Module openj9.sharedclasses

Package com.ibm.oti.shared.provider

Class SharedClassProviderImpl

java.lang.Object

com.ibm.oti.shared.provider.SharedClassProviderImpl

All Implemented Interfaces:

com.ibm.sharedclasses.spi.SharedClassProvider

public class SharedClassProviderImpl
extends Object
implements com.ibm.sharedclasses.spi.SharedClassProvider

Implementation of SharedClassProvider.

Constructor Summary

Constructors

Constructor	Description
SharedClassProviderImpl()

Method Summary

Modifier and Type	Method	Description
BasicPermission	createPermission(String classLoaderClassName, String actions)	Constructs a new instance of SharedClassPermission which is a sub-class of BasicPermission.
byte[]	findSharedClassURL(URL path, String className)	Finds a class in the shared cache by using a specific URL and class name.
byte[]	findSharedClassURLClasspath(String className, IntConsumer indexConsumer)	Finds a class in the shared cache by using the class name given (implicitly using the caller's classpath).
long	getCacheSize()	Returns the size of the cache that the JVM is currently connected to.
long	getFreeSpace()	Returns the free space in bytes of the cache that the JVM is currently connected to.
long	getMaxAotBytes()	Returns the maximum space allowed for AOT data of the cache that the JVM is currently connected to.
long	getMaxJitDataBytes()	Returns the maximum space allowed for JIT data of the cache that the JVM is currently connected to.
long	getMinAotBytes()	Returns the minimum space reserved for AOT data of the cache that the JVM is currently connected to.
long	getMinJitDataBytes()	Returns the minimum space reserved for JIT data of the cache that the JVM is currently connected to.
long	getSoftmxBytes()	Returns the soft limit in bytes for the available space of the cache that the JVM is currently connected to.
com.ibm.sharedclasses.spi.SharedClassProvider	initializeProvider(ClassLoader loader, URL[] classpath)	Initializes a SharedClassProvider.
com.ibm.sharedclasses.spi.SharedClassProvider	initializeProvider(ClassLoader loader, URL[] classpath, boolean urlHelper, boolean tokenHelper)	Initializes a SharedClassProvider.
boolean	isSharedClassEnabled()	Checks whether shared classes are enabled for this JVM.
boolean	setURLClasspath(URL[] newClasspath)	Updates the URLClasspath helper's classpath with a new classpath.
boolean	storeSharedClassURL(URL path, Class<?> clazz)	Stores a class in the shared cache by using the URL location it was loaded from.
boolean	storeSharedClassURLClasspath(Class<?> clazz, int foundAtIndex)	Stores a class in the shared cache by using the caller's URL classpath.

Methods declared in class java.lang.Object

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

Constructor Details

SharedClassProviderImpl

public SharedClassProviderImpl()

Method Details

isSharedClassEnabled

public boolean isSharedClassEnabled()

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Checks whether shared classes are enabled for this JVM.

Specified by:

isSharedClassEnabled in interface com.ibm.sharedclasses.spi.SharedClassProvider

Returns:

boolean True if shared classes are enabled (using -Xshareclasses on the command-line), false otherwise.

initializeProvider

public com.ibm.sharedclasses.spi.SharedClassProvider initializeProvider(ClassLoader loader,
 URL[] classpath)

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Initializes a SharedClassProvider.

Specified by:

initializeProvider in interface com.ibm.sharedclasses.spi.SharedClassProvider

Parameters:

loader - ClassLoader The ClassLoader that uses SharedClassProvider.

classpath - URL[] The current URL classpath array of the ClassLoader.

Returns:

SharedClassProvider A SharedClassProvider if it is successfully initialized, or null otherwise.

initializeProvider

public com.ibm.sharedclasses.spi.SharedClassProvider initializeProvider(ClassLoader loader,
 URL[] classpath,
 boolean urlHelper,
 boolean tokenHelper)

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Initializes a SharedClassProvider.

Specified by:

initializeProvider in interface com.ibm.sharedclasses.spi.SharedClassProvider

Parameters:

loader - ClassLoader The ClassLoader that uses SharedClassProvider.

classpath - URL[] The current URL classpath array of the ClassLoader.

urlHelper - True if a SharedClassURLHelper needs to be created for this class loader, false otherwise.

tokenHelper - True if a SharedClassTokenHelper needs to be created for this class loader, false otherwise.

Returns:

SharedClassProvider A SharedClassProvider if it is successfully initialized, or null otherwise.

findSharedClassURL

public byte[] findSharedClassURL(URL path,
 String className)

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Finds a class in the shared cache by using a specific URL and class name. A class will be returned if it was stored against the same URL.

Null is returned if the class cannot be found or if it is stale (see Dynamic cache updates).

To obtain an instance of the class, the byte[] returned must be passed to defineClass by the caller ClassLoader.

Specified by:

findSharedClassURL in interface com.ibm.sharedclasses.spi.SharedClassProvider

Parameters:

path - URL. A URL path. Cannot be null.

className - String. The name of the class to be found

Returns:

byte[]. A byte array describing the class found, or null.

storeSharedClassURL

public boolean storeSharedClassURL(URL path,
 Class<?> clazz)

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Stores a class in the shared cache by using the URL location it was loaded from. The class that is being stored must have been defined by the caller ClassLoader and must exist in the URL location specified. Returns true if the class is stored successfully or false otherwise.

Will return false if the class that is being stored was not defined by the caller ClassLoader.

Also returns false if the URL is not a file URL or if the resource it refers to does not exist.

