Timeouts
Related Docs:
object Timeouts
| package concurrent
Executes the passed function, enforcing the passed time limit by attempting to interrupt the function if the
time limit is exceeded, and throwing TestCanceledException if the time limit has been
exceeded after the function completes.
Executes the passed function, enforcing the passed time limit by attempting to interrupt the function if the
time limit is exceeded, and throwing TestCanceledException if the time limit has been
exceeded after the function completes.
If the function completes before the timeout expires:
If the function completes after the timeout expires:
TestCanceledException.TestCanceledException that includes the exception thrown by the function as its cause.If the interrupted status of the main test thread (the thread that invoked cancelAfter) was not invoked
when cancelAfter was invoked, but is set after the operation times out, it is reset by this method before
it completes abruptly with a TestCanceledException. The interrupted status will be set by
ThreadInterruptor, the default Interruptor implementation.
the maximimum amount of time allowed for the passed operation
the operation on which to enforce the passed timeout
a strategy for interrupting the passed operation
Implicit Interruptor value defining a default interruption strategy for the failAfter and cancelAfter method.
Implicit Interruptor value defining a default interruption strategy for the failAfter and cancelAfter method.
To change the default Interruptor configuration, override or hide this val with another implicit
Interruptor.
Executes the passed function, enforcing the passed time limit by attempting to interrupt the function if the
time limit is exceeded, and throwing TestFailedDueToTimeoutException if the time limit has been
exceeded after the function completes.
Executes the passed function, enforcing the passed time limit by attempting to interrupt the function if the
time limit is exceeded, and throwing TestFailedDueToTimeoutException if the time limit has been
exceeded after the function completes.
If the function completes before the timeout expires:
If the function completes after the timeout expires:
TestFailedDueToTimeoutException.TestFailedDueToTimeoutException that includes the exception thrown by the function as its cause.If the interrupted status of the main test thread (the thread that invoked failAfter) was not invoked
when failAfter was invoked, but is set after the operation times out, it is reset by this method before
it completes abruptly with a TestFailedDueToTimeoutException. The interrupted status will be set by
ThreadInterruptor, the default Interruptor implementation.
the maximimum amount of time allowed for the passed operation
the operation on which to enforce the passed timeout
a strategy for interrupting the passed operation
Trait that provides a
failAfterandcancelAfterconstruct, which allows you to specify a time limit for an operation passed as a by-name parameter, as well as a way to interrupt it if the operation exceeds its time limit.The time limit is passed as the first parameter, as a
Span. The operation is passed as the second parameter. And anInterruptor, a strategy for interrupting the operation, is passed as an implicit third parameter. Here's a simple example of its use:failAfter(Span(100, Millis)) { Thread.sleep(200) }The above code, after 100 milliseconds, will produce a
TestFailedDueToTimeoutExceptionwith a message that indicates a timeout expired:The code passed to failAfter did not complete within 100 milliseconds.If you use
cancelAfterin place offailAfter, aTestCanceledExceptionwith a message that indicates a timeout expired:The code passed to cancelAfter did not complete within 100 milliseconds.If you prefer you can mix in or import the members of
SpanSugarand place a units value after the integer timeout. Here are some examples:import org.scalatest.time.SpanSugar._ failAfter(100 millis) { Thread.sleep(200) } failAfter(1 second) { Thread.sleep(2000) }The code passed via the by-name parameter to
failAfterorcancelAfterwill be executed by the thread that invokedfailAfterorcancelAfter, so that no synchronization is necessary to access variables declared outside the by-name.var result = -1 // No need to make this volatile failAfter(100 millis) { result = accessNetService() } result should be (99)The
failAfterorcancelAftermethod will create a timer that runs on a different thread than the thread that invokedfailAfterorcancelAfter, so that it can detect when the timeout has expired and attempt to interrupt the main thread. Because different operations can require different interruption strategies, thefailAfterorcancelAftermethod accepts an implicit third parameter of typeInterruptorthat is responsible for interrupting the main thread.Configuring
failAfterorcancelAfterwith anInterruptorThis trait declares an implicit
valnameddefaultInterruptor, initialized with aThreadInterruptor, which attempts to interrupt the main thread by invokingThread.interrupt. If you wish to use a different strategy, you can override thisval(or hide it, for example if you imported the members ofTimeoutsrather than mixing it in). Here's an example in which the default interruption method is changed toDoNotInterrupt, which does not attempt to interrupt the main thread in any way:override val defaultInterruptor = DoNotInterrupt failAfter(100 millis) { Thread.sleep(500) }As with the default
Interruptor, the above code will eventually produce aTestFailedDueToTimeoutExceptionwith a message that indicates a timeout expired. However, instead of throwing the exception after approximately 100 milliseconds, it will throw it after approximately 500 milliseconds.This illustrates an important feature of
failAfterandcancelAfter: it will throw aTestFailedDueToTimeoutException(orTestCanceledExceptionin case ofcancelAfter) if the code passed as the by-name parameter takes longer than the specified timeout to execute, even if it is allowed to run to completion beyond the specified timeout and returns normally.ScalaTest provides the following
Interruptorimplementations:Interruptorimplementationinterrupton the main test thread. This will set the interrupted status for the main test thread and, if the main thread is blocked, will in some cases cause the main thread to complete abruptly with anInterruptedException.wakeupon the passedjava.nio.channels.Selector, which will cause the main thread, if blocked inSelector.select, to complete abruptly with aClosedSelectorException.closeon thejava.io.Socket, which will cause the main thread, if blocked in a read or write of anjava.io.InputStreamorjava.io.OutputStreamthat uses theSocket, to complete abruptly with aSocketException.You may wish to create your own
Interruptorin some situations. For example, if your operation is performing a loop and can check a volatile flag each pass through the loop. You could in that case write anInterruptorthat sets that flag so that the next time around, the loop would exit.