Module openj9.dtfj

Package com.ibm.dtfj.java.j9

Class JavaRuntime

java.lang.Object

com.ibm.dtfj.java.j9.JavaRuntime

All Implemented Interfaces:

JavaRuntime, ManagedRuntime

public class JavaRuntime
extends Object
implements JavaRuntime

Constructor Summary

Constructors

Constructor	Description
JavaRuntime(ImageProcess containingProc, ImagePointer baseAddress, String runtimeVersion)

Method Summary

Modifier and Type	Method	Description
void	addClass(JavaAbstractClass theClass)
void	addClassLoader(JavaClassLoader loader)
void	addHeap(JavaHeap heap)
void	addHeapRoot(JavaReference heapRoot)
void	addMethodForID(JavaMethod method, long id)
void	addMonitor(JavaMonitor monitor)
void	addSpecialObject(JavaObject obj)
void	addThread(JavaThread thread, long blockedOnMonitor, long waitingOnMonitor)	Adds a JavaThread to the runtime along with optional IDs of monitors that it is blocked on or waiting on
int	bytesPerPointer()	A helper method required by some of the structures hanging off of the VM.
JavaVMInitArgs	createJavaVMInitArgs(int version, boolean ignoreUnrecognized)
boolean	equals(Object obj)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected Iterator	getClasses()
JavaClass	getClassForID(long classID)
JavaClassLoader	getClassLoaderForID(long loaderID)
Iterator	getCompiledMethods()	This is short cut method.
String	getFullVersion()	Get the 'full' version information for this runtime.
Iterator	getHeapRoots()	Get the set of object and class roots known to the VM.
Iterator	getHeaps()	Get the set of heaps known by the VM
Iterator	getJavaClassLoaders()	Get the set of class loaders active in this VM
ImagePointer	getJavaVM()	Get the object that represents the virtual machine
JavaVMInitArgs	getJavaVMInitArgs()	Fetch the JavaVMInitArgs which were used to create this VM.
Properties	getJITProperties()	Get any vendor specific properties in use by the JIT for this Java runtime
Iterator	getMemoryCategories()	Returns iterator of the top-level memory categories used by this Java runtime.
Iterator	getMemorySections(boolean includeFreed)	Returns an iterator of JavaRuntimeMemorySection objects corresponding to the blocks of memory allocated by the JavaRuntime.
Iterator	getMonitors()	Provides access to the collection of monitors used in the JavaVM.
JavaObject	getObjectAtAddress(ImagePointer address)	Gets the object located at address address in the heap.
JavaObject	getSpecialObject(ImagePointer address)
long	getStartTime()	Get the time when the JVM was started.
long	getStartTimeNanos()	Get the value of the JVM's high-resolution timer when the JVM was started.
String	getSystemProperty(String key)	Get a system property of the virtual machine.
String	getSystemProperty(String key, String defaultValue)
Iterator	getThreads()	Get the set of Java threads known by the VM
Object	getTraceBuffer(String bufferName, boolean formatted)	Fetches implementation specific trace buffers, like the verbose GC buffer or the Universal Trace Engine (UTE) buffer
String	getVersion()	Get the version data available for this runtime instance.
int	hashCode()	Answers an integer hash code for the receiver.
boolean	isJITEnabled()	Determine if the JIT was enabled for this Java runtime.
JavaMethod	methodForID(long method)
ImageThread	nativeThreadForID(long nativeID)
ImagePointer	pointerInAddressSpace(long id)	Since a JavaVM cannot span address spaces, use the VM's container address space to build this pointer, given the raw ID
void	setSystemProperty(String key, String value)
void	setTraceBufferForName(TraceBuffer buffer, String key)

Methods declared in class java.lang.Object

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

Constructor Details

JavaRuntime

public JavaRuntime(ImageProcess containingProc,
 ImagePointer baseAddress,
 String runtimeVersion)

Method Details

getJavaVM

public ImagePointer getJavaVM()
                       throws CorruptDataException

Description copied from interface: JavaRuntime

Get the object that represents the virtual machine

Specified by:

getJavaVM in interface JavaRuntime

Returns:

the address of the JavaVM structure which represents this JVM instance in JNI

Throws:

CorruptDataException

getJavaClassLoaders

public Iterator getJavaClassLoaders()

Description copied from interface: JavaRuntime

Get the set of class loaders active in this VM

Specified by:

getJavaClassLoaders in interface JavaRuntime

Returns:

an iterator of all of the class loaders within this JavaVM

See Also:

• JavaClassLoader
• CorruptData

getThreads

public Iterator getThreads()

Description copied from interface: JavaRuntime

Get the set of Java threads known by the VM

Specified by:

getThreads in interface JavaRuntime

Returns:

an iterator of the JavaThreads in the runtime

See Also:

• JavaThread
• CorruptData

getCompiledMethods

public Iterator getCompiledMethods()

Description copied from interface: JavaRuntime

This is short cut method. The same result can be found by iterating over all methods in all class loaders in all classes.

