Manages a linked list of general purpose Object-attributes that can be attached to arbitrary org.python.core.PyObjects. This method replaces the formerly used method of maintaining weak hash-maps (java.util.WeakHashMap) for such cases. These weak hash-maps were used to map PyObjects to such attributes, for instance to attach org.python.modules._weakref.GlobalRef-objects in the org.python.modules._weakref.WeakrefModule.

Attributes attached via the weak hash-map-method break, if the PyObject is resurrected in its finalizer. The JyAttribute-method is resurrection-safe.

To reduce memory footprint of PyObjects, the fields for org.python.core.finalization.FinalizeTriggers and javaProxy are included in the list; javaProxy always on top so there is no speed-regression, org.python.core.finalization.FinalizeTrigger on bottom, as it is usually never accessed.

Nested and Inner Type Summary

Modifier and Type	Class and Description
pack-priv static class	JyAttribute.AttributeLink
pack-priv static class	JyAttribute.TransientAttributeLink

Field Summary

Modifier and Type	Field and Description
pack-priv byte	attr_type
public static final byte	FINALIZE_TRIGGER_ATTR
public static final byte	GC_CYCLE_MARK_ATTR Used by `org.python.modules.gc`-module to mark cyclic trash.
public static final byte	GC_DELAYED_FINALIZE_CRITICAL_MARK_ATTR Used by `org.python.modules.gc`-module to mark finalizable objects that might have been resurrected during a delayed finalization process.
public static final byte	JAVA_PROXY_ATTR
public static final byte	JYNI_HANDLE_ATTR Reserved for use by JyNI.
private static byte	nonBuiltinAttrTypeOffset
private static byte	nonBuiltinTransientAttrTypeOffset
public static final byte	PY_ID_ATTR Allows the id of a `org.python.core.PyObject` to persist resurrection of that object.
public static final byte	PYCLASS_PY2JY_CACHE_ATTR Only used internally by `Py#javaPyClass(PyObject, Class)`
public static final byte	WEAK_REF_ATTR Stores list of weak references linking to this `PyObject`.
public static final byte	WEAKREF_PENDING_GET_ATTR Holds the current thread for an `org.python.modules._weakref.AbstractReference` while referent-retrieval is pending due to a potentially restored-by-resurrection weak reference.

Access	Constructor and Description
protected	JyAttribute(byte attr_type)

Method Summary

Modifier and Type	Method and Description
public static void	debugPrintAttributes(PyObject o, PrintStream out) Prints the current state of the attribute-list of the given object to the given stream.
public static void	delAttr(PyObject ob, byte attr_type) Removes the attribute of given type from the given object's attribute-list (if it existed at all).
public static Object	getAttr(PyObject ob, byte attr_type) Retrieves the attribute of the given type from the given `org.python.core.PyObject`.
protected abstract JyAttribute	getNext()
protected abstract Object	getValue()
public static boolean	hasAttr(PyObject ob, byte attr_type) Checks whether the given `org.python.core.PyObject` has an attribute of the given type attached.
public static byte	Returns: a non-transient attr type for custom use reserveCustomAttrType() Reserves and returns a new non-transient attr type for custom use.
public static byte	Returns: a transient attr type for custom use reserveTransientCustomAttrType() Reserves and returns a new transient attr type for custom use.
public static void	setAttr(PyObject ob, byte attr_type, Object value) Sets the attribute of type `attr_type` in `ob` to `value`.
protected abstract void	setNext(JyAttribute next)
protected abstract void	setValue(Object value)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

attr_type	back to summary
pack-priv byte attr_type

FINALIZE_TRIGGER_ATTR	back to summary
public static final byte FINALIZE_TRIGGER_ATTR

GC_CYCLE_MARK_ATTR	back to summary
public static final byte GC_CYCLE_MARK_ATTR Used by `org.python.modules.gc`-module to mark cyclic trash. Searching for cyclic trash is usually not required by Jython. It is only done if gc-features are enabled that mimic CPython behavior.

