Module openj9.dtfj
Package com.ibm.j9ddr.vm29.pointer.helper

Class ValueTypeHelper

java.lang.Object
com.ibm.j9ddr.vm29.pointer.helper.ValueTypeHelper
public class ValueTypeHelper extends Object
Value type helper class areValueTypesSupported() must return true before using any other methods in this class

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected static final Logger
    logger
     

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    areValueTypesSupported()
    Queries if the JVM that produced the core file supports value types.
    boolean
    classRequires4BytePrePadding(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz)
    Queries if class is has 4byte pre-padding in the stand-alone case
    com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer
    findJ9ClassInFlattenedClassCacheWithFieldName(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz, String fieldName)
    Searches the flattenedClassCache (FCC) for a J9Class given a field name.
    com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer
    findJ9ClassInFlattenedClassCacheWithSigName(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz, String fieldSig)
    Searches the flattenedClassCache (FCC) for a J9Class given a field signature.
    com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer[]
    findNestedClassHierarchy(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer containerClazz, String[] nestingHierarchy)
    Returns an array of J9ClassPointers that contains the containerClazz passed in addition to the J9ClassPointers that correspond to the types of the field names passed in the nestingHierarchy array.
    static ValueTypeHelper
    getValueTypeHelper()
    Factory method that returns a valueTypeHelper instance.
    boolean
    isFieldInClassFlattened(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz, com.ibm.j9ddr.vm29.pointer.generated.J9ROMFieldShapePointer fieldShape)
    Queries whether field is flattened of not.
    boolean
    isFlattenableFieldSignature(String signature)
    Queries if field signature is flattenable
    boolean
    isJ9ClassAValueType(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz)
    Queries if J9Class is a value type
    boolean
    isJ9ClassIsFlattened(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz)
    Queries if class is flattened
    boolean
    isJ9ClassLargestAlignmentConstraintDouble(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz)
    Queries if class contains a field with a double (64 bit) alignment constraint
    boolean
    isJ9ClassLargestAlignmentConstraintReference(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz)
    Queries if class contains a field with a reference alignment constraint
    boolean
    isJ9FieldIsFlattened(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer fieldClazz, com.ibm.j9ddr.vm29.pointer.generated.J9ROMFieldShapePointer fieldShape)
    Queries if a field in a class is flattened
    boolean
    isRomClassAValueType(com.ibm.j9ddr.vm29.pointer.generated.J9ROMClassPointer romClass)
    Queries if J9ROMClass is a value type

    Methods declared in class java.lang.Object

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

  • Field Details

    • logger

      protected static final Logger logger

  • Method Details

    • getValueTypeHelper

      public static ValueTypeHelper getValueTypeHelper()
      Factory method that returns a valueTypeHelper instance.
      Returns:
      valueTypeHelper

    • areValueTypesSupported

      public boolean areValueTypesSupported()
      Queries if the JVM that produced the core file supports value types. This must be called before any other ValueTypeHelper functions are called.
      Returns:
      true if value types are supported, false otherwise

    • findJ9ClassInFlattenedClassCacheWithFieldName

      public com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer findJ9ClassInFlattenedClassCacheWithFieldName(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz, String fieldName) throws CorruptDataException
      Searches the flattenedClassCache (FCC) for a J9Class given a field name. areValueTypesSupported() must return true before using this method.
      Parameters:
      clazz - J9Class pointer that owns the FCC to be searched
      fieldName - name of the field to lookup in the FCC
      Returns:
      J9Class of the fieldName if found, J9ClassPointer.NULL otherwise
      Throws:
      CorruptDataException

    • findNestedClassHierarchy

      public com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer[] findNestedClassHierarchy(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer containerClazz, String[] nestingHierarchy) throws CorruptDataException
      Returns an array of J9ClassPointers that contains the containerClazz passed in addition to the J9ClassPointers that correspond to the types of the field names passed in the nestingHierarchy array. Each subsequent field name in the nestingHierarchy array is a nested field of the previous element. For example nestingHierarchy[1] is a member of nestingHierarchy[0], and nestingHierarchy[2] is a member of nestingHierarchy[1]. nestingHierarchy[0] is the first nested member in the containerClazz. The resulting array contains at least one element (containerClazz). areValueTypesSupported() must return true before using this method.
      Parameters:
      containerClazz - type that contains all the nested members
      nestingHierarchy - array that contains field names for nested members. Must be non-NULL
      Returns:
      an array containing at least the containerClazz, and J9ClassPointer's corresponding to the names passed in the nestingHierarchy
      Throws:
      CorruptDataException

