ch.grengine.load

Class LayeredClassLoader

java.lang.Object

java.lang.ClassLoader

ch.grengine.load.SourceClassLoader

ch.grengine.load.LayeredClassLoader

All Implemented Interfaces:

Cloneable

public class LayeredClassLoader
extends SourceClassLoader

SourceClassLoader based on layers of BytecodeClassLoader plus optionally a TopCodeCache.

Depending on load modes, classes are first searched in the parent class loader, the individual layers or optionally created on-the-fly from source as part of the top code cache.

Since:

1.0

Author:

Alain Stalder, Made in Switzerland.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	LayeredClassLoader.Builder Builder for instances of LayeredClassLoader.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	LayeredClassLoader(LayeredClassLoader.Builder builder) constructor from builder, based on already compiled code layers.
protected	LayeredClassLoader(LayeredClassLoader.Builder builder, boolean fromSourcesLayers) constructor from builder, based on sources to compile to code layers or on already compiled code layers.

Method Summary

Modifier and Type	Method and Description
LayeredClassLoader	clone() creates a clone with the same code layers and with shared top code cache.
LayeredClassLoader	cloneWithSeparateTopCodeCache() creates a clone with the same code layers and a separate top code cache (initially with the same cached bytecode).
BytecodeClassLoader	findBytecodeClassLoaderBySource(Source source) tries to find the bytecode class loader that can load classes that were created by compiling the given source.
LayeredClassLoader.Builder	getBuilder() gets the builder.
List<Code>	getCodeLayers() gets the code layers.
LoadMode	getLoadMode() gets the load mode.
TopCodeCache	getTopCodeCache() gets the top code cache.
Class<?>	loadClass(Source source, String name) loads a class with the given name and from the given source.
protected Class<?>	loadClass(String name, boolean resolve)
Class<?>	loadMainClass(Source source) loads the main class of the given source.
void	releaseClasses(ClassReleaser releaser) release metadata for all classed ever loaded by this class loader.

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findClass, findLibrary, findLoadedClass, findResource, findResources, findSystemClass, getClassLoadingLock, getPackage, getPackages, getParent, getResource, getResourceAsStream, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, registerAsParallelCapable, resolveClass, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

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

Constructor Detail

LayeredClassLoader

protected LayeredClassLoader(LayeredClassLoader.Builder builder)

constructor from builder, based on already compiled code layers.

Parameters:

builder - builder

Since:

1.0

LayeredClassLoader

protected LayeredClassLoader(LayeredClassLoader.Builder builder,
                             boolean fromSourcesLayers)

constructor from builder, based on sources to compile to code layers or on already compiled code layers.

Parameters:

builder - builder

fromSourcesLayers - if based on sources to compile to code layers or on already compiled code layers

Throws:

CompileException - if based on sources and compiling the sources layers failed

Since:

1.0

Method Detail

loadClass

protected Class<?> loadClass(String name,
                             boolean resolve)
                      throws ClassNotFoundException

Overrides:

loadClass in class ClassLoader

Throws:

ClassNotFoundException

loadMainClass

public Class<?> loadMainClass(Source source)

loads the main class of the given source.

First searches for the source, then loads the main class that resulted from compiling the source.

Specifically for LayeredClassLoader, the source is eventually compiled on-the-fly from the given source if top code cache is on. First, the class corresponding to the source is searched in static layers using findBytecodeClassLoaderBySource(Source). If not found, uses the source of the top code cache (compiling it, if necessary). If found, uses the source of the top code cache (compiling it, if necessary) if the source had changed since compiled in static layers (or top code cache) and if top load mode is current first.

Specified by:

loadMainClass in class SourceClassLoader

Parameters:

source - source

Returns:

main class

Throws:

CompileException - if compilation was necessary to load the class and failed

LoadException - if loading failed, including if the class was not found

Since:

1.0

loadClass

public Class<?> loadClass(Source source,
                          String name)

loads a class with the given name and from the given source.

First searches for the source, only then for the class with given name as part of the classes that resulted from compiling the source.

Specifically for LayeredClassLoader, the source is eventually compiled on-the-fly from the given source if top code cache is on. First, the class corresponding to the source is searched in static layers using findBytecodeClassLoaderBySource(Source). If not found, uses the source of the top code cache (compiling it, if necessary). If found, uses the source of the top code cache (compiling it, if necessary) if the source had changed since compiled in static layers (or top code cache) and if top load mode is current first.

Specified by:

loadClass in class SourceClassLoader

Parameters:

source - source

name - class name

Returns:

class

Throws:

CompileException - if compilation was necessary to load the class and failed

LoadException - if loading failed, including if the class was not found

Since:

1.0

findBytecodeClassLoaderBySource

public BytecodeClassLoader findBytecodeClassLoaderBySource(Source source)

tries to find the bytecode class loader that can load classes that were created by compiling the given source.

Specifically for LayeredClassLoader, top code cache is not involved; the search is limited to static code layers and the parent class loader.

Specified by:

findBytecodeClassLoaderBySource in class SourceClassLoader

Parameters:

source - source

Returns:

bytecode class loader if found, null otherwise

Since:

1.0

getLoadMode

public LoadMode getLoadMode()

Description copied from class: SourceClassLoader

gets the load mode.

Specified by:

getLoadMode in class SourceClassLoader

Returns:

load mode

clone

public LayeredClassLoader clone()

creates a clone with the same code layers and with shared top code cache.

Specified by:

clone in class SourceClassLoader

Returns:

clone

Since:

1.0

releaseClasses

public void releaseClasses(ClassReleaser releaser)

Description copied from class: SourceClassLoader

release metadata for all classed ever loaded by this class loader.

Allows to remove metadata associated by Groovy (or Java) with a class, which is often necessary to get on-the-fly garbage collection.

Generally call only when really done using this class loader and all loaded classes; subsequently trying to use this class loader or its classes results generally in undefined behavior.

Specified by:

releaseClasses in class SourceClassLoader

Parameters:

releaser - class releaser

cloneWithSeparateTopCodeCache

public LayeredClassLoader cloneWithSeparateTopCodeCache()

creates a clone with the same code layers and a separate top code cache (initially with the same cached bytecode).

Returns:

clone

Since:

1.0

getCodeLayers

public List<Code> getCodeLayers()

gets the code layers.

Returns:

code layers

Since:

1.0

getBuilder

public LayeredClassLoader.Builder getBuilder()

gets the builder.

Returns:

builder

Since:

1.0

getTopCodeCache

public TopCodeCache getTopCodeCache()

gets the top code cache.

Returns:

top code cache

Since:

1.0