com.ebay.bascomtask.runners

Class ProfilingTaskRunner

java.lang.Object

com.ebay.bascomtask.runners.ProfilingTaskRunner

All Implemented Interfaces:

TaskRunner

public class ProfilingTaskRunner
extends Object
implements TaskRunner

Tracks and creates a task execution profile on demand.

Author:

Brendan McCarthy

See Also:

format()

Constructor Summary

Constructors

Constructor and Description
ProfilingTaskRunner()

Method Summary

Modifier and Type	Method and Description
Object	before(TaskRun taskRun) Called before TaskRunner.executeTaskMethod(TaskRun, Thread, Object), but in the parent thread.
Object	executeTaskMethod(TaskRun taskRun, Thread parentThread, Object fromBefore) Task invocation -- an implementation should invoke TaskRun.run() to complete the invocation (unless there is some reason to prevent it, but then the implementation must take responsibility to ensure the all CompletableFuture return values are completed).
String	format() Returns a tabular execution profile with events as rows and threads as columns.
void	onComplete(TaskRun taskRun, Object fromBefore, boolean doneOnExit) Called once any CompletableFuture return result completes, which may be before the call to TaskRun.run() or after if a method returns an incomplete CompletableFuture.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ProfilingTaskRunner

public ProfilingTaskRunner()

Method Detail

before

public Object before(TaskRun taskRun)

Description copied from interface: TaskRunner

Called before TaskRunner.executeTaskMethod(TaskRun, Thread, Object), but in the parent thread. If there is no immediate spawning then it will be the same thread. The returned object will simply be passed to executeTaskMethod and is otherwise not read or modified by the framework.

Specified by:

before in interface TaskRunner

Parameters:

taskRun - that will also be passed to executeTaskMethod

Returns:

a possibly-null object to pass to executeTaskMethod

executeTaskMethod

public Object executeTaskMethod(TaskRun taskRun,
                                Thread parentThread,
                                Object fromBefore)

Description copied from interface: TaskRunner

Task invocation -- an implementation should invoke TaskRun.run() to complete the invocation (unless there is some reason to prevent it, but then the implementation must take responsibility to ensure the all CompletableFuture return values are completed). A typical subclass implementation would be to simply surround the call, e.g.:

     public Object executeTaskMethod(TaskRun taskRun, Thread parentThread, Object fromBefore) {
         LOG.info("STARTED " + taskRun.getTaskPlusMethodName());
         try {
             taskRun.run()
         } finally {
             LOG.info("ENDED " + taskRun.getTaskPlusMethodName());
         }
     }
 

Specified by:

executeTaskMethod in interface TaskRunner

Parameters:

taskRun - to execute

parentThread - of spawned task, which may be same as Thread.currentThread()

fromBefore - value returned from TaskRunner.before(TaskRun)

Returns:

return value from task invocation

onComplete

public void onComplete(TaskRun taskRun,
                       Object fromBefore,
                       boolean doneOnExit)

Description copied from interface: TaskRunner

Called once any CompletableFuture return result completes, which may be before the call to TaskRun.run() or after if a method returns an incomplete CompletableFuture.

The provided doneOnExit parameter indicates whether a CompletableFuture return value had isDone()==true when the method completed. This should not be taken as very close but not exactly precise, since there are very small time intervals involved in the steps behind making that determination.

Specified by:

onComplete in interface TaskRunner

Parameters:

taskRun - that was executed

fromBefore - value returned from TaskRunner.before(TaskRun)

doneOnExit - false iff a CompletableFuture was returned and it was not done when the method exited

format

public String format()

Returns a tabular execution profile with events as rows and threads as columns. The first column is the millisecond timestamp relative to the start of execution. The second column is the task method name. The third column rightward are execution threads, labeled with unique numbers and letters except that for the thread calling this (format) method, a caret is displayed since that typically represents the calling thread for orchestration execution.

A row is created any time (millisecond granularity) during which at least one task-related event occurred. A task start and end is indicated is by '---' entries, and if active between these two points then just a a '- entry. For example,

                    0
     0| gold.pond  ---
    10|            ---
 

and

                    0
     0| gold.pond  ---
     5|             -
    10|            ---
 

These each indicate that gold.pond ended 10 ms after start; the value at 5 indicates that it was active and would only be drawn if there were additional columns (not shown above) because other things of interest (not shown above) occurred at that time.

When a task immediately follows another within the same timestamp value, the end of the first is omitted and the new task entry has '=' markers instead of '-'. In the following, for example, gold.pond ends at timestamp 10 and gold.fish begins at that same timestamp, so the entry is '=-=' (the middle char serves other purposes, see next paragraph):

                    0
     0| gold.pond  ---
    10| gold.fish  =-=
    20|            ---
 

Tasks that return non-completed CompletableFutures have by definition a thread outside of BascomTask control. Each of these is represented in its own column and such columns are letter-numbered beginning with 'A'. The markers are '-+-' and '+', replacing the corresponding markers used in BascomTask-controlled threads. A task _always_ has a beginning '---' or '=-=' marker in a BascomTask-controlled thread, and it it _may also_ have a '-+-' entry on the same line in a letter-valued column.

Returns:

table-formatted execution summary