org.jikesrvm.mm.mmtk

Class Statistics

java.lang.Object

org.mmtk.vm.Statistics

org.jikesrvm.mm.mmtk.Statistics

public final class Statistics
extends Statistics

Field Summary

Fields

Modifier and Type	Field and Description
private PerfEvent[]	perfEvents

Constructor Summary

Constructors

Constructor and Description
Statistics()

Method Summary

Modifier and Type	Method and Description
long	cycles() Read a cycle counter (high resolution, non-monotonic clock).
long	millisToNanos(double t) Converts milliseconds to nanoseconds
double	nanosToMillis(long c) Converts nanoseconds to milliseconds
double	nanosToSecs(long c) Converts nanoseconds to seconds
long	nanoTime() Read nanoTime (high resolution, monotonically increasing clock).
void	perfEventInit(String events) Initializes performance events.
void	perfEventRead(int id, long[] values) Reads a performance event value.
long	secsToNanos(double t) Convert seconds to nanoseconds

Methods inherited from class java.lang.Object

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

Field Detail

perfEvents

private PerfEvent[] perfEvents

Constructor Detail

Statistics

public Statistics()

Method Detail

nanoTime

public long nanoTime()

Read nanoTime (high resolution, monotonically increasing clock). Has same semantics as java.lang.System.nanoTime().

Specified by:

nanoTime in class Statistics

Returns:

current time in nanoseconds

cycles

public long cycles()

Read a cycle counter (high resolution, non-monotonic clock). This method should be used with care as the cycle counters (especially on IA32 SMP machines) are not a reliably time source.

Specified by:

cycles in class Statistics

Returns:

number of cycles

nanosToMillis

public double nanosToMillis(long c)

Description copied from class: Statistics

Converts nanoseconds to milliseconds

Specified by:

nanosToMillis in class Statistics

Parameters:

c - time in nanoseconds

Returns:

time in milliseconds

nanosToSecs

public double nanosToSecs(long c)

Description copied from class: Statistics

Converts nanoseconds to seconds

Specified by:

nanosToSecs in class Statistics

Parameters:

c - time in nanoseconds

Returns:

time in seconds

millisToNanos

public long millisToNanos(double t)

Description copied from class: Statistics

Converts milliseconds to nanoseconds

Specified by:

millisToNanos in class Statistics

Parameters:

t - time in milliseconds

Returns:

time in nanoseconds

secsToNanos

public long secsToNanos(double t)

Description copied from class: Statistics

Convert seconds to nanoseconds

Specified by:

secsToNanos in class Statistics

Parameters:

t - time in seconds

Returns:

time in nanoseconds

perfEventInit

public void perfEventInit(String events)

Description copied from class: Statistics

Initializes performance events.

Specified by:

perfEventInit in class Statistics

Parameters:

events - the events to initialize. This is a comma-separated list of event names.

perfEventRead

public void perfEventRead(int id,
                          long[] values)

Description copied from class: Statistics

Reads a performance event value.

Specified by:

perfEventRead in class Statistics

Parameters:

id - the event's id

values - a buffer that will hold the return values of the read (3 64-bit values).