JSS 3.1.2

org.mozilla.jss.util
Class NativeProxy

java.lang.Object
  |
  +--org.mozilla.jss.util.NativeProxy
Direct Known Subclasses:
CertProxy, CipherContextProxy, KeyProxy, ModuleProxy, PK12TokenProxy, SigContextProxy, SocketProxy, TokenProxy

public abstract class NativeProxy
extends java.lang.Object

NativeProxy, a superclass for Java classes that mirror C data structures. It contains some code to help make sure that native memory is getting freed properly.


Field Summary
(package private) static java.util.Random indexGenerator
           
private  byte[] mPointer
          Byte array containing native pointer bytes.
(package private) static java.util.Hashtable registry
           
private  long registryIndex
          Native Proxy Registry
 
Constructor Summary
private NativeProxy()
          Default constructor.
  NativeProxy(byte[] pointer)
          Create a NativeProxy from a byte array representing a C pointer.
 
Method Summary
(package private) static void ()
           
static void assertRegistryEmpty()
          Assert that the Registry is empty.
 boolean equals(java.lang.Object obj)
          Deep comparison operator.
protected  void finalize()
          Finalize this NativeProxy by releasing its native resources.
 long getRegistryIndex()
           
static java.util.Enumeration getRegistryIndices()
           
private static long register()
          Register a NativeProxy instance.
protected abstract  void releaseNativeResources()
          Release the native resources used by this proxy.
private static void unregister(long index)
          Unregister a NativeProxy instance.
 
Methods inherited from class java.lang.Object
clone, getClass, hashCode, notify, notifyAll, registerNatives, toString, wait, wait, wait
 

Field Detail

mPointer

private byte[] mPointer
Byte array containing native pointer bytes.

registryIndex

private long registryIndex

Native Proxy Registry

In debug mode, we keep track of all NativeProxy objects in a static registry. Whenever a NativeProxy is constructed, it registers. Whenever it finalizes, it unregisters. At the end of the game, we should be able to garbage collect and then assert that the registry is empty. This could be done, for example, in the jssjava JVM after main() completes. This registration process verifies that people are calling NativeProxy.finalize() from their subclasses of NativeProxy, so that releaseNativeResources() gets called.


registry

static java.util.Hashtable registry

indexGenerator

static java.util.Random indexGenerator
Constructor Detail

NativeProxy

private NativeProxy()
Default constructor. Should not be called.

NativeProxy

public NativeProxy(byte[] pointer)
Create a NativeProxy from a byte array representing a C pointer. This is the only way to create a NativeProxy, it should be called from the constructor of your subclass.
Parameters:
pointer - A byte array, created with JSS_ptrToByteArray, that contains a pointer pointing to a native data structure. The NativeProxy instance acts as a proxy for that native data structure.
Method Detail

equals

public boolean equals(java.lang.Object obj)
Deep comparison operator.
Overrides:
equals in class java.lang.Object
Returns:
true if obj has the same underlying native pointer. false if the obj is null or has a different underlying native pointer.

releaseNativeResources

protected abstract void releaseNativeResources()
Release the native resources used by this proxy. Subclasses of NativeProxy must define this method to clean up data structures in C code that are referenced by this proxy. releaseNativeResources() will usually be implemented as a native method.

You don't call this method; NativeProxy.finalize() calls it for you.

You must declare a finalize() method which calls super.finalize().


finalize

protected void finalize()
                 throws java.lang.Throwable
Finalize this NativeProxy by releasing its native resources. The finalizer calls releaseNativeResources() so you don't have to. This finalizer should be called from the finalize() method of all subclasses: class MyProxy extends NativeProxy { [...] protected void finalize() throws Throwable { // do any object-specific finalization other than // releasing native resources [...] super.finalize(); } }
Overrides:
finalize in class java.lang.Object

static void ()

register

private static long register()
Register a NativeProxy instance.
Returns:
The unique index of this object in the registry.

unregister

private static void unregister(long index)
Unregister a NativeProxy instance.
Parameters:
index - The index of this object in the registry, as returned from the previous call to register().

getRegistryIndices

public static java.util.Enumeration getRegistryIndices()
Returns:
A list of the indices in the registry. Each element is a Long.
See Also:
getRegistryIndex()

getRegistryIndex

public long getRegistryIndex()
Returns:
The index of this NativeProxy in the NativeProxy registry.
See Also:
getRegistryIndices()

assertRegistryEmpty

public static void assertRegistryEmpty()
Assert that the Registry is empty. Only works in debug mode; in ship mode, it is a no-op. If the Registry is not empty when this is called, an assertion (org.mozilla.jss.util.AssertionException) is thrown.

JSS 3.1.2