Package jnr.ffi.byref

Class IntByReference

All Implemented Interfaces:
Serializable, ByReference<Integer>

public final class IntByReference extends AbstractNumberReference<Integer>
IntByReference is used when the address of a primitive int must be passed as a parameter to a function.

For example, the following C code,

 
 extern void get_a(int * ap);

 int foo(void) {
     int 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 IntByReference ap);
 }
 
 

and used like this

 IntByReference ap = new IntByReference();
 lib.get_a(ap);
 System.out.printf("a from lib=%d\n", a.intValue());
 
See Also:
  • Constructor Details

    • IntByReference

      public IntByReference()
      Creates a new reference to an integer value initialized to zero.
    • IntByReference

      public IntByReference(Integer value)
      Creates a new reference to an integer value
      Parameters:
      value - the initial native value
    • IntByReference

      public IntByReference(int value)
      Creates a new reference to an integer value
      Parameters:
      value - the initial native value
  • Method Details

    • toNative

      public void toNative(Runtime runtime, Pointer buffer, long offset)
      Copies the integer value to native memory
      Parameters:
      runtime - the current runtime.
      buffer - the native memory buffer.
      offset - the memory offset.
    • fromNative

      public void fromNative(Runtime runtime, Pointer buffer, long offset)
      Copies the integer value from native memory
      Parameters:
      runtime - the current runtime.
      buffer - the native memory buffer.
      offset - the memory offset.
    • nativeSize

      public int nativeSize(Runtime runtime)
      Gets the native size of type of reference
      Parameters:
      runtime - The current runtime.
      Returns:
      Integer.SIZE