Module openj9.dtfj

Package com.ibm.dtfj.java.javacore

Class JCJavaRuntime

java.lang.Object

com.ibm.dtfj.java.javacore.JCJavaRuntime

All Implemented Interfaces:

JavaRuntime, ManagedRuntime

public class JCJavaRuntime
extends Object
implements JavaRuntime

A javacore-based implementation of JavaRuntime. This supports partial object creation, meaning that a javaclass, javathread, etc.. can be partially constructed and stored, and at a later time during the javacore parsing, when more information is available, existing javaclasses, javathreads, and so on can be looked up and data added.

However, all partial objects must contain at least one immutable field. See the implementation of each runtime component for more information.

Rudimentary multiplatform support is also added in the form of unique runtime ids that must be passed during construction.

See Also:

• JCJavaClass
• JCJavaClassLoader
• JCJavaThread
• JCJavaMonitor
• JavaRuntime

Constructor Summary

Constructors

Constructor	Description
JCJavaRuntime(JCImageProcess imageProcess, String id)

Method Summary

Modifier and Type	Method	Description
void	addJavaClass(JCJavaClass javaClass)	NON-DTFJ For internal building purposes only.
void	addJavaClassLoader(JCJavaClassLoader javaClassLoader)	NON-DTFJ For internal building purposes only.
void	addJavaThread(JCJavaThread javaThread)	NON-DTFJ For internal building purposes only.
void	addJavaVMInitArgs(JCJavaVMInitArgs args)	NON-DTFJ For internal building purposes only.
void	addJITProperty(String name, String value)
void	addMonitor(JCJavaMonitor monitor)	NON-DTFJ For internal building purposes only.
void	addTopLevelMemoryCategory(JCJavaRuntimeMemoryCategory category)
JCJavaClass	findJavaClass(long id)	NON-DTFJ For internal building purposes only.
JCJavaClass	findJavaClass(String javaClassName)	NON-DTFJ For internal building purposes only.
JCJavaClassLoader	findJavaClassLoader(long clLoaderID)	NON-DTFJ For internal building purposes only.
JCJavaThread	findJavaThread(long threadID)	NON-DTFJ For internal building purposes only.
JCJavaMonitor	findMonitor(long id)	NON-DTFJ For internal building purposes only.
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
JCImageProcess	getImageProcess()	NON-DTFJ For internal building purposes only.
String	getInternalID()	NON-DTFJ For internal building purposes only.
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.
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.
Iterator	getThreads()	Get the set of Java threads known by the VM
Object	getTraceBuffer(String arg0, boolean arg1)	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.
boolean	isJITEnabled()	Determine if the JIT was enabled for this Java runtime.
void	setJITEnabled(boolean enabled)
void	setStartTime(long startTime)
void	setStartTimeNanos(long nanoTime)
void	setVersion(String version)	NON-DTFJ For internal building purposes only.

Methods declared in class java.lang.Object

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

Methods declared in interface com.ibm.dtfj.java.JavaRuntime

equals, getSystemProperty, hashCode

Constructor Details

JCJavaRuntime

public JCJavaRuntime(JCImageProcess imageProcess,
 String id)
              throws JCInvalidArgumentsException

Throws:

JCInvalidArgumentsException

Method Details

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:

• JavaRuntime.getCompiledMethods()

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:

• JavaRuntime.getHeaps()

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:

• JavaRuntime.getJavaClassLoaders()

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:

• JavaRuntime.getMonitors()

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:

• JavaRuntime.getThreads()

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

See Also:

• JavaRuntime.getJavaVMInitArgs()

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

See Also:

• JavaRuntime.getJavaVM()

getTraceBuffer

public Object getTraceBuffer(String arg0,
 boolean arg1)
                      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:

arg0 - a String naming the buffer to be fetched

arg1 - 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

See Also:

• invalid reference

  com.ibm.dtfj.java.JavaRuntime#getTraceBuffer()

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.getFullVersion()

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

See Also:

• ManagedRuntime.getVersion()

getInternalID

public String getInternalID()

NON-DTFJ
For internal building purposes only. Do not call outside the DTFJ implementation.

