org.springsource.loaded
Class ReloadableType

java.lang.Object
  org.springsource.loaded.ReloadableType

public class ReloadableType
extends java.lang.Object

Represents a type that has been processed such that it can be reloaded at runtime.

Since:

0.5.0

Field Summary

byte[]	bytesInitial The bytes for the original implementation as first loaded, before rewriting
byte[]	bytesLoaded The bytes for the original implementation as first loaded, after rewriting
java.lang.String	dottedtypename The dotted typename
byte[]	interfaceBytes The bytes for the interface representing the first loaded implementation
java.util.Map<java.lang.String,java.util.Map<java.lang.String,Invoker>>	invokerCache_getDeclaredMethod
java.util.Map<java.lang.String,java.util.Map<java.lang.String,Invoker>>	invokerCache_getMethod
java.util.List<Invoker>	invokersCache_getDeclaredMethods Cache of the invokers used to answer getDeclaredMethods() call made on this type
java.util.Collection<Invoker>	invokersCache_getMethods
java.lang.ref.Reference<java.lang.reflect.Method[]>	jlClassGetDeclaredMethods_cache
java.lang.ref.Reference<java.lang.reflect.Method[]>	jlClassGetMethods_cache
static ReloadableType	NOT_RELOADABLE_TYPE
static java.lang.ref.WeakReference<ReloadableType>	NOT_RELOADABLE_TYPE_REF
java.lang.String	slashedtypename The slashed typename
TypeDescriptor	typedescriptor A type descriptor describing the shape of the type at first load
TypeRegistry	typeRegistry The registry maintaining this reloadable type

Constructor Summary

ReloadableType(java.lang.String dottedtypename, byte[] initialBytes, int id, TypeRegistry typeRegistry, TypeDescriptor typeDescriptor)
Construct a new ReloadableType with the specified name and the specified initial bytecode.

Method Summary

java.lang.Object	cchanged(int ctorId)
boolean	cchanged(java.lang.String descriptor)
int	changed(int methodId) Check if the specified method is different to the original form from the type as loaded.
void	clearClassloaderLinks()
int	clinitchanged()
__DynamicallyDispatchable	determineDispatcher(java.lang.Object instance, java.lang.String nameAndDescriptor) Intended to handle dynamic dispatch.
java.lang.Object	fetchLatest()
java.lang.Object	fetchLatestIfExists(int methodId)
FieldMember	findInstanceField(java.lang.String name) Find the named instance field either on this reloadable type or on a reloadable supertype - it will not go into the non-reloadable types.
FieldMember	findStaticField(java.lang.String name) Search for a static field from this type upwards, as far as the topmost reloadable types.
void	fixupGroovyType() Groovy types need some extra fixup: they contain a callsite array that caches destinations for calls.
java.lang.String	getBaseName()
byte[]	getBytesInitial()
byte[]	getBytesLoaded()
java.lang.Class<?>	getClazz()
MethodMember	getConstructor(java.lang.String descriptor)
MethodMember	getCurrentConstructor(java.lang.String desc)
MethodMember	getCurrentMethod(java.lang.String name, java.lang.String descriptor) Gets the method corresponding to given name and descriptor, taking into consideration changes that have happened by reloading.
__DynamicallyDispatchable	getDispatcher()
java.lang.Object	getField(java.lang.Object instance, java.lang.String fieldname, boolean isStatic) Attempt to set the value of a field on an instance to the specified value.
FieldReaderWriter	getFieldInHierarchy(java.lang.String name)
MethodMember	getFromLatestByDescriptor(java.lang.String nameAndDescriptor)
int	getId()
byte[]	getInterfaceBytes()
JavaMethodCache	getJavaMethodCache()
byte[]	getLatestDispatcherBytes()
java.lang.Class<?>	getLatestDispatcherClass()
java.lang.Object	getLatestDispatcherInstance()
java.lang.Object	getLatestDispatcherInstance(boolean b)
java.lang.String	getLatestDispatcherName()
byte[]	getLatestExecutorBytes()
java.lang.Class<?>	getLatestExecutorClass()
java.lang.String	getLatestExecutorName()
TypeDescriptor	getLatestTypeDescriptor()
CurrentLiveVersion	getLiveVersion()
MethodMember	getMethod(java.lang.String nameAndDescriptor)
MethodMember	getMethod(java.lang.String name, java.lang.String descriptor) Gets the 'orignal' method corresponding to given name and method descriptor.
java.lang.String	getName()
MethodMember	getOriginalConstructor(java.lang.String desc)
MethodMember	getOriginalMethod(java.lang.String nameAndDescriptor) Gets the method corresponding to given name and descriptor, from the original type descriptor.
java.lang.String	getSlashedName()
java.lang.String	getSlashedSupertypeName()
ReloadableType	getSuperRtype()
TypeDescriptor	getTypeDescriptor()
TypeRegistry	getTypeRegistry()
int	getTypeRegistryId()
boolean	hasBeenReloaded()
boolean	hasFieldChangedInHierarchy(java.lang.String name) Want to check if this field looks the same as originally declared and is on the same type as it was
boolean	isResolved()
boolean	loadNewVersion(byte[] newbytedata)
boolean	loadNewVersion(java.lang.String versionsuffix, byte[] newbytedata) Load a new version of this type, using the specified suffix to tag the newly generated artifact class names.
boolean	loadNewVersion(java.lang.String versionsuffix, byte[] newbytedata, boolean shouldRerunStaticInitializer)
FieldReaderWriter	locateField(java.lang.String name) Find the field according to the rules of section 5.4.3.2 of the spec.
void	reloadMostRecentDispatcherAndExecutor()
void	rewriteCallSitesAndDefine() Rewrite the code for this reloadable type.
void	runStaticInitializer()
void	setField(java.lang.Object instance, java.lang.String fieldname, boolean isStatic, java.lang.Object newValue) Attempt to set the value of a field on an instance to the specified value.
void	setResolved()
void	setSuperclass(java.lang.Class<?> superclazz)
boolean	simulateReload()
java.lang.String	toString()
void	trackLiveInstance(java.lang.Object instance)
FieldReaderWriter	walk(java.lang.String name, TypeDescriptor typeDescriptor)

