Package org.mozilla.jss.util

Class NativeProxy

  • All Implemented Interfaces:
    java.lang.AutoCloseable
    Direct Known Subclasses:
    BufferProxy, GlobalRefProxy, PRFDProxy, StaticVoidPointer, TokenProxy
    public abstract class NativeProxy
extends java.lang.Object
implements java.lang.AutoCloseable
    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

      Fields 
      Modifier and Type Field Description
      static org.slf4j.Logger logger  

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
        NativeProxy​(byte[] pointer)
      Create a NativeProxy from a byte array representing a C pointer.
      protected NativeProxy​(byte[] pointer, boolean track)
      Create a NativeProxy from a byte array representing a C pointer.

    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      static void assertRegistryEmpty()
      Assert that the Registry is empty.
      void clear()
      Call clear(...) to clear the value of the pointer, setting it to null.
      void close()
      Close this NativeProxy by releasing its native resources if they haven't otherwise been freed.
      boolean equals​(java.lang.Object obj)
      Deep comparison operator.
      protected void finalize()
      Deprecated.
      finalize() in Object has been deprecated.
      int hashCode()
      Hash code based around mPointer value.
      boolean isNull()
      Whether or not this is a null pointer.
      static void purgeAllInRegistry()
      Unsafe: Purges all NativeProxies from memory.
      protected abstract void releaseNativeResources()
      Release the native resources used by this proxy.
      java.lang.String toString()  

      • Methods inherited from class java.lang.Object

        clone, getClass, notify, notifyAll, wait, wait, wait

    • Field Detail

      • logger

        public static org.slf4j.Logger logger

    • Constructor Detail

      • NativeProxy

        public NativeProxy​(byte[] pointer)
        Create a NativeProxy from a byte array representing a C pointer. This is the primary way of creating 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.

      • NativeProxy

        protected NativeProxy​(byte[] pointer,
                      boolean track)
        Create a NativeProxy from a byte array representing a C pointer. This allows for creating an untracked NativeProxy instance (when track=false), which allows for creating NativeProxy instances out of stack-allocated variables and/or creating NativeProxies which aren't freed.

    • 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.

      • hashCode

        public int hashCode()
        Hash code based around mPointer value. Note that Object.hashCode() isn't sufficient as it tries to determine the Object's value based on all internal variables. Because we want a single static hashCode that is unique to each instance of nativeProxy, we construct it up front based on an incrementing counter and cache it throughout the lifetime of this object.
        Overrides:
        hashCode in class java.lang.Object

      • releaseNativeResources

        protected abstract void releaseNativeResources()
                                        throws java.lang.Exception
        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() or close() calls it for you.

        If you free these resources explicitly, call clear(); instead.
        Throws:
        java.lang.Exception

      • finalize

        @Deprecated
protected void finalize()
                 throws java.lang.Throwable
        Deprecated.
        finalize() in Object has been deprecated. Use close(...) from the AutoCloseable interface instead.
        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
        Throws:
        java.lang.Throwable

      • close

        public final void close()
                 throws java.lang.Exception
        Close this NativeProxy by releasing its native resources if they haven't otherwise been freed. See comment in finalize.
        Specified by:
        close in interface java.lang.AutoCloseable
        Throws:
        java.lang.Exception

      • clear

        public final void clear()
        Call clear(...) to clear the value of the pointer, setting it to null. This should be used when the pointer has been freed by another means. Similar to finalize(...) or close(...), except that it doesn't call releaseNativeResources(...). See also: JSS_clearPtrFromProxy(...) in jssutil.h

      • isNull

        public boolean isNull()
        Whether or not this is a null pointer.

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • 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.

      • purgeAllInRegistry

        public static void purgeAllInRegistry()
                               throws java.lang.Exception
        Unsafe: Purges all NativeProxies from memory. In the rare instances where we wish to shutdown an existing CryptoManager, all native proxies need to be cleared and freed. This will result in any lingering references to stop working, but should ensure that an application can recover from this scenario.
        Throws:
        java.lang.Exception