GC_DELAYED_FINALIZE_CRITICAL_MARK_ATTR	back to summary
public static final byte GC_DELAYED_FINALIZE_CRITICAL_MARK_ATTR Used by `org.python.modules.gc`-module to mark finalizable objects that might have been resurrected during a delayed finalization process.

JAVA_PROXY_ATTR	back to summary
public static final byte JAVA_PROXY_ATTR

JYNI_HANDLE_ATTR	back to summary
public static final byte JYNI_HANDLE_ATTR Reserved for use by JyNI.

nonBuiltinAttrTypeOffset	back to summary
private static byte nonBuiltinAttrTypeOffset

nonBuiltinTransientAttrTypeOffset	back to summary
private static byte nonBuiltinTransientAttrTypeOffset

PY_ID_ATTR	back to summary
public static final byte PY_ID_ATTR Allows the id of a `org.python.core.PyObject` to persist resurrection of that object.

PYCLASS_PY2JY_CACHE_ATTR	back to summary
public static final byte PYCLASS_PY2JY_CACHE_ATTR Only used internally by `Py#javaPyClass(PyObject, Class)`

WEAK_REF_ATTR	back to summary
public static final byte WEAK_REF_ATTR Stores list of weak references linking to this `PyObject`. This list is weakref-based, so it does not keep the weakrefs alive. This is the only way to find out which weakrefs (i.e. `org.python.modules._weakref.AbstractReference`) linked to the object after a resurrection. A weak hash-map-based approach for this purpose would break on resurrection.

WEAKREF_PENDING_GET_ATTR	back to summary
public static final byte WEAKREF_PENDING_GET_ATTR Holds the current thread for an `org.python.modules._weakref.AbstractReference` while referent-retrieval is pending due to a potentially restored-by-resurrection weak reference. After the restore has happened or the clear was confirmed, the thread is interrupted and the attribute is cleared.

Constructor Detail

JyAttribute	back to summary
protected JyAttribute(byte attr_type)

Method Detail

debugPrintAttributes	back to summary
public static void debugPrintAttributes(PyObject o, PrintStream out) Prints the current state of the attribute-list of the given object to the given stream. (Intended for debugging)

delAttr	back to summary
public static void delAttr(PyObject ob, byte attr_type) Removes the attribute of given type from the given object's attribute-list (if it existed at all). This is equivalent to calling `setAttr(ob, attr_type, null)`.

getAttr	back to summary
public static Object getAttr(PyObject ob, byte attr_type) Retrieves the attribute of the given type from the given `org.python.core.PyObject`. If no attribute of the given type is attached, null is returned.

getNext	back to summary
protected abstract JyAttribute getNext()

getValue	back to summary
protected abstract Object getValue()

hasAttr	back to summary
public static boolean hasAttr(PyObject ob, byte attr_type) Checks whether the given `org.python.core.PyObject` has an attribute of the given type attached.

reserveCustomAttrType	back to summary
public static byte reserveCustomAttrType() Reserves and returns a new non-transient attr type for custom use. Returns:byte a non-transient attr type for custom use

reserveCustomAttrType

back to summary

public static byte reserveCustomAttrType()

Reserves and returns a new non-transient attr type for custom use.

Returns:byte: a non-transient attr type for custom use

reserveTransientCustomAttrType	back to summary
public static byte reserveTransientCustomAttrType() Reserves and returns a new transient attr type for custom use. Returns:byte a transient attr type for custom use

reserveTransientCustomAttrType

back to summary

public static byte reserveTransientCustomAttrType()

Reserves and returns a new transient attr type for custom use.