Specified by:

getCompiledMethods in interface JavaRuntime

Returns:

an iterator over all of the JavaMethods in the JavaRuntime which have been compiled

See Also:

• JavaMethod
• CorruptData

getMonitors

public Iterator getMonitors()

Description copied from interface: JavaRuntime

Provides access to the collection of monitors used in the JavaVM. This collection includes both monitors associated with managed objects (e.g. object monitors) and monitors associated with internal control structures (e.g. raw monitors)

Specified by:

getMonitors in interface JavaRuntime

Returns:

an iterator over the collection of monitors

See Also:

• JavaMonitor
• CorruptData

getHeaps

public Iterator getHeaps()

Description copied from interface: JavaRuntime

Get the set of heaps known by the VM

Specified by:

getHeaps in interface JavaRuntime

Returns:

an iterator for all of the Java heaps within this runtime. Heaps may be specific to this JavaVM instance, or may be shared between multiple JavaVM instances

See Also:

• JavaHeap
• CorruptData

getTraceBuffer

public Object getTraceBuffer(String bufferName,
 boolean formatted)
                      throws CorruptDataException

Description copied from interface: JavaRuntime

Fetches implementation specific trace buffers, like the verbose GC buffer or the Universal Trace Engine (UTE) buffer

Specified by:

getTraceBuffer in interface JavaRuntime

Parameters:

bufferName - a String naming the buffer to be fetched

formatted - true if formatting should be performed on the buffer, or false if the raw buffer contents should be returned

Returns:

an implementation specific result, depending on the parameters

Throws:

CorruptDataException

getFullVersion

public String getFullVersion()
                      throws CorruptDataException

Description copied from interface: ManagedRuntime

Get the 'full' version information for this runtime.

Specified by:

getFullVersion in interface ManagedRuntime

Returns:

a string representation of the version information for this runtime instance

Throws:

CorruptDataException - If the runtime presents no understandable version data

See Also:

• ManagedRuntime.getVersion()

getVersion

public String getVersion()
                  throws CorruptDataException

Description copied from interface: ManagedRuntime

Get the version data available for this runtime instance.

Specified by:

getVersion in interface ManagedRuntime

Returns:

a string representing all the version data available for this runtime instance.

Throws:

CorruptDataException - If the runtime presents no understandable version data

addClass

public void addClass(JavaAbstractClass theClass)

addClassLoader

public void addClassLoader(JavaClassLoader loader)

getClassForID

public JavaClass getClassForID(long classID)

getClassLoaderForID

public JavaClassLoader getClassLoaderForID(long loaderID)

addMonitor

public void addMonitor(JavaMonitor monitor)

addHeap

public void addHeap(JavaHeap heap)

addHeapRoot

public void addHeapRoot(JavaReference heapRoot)

addThread

public void addThread(JavaThread thread,
 long blockedOnMonitor,
 long waitingOnMonitor)

Adds a JavaThread to the runtime along with optional IDs of monitors that it is blocked on or waiting on

Parameters:

thread - The JavaThread to add to the runtime

blockedOnMonitor - The ID of the monitor that this thread is blocked on (0 if it is not blocked)

waitingOnMonitor - The ID of the monitor that this thread is waiting on (0 if it is not waiting)

setTraceBufferForName

public void setTraceBufferForName(TraceBuffer buffer,
 String key)

getSystemProperty

public String getSystemProperty(String key)

Description copied from interface: JavaRuntime

Get a system property of the virtual machine.

Specified by:

getSystemProperty in interface JavaRuntime

Parameters:

key - the name of the property to retrieve

Returns:

the value of the requested system property from this VM

getSystemProperty

public String getSystemProperty(String key,
 String defaultValue)

setSystemProperty

public void setSystemProperty(String key,
 String value)

equals

public boolean equals(Object obj)

Description copied from class: java.lang.Object

Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison. The implementation in Object answers true only if the argument is the exact same object as the receiver (==).

Specified by:

equals in interface JavaRuntime

Overrides:

equals in class Object

Parameters:

obj -

Returns:

True if the given object refers to the same Java Runtime in the image

See Also:

• Object.hashCode()

hashCode

public int hashCode()

Description copied from class: java.lang.Object

Answers an integer hash code for the receiver. Any two objects which answer true when passed to .equals must answer the same value for this method.

Specified by:

hashCode in interface JavaRuntime

Overrides:

hashCode in class Object

Returns:

the receiver's hash.

See Also:

• Object.equals(java.lang.Object)

getJavaVMInitArgs

public JavaVMInitArgs getJavaVMInitArgs()
                                 throws DataUnavailable,
CorruptDataException

Description copied from interface: JavaRuntime

Fetch the JavaVMInitArgs which were used to create this VM. See JNI_CreateJavaVM in the JNI Specification for more details.

