org.openide.execution

Class ExecutionEngine

java.lang.Object

org.openide.execution.ExecutionEngine

public abstract class ExecutionEngine
extends Object

Engine providing the environment necessary to run long-lived processes. May perform tasks such as setting up thread groups, etc. Modules should not implement this class.

Note for implementors: it is highly advised that the value Lookup#getDefault is saved, and established in the forked thread before the executed Runnable is called. This is done by OpenIDE libraries If the ExecutionEngine implementation uses RequestProcessor for planning the tasks.

Constructor Summary

Constructors

Constructor and Description
ExecutionEngine()

Method Summary

Modifier and Type	Method and Description
protected abstract NbClassPath	createLibraryPath() Deprecated. There are generally no excuses to be using this method as part of a normal module; its exact meaning is vague, and probably not what you want.
protected abstract PermissionCollection	createPermissions(CodeSource cs, InputOutput io) Users that want to link their classes with NetBeans module classes should do this through internal execution.
abstract ExecutorTask	execute(String name, Runnable run, InputOutput io) Run some task in the execution engine.
static ExecutionEngine	getDefault() Obtains default instance of the execution engine.

Methods inherited from class java.lang.Object

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

Constructor Detail

ExecutionEngine

public ExecutionEngine()

Method Detail

execute

public abstract ExecutorTask execute(String name,
                                     Runnable run,
                                     InputOutput io)

Run some task in the execution engine.

Parameters:

name - a name of the new process

run - a runnable to execute

io - an I/O handle to automatically redirect system I/O streams in the dynamic scope of the task to, or InputOutput.NULL if no such redirection is required

Returns:

an executor task that can control the execution

createPermissions

protected abstract PermissionCollection createPermissions(CodeSource cs,
                                                          InputOutput io)

Users that want to link their classes with NetBeans module classes should do this through internal execution. The NbClassLoader used in internal execution will assume that calling this method and giving the permission collection to the class being defined will trigger automatic redirection of system output, input, and error streams into the given I/O tab. Implementations of the engine should bind the tab and returned permissions. Since the permission collection is on the stack when calling methods on System.out etc., it is possible to find the appropriate tab for redirection.

Parameters:

cs - code source to construct the permission collection for

io - an I/O tab

Returns:

a permission collection

createLibraryPath

protected abstract NbClassPath createLibraryPath()

Deprecated. There are generally no excuses to be using this method as part of a normal module; its exact meaning is vague, and probably not what you want.

Method that allows implementor of the execution engine to provide class path to all libraries that one could find useful for development in the system.

Returns:

class path to libraries

getDefault

public static ExecutionEngine getDefault()

Obtains default instance of the execution engine. If default Lookup contains an instance of ExecutionEngine, that is used. Otherwise, a trivial basic implementation is returned with the following behavior:

• ExecutionEngine.execute(java.lang.String, java.lang.Runnable, org.openide.windows.InputOutput) just runs the runnable immediately and pretends to be done.
• ExecutionEngine.createPermissions(java.security.CodeSource, org.openide.windows.InputOutput) just uses AllPermission. No I/O redirection or System.exit(int) trapping is done.
• ExecutionEngine.createLibraryPath() produces an empty path.

This basic implementation is helpful in unit tests and perhaps in standalone usage of other libraries.

Returns:

some execution engine implementation (never null)

Since:

2.16