Package org.optaplanner.core.config.solver

Enum EnvironmentMode

  • All Implemented Interfaces:
    Serializable, Comparable<EnvironmentMode>
    public enum EnvironmentMode
extends Enum<EnvironmentMode>
    The environment mode also allows you to detect common bugs in your implementation.

    Also, a Solver has a single Random instance. Some optimization algorithms use the Random instance a lot more than others. For example simulated annealing depends highly on random numbers, while tabu search only depends on it to deal with score ties. This environment mode influences the seed of that Random instance.

    • Enum Constant Detail

      • FULL_ASSERT

        public static final EnvironmentMode FULL_ASSERT
        This mode turns on all assertions to fail-fast on a bug in a Move implementation, a constraint, the engine itself or something else at a horrible performance cost.

        This mode is reproducible (see REPRODUCIBLE mode).

        This mode is intrusive because it calls the ScoreDirector.calculateScore() more frequently than a non assert mode.

        This mode is horribly slow.

      • NON_INTRUSIVE_FULL_ASSERT

        public static final EnvironmentMode NON_INTRUSIVE_FULL_ASSERT
        This mode turns on several assertions (but not all of them) to fail-fast on a bug in a Move implementation, a constraint, the engine itself or something else at an overwhelming performance cost.

        This mode is reproducible (see REPRODUCIBLE mode).

        This mode is non-intrusive, unlike FULL_ASSERT and FAST_ASSERT.

        This mode is horribly slow.

      • FAST_ASSERT

        public static final EnvironmentMode FAST_ASSERT
        This mode turns on several assertions (but not all of them) to fail-fast on a bug in a Move implementation, a constraint rule, the engine itself or something else at a reasonable performance cost (in development at least).

        This mode is reproducible (see REPRODUCIBLE mode).

        This mode is intrusive because it calls the ScoreDirector.calculateScore() more frequently than a non assert mode.

        This mode is slow.

      • REPRODUCIBLE

        public static final EnvironmentMode REPRODUCIBLE
        The reproducible mode is the default mode because it is recommended during development. In this mode, 2 runs on the same computer will execute the same code in the same order. They will also yield the same result, except if they use a time based termination and they have a sufficiently large difference in allocated CPU time. This allows you to benchmark new optimizations (such as a new Move implementation) fairly and reproduce bugs in your code reliably.

        Warning: some code can disrupt reproducibility regardless of this mode. See the reference manual for more info.

        In practice, this mode uses the default random seed, and it also disables certain concurrency optimizations (such as work stealing).

      • NON_REPRODUCIBLE

        public static final EnvironmentMode NON_REPRODUCIBLE
        The non reproducible mode is equally fast or slightly faster than REPRODUCIBLE.

        The random seed is different on every run, which makes it more robust against an unlucky random seed. An unlucky random seed gives a bad result on a certain data set with a certain solver configuration. Note that in most use cases the impact of the random seed is relatively low on the result. An occasional bad result is far more likely to be caused by another issue (such as a score trap).

        In multithreaded scenarios, this mode allows the use of work stealing and other non deterministic speed tricks.

    • Method Detail

      • values

        public static EnvironmentMode[] values()
        Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows: 
        for (EnvironmentMode c : EnvironmentMode.values())
    System.out.println(c);
        Returns:
        an array containing the constants of this enum type, in the order they are declared

      • valueOf

        public static EnvironmentMode valueOf​(String name)
        Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
        Parameters:
        name - the name of the enum constant to be returned.
        Returns:
        the enum constant with the specified name
        Throws:
        IllegalArgumentException - if this enum type has no constant with the specified name
        NullPointerException - if the argument is null

      • isAsserted

        public boolean isAsserted()

      • isNonIntrusiveFullAsserted

        public boolean isNonIntrusiveFullAsserted()

      • isIntrusiveFastAsserted

        public boolean isIntrusiveFastAsserted()

      • isReproducible

        public boolean isReproducible()