org.jikesrvm.runtime
Class StackTrace

java.lang.Object
  org.jikesrvm.runtime.StackTrace

public class StackTrace
extends Object

A list of compiled method and instructionOffset pairs that describe the state of the call stack at a particular instant.

compiledMethods

private final int[] compiledMethods

The compiled method ids of the stack trace. Ordered with the top of the stack at 0 and the bottom of the stack at the end of the array

instructionOffsets

private final int[] instructionOffsets

The offset of the instruction within the compiled method

lastTraceIndex

private static int lastTraceIndex

Index of the last stack trace; only used to support VM.VerboseStackTracePeriod

StackTrace

public StackTrace()

Create a trace for the call stack of RVMThread.getThreadForStackTrace (normally the current thread unless we're in GC)

countFramesNoGC

private int countFramesNoGC(RVMThread stackTraceThread)

Walk the stack counting the number of stack frames encountered. The stack being walked isn't our stack so GC must be disabled.

Returns:

number of stack frames encountered

recordFramesNoGC

private void recordFramesNoGC(RVMThread stackTraceThread)

Walk the stack recording the stack frames encountered. The stack being walked isn't our stack so GC must be disabled.

countFramesUninterruptible

private int countFramesUninterruptible(RVMThread stackTraceThread)

Walk the stack counting the number of stack frames encountered. The stack being walked is our stack, so code is Uninterrupible to stop the stack moving.

Returns:

number of stack frames encountered

recordFramesUninterruptible

private void recordFramesUninterruptible(RVMThread stackTraceThread)

Walk the stack recording the stack frames encountered The stack being walked is our stack, so code is Uninterrupible to stop the stack moving.

getCompiledMethod

private CompiledMethod getCompiledMethod(int element)

Get the compiled method at element

getStackTrace

public StackTrace.Element[] getStackTrace(Throwable cause)

Return the stack trace for use by the Throwable API

countFrames

private int countFrames(int first,
                        int last)

Count number of stack frames including those inlined by the opt compiler

Parameters:

first - the first compiled method to look from

last - the last compiled method to look to

firstRealMethod

private int firstRealMethod(Throwable cause)

Find the first non-VM method/exception initializer method in the stack trace. As we're working with the compiled methods we're assumig the constructor of the exception won't have been inlined into the throwing method.

Parameters:

cause - the cause of generating the stack trace marking the end of the frames to elide

Returns:

the index of the method throwing the exception or else 0

lastRealMethod

private int lastRealMethod(int first)

Find the first non-VM method at the end of the stack trace

Parameters:

first - the first real method of the stack trace

Returns:

compiledMethods.length-1 if no non-VM methods found else the index of the method