Methods inherited from class java.lang.Object

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

Field Detail

typeRegistry

public TypeRegistry typeRegistry

The registry maintaining this reloadable type

dottedtypename

public final java.lang.String dottedtypename

The dotted typename

slashedtypename

public final java.lang.String slashedtypename

The slashed typename

bytesInitial

public byte[] bytesInitial

The bytes for the original implementation as first loaded, before rewriting

bytesLoaded

public byte[] bytesLoaded

The bytes for the original implementation as first loaded, after rewriting

interfaceBytes

public final byte[] interfaceBytes

The bytes for the interface representing the first loaded implementation

typedescriptor

public TypeDescriptor typedescriptor

A type descriptor describing the shape of the type at first load

invokersCache_getDeclaredMethods

public java.util.List<Invoker> invokersCache_getDeclaredMethods

Cache of the invokers used to answer getDeclaredMethods() call made on this type

invokersCache_getMethods

public java.util.Collection<Invoker> invokersCache_getMethods

invokerCache_getMethod

public java.util.Map<java.lang.String,java.util.Map<java.lang.String,Invoker>> invokerCache_getMethod

invokerCache_getDeclaredMethod

public java.util.Map<java.lang.String,java.util.Map<java.lang.String,Invoker>> invokerCache_getDeclaredMethod

NOT_RELOADABLE_TYPE

public static final ReloadableType NOT_RELOADABLE_TYPE

NOT_RELOADABLE_TYPE_REF

public static final java.lang.ref.WeakReference<ReloadableType> NOT_RELOADABLE_TYPE_REF

jlClassGetDeclaredMethods_cache

public java.lang.ref.Reference<java.lang.reflect.Method[]> jlClassGetDeclaredMethods_cache

jlClassGetMethods_cache

public java.lang.ref.Reference<java.lang.reflect.Method[]> jlClassGetMethods_cache

Constructor Detail

ReloadableType

public ReloadableType(java.lang.String dottedtypename,
                      byte[] initialBytes,
                      int id,
                      TypeRegistry typeRegistry,
                      TypeDescriptor typeDescriptor)

Construct a new ReloadableType with the specified name and the specified initial bytecode.

