Java Oop类代码示例

import sun.jvm.hotspot.oops.Oop; //导入依赖的package包/类
public List threads() {
    // Each element of this array is the Oop for a thread;
    // NOTE it is not the JavaThread that we need to create
    // a ThreadReferenceImpl.
    Oop[] myThreads = OopUtilities.threadGroupOopGetThreads(ref());

    ArrayList myList = new ArrayList(myThreads.length);
    for (int ii = 0; ii < myThreads.length; ii++) {
        JavaThread jt = OopUtilities.threadOopGetJavaThread(myThreads[ii]);
        if (jt != null) {
            ThreadReferenceImpl xx = (ThreadReferenceImpl)vm.threadMirror(jt);
            myList.add(xx);
        }
    }
    return myList;
}
 

import sun.jvm.hotspot.oops.Oop; //导入依赖的package包/类
/**
 * Walk backwards to find the start of the object at probeAddress, but don't walk past the bottom
 * of the live region.
 */
private Oop probeForObject(Address probeAddress, Address bottom) {
  OopHandle cur = probeAddress.andWithMask(~(heapWordSize - 1)).addOffsetToAsOopHandle(0);
  while (cur.greaterThanOrEqual(bottom)) {
    Oop oop = objectHeap.newOopIfPossible(cur, bottom);
    if (oop != null) {
      if (cur.addOffsetToAsOopHandle(oop.getObjectSize()).greaterThan(probeAddress)) {
        return oop; // original address was within the nearest object
      } else {
        // declare this a "miss" even though we might not have walked far enough, and we just
        // stumbled on some spurious data that looked like an Oop header, but the size is busted
        return null;
      }
    }
    cur = cur.addOffsetToAsOopHandle(-heapWordSize);
  }
  return null; // not found
}
 

import sun.jvm.hotspot.oops.Oop; //导入依赖的package包/类
public int compareTo(ReferenceType refType) {
    /*
     * Note that it is critical that compareTo() == 0
     * implies that equals() == true. Otherwise, TreeSet
     * will collapse classes.
     *
     * (Classes of the same name loaded by different class loaders
     * or in different VMs must not return 0).
     */
    ReferenceTypeImpl other = (ReferenceTypeImpl)refType;
    int comp = name().compareTo(other.name());
    if (comp == 0) {
        Oop rf1 = ref();
        Oop rf2 = other.ref();
        // optimize for typical case: refs equal and VMs equal
        if (rf1.equals(rf2)) {
            // sequenceNumbers are always positive
            comp = vm.sequenceNumber -
             ((VirtualMachineImpl)(other.virtualMachine())).sequenceNumber;
        } else {
            comp = rf1.getHandle().minus(rf2.getHandle()) < 0? -1 : 1;
        }
    }
    return comp;
}
 

import sun.jvm.hotspot.oops.Oop; //导入依赖的package包/类
@Override
public void run() {
    SystemDictionary dictionary = VM.getVM().getSystemDictionary();
    Klass klass = dictionary.find("java/security/PrivateKey", null, null);

    VM.getVM().getObjectHeap().iterateObjectsOfKlass(new DefaultHeapVisitor() {
        @Override
        public boolean doObj(Oop oop) {
            oop.iterate(new KeyPrinter(), false);
            return false;
        }
    }, klass);
}
 

import sun.jvm.hotspot.oops.Oop; //导入依赖的package包/类
void printOopValue(Oop oop) {
    if (oop != null) {
        Klass k = oop.getKlass();
        Symbol s = k.getName();
        if (s != null) {
            out.print("Oop for " + s.asString() + " @ ");
        } else {
            out.print("Oop @ ");
        }
        Oop.printOopAddressOn(oop, out);
    } else {
        out.print("null");
    }
}
 

import sun.jvm.hotspot.oops.Oop; //导入依赖的package包/类
public List instances(long maxInstances) {
    if (!vm.canGetInstanceInfo()) {
        throw new UnsupportedOperationException(
                  "target does not support getting instances");
    }

    if (maxInstances < 0) {
        throw new IllegalArgumentException("maxInstances is less than zero: "
                                          + maxInstances);
    }

    final List objects = new ArrayList(0);
    if (isAbstract() || (this instanceof InterfaceType)) {
        return objects;
    }

    final Klass givenKls = this.ref();
    final long max = maxInstances;
    vm.saObjectHeap().iterate(new DefaultHeapVisitor() {
            private long instCount=0;
            public boolean doObj(Oop oop) {
                if (givenKls.equals(oop.getKlass())) {
                    objects.add(vm.objectMirror(oop));
                                            instCount++;
                }
                if (max > 0 && instCount >= max) {
                    return true;
                                    }
                                    return false;
            }
        });
    return objects;
}
 

import sun.jvm.hotspot.oops.Oop; //导入依赖的package包/类
public List referringObjects(long maxReferrers) {
    if (!vm.canGetInstanceInfo()) {
        throw new UnsupportedOperationException(
                  "target does not support getting instances");
    }
    if (maxReferrers < 0) {
        throw new IllegalArgumentException("maxReferrers is less than zero: "
                                          + maxReferrers);
    }
    final ObjectReference obj = this;
    final List objects = new ArrayList(0);
    final long max = maxReferrers;
            vm.saObjectHeap().iterate(new DefaultHeapVisitor() {
            private long refCount = 0;
            public boolean doObj(Oop oop) {
                                    try {
                                            ObjectReference objref = vm.objectMirror(oop);
                                            List fields = objref.referenceType().allFields();
                                            for (int i=0; i < fields.size(); i++) {
                                                    Field fld = (Field)fields.get(i);
                                                    if (objref.getValue(fld).equals(obj) && !objects.contains(objref)) {
                                                            objects.add(objref);
                                                            refCount++;
                                                    }
                                            }
                                            if (max > 0 && refCount >= max) {
                                                    return true;
                                            }
                                    } catch  (RuntimeException x) {
                                      // Ignore RuntimeException thrown from vm.objectMirror(oop)
                                      // for bad oop. It is possible to see some bad oop
                                      // because heap might be iterating at no safepoint.
                                    }
                                    return false;

