

  add_to_queue[label="Add condition to queue"]

  wait[label="Wait for notification"]

  remove_from_queue[label="Remove from queue"]

  /* Conditions */

  alone[label="Empty queue and can acquire?", shape=diamond]

  have_timeout[label="Do I have timeout?", shape=diamond]

  top_of_queue_and_can_acquire[

    label="On top of queue and can acquire lock?",

    shape=diamond,

    ]

  /* Lines */

  alone->acquire[label="Yes"]

  alone->add_to_queue[label="No"]

  have_timeout->abort[label="Yes"]

  have_timeout->wait[label="No"]

  top_of_queue_and_can_acquire->acquire[label="Yes"]

  top_of_queue_and_can_acquire->have_timeout[label="No"]

  add_to_queue->wait

  wait->top_of_queue_and_can_acquire

  acquire->remove_from_queue

}