org.optaplanner.core.config.solver

Enum EnvironmentMode

java.lang.Object

java.lang.Enum<EnvironmentMode>

org.optaplanner.core.config.solver.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 Summary

Enum Constants

Enum Constant and Description
FAST_ASSERT This mode turns on several assertions (but not all of them) to fail-fast on a bug in a Move implementation, a score rule, the rule engine itself or something else at a reasonable performance cost (in development at least).
FULL_ASSERT This mode turns on all assertions to fail-fast on a bug in a Move implementation, a score rule, the rule engine itself or something else at a horrible performance cost.
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 score rule, the rule engine itself or something else at a horrible performance cost.
PRODUCTION The production mode is the fastest, but not reproducible.
REPRODUCIBLE The reproducible mode is the default mode because it is recommended during development.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	isAsserted()
boolean	isIntrusiveFastAsserted()
boolean	isNonIntrusiveFullAsserted()
static EnvironmentMode	valueOf(String name) Returns the enum constant of this type with the specified name.
static EnvironmentMode[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

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 score rule, the rule 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 score rule, the rule engine itself or something else at a horrible 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 score rule, the rule 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.

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

The reproducible mode is slightly slower than the production mode.

In practice, this mode uses the default random seed, and it also disables certain concurrency optimizations (such as work stealing). TODO: PLANNER-76 Multi-threaded support which implement those concurrency optimizations

PRODUCTION

public static final EnvironmentMode PRODUCTION

The production mode is the fastest, but not reproducible. It is recommended for a production environment, unless reproducibility is required.

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).

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()