Returns:byte: a transient attr type for custom use

setAttr	back to summary
public static void setAttr(PyObject ob, byte attr_type, Object value) Sets the attribute of type `attr_type` in `ob` to `value`. If no corresponding attribute exists yet, one is created. If `value == null`, the attribute is removed (if it existed at all).

setNext	back to summary
protected abstract void setNext(JyAttribute next)

setValue	back to summary
protected abstract void setValue(Object value)

org.python.core back to summary

pack-priv Class JyAttribute.AttributeLink

Class Inheritance

extends JyAttribute

java.lang.Object
org.python.core.JyAttribute
org.python.core.JyAttribute.AttributeLink

Field Summary

Modifier and Type	Field and Description
pack-priv JyAttribute	next
pack-priv Object	value

Inherited from org.python.core.JyAttribute:: attr_type FINALIZE_TRIGGER_ATTR GC_CYCLE_MARK_ATTR GC_DELAYED_FINALIZE_CRITICAL_MARK_ATTR JAVA_PROXY_ATTR JYNI_HANDLE_ATTR PY_ID_ATTR PYCLASS_PY2JY_CACHE_ATTR WEAK_REF_ATTR WEAKREF_PENDING_GET_ATTR

Constructor Summary

Access	Constructor and Description
protected	AttributeLink(byte attr_type, Object value)

Method Summary

Modifier and Type	Method and Description
protected JyAttribute	getNext() Implements abstract org.python.core.JyAttribute.getNext.
protected Object	getValue() Implements abstract org.python.core.JyAttribute.getValue.
protected void	setNext(JyAttribute next) Implements abstract org.python.core.JyAttribute.setNext.
protected void	setValue(Object value) Implements abstract org.python.core.JyAttribute.setValue.

Inherited from org.python.core.JyAttribute:: debugPrintAttributes delAttr getAttr hasAttr reserveCustomAttrType reserveTransientCustomAttrType setAttr

Field Detail

next	back to summary
pack-priv JyAttribute next

value	back to summary
pack-priv Object value

Constructor Detail

AttributeLink	back to summary
protected AttributeLink(byte attr_type, Object value)

Method Detail

getNext	back to summary
protected JyAttribute getNext() Implements abstract org.python.core.JyAttribute.getNext. Annotations @Override

getNext

back to summary

protected JyAttribute getNext()

Implements abstract org.python.core.JyAttribute.getNext.

Annotations

@Override

getValue	back to summary
protected Object getValue() Implements abstract org.python.core.JyAttribute.getValue. Annotations @Override

getValue

back to summary

protected Object getValue()

Implements abstract org.python.core.JyAttribute.getValue.

Annotations

@Override

setNext	back to summary
protected void setNext(JyAttribute next) Implements abstract org.python.core.JyAttribute.setNext. Annotations @Override

setNext

back to summary

protected void setNext(JyAttribute next)

Implements abstract org.python.core.JyAttribute.setNext.

Annotations

@Override

setValue	back to summary
protected void setValue(Object value) Implements abstract org.python.core.JyAttribute.setValue. Annotations @Override

setValue

back to summary

protected void setValue(Object value)

Implements abstract org.python.core.JyAttribute.setValue.

Annotations

@Override

org.python.core back to summary

pack-priv Class JyAttribute.TransientAttributeLink

Class Inheritance

extends JyAttribute

java.lang.Object
org.python.core.JyAttribute
org.python.core.JyAttribute.TransientAttributeLink

Field Summary

Modifier and Type	Field and Description
pack-priv transient JyAttribute	next
pack-priv transient Object	value

Inherited from org.python.core.JyAttribute:: attr_type FINALIZE_TRIGGER_ATTR GC_CYCLE_MARK_ATTR GC_DELAYED_FINALIZE_CRITICAL_MARK_ATTR JAVA_PROXY_ATTR JYNI_HANDLE_ATTR PY_ID_ATTR PYCLASS_PY2JY_CACHE_ATTR WEAK_REF_ATTR WEAKREF_PENDING_GET_ATTR

Constructor Summary

Access	Constructor and Description
protected	TransientAttributeLink(byte attr_type, Object value)

Method Summary

Modifier and Type	Method and Description
protected JyAttribute	getNext() Implements abstract org.python.core.JyAttribute.getNext.
protected Object	getValue() Implements abstract org.python.core.JyAttribute.getValue.
protected void	setNext(JyAttribute next) Implements abstract org.python.core.JyAttribute.setNext.
protected void	setValue(Object value) Implements abstract org.python.core.JyAttribute.setValue.