            }
        });
    return objects;
}
 

import sun.jvm.hotspot.oops.Oop; //导入依赖的package包/类
public List threadGroups() {
    Oop[] myGroups = OopUtilities.threadGroupOopGetGroups(ref());
    ArrayList myList = new ArrayList(myGroups.length);
    for (int ii = 0; ii < myGroups.length; ii++) {
        ThreadGroupReferenceImpl xx = (ThreadGroupReferenceImpl)vm.threadGroupMirror(
                                      (Instance)myGroups[ii]);
        myList.add(xx);

    }
    return myList;
}
 

import sun.jvm.hotspot.oops.Oop; //导入依赖的package包/类
public List/*<ObjectReference>*/ allObjects() {
    final List objects = new ArrayList(0);
    saObjectHeap.iterate(
        new DefaultHeapVisitor() {
            public boolean doObj(Oop oop) {
                objects.add(objectMirror(oop));
                                    return false;
            }
        });
    return objects;
}
 

import sun.jvm.hotspot.oops.Oop; //导入依赖的package包/类
private List/*<ObjectReference>*/ objectsByExactType(ReferenceType type) {
    final List objects = new ArrayList(0);
    final Klass givenKls = ((ReferenceTypeImpl)type).ref();
    saObjectHeap.iterate(new DefaultHeapVisitor() {
            public boolean doObj(Oop oop) {
                if (givenKls.equals(oop.getKlass())) {
                    objects.add(objectMirror(oop));
                }
                    return false;
            }
        });
    return objects;
}
 

import sun.jvm.hotspot.oops.Oop; //导入依赖的package包/类
private List/*<ObjectReference>*/ objectsBySubType(ReferenceType type) {
    final List objects = new ArrayList(0);
    final ReferenceType givenType = type;
    saObjectHeap.iterate(new DefaultHeapVisitor() {
            public boolean doObj(Oop oop) {
                ReferenceTypeImpl curType = (ReferenceTypeImpl) referenceType(oop.getKlass());
                if (curType.isAssignableTo(givenType)) {
                    objects.add(objectMirror(oop));
                }
                    return false;
            }
        });
    return objects;
}
 

import sun.jvm.hotspot.oops.Oop; //导入依赖的package包/类
protected void writeGlobalJNIHandle(Address handleAddr) throws IOException {
  OopHandle oopHandle = handleAddr.getOopHandleAt(0);
  Oop oop = objectHeap.newOop(oopHandle);
  // exclude JNI handles of hotspot internal objects
  if (oop != null && isJavaVisible(oop)) {
    out.writeByte((byte) HPROF_GC_ROOT_JNI_GLOBAL);
    writeObjectID(oop);
    // use JNIHandle address as ID
    writeObjectID(getAddressValue(handleAddr));
  }
}
 

import sun.jvm.hotspot.oops.Oop; //导入依赖的package包/类
private void addToGraph(Graph graph, Oop object) {
  Klass klass = object.getKlass();
  Node node = graph.nodes.get(klass.getAddress());
  if (node == null) {
    node = new Node();
    node.klass = klass;
    graph.nodes.put(klass.getAddress(), node);
  }
  node.hits++;
  node.size += object.getObjectSize();
}
 

import sun.jvm.hotspot.oops.Oop; //导入依赖的package包/类
@Override
public Oop newOop(OopHandle handle) {
  if (handle == null) {
    return null;
  }

  Address klassAddress;
  if (VM.getVM().isCompressedKlassPointersEnabled()) {
    klassAddress = handle.getCompKlassAddressAt(oopCompressedKlass.getOffset());
  } else {
    klassAddress = handle.getAddressAt(oopKlass.getOffset());
  }

  int layoutHelper = klassAddress.getJIntAt(klassLayoutHelper.getOffset());
  int tag = layoutHelper >> Klass.LH_ARRAY_TAG_SHIFT;

  if (tag == Klass.LH_ARRAY_TAG_OBJ_VALUE) {
    // object array
    Klass bottomKlass = getKlassAtAddress(objArrayBottomKlass.getValue(klassAddress));
    return new FastObjArray(handle, this, new FastObjArrayKlass(klassAddress, bottomKlass));
  } else if (tag == Klass.LH_ARRAY_TAG_TYPE_VALUE) {
    // primitive array
    return new FastTypeArray(handle, this, new TypeArrayKlass(klassAddress));
  } else {
    Symbol name = Symbol.create(klassAddress.getAddressAt(klassName.getOffset()));
    if (javaLangClass.equals(name)) {
      // instance of java.lang.Class, which has special handling for static members
      return new FastInstance(handle, this, new FastInstanceMirrorKlass(klassAddress));
    } else {
      // instance of anything else. we don't handle InstanceRefKlass or InstanceClassLoaderKlass
      // because they contain no extra logic
      return new FastInstance(handle, this, new FastInstanceKlass(klassAddress));
    }
  }
}
 

import sun.jvm.hotspot.oops.Oop; //导入依赖的package包/类
public Klass getKlassForClass(Oop instanceOfJavaLangClass) {
  Address address = instanceOfJavaLangClass.getHandle().getAddressAt(oopKlassOffset);
  if (address == null) {
    return null;
  }
  return getKlassAtAddress(address);
}