comptr.java

用于Java 组件和通过Windows COM 对象或Windows DLL 来公开的组件之间的互操作

//******************************************************************
// Released under the DevelopMentor OpenSource Software License.
// Please consult the LICENSE file in the project root directory,
// or at http://www.develop.com for details before using this
// software.
//******************************************************************

package com.develop.jawin;

import com.develop.jawin.marshal.GenericStub;
import java.io.*;

abstract public class COMPtr implements IUnknown {
  /**
   * GIT cookie
   */
  private int peer;
  /** 
   * raw, context specific vtable ptr   */
  private int unknown;

  void setPeer(int peer) {
    if (this.peer != 0) throw new COMError("peer already exists");
    this.peer = peer;
    if (peer != 0) {
      Identity i = IdentityManager.IncRef(peer);
    }
  }
  void setUnknown(int unknown) {
    if (this.unknown != 0) throw new COMError("unknown already exists");
    this.unknown = unknown;
  }
  protected COMPtr() {
  }
  /**
   * Only the IdentityManager creates COMPtrs
   */ 
  protected COMPtr(int peer, int unk) {
    this.peer = peer;
    this.unknown = unk;
  }
  
  /**
   * Steal the native unknown pointer from another COMPtr. This should 
   * only be used inside the marshalling layer when manipulating temporaries
   */
  protected void stealUnknown(COMPtr src) {
    setUnknown(src.unknown);
    src.unknown = 0;
    if (IdentityManager.traceRefs) {
      System.out.println(this + " assigned reference");
    }
  }

  public byte[] comInvoke(int vtable, String instructions, int stackSize, int arraySize, byte[] argStream) 
    throws COMException, IOException
  {
    return GenericStub.comInvokeString(instructions, stackSize, arraySize, argStream, null, vtable, getGuidToken(), peer, unknown);
  }

  protected void copyUnknown(COMPtr src) {
    setUnknown(src.unknown);
    int count = Bootstrap.directCOM(src.unknown, 1);
    if (IdentityManager.traceRefs) {
      System.out.println(this + " AddRef = " + count);
    }
  }

  public String toString() {
    return getClass().getName() + "[" + Integer.toHexString(peer)+","+Integer.toHexString(unknown)+"]";
  }
  public synchronized int getPeer() {
    return peer;
  }
  public synchronized int getUnknown() {
    return unknown;
  }
  public synchronized IUnknown queryInterface(Class newItf) {
    return IdentityManager.queryInterface(newItf, this);
  }

  protected void finalize() {
    if (unknown != 0) {
      if (IdentityManager.traceRefs) {
	System.err.println("****Failed to release reference to " + this);
      }
    }
    synchronized (this) {
      if (peer != 0) {
	IdentityManager.DecRef(peer);
	peer = 0;
      }
    }
  }

  public synchronized void close() {
    releaseUnknown();
    if (peer != 0) {
      IdentityManager.DecRef(peer);
      peer = 0;
    }
  }
  
  /**
   * call only from a synchronized method
   */
  private void releaseUnknown() {
    if (unknown != 0) {
      int count = Bootstrap.directCOM(unknown, 2);
      if (IdentityManager.traceRefs) {
        System.out.println(this + " Release = " + count);
      }
    }
    unknown = 0;
  }

}