Parameters:

dottedtypename - the dotted name

initialBytes - the bytecode for the initial version

id - for this reloadable type, allocated by the registry

typeRegistry - the registry managing this type

typeDescriptor - the type descriptor (if it has already been worked out), otherwise null

Method Detail

getClazz

public java.lang.Class<?> getClazz()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getTypeDescriptor

public TypeDescriptor getTypeDescriptor()

getMethod

public MethodMember getMethod(java.lang.String name,
                              java.lang.String descriptor)

Gets the 'orignal' method corresponding to given name and method descriptor. This only considers methods that exist in the first (non-reloaded) version of the type.

getConstructor

public MethodMember getConstructor(java.lang.String descriptor)

loadNewVersion

public boolean loadNewVersion(byte[] newbytedata)

simulateReload

public boolean simulateReload()

loadNewVersion

public boolean loadNewVersion(java.lang.String versionsuffix,
                              byte[] newbytedata,
                              boolean shouldRerunStaticInitializer)

loadNewVersion

public boolean loadNewVersion(java.lang.String versionsuffix,
                              byte[] newbytedata)

Load a new version of this type, using the specified suffix to tag the newly generated artifact class names.

fixupGroovyType

public void fixupGroovyType()

Groovy types need some extra fixup:

• they contain a callsite array that caches destinations for calls. It needs clearing (it will be reinitialized when required)
• not quite sure about the two: $staticClassInfo and GroovySystem removeMetaClass
• ClassScope.getClassInfo(Foo.class).cachedClassRef.clear()

getLatestDispatcherBytes

public byte[] getLatestDispatcherBytes()

getLatestDispatcherClass

public java.lang.Class<?> getLatestDispatcherClass()

getInterfaceBytes

public byte[] getInterfaceBytes()

getLatestDispatcherInstance

public java.lang.Object getLatestDispatcherInstance()

getLatestDispatcherInstance

public java.lang.Object getLatestDispatcherInstance(boolean b)

getLatestDispatcherName

public java.lang.String getLatestDispatcherName()

getBytesInitial

public byte[] getBytesInitial()

getBytesLoaded

public byte[] getBytesLoaded()

getLatestExecutorBytes

public byte[] getLatestExecutorBytes()

getLatestExecutorClass

public java.lang.Class<?> getLatestExecutorClass()

getLatestExecutorName

public java.lang.String getLatestExecutorName()

getCurrentMethod

public MethodMember getCurrentMethod(java.lang.String name,
                                     java.lang.String descriptor)

Gets the method corresponding to given name and descriptor, taking into consideration changes that have happened by reloading.

getOriginalMethod

public MethodMember getOriginalMethod(java.lang.String nameAndDescriptor)

Gets the method corresponding to given name and descriptor, from the original type descriptor.

getName

public java.lang.String getName()

Returns:

the dotted type name, eg. java.lang.String

getSlashedName

public java.lang.String getSlashedName()

Returns:

the slashed type name, eg. java/lang/String

getTypeRegistry

public TypeRegistry getTypeRegistry()

Returns:

the type registry responsible for this type

getTypeRegistryId

public int getTypeRegistryId()

Returns:

the reference number for the type registry responsible for this type

getId

public int getId()

rewriteCallSitesAndDefine

public void rewriteCallSitesAndDefine()

Rewrite the code for this reloadable type. This involves:

• rewriting the method bodies to add the condition check as to whether they are the most up to date version
• rewriting the call sites for target methods to check they are there
• filling in catcher methods

fetchLatest

public java.lang.Object fetchLatest()

Returns:

the most recent dispatcher

hasBeenReloaded

public boolean hasBeenReloaded()

getLiveVersion

public CurrentLiveVersion getLiveVersion()

cchanged

public boolean cchanged(java.lang.String descriptor)

cchanged

public java.lang.Object cchanged(int ctorId)

changed

public int changed(int methodId)

Check if the specified method is different to the original form from the type as loaded.

