Common Properties Of Monitor Views


  Monitor views show a table where every row corresponds to a waiting or blocking event on a monitor. There are two monitor views:
  • current monitors view
    The current monitors view shows monitors that are currently involved in a waiting or blocking operation.
  • monitor history view
    The monitor history view shows the sequence of waiting and blocking operations on monitors.
  The monitor views show the following 6 columns: sortable.
  • Time
    The start time of the event.
  • Duration
    The duration of the event. The event may still be in progress.
  • Type
    The type of the event, one of "waiting" or "blocked".
  • Monitor ID
    The ID of the monitor for identifying multiple events on a particular monitor instance.
  • Monitor class
    The class of the monitor. If no Java object is associated with this monitor [raw monitor] is displayed.
  • Waiting thread
    The thread that is or was waiting during the event.
  • Owning thread
    The thread holding the monitor which is blocking the waiting thread is displayed. The owning thread is only relevant for the "blocked" event type.
  In the lower part of the split pane, the stack traces of the waiting thread and - if applicable - of the owning thread are displayed. Stack traces can only be displayed if CPU data is being recorded.
  You can show any monitor in the heap walker by selecting the table row and choosing Show Selection In Heap Walker from the context menu. If a heap dump was already taken, you can choose to select the object in the current heap dump, otherwise a new heap dump will be taken.

Note that the selected monitor might not exist in the heap dump because the heap dump might have been taken before the monitor was allocated or after the monitor was garbage collected.