Specified by:

storeSharedClassURL in interface com.ibm.sharedclasses.spi.SharedClassProvider

Parameters:

path - URL. The URL path that the class was loaded from. Cannot be null.

clazz - Class. The class to store in the shared cache

Returns:

boolean. True if the class was stored successfully, false otherwise.

findSharedClassURLClasspath

public byte[] findSharedClassURLClasspath(String className,
 IntConsumer indexConsumer)

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Finds a class in the shared cache by using the class name given (implicitly using the caller's classpath).

See Using classpaths for rules on when a class will be found.
Null is returned if the class cannot be found, if it is stale (see Dynamic cache updates) or if it is found for an unconfirmed entry (see Using classpaths).

Specified by:

findSharedClassURLClasspath in interface com.ibm.sharedclasses.spi.SharedClassProvider

Parameters:

className - String. The name of the class to be found

indexConsumer - IntConsumer. The consumer used to receive the classpath index if desired.

Returns:

byte[]. A byte array describing the class found, or null.

storeSharedClassURLClasspath

public boolean storeSharedClassURLClasspath(Class<?> clazz,
 int foundAtIndex)

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Stores a class in the shared cache by using the caller's URL classpath.

The class being stored must have been defined by the caller ClassLoader and must exist in the URL location specified.

Returns true if the class is stored successfully or false otherwise.

Will return false if the class being stored was not defined by the caller ClassLoader.

Also returns false if the URL at foundAtIndex is not a file URL or if the resource it refers to does not exist.

Specified by:

storeSharedClassURLClasspath in interface com.ibm.sharedclasses.spi.SharedClassProvider

Parameters:

clazz - Class. The class to store in the shared cache

foundAtIndex - int. The index in the caller's classpath where the class was loaded from (first entry is 0).

Returns:

boolean. True if the class was stored successfully, false otherwise.

setURLClasspath

public boolean setURLClasspath(URL[] newClasspath)

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Updates the URLClasspath helper's classpath with a new classpath.

This function is useful for ClassLoaders that compute their classpath lazily. The initial classpath is passed to the constructor optimistically, but if the classloader discovers a change while reading an entry, it can update the classpath by using this function.

Note: It is essential that the helper's classpath is kept up-to-date with the classloader.

The classpath that is passed to this function must be exactly the same as the original classpath up to and including the right-most entry that classes have been loaded from (the right-most confirmed entry).

After the classpath has been updated, any indexes passed to storeSharedClassURLClasspath and returned from findSharedClassURLClasspath correspond to the new classpath.

Specified by:

setURLClasspath in interface com.ibm.sharedclasses.spi.SharedClassProvider

Parameters:

newClasspath - The new URL classpath array

Returns:

boolean. True if the classpath has been set, false otherwise.

getCacheSize

public long getCacheSize()

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Returns the size of the cache that the JVM is currently connected to.

Specified by:

getCacheSize in interface com.ibm.sharedclasses.spi.SharedClassProvider

Returns:

long. The total size in bytes of the shared cache.

getSoftmxBytes

public long getSoftmxBytes()

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Returns the soft limit in bytes for the available space of the cache that the JVM is currently connected to.

Specified by:

getSoftmxBytes in interface com.ibm.sharedclasses.spi.SharedClassProvider

Returns:

long. The soft max size or cache size in bytes if it is not set.

getMinAotBytes

public long getMinAotBytes()

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Returns the minimum space reserved for AOT data of the cache that the JVM is currently connected to.

Specified by:

getMinAotBytes in interface com.ibm.sharedclasses.spi.SharedClassProvider

Returns:

long. The minimum shared classes cache space reserved for AOT data in bytes or -1 if it is not set.

getMaxAotBytes

public long getMaxAotBytes()

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Returns the maximum space allowed for AOT data of the cache that the JVM is currently connected to.

Specified by:

getMaxAotBytes in interface com.ibm.sharedclasses.spi.SharedClassProvider

Returns:

long. The maximum shared classes cache space allowed for AOT data in bytes or -1 if it is not set.

getMinJitDataBytes

public long getMinJitDataBytes()

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Returns the minimum space reserved for JIT data of the cache that the JVM is currently connected to.

Specified by:

getMinJitDataBytes in interface com.ibm.sharedclasses.spi.SharedClassProvider

Returns:

long. The minimum shared classes cache space reserved for JIT data in bytes or -1 if it is not set.

getMaxJitDataBytes

public long getMaxJitDataBytes()

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Returns the maximum space allowed for JIT data of the cache that the JVM is currently connected to.

Specified by:

getMaxJitDataBytes in interface com.ibm.sharedclasses.spi.SharedClassProvider

Returns:

long. The maximum shared classes cache space allowed for JIT data in bytes or -1 if it is not set.

getFreeSpace

public long getFreeSpace()

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Returns the free space in bytes of the cache that the JVM is currently connected to.

Specified by:

getFreeSpace in interface com.ibm.sharedclasses.spi.SharedClassProvider

Returns:

long. The free space of the shared classes cache.

createPermission

public BasicPermission createPermission(String classLoaderClassName,
 String actions)

Description copied from interface: com.ibm.sharedclasses.spi.SharedClassProvider

Constructs a new instance of SharedClassPermission which is a sub-class of BasicPermission.

Specified by:

createPermission in interface com.ibm.sharedclasses.spi.SharedClassProvider

Parameters:

classLoaderClassName - java.lang.String. The class name of the class loader requiring the permission.

actions - java.lang.String. The actions which are applicable to it.

Returns:

BasicPermission. A new instance of SharedClassPermission which is a sub-class of BasicPermission, or null if shared classes are not enabled.