Viewing Thread Dump Analysis Results

Prerequisites

A sampling analysis task has been created and the analysis is complete.

Procedure

1. In the Task/Report List area of the Java Profiler page, click the name of the analysis task under Sampling Profiling.

   Click the CPU tab.

2. Click the Thread Dump tab.
   The Lock Analysis result is displayed by default. Click a thread dump to view the thread lock analysis diagram. See Figure 1.

   

   • In the lock analysis diagram, threads are displayed on the left marked in various colors, each color indicating a state (green as RUNNABLE, red as BLOCKED, yellow as WAITING, and orange as TIMED_WAITING). Lock instances are displayed on the right.
   • The lock analysis diagram uses lines to show the lock occupation by threads. A solid line indicates that the lock is used by the thread, and a dashed line indicates that the thread is blocked on the lock instance and waits for other threads to release the lock.
   • Observation: After enabling this mode, you can select required locks to highlight the locks and corresponding threads. You can also switch to the Thread dimension using the filter box and select required threads to highlight the threads and their locks.
   • Comparison: After enabling this mode, you can select the thread dumps to be compared. By default, the comparison results of the two threads and their locks are displayed from the Lock dimension. By using the comparison mode and the observation mode together, you can better observe the status change of threads and locks at two time points. You can also switch to the Thread dimension using the filter box to observe the status change of a lock and its requesting threads at two time points. The comparison mode can be enabled only after two or more thread dumps are performed.
   • Deadlocks in the target Java application can be detected. You can locate the cause of a deadlock based on the thread dump.
   • In the lower right corner, you can zoom in or out the lock analysis diagram or view it in full screen by clicking the corresponding icon.
   Figure 1 Lock analysis diagram
   
3. Click Lock Analysis and select Raw data from the drop-down list.

   On the page that is displayed, expand the target thread dump and click a thread name to view call stack information of the thread. See Figure 2.

   Figure 2 Raw data