Specified by:

getJavaVMInitArgs in interface JavaRuntime

Returns:

the JavaVMInitArgs which were used to create this VM.

Throws:

DataUnavailable - if the arguments are not available

CorruptDataException

pointerInAddressSpace

public ImagePointer pointerInAddressSpace(long id)

Since a JavaVM cannot span address spaces, use the VM's container address space to build this pointer, given the raw ID

Parameters:

id -

Returns:

nativeThreadForID

public ImageThread nativeThreadForID(long nativeID)

methodForID

public JavaMethod methodForID(long method)

addMethodForID

public void addMethodForID(JavaMethod method,
 long id)

createJavaVMInitArgs

public JavaVMInitArgs createJavaVMInitArgs(int version,
 boolean ignoreUnrecognized)

bytesPerPointer

public int bytesPerPointer()

A helper method required by some of the structures hanging off of the VM. Returns the number of bytes required to express a native pointer on the VM target platform

Returns:

4 or 8, depending on the pointer size of the target platform

getClasses

protected Iterator getClasses()

getHeapRoots

public Iterator getHeapRoots()

Description copied from interface: JavaRuntime

Get the set of object and class roots known to the VM. Stack frame roots are not included in the set, they can be retrieved using JavaStackFrame.getHeapRoots().

Specified by:

getHeapRoots in interface JavaRuntime

Returns:

an iterator over the collection of JavaReferences representing the known global heap roots within this runtime.

See Also:

• JavaReference
• JavaStackFrame
• CorruptData

getObjectAtAddress

public JavaObject getObjectAtAddress(ImagePointer address)
                              throws CorruptDataException,
IllegalArgumentException

Description copied from interface: JavaRuntime

Gets the object located at address address in the heap.

Specified by:

getObjectAtAddress in interface JavaRuntime

Parameters:

address - the ImagePointer instance representing the start address of object in the heap;

Returns:

the JavaObject instance representing the located object.

Throws:

CorruptDataException - if any data needed to build the returned instance of JavaObject is corrupt.

IllegalArgumentException - if address is outside the heap's boundaries, or if it doesn't point to the start location of an object;

See Also:

• JavaObject

addSpecialObject

public void addSpecialObject(JavaObject obj)

getSpecialObject

public JavaObject getSpecialObject(ImagePointer address)

getMemoryCategories

public Iterator getMemoryCategories()
                             throws DataUnavailable

Description copied from interface: JavaRuntime

Returns iterator of the top-level memory categories used by this Java runtime.

Specified by:

getMemoryCategories in interface JavaRuntime

Returns:

Iterator of memory categories

Throws:

DataUnavailable

See Also:

• CorruptData

getMemorySections

public Iterator getMemorySections(boolean includeFreed)
                           throws DataUnavailable

Description copied from interface: JavaRuntime

Returns an iterator of JavaRuntimeMemorySection objects corresponding to the blocks of memory allocated by the JavaRuntime.

Specified by:

getMemorySections in interface JavaRuntime

Parameters:

includeFreed - If true, iterator will iterate over blocks of memory that have been freed, but haven't been re-used yet.

Returns:

Iterator of memory sections.

Throws:

DataUnavailable

See Also:

• CorruptData

isJITEnabled

public boolean isJITEnabled()
                     throws DataUnavailable,
CorruptDataException

Description copied from interface: JavaRuntime

Determine if the JIT was enabled for this Java runtime.

Specified by:

isJITEnabled in interface JavaRuntime

Returns:

true if the JIT was enabled, false if not

Throws:

DataUnavailable - if it is not possible to determine the JIT status

CorruptDataException

getJITProperties

public Properties getJITProperties()
                            throws DataUnavailable,
CorruptDataException

Description copied from interface: JavaRuntime

Get any vendor specific properties in use by the JIT for this Java runtime

Specified by:

getJITProperties in interface JavaRuntime

Returns:

the set of properties, which may be empty if none were set.

Throws:

DataUnavailable - if the JIT was not enabled for this runtime

CorruptDataException

getStartTime

public long getStartTime()
                  throws DataUnavailable,
CorruptDataException

Description copied from interface: JavaRuntime

Get the time when the JVM was started.

Specified by:

getStartTime in interface JavaRuntime

Returns:

the time the JVM was started, in milliseconds since 1970

Throws:

DataUnavailable - if the JVM start time is not available

CorruptDataException - if the JVM start time is corrupted

getStartTimeNanos

public long getStartTimeNanos()
                       throws DataUnavailable,
CorruptDataException

Description copied from interface: JavaRuntime

Get the value of the JVM's high-resolution timer when the JVM was started.

Specified by:

getStartTimeNanos in interface JavaRuntime

Returns:

the value of the high-resolution timer when the JVM was started, in nanoseconds

Throws:

DataUnavailable - if the JVM start time is not available

CorruptDataException - if the JVM start time is corrupted