Module openj9.sharedclasses

Package com.ibm.oti.shared

Class SharedClassUtilities

java.lang.Object

com.ibm.oti.shared.SharedClassUtilities

public class SharedClassUtilities
extends Object

SharedClassUtilities provides APIs to get information about all shared class caches in a directory and to destroy a particular shared class cache.

See Also:

• SharedClassCacheInfo

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DESTROY_FAILED_CURRENT_GEN_CACHE	Returned by destroySharedCache(java.lang.String, int, java.lang.String, boolean) to indicate that the method has failed to destroy the current generation cache.
static final int	DESTROY_FAILED_OLDER_GEN_CACHE	Returned by destroySharedCache(java.lang.String, int, java.lang.String, boolean) to indicate that the method has failed to destroy one or more older generation caches, and either a current generation cache does not exist or is successfully destroyed.
static final int	DESTROYED_ALL_CACHE	Returned by destroySharedCache(java.lang.String, int, java.lang.String, boolean) to indicate either no cache exists or the method has successfully destroyed caches of all generations.
static final int	DESTROYED_NONE	Returned by destroySharedCache(java.lang.String, int, java.lang.String, boolean) to indicate that the method failed to destroy any cache.
static final int	NO_FLAGS	Value to be passed to flags parameter of the getSharedCacheInfo(java.lang.String, int, boolean) method.
static final int	NONPERSISTENT	Specifies a non-persistent cache.
static final int	PERSISTENCE_DEFAULT	Uses the platform dependent default value as the cache type.
static final int	PERSISTENT	Specifies a persistent cache.
static final int	SNAPSHOT	Specifies a cache snapshot.

Constructor Summary

Constructors

Constructor	Description
SharedClassUtilities()	Deprecated.

Method Summary

Modifier and Type	Method	Description
static int	destroySharedCache(String cacheDir, int cacheType, String cacheName, boolean useCommandLineValues)	Destroys a named shared class cache of a given type in a given directory.
static List<SharedClassCacheInfo>	getSharedCacheInfo(String cacheDir, int flags, boolean useCommandLineValues)	Iterates through all shared class caches present in the given directory and returns their information in a List.

Methods declared in class java.lang.Object

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

Field Details

NO_FLAGS

public static final int NO_FLAGS

Value to be passed to flags parameter of the getSharedCacheInfo(java.lang.String, int, boolean) method.

See Also:

• Constant Field Values

PERSISTENCE_DEFAULT

public static final int PERSISTENCE_DEFAULT

Uses the platform dependent default value as the cache type.

See Also:

• Constant Field Values

PERSISTENT

public static final int PERSISTENT

Specifies a persistent cache.

See Also:

• Constant Field Values

NONPERSISTENT

public static final int NONPERSISTENT

Specifies a non-persistent cache.

See Also:

• Constant Field Values

SNAPSHOT

public static final int SNAPSHOT

Specifies a cache snapshot.

See Also:

• Constant Field Values

DESTROYED_ALL_CACHE

public static final int DESTROYED_ALL_CACHE

Returned by destroySharedCache(java.lang.String, int, java.lang.String, boolean) to indicate either no cache exists or the method has successfully destroyed caches of all generations.

See Also:

• Constant Field Values

DESTROYED_NONE

public static final int DESTROYED_NONE

Returned by destroySharedCache(java.lang.String, int, java.lang.String, boolean) to indicate that the method failed to destroy any cache.

See Also:

• Constant Field Values

DESTROY_FAILED_CURRENT_GEN_CACHE

public static final int DESTROY_FAILED_CURRENT_GEN_CACHE

Returned by destroySharedCache(java.lang.String, int, java.lang.String, boolean) to indicate that the method has failed to destroy the current generation cache.

See Also:

• Constant Field Values

DESTROY_FAILED_OLDER_GEN_CACHE

public static final int DESTROY_FAILED_OLDER_GEN_CACHE

Returned by destroySharedCache(java.lang.String, int, java.lang.String, boolean) to indicate that the method has failed to destroy one or more older generation caches, and either a current generation cache does not exist or is successfully destroyed.

See Also:

• Constant Field Values

Constructor Details

SharedClassUtilities

@Deprecated
public SharedClassUtilities()

Deprecated.

Constructs a new instance of this class.

Method Details

getSharedCacheInfo

public static List<SharedClassCacheInfo> getSharedCacheInfo(String cacheDir,
 int flags,
 boolean useCommandLineValues)

Iterates through all shared class caches present in the given directory and returns their information in a List.

If useCommandLineValues is true then use the command line value as the directory to search in. If the command line value is not available, use the platform dependent default value. If useCommandLineValues is false, then use cacheDir as the directory to search in. cacheDir can be null. In such a case, use the platform dependent default value.

Parameters:

cacheDir - Absolute path of the directory to look for the shared class caches

flags - Reserved for future use. Always pass NO_FLAGS

useCommandLineValues - Use command line values instead of using parameter values

Returns:

List of SharedClassCacheInfo corresponding to shared class caches which are present in the specified directory, null on failure.

Throws:

IllegalStateException - If shared classes is disabled for this JVM (that is -Xshareclasses:none is present).

IllegalArgumentException - If flags is not a valid value.

SecurityException - If a security manager is enabled and the calling thread does not have SharedClassesNamedPermission("getSharedCacheInfo")

destroySharedCache

public static int destroySharedCache(String cacheDir,
 int cacheType,
 String cacheName,
 boolean useCommandLineValues)

Destroys a named shared class cache of a given type in a given directory. If the shared class cache has multiple layers, this function will destroy the top layer only.

If useCommandLineValues is true, then use the command line value to get the shared class cache name, its type and its directory. If any of these is not available, then use the default value. If useCommandLineValues is false, then use cacheDir, persistence, and cacheName to identify the cache to be destroyed. To accept the default value for cacheDir or cacheName, specify the parameter with a null value.

The return value of this method depends on the status of existing current and older generation caches.

• If it fails to destroy any existing cache with the given name, it returns DESTROYED_NONE.
• If no cache exists or it is able to destroy all existing caches of all generations, it returns DESTROYED_ALL_CACHE.
  
• If it fails to destroy an existing current generation cache, irrespective of the state of older generation caches, it returns DESTROY_FAILED_CURRENT_GEN_CACHE.
  
• If it fails to destroy one or more older generation caches, and either a current generation cache does not exist or is successfully destroyed, it returns DESTROY_FAILED_OLDER_GEN_CACHE.
  

Parameters:

cacheDir - Absolute path of the directory where the shared class cache is present

cacheType - Type of the cache. The type has one of the following values:

• PERSISTENCE_DEFAULT
• PERSISTENT
• NONPERSISTENT
• SNAPSHOT

cacheName - Name of the cache to be deleted

useCommandLineValues - Use command line values instead of using parameter values

Returns:

Returns one of the following values:

• DESTROYED_ALL_CACHE
• DESTROYED_NONE
• DESTROY_FAILED_CURRENT_GEN_CACHE
• DESTROY_FAILED_OLDER_GEN_CACHE

Throws:

IllegalStateException - If shared classes is disabled for this JVM (that is -Xshareclasses:none is present).

IllegalArgumentException - If cacheType is not a valid value.

SecurityException - If a security manager is enabled and the calling thread does not have SharedClassesNamedPermission("destroySharedCache")