FULL PRODUCT VERSION :
java version "1.5.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-b64)
Java HotSpot(TM) Client VM (build 1.5.0-b64, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Linux pawelp 2.4.25-1-386 #2 Wed Apr 14 19:38:08 EST 2004 i686

EXTRA RELEVANT SYSTEM CONFIGURATION :
P4 2.7
512 MB Ram
32 MB Video Card

A DESCRIPTION OF THE PROBLEM :
I implement the MyCanvas example of the Jawt native interface.

This allows me to draw in c++ directly on the java canvas.

When I run the code on java 1.5 the "lock = ds->Lock(ds);"
does not lock the draw surface and throughs an "JAWT_LOCK_ERROR"
Exception.

The code does run on java 1.4.2 with out an exception.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Compile the c++ code to generate a .o file.
2. Link library to make a libtest.so.
3. Compile Java Code.
4. set LD_LIBRARY_PATH to include libtest.so.
5. Run java Code.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
No errors are shown.
ACTUAL -
Exception is thrown that states "Error locking surface".

ERROR MESSAGES/STACK TRACES THAT OCCUR :
"Error locking surface".

The java Error is "JAWT_LOCK_ERROR".

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------

MyCanvas.c

---------------------------------

#include <jawt_md.h>
#include "MyCanvas.h"


JNIEXPORT void JNICALL Java_com_ads_mapping_MyCanvas_paint
(JNIEnv* env, jobject canvas, jobject graphics)
{
    JAWT awt;
    JAWT_DrawingSurface* ds;
    JAWT_DrawingSurfaceInfo* dsi;
    JAWT_X11DrawingSurfaceInfo* dsi_x11;
    jboolean result;
    jint lock;
    GC gc;

    /* Get the AWT */
    awt.version = JAWT_VERSION_1_4;
    if (JAWT_GetAWT(env, &awt) == JNI_FALSE) {
        printf("AWT Not found\n");
        return;
    }

    /* Get the drawing surface */
    ds = awt.GetDrawingSurface(env, canvas);
    if (ds == NULL) {
        printf("NULL drawing surface\n");
        return;
    }

    /* Lock the drawing surface */
    lock = ds->Lock(ds);
    if((lock & JAWT_LOCK_ERROR) != 0) {
        printf("Error locking surface\n");
awt.FreeDrawingSurface(ds);
        return;
    }

    /* Get the drawing surface info */
    dsi = ds->GetDrawingSurfaceInfo(ds);
    if (dsi == NULL) {
        printf("Error getting surface info\n");
        ds->Unlock(ds);
        awt.FreeDrawingSurface(ds);
        return;
    }

    /* Get the platform-specific drawing info */
    dsi_x11 = (JAWT_X11DrawingSurfaceInfo*)dsi->platformInfo;


    /* Now paint */


    /* End paint */

    /* Free the drawing surface info */
    ds->FreeDrawingSurfaceInfo(dsi);

    /* Unlock the drawing surface */
    ds->Unlock(ds);

    /* Free the drawing surface */
    awt.FreeDrawingSurface(ds);

}

------------------------------------

MyCanvas.h

------------------------------------

#include <jni.h>
#include <map>
/* Header for class MyCanvas */

#ifndef _Included_MyCanvas
#define _Included_MyCanvas
#ifdef __cplusplus
extern "C" {
#endif

/*
 * Class: MyCanvas
 * Method: paint
 * Signature: (Ljava/awt/Graphics;)V
 */

JNIEXPORT void JNICALL Java_com_ads_mapping_MyCanvas_paint
(JNIEnv* env, jobject canvas, jobject graphics);

#ifdef __cplusplus
}
#endif
#endif

------------------------------------

MyCanvas.java

import java.awt.*;
import java.awt.event.*;

public class MyCanvas extends Canvas {
    static {
        System.loadLibrary("test");
    }
    public native void paint(Graphics g);

    public static void main(String[] args) {
        Frame f = new Frame();
        f.setBounds(0, 0, 500, 110);
        f.add( new MyCanvas() );
        f.addWindowListener( new WindowAdapter() {
            public void windowClosing(WindowEvent ev) {
                System.exit(0);
            }
        } );
        f.show();
    }
}
---------- END SOURCE ----------

Release Regression From : 1.4.2
The above release value was the last known release where this
bug was known to work. Since then there has been a regression.
###@###.### 2004-12-07 00:53:24 GMT