de.uni_hildesheim.sse.monitoring.runtime.recording

Class Lock

java.lang.Object

de.uni_hildesheim.sse.monitoring.runtime.recording.Lock

public class Lock
extends java.lang.Object

Provides a simple global locking mechanism for the entire instrumenter / SPASS-meter. As memory allocation is currently the most pressing performance problem, this class just focuses on enabling or disabling memory as an accountable resource. However, at the moment this class performs a mapping between string and numeric identifiers. This shall be propagated through the framework in future versions.

Since:

1.00

Version:

1.00

Author:

Holger Eichelberger

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	Lock.GroupInfo Descriptive information about a monitoring group.
private static class	Lock.MemRecordingType Defines basic memory recording types for executing the allocation recording.

Field Summary

Fields

Modifier and Type	Field and Description
private static int	nextId Stores the next numeric id.
private static HashMap<java.lang.String,Lock.GroupInfo>	REGISTERED_GROUPS Stores the registered monitoring groups (name-shall memory be monitored).
private static IntHashMap<java.lang.String>	REGISTERED_IDS Stores the reverse mapping from REGISTERED_GROUPS.
(package private) static LongRecordingStackHashMap	THREAD_STACKS Stores the memory resource monitoring flag for the individual threads in terms of stacks.

Constructor Summary

Constructors

Modifier	Constructor and Description
private	Lock() Prevents this class from being instantiated from outside.

Method Summary

Modifier and Type	Method and Description
(package private) static java.lang.String	getRecorderId(int id) Returns the recorder id for the given (internal) numeric id.
static long	isStackTopMemoryAccounting(long threadId) Returns whether the top element on the stack enables memory accounting.
(package private) static void	popFromStack(long threadId, java.lang.String recId) Pops the latest element from the stack.
(package private) static void	pushToStack(long threadId, java.lang.String recId) Pushes a recording group via its recId to the execution stack of threadId.
static void	registerGroup(java.lang.String className, java.lang.String recId, MonitoringGroupConfiguration conf) Registers a monitoring group.
static void	setStackTopMemoryAccounting(long threadId, long account) Changes whether memory shall be accounted for the top element of the execution stack of a thread.

Methods inherited from class java.lang.Object

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

Field Detail

THREAD_STACKS

static final LongRecordingStackHashMap THREAD_STACKS

Stores the memory resource monitoring flag for the individual threads in terms of stacks. This could also be handled via ThreadLocals but this would introduce instrumented classes of lower performance here.

REGISTERED_GROUPS

private static final HashMap<java.lang.String,Lock.GroupInfo> REGISTERED_GROUPS

Stores the registered monitoring groups (name-shall memory be monitored).

REGISTERED_IDS

private static final IntHashMap<java.lang.String> REGISTERED_IDS

Stores the reverse mapping from REGISTERED_GROUPS.

nextId

private static int nextId

Stores the next numeric id.

Constructor Detail

Lock

private Lock()

Prevents this class from being instantiated from outside.

Since:

1.00

Method Detail

registerGroup

public static final void registerGroup(java.lang.String className,
                                       java.lang.String recId,
                                       MonitoringGroupConfiguration conf)

Registers a monitoring group.

Parameters:

className - the name of the class being monitored.

recId - the recording identification

conf - the monitoring configuration

Since:

1.00

isStackTopMemoryAccounting

public static final long isStackTopMemoryAccounting(long threadId)

Returns whether the top element on the stack enables memory accounting. As a side effect, this method disables memory accounting for the top element (lock). Memory accounting needs to be enabled explicitly using setStackTopMemoryAccounting(long, long).

Parameters:

threadId - the thread identification

Returns:

the current value, negative if disabled

Since:

1.00

setStackTopMemoryAccounting

public static final void setStackTopMemoryAccounting(long threadId,
                                                     long account)

Changes whether memory shall be accounted for the top element of the execution stack of a thread.

Parameters:

threadId - the thread identification

account - the current value, negative if disabled

Since:

1.00

pushToStack

static final void pushToStack(long threadId,
                              java.lang.String recId)

Pushes a recording group via its recId to the execution stack of threadId.

Parameters:

threadId - the thread identification

recId - the recording identification according to which the monitoring configuration can be determined

Since:

1.00

popFromStack

static final void popFromStack(long threadId,
                               java.lang.String recId)

Pops the latest element from the stack.

Parameters:

threadId - the thread identification

recId - the recording identification which shall be on the top of the stack (currently just checked whether the recording identification is not null)

Since:

1.00

getRecorderId

static final java.lang.String getRecorderId(int id)

Returns the recorder id for the given (internal) numeric id.

Parameters:

id - the numeric id

Returns:

the recorder id (may be null)

Since:

1.00