    • findJ9ClassInFlattenedClassCacheWithSigName

      public com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer findJ9ClassInFlattenedClassCacheWithSigName(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz, String fieldSig) throws CorruptDataException
      Searches the flattenedClassCache (FCC) for a J9Class given a field signature. areValueTypesSupported() must return true before using this method.
      Parameters:
      clazz - J9Class pointer that owns the FCC to be searched
      fieldSig - signature to lookup in the FCC
      Returns:
      J9ClassPointer corresponding to the signature if found, J9ClassPointer.NULL otherwise
      Throws:
      CorruptDataException

    • isRomClassAValueType

      public boolean isRomClassAValueType(com.ibm.j9ddr.vm29.pointer.generated.J9ROMClassPointer romClass) throws CorruptDataException
      Queries if J9ROMClass is a value type
      Parameters:
      romClass - clazz to query
      Returns:
      true if romClass is a value type, false otherwise
      Throws:
      CorruptDataException

    • isJ9ClassAValueType

      public boolean isJ9ClassAValueType(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz) throws CorruptDataException
      Queries if J9Class is a value type
      Parameters:
      clazz - clazz to query
      Returns:
      true if class is a value type, false otherwise
      Throws:
      CorruptDataException

    • isFieldInClassFlattened

      public boolean isFieldInClassFlattened(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz, com.ibm.j9ddr.vm29.pointer.generated.J9ROMFieldShapePointer fieldShape) throws CorruptDataException
      Queries whether field is flattened of not.
      Parameters:
      clazz - clazz containing the field
      fieldShape - J9ROMFieldShapePointer
      Returns:
      true if field is flattened, false otherwise
      Throws:
      CorruptDataException

    • isFlattenableFieldSignature

      public boolean isFlattenableFieldSignature(String signature)
      Queries if field signature is flattenable
      Parameters:
      signature - field signature
      Returns:
      true if field signature is flattenable, false otherwise

    • isJ9ClassLargestAlignmentConstraintDouble

      public boolean isJ9ClassLargestAlignmentConstraintDouble(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz) throws CorruptDataException
      Queries if class contains a field with a double (64 bit) alignment constraint
      Parameters:
      clazz - J9Class
      Returns:
      true if clazz has double alignment constraint, false otherwise
      Throws:
      CorruptDataException

    • isJ9ClassLargestAlignmentConstraintReference

      public boolean isJ9ClassLargestAlignmentConstraintReference(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz) throws CorruptDataException
      Queries if class contains a field with a reference alignment constraint
      Parameters:
      clazz - J9Class
      Returns:
      true if clazz has reference alignment constraint, false otherwise
      Throws:
      CorruptDataException

    • isJ9ClassIsFlattened

      public boolean isJ9ClassIsFlattened(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz) throws CorruptDataException
      Queries if class is flattened
      Parameters:
      clazz - J9Class
      Returns:
      true if clazz is flattened, false otherwise
      Throws:
      CorruptDataException

    • isJ9FieldIsFlattened

      public boolean isJ9FieldIsFlattened(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer fieldClazz, com.ibm.j9ddr.vm29.pointer.generated.J9ROMFieldShapePointer fieldShape) throws CorruptDataException
      Queries if a field in a class is flattened
      Parameters:
      fieldClazz - J9Class of the field
      fieldShape - J9ROMFieldShapePointer
      Returns:
      true if the field is flattened, false otherwise
      Throws:
      CorruptDataException

    • classRequires4BytePrePadding

      public boolean classRequires4BytePrePadding(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz) throws CorruptDataException
      Queries if class is has 4byte pre-padding in the stand-alone case
      Parameters:
      clazz - J9Class
      Returns:
      true if clazz is requires pre-padding, false otherwise
      Throws:
      CorruptDataException