jnr.ffi.byref
Class NativeLongByReference

java.lang.Object
  java.lang.Number
      jnr.ffi.byref.AbstractNumberReference<NativeLong>
          jnr.ffi.byref.NativeLongByReference

All Implemented Interfaces:

Serializable, ByReference<NativeLong>

public final class NativeLongByReference
extends AbstractNumberReference<NativeLong>

NativeLongByReference is used when the address of a primitive C long must be passed as a parameter to a function.

For example, the following C code,

 extern void get_a(long * ap);

 long foo(void) {
     long a;
     // pass a reference to 'a' so get_a() can fill it out
     get_a(&a);

     return a;
 }
 
 

Would be declared in java as

 interface Lib {
     void get_a(@Out NativeLongByReference ap);
 }
 
 

and used like this

 NativeLongByReference ap = new NativeLongByReference();
 lib.get_a(ap);
 System.out.printf("a from lib=%d\n", a.longValue());
 

See Also:

Serialized Form

Constructor Summary

NativeLongByReference()
Creates a new reference to a native long value initialized to zero.

NativeLongByReference(long value)
Creates a new reference to a native long value

NativeLongByReference(NativeLong value)
Creates a new reference to a native long value

Method Summary

void	marshal(Pointer memory, long offset) Copies the long value to native memory
int	nativeSize(Runtime runtime) Gets the native size of type of reference in bytes.
void	unmarshal(Pointer memory, long offset) Copies the long value from native memory

Methods inherited from class jnr.ffi.byref.AbstractNumberReference

byteValue, checkNull, doubleValue, floatValue, getValue, intValue, longValue, shortValue

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

NativeLongByReference

public NativeLongByReference()

Creates a new reference to a native long value initialized to zero.

NativeLongByReference

public NativeLongByReference(NativeLong value)

Creates a new reference to a native long value

Parameters:

value - the initial native value

NativeLongByReference

public NativeLongByReference(long value)

Creates a new reference to a native long value

Parameters:

value - the initial native value

Method Detail

marshal

public void marshal(Pointer memory,
                    long offset)

Copies the long value to native memory

Parameters:

memory - the native memory buffer

unmarshal

public void unmarshal(Pointer memory,
                      long offset)

Copies the long value from native memory

Parameters:

memory - the native memory buffer.

nativeSize

public final int nativeSize(Runtime runtime)

Gets the native size of type of reference in bytes.

Returns:

the size of a byte in bytes