May be used in multiple runtime environments, where each runtime in a javacore is identified uniquely. This method is generally just used during the building process only.

addJavaClassLoader

public void addJavaClassLoader(JCJavaClassLoader javaClassLoader)
                        throws JCInvalidArgumentsException

NON-DTFJ
For internal building purposes only. Do not call outside the DTFJ implementation.

Parameters:

javaClassLoader -

findJavaClassLoader

public JCJavaClassLoader findJavaClassLoader(long clLoaderID)

NON-DTFJ
For internal building purposes only. Do not call outside the DTFJ implementation.

Parameters:

javaClassLoaderName -

Returns:

javaclassloader if found or null

addMonitor

public void addMonitor(JCJavaMonitor monitor)
                throws JCInvalidArgumentsException

NON-DTFJ
For internal building purposes only. Do not call outside the DTFJ implementation.

Parameters:

monitor - must not be null

findMonitor

public JCJavaMonitor findMonitor(long id)

NON-DTFJ
For internal building purposes only. Do not call outside the DTFJ implementation.

Parameters:

id -

Returns:

found java monitor or null

addJavaThread

public void addJavaThread(JCJavaThread javaThread)
                   throws JCInvalidArgumentsException

NON-DTFJ
For internal building purposes only. Do not call outside the DTFJ implementation.

Parameters:

javaThread - must not be null.

findJavaThread

public JCJavaThread findJavaThread(long threadID)

NON-DTFJ
For internal building purposes only. Do not call outside the DTFJ implementation.

In most cases, the threadID is the tid in a javacore, but in some other occasions, the id passed could be the system_thread_id or even the native thread. If a java thread is not found via tid, see if it can be found indirectly by an image thread that may be associated with the java thread (the image thread has a system thread ID as well as a native thread ID).

Parameters:

threadID - usually, tid in a javacore, may be id of some other internal vm datastructure.

Returns:

found java thread or null.

getImageProcess

public JCImageProcess getImageProcess()

NON-DTFJ
For internal building purposes only. Do not call outside the DTFJ implementation.

Returns:

image process containing this java runtime. This should never be null.

addJavaClass

public void addJavaClass(JCJavaClass javaClass)
                  throws JCInvalidArgumentsException

NON-DTFJ
For internal building purposes only. Do not call outside the DTFJ implementation.

Two separate maps are kept for classes. One based on class ID, the other based on class name. Both are used for lookups while building the runtime object. When a valid javaclass is added, it gets added at least the name-based map, and may be added to the ID-based map if the ID is available. The class name of the java class is a requirement, so this field must be set in the java class being passed.

Parameters:

javaClass - must not be null or exception thrown

findJavaClass

public JCJavaClass findJavaClass(String javaClassName)

NON-DTFJ
For internal building purposes only. Do not call outside the DTFJ implementation.

Parameters:

javaClassName -

Returns:

found class or null if not found

findJavaClass

public JCJavaClass findJavaClass(long id)

NON-DTFJ
For internal building purposes only. Do not call outside the DTFJ implementation.

In some cases, all that is available is a class ID, so it should be possible to retrieve a class based on just an ID.

Parameters:

id - class address

Returns:

found class or null if not found

addJavaVMInitArgs

public void addJavaVMInitArgs(JCJavaVMInitArgs args)
                       throws JCInvalidArgumentsException

NON-DTFJ
For internal building purposes only. Do not call outside the DTFJ implementation.

Parameters:

args - , must not be null

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 DataUnavailable

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:

DataUnavailable - if any data needed to build the returned instance of JavaObject is not available.

See Also:

• JavaObject

setVersion

public void setVersion(String version)

NON-DTFJ
For internal building purposes only. Do not call outside the DTFJ implementation.

Parameters:

args - , the version string

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

addTopLevelMemoryCategory

public void addTopLevelMemoryCategory(JCJavaRuntimeMemoryCategory category)

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

setJITEnabled

public void setJITEnabled(boolean enabled)

addJITProperty

public void addJITProperty(String name,
 String value)

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

setStartTime

public void setStartTime(long startTime)

setStartTimeNanos

public void setStartTimeNanos(long nanoTime)