com.spotify.helios.common.context

Class Context

java.lang.Object

com.spotify.helios.common.context.Context

public final class Context
extends Object

Include call origin information in stacktraces of Callables and Runnables. For brevity, *able will stand in for both Callable and Runnable below. Normally, if you call .get() on a Future of a *able that fails, you get an ExecutionException wrapping the actual Exception thrown from within the *able. Unfortunately, you do not get the call path that got you to the submission of the *able into the Executor. This class is designed to fix that. All you do is call makeContextCallable or makeContextRunnable on your *able and submit the result instead of the original *able. So, if you look at ContextTest, if the exception wasn't caught, you'd see (edited for brevity): java.util.concurrent.ExecutionException: java.lang.RuntimeException: No boolean for you at java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.util.concurrent.FutureTask.get(FutureTask.java:188) at com.spotify.helios.common.ContextTest.testContextCallable(ContextTest.java:57) .... at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192) Caused by: java.lang.RuntimeException: No boolean for you at com.spotify.helios.common.ContextTest$1.call(ContextTest.java:55) at com.spotify.helios.common.ContextTest$1.call(ContextTest.java:1) at com.spotify.helios.common.Context$1.call(Context.java:44) at java.util.concurrent.FutureTask.run(FutureTask.java:262) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:744) Caused by: com.spotify.helios.common.CallPathToExecutorException at com.spotify.helios.common.Context.makeContextCallable(Context.java:38) at com.spotify.helios.common.ContextTest.testContextCallable(ContextTest.java:52) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) .... at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192) Normally, you'd not see anything from the CallPathToExcecutorException line on down. Here, you can see that it originated in the method testContextCallable, and the normal information lists the call site of the get (third line down from the top).

Constructor Summary

Constructors

Constructor and Description
Context()

Method Summary

Modifier and Type	Method and Description
static Executor	decorate(Executor executor) Returns an Executor that wraps Runnables before submission to the passed in Executor.
static ExecutorService	decorate(ExecutorService executorService) Returns an ExecutorService that wraps *ables before submission to the passed in ExecutorService.
static com.google.common.util.concurrent.ListeningExecutorService	decorate(com.google.common.util.concurrent.ListeningExecutorService service) Returns a ListeningExecutorService that wraps *ables before submission to the passed in ListeningExecutorService.
static com.google.common.util.concurrent.ListeningScheduledExecutorService	decorate(com.google.common.util.concurrent.ListeningScheduledExecutorService service) Returns a ListeningScheduledExecutorService that wraps *ables before submission to the passed in ListeningScheduledExecutorService.
static ScheduledExecutorService	decorate(ScheduledExecutorService service) Returns a ScheduledExecutorService that wraps *ables before submission to the passed in ScheduledExecutorService.
static <T> Callable<T>	makeContextCallable(Callable<T> in) Returns a Callable that will retain the stack trace information about where it originated from.
static Runnable	makeContextRunnable(Runnable in) Returns a Runnable that will retain the stack trace information about where it originated from.

Methods inherited from class java.lang.Object

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

Constructor Detail

Context

public Context()

Method Detail

makeContextCallable

public static <T> Callable<T> makeContextCallable(Callable<T> in)

Returns a Callable that will retain the stack trace information about where it originated from.

Type Parameters:

T - The result type.

Parameters:

in - The original Callable.

Returns:

The ContextCallable.

makeContextRunnable

public static Runnable makeContextRunnable(Runnable in)

Returns a Runnable that will retain the stack trace information about where it originated from.

Parameters:

in - The original Runnable

Returns:

The ContextRunnable.

decorate

public static Executor decorate(Executor executor)

Returns an Executor that wraps Runnables before submission to the passed in Executor.

Parameters:

executor - The executor to decorate.

Returns:

The decorated executor.

decorate

public static ExecutorService decorate(ExecutorService executorService)

Returns an ExecutorService that wraps *ables before submission to the passed in ExecutorService.

Parameters:

executorService - The ExecutorService to decorate.

Returns:

The decorated ExecutorService.

decorate

public static ScheduledExecutorService decorate(ScheduledExecutorService service)

Returns a ScheduledExecutorService that wraps *ables before submission to the passed in ScheduledExecutorService.

Parameters:

service - The ScheduledExecutorService to decorate.

Returns:

The decorated ScheduledExecutorService.

decorate

public static com.google.common.util.concurrent.ListeningExecutorService decorate(com.google.common.util.concurrent.ListeningExecutorService service)

Returns a ListeningExecutorService that wraps *ables before submission to the passed in ListeningExecutorService.

Parameters:

service - The ListeningExecutorService to decorate.

Returns:

The decorated ListeningExecutorService.

decorate

public static com.google.common.util.concurrent.ListeningScheduledExecutorService decorate(com.google.common.util.concurrent.ListeningScheduledExecutorService service)

Returns a ListeningScheduledExecutorService that wraps *ables before submission to the passed in ListeningScheduledExecutorService.

Parameters:

service - The ListeningScheduledExecutorService to decorate.

Returns:

The decorated ListeningScheduledExecutorService.