Parameters:

methodId - the ID of the method currently executing

Returns:

0 if the method cannot have changed. 1 if the method has changed. 2 if the method has been deleted in a new version.

clinitchanged

public int clinitchanged()

fetchLatestIfExists

public java.lang.Object fetchLatestIfExists(int methodId)

getSlashedSupertypeName

public java.lang.String getSlashedSupertypeName()

getDispatcher

public __DynamicallyDispatchable getDispatcher()

determineDispatcher

public __DynamicallyDispatchable determineDispatcher(java.lang.Object instance,
                                                     java.lang.String nameAndDescriptor)

Intended to handle dynamic dispatch. This will determine the right type to handle the specified method and return a dispatcher that can handle it.

Parameters:

instance -

nameAndDescriptor - an encoded method name and descriptor, e.g. foo(Ljava/langString;)V

getBaseName

public java.lang.String getBaseName()

Returns:

type name without the package prefix

getLatestTypeDescriptor

public TypeDescriptor getLatestTypeDescriptor()

getFromLatestByDescriptor

public MethodMember getFromLatestByDescriptor(java.lang.String nameAndDescriptor)

getMethod

public MethodMember getMethod(java.lang.String nameAndDescriptor)

getCurrentConstructor

public MethodMember getCurrentConstructor(java.lang.String desc)

getOriginalConstructor

public MethodMember getOriginalConstructor(java.lang.String desc)

getJavaMethodCache

public JavaMethodCache getJavaMethodCache()

findInstanceField

public FieldMember findInstanceField(java.lang.String name)

Find the named instance field either on this reloadable type or on a reloadable supertype - it will not go into the non-reloadable types. This method also avoids interfaces because it is looking for instance fields. This is slightly naughty but if we assume the code we are reloading is valid code, it should never be referring to interface fields.

Parameters:

name - the name of the field to locate

Returns:

the FieldMember or null if the field is not found

findStaticField

public FieldMember findStaticField(java.lang.String name)

Search for a static field from this type upwards, as far as the topmost reloadable types. This is searching for a field, it is not checking the result. It is up to the caller to check they have not ended up with an instance field and throw the appropriate exception.

Parameters:

name - the name of the field to look for

Returns:

a FieldMember for the named field or null if not found

setField

public void setField(java.lang.Object instance,
                     java.lang.String fieldname,
                     boolean isStatic,
                     java.lang.Object newValue)
              throws java.lang.IllegalAccessException

Attempt to set the value of a field on an instance to the specified value.

Parameters:

instance - the object upon which to set the field (maybe null for static fields)

fieldname - the name of the field

-

newValue - the new value to put into the field

Throws:

java.lang.IllegalAccessException

getField

public java.lang.Object getField(java.lang.Object instance,
                                 java.lang.String fieldname,
                                 boolean isStatic)
                          throws java.lang.IllegalAccessException

Attempt to set the value of a field on an instance to the specified value. Simply locate the field, which returns an object capable of reading/writing it, then use that to retrieve the value.

Parameters:

instance - the object upon which to set the field (maybe null for static fields)

fieldname - the name of the field

-

newValue - the new value to put into the field

Throws:

java.lang.IllegalAccessException

locateField

public FieldReaderWriter locateField(java.lang.String name)

Find the field according to the rules of section 5.4.3.2 of the spec.

walk

public FieldReaderWriter walk(java.lang.String name,
                              TypeDescriptor typeDescriptor)

hasFieldChangedInHierarchy

public boolean hasFieldChangedInHierarchy(java.lang.String name)

Want to check if this field looks the same as originally declared and is on the same type as it was

getFieldInHierarchy

public FieldReaderWriter getFieldInHierarchy(java.lang.String name)

clearClassloaderLinks

public void clearClassloaderLinks()

reloadMostRecentDispatcherAndExecutor

public void reloadMostRecentDispatcherAndExecutor()

trackLiveInstance

public void trackLiveInstance(java.lang.Object instance)

runStaticInitializer

public void runStaticInitializer()

isResolved

public boolean isResolved()

setResolved

public void setResolved()

setSuperclass

public void setSuperclass(java.lang.Class<?> superclazz)

getSuperRtype

public ReloadableType getSuperRtype()