Package spock.util.concurrent

Class BlockingVariable<T>

  • Type Parameters:
    T - the variable's type
    public class BlockingVariable<T>
extends java.lang.Object
    A statically typed variable whose get() method will block until some other thread has set a value with the set() method, or a timeout expires. Useful for verifying state in an expect- or then-block that has been captured in some other thread.

    Example: 

     // create object under specification
 def machine = new Machine()

 def result = new BlockingVariable<WorkResult>

 // register async callback
 machine.workDone << { r ->
  result.set(r)
 }

 when:
 machine.start()

 then:
 // blocks until workDone callback has set result, or a timeout expires
 result.get() == WorkResult.OK

 cleanup:
 // shut down all threads
 machine?.shutdown()

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      T get()
      Blocks until a value has been set for this variable, or a timeout expires.
      double getTimeout()
      Returns the timeout (in seconds).
      void set​(T value)
      Sets a value for this variable.

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • BlockingVariable

        public BlockingVariable()
        Same as BlockingVariable(1).

      • BlockingVariable

        public BlockingVariable​(double timeout)
        Instantiates a BlockingVariable with the specified timeout in seconds.
        Parameters:
        timeout - the timeout (in seconds) for calls to get().

      • BlockingVariable

        @Deprecated
public BlockingVariable​(int timeout,
                        java.util.concurrent.TimeUnit unit)
        Deprecated.
        use BlockingVariable(double) instead
        Instantiates a BlockingVariable with the specified timeout.
        Parameters:
        timeout - the timeout for calls to get().
        unit - the time unit

    • Method Detail

      • getTimeout

        public double getTimeout()
        Returns the timeout (in seconds).
        Returns:
        the timeout (in seconds)

      • get

        public T get()
      throws java.lang.InterruptedException
        Blocks until a value has been set for this variable, or a timeout expires.
        Returns:
        the variable's value
        Throws:
        java.lang.InterruptedException - if the calling thread is interrupted

      • set

        public void set​(T value)
        Sets a value for this variable. Wakes up all threads blocked in get().
        Parameters:
        value - the value to be set for this variable