Creates a task instance.

Every task instance is used for only one invocation.

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

• It is reflexive: for any non-null reference value x, x.equals(x) should return true.
• It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
• It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
• For any non-null reference value x, x.equals(null) should return false.

The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).

Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.

Gets the capabilities of this task.

Unrecognized capabilities will be silently ignored by the build system.

Gets an environment selector to determine if the task can execute in a given build environment.

If two task factories equal, then their returned environment selectors should equal as well.

If an environment selector fails to find a suitable environment, then an exception instance of TaskEnvironmentSelectionFailedException will be thrown by the build system and the build execution will abort.

The default implementation returns a selector which enables the task to use any build environment.

Gets the invocation configuration for this build task.

The invocation configuration defines the nature of how the task executor should run the build task. See the properties of TaskInvocationConfiguration get familiar with possible configurations.

Use TaskInvocationConfiguration.builder() to create a new instance.

The default implementation constructs a configuration based on the deprecated methods TaskFactory.getCapabilities(), TaskFactory.getExecutionEnvironmentSelector(), and TaskFactory.getRequestedComputationTokenCount().

Gets the computation token count consumed by this task during execution.

Computation tokens are used to prevent thrashing of the execution machine when too many concurrent operations are running. A computation token represents one unit of computational operation that uses one CPU thread on 100%. This method returns the average number of computation tokens the task uses during its execution. The task will start to run when the requested number of tokens are available for it.

If a task returns > 0 amount of computation tokens then a restriction is placed on them that they can't wait for other tasks in the build system. This is in order to prevent involuntarily deadlocking the execution.

(Reasoning: Tasks will not start execution until they can allocate the required amount of computation tokens for themselves. If a tasks attempts to wait for a task which cannot start due to not being able to allocate enough computation tokens will deadlock the build execution, although they could probably finish if computation tokens didn't exist. Implementing active deadlock detection for this behaviour is not deemed to be feasible, so the above restriction is placed on tasks which require computation tokens.)

If your task really needs to wait for an input task then we recommend waiting for them in a parent task and start the actual computation in a sub-task with computation tokens. Dependencies on input tasks can be specified by using the finished retrieval methods of the task futures which do not require waiting for the subject task.

The default implementation returns 0, meaning no computation tokens requested.

Gets the task identifier which should be used when starting an instance of TaskInvocationRunnerTaskFactory.

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

The general contract of hashCode is:

• Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
• If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
• It is not required that if two objects are unequal according to the Object.equals(Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the Java™ programming language.)

The object implements the readExternal method to restore its contents by calling the methods of DataInput for primitive types and readObject for objects, strings and arrays. The readExternal method must read the values in the same sequence and with the same types as were written by writeExternal.

Executes this task.

If this task is an intance of ParameterizableTask, then ParameterizableTask.initParameters(TaskContext, NavigableMap<String, ? extends TaskIdentifier>) will be called prior to this.

This method is called at most once during the lifetime of the task object.

Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

 getClass().getName() + '@' + Integer.toHexString(hashCode())
 

The object implements the writeExternal method to save its contents by calling the methods of DataOutput for its primitive values or calling the writeObject method of ObjectOutput for objects, strings, and arrays.