Bug 1303

Reported in thread http://forum.jogamp.org/How-to-retain-a-CLBuffer-possibly-calling-clRetainMemObject-td4036615.html#a4036637

Desired usage example:

try {
CLProgram program = context.createProgram(Resize.class.getResourceAsStream("/kernels.cl")).build(); 

CLKernel kernel1 = program.createCLKernel("kernel1"); 
CLKernel kernel2 = program.createCLKernel("kernel2"); 

CLCommandQueue queue = device.createCommandQueue(); 
try { 
    CLBuffer<IntBuffer> clBuffer = context.createIntBuffer(samples.length, Mem.READ_WRITE); 
    clBuffer.registerDestructorCallback(new DebugRelease("clBuffer")); 

    CLBuffer<IntBuffer> clBufferResult = context.createIntBuffer(samples.length, Mem.READ_WRITE); 
    clBufferResult.registerDestructorCallback(new DebugRelease("clBufferResult")); 

    clBuffer.getBuffer().put(samples).flip(); 
                                
    try { 
        // I would expect the following to be possible calling 
        // clRetainMemObject on 
        //clBuffer.retain(); 

        queue.putWriteBuffer(clBuffer, true); 
                                        
        kernel1.rewind().putArg(clBuffer).putArg(clBufferResult).putArg(samples.length); 
        globalWidth=samples.length; 
        queue.put1DRangeKernel(kernel1, 0, globalWidth, workGroupWidth); 
        queue.putReadBuffer(clBufferResult, true); 
                                        
        //Ideally this line should not be needed 
        queue.putReadBuffer(clBuffer, true); 
        IntBuffer intBuffer = clBufferResult.getBuffer(); 

        // ....process results from first kernel 
                                        
        clBufferResult.release(); 
                                        
        //Ideally this line should not be needed 
        //clBuffer.release(); 
                                        
        //ShortBuffer tempBuffer = (ShortBuffer) clBuffer.getBuffer().rewind(); 
        //clBuffer = context.createShortBuffer(samples.length, Mem.READ_WRITE); 
        //clBuffer.getBuffer().put(tempBuffer).rewind(); 
        //queue.putWriteBuffer(clBuffer, true); 

        //... do work on host here 
                                        
        kernel2.rewind().putArg(clBuffer).putArg(samples.length); 
        queue.put1DRangeKernel(kernel2, 0, globalWidth, workGroupWidth); 
        queue.putReadBuffer(clBuffer, true); 

        // ...use result 
    } finally { 
        //release the buffer we retained earlier 
        clBuffer.release(); 
    } 
} finally {
    queue.release(); 
} 
} finally { 
    context.release(); 
}