added put/setNullArg(int size) for setting NULL ranges as kernel argu…

…ment to CLKernel.

added missing flush() to CLCommandQueue.
added CLMemory.getCapacity() utility method.

src/com/mbien/opencl/CLCommandQueue.java

@@ -989,6 +989,15 @@ public CLCommandQueue finish() {
         return this;
     }
 
+    /**
+     * Calls {@native clFlush}.
+     */
+    public CLCommandQueue flush() {
+        int ret = cl.clFlush(ID);
+        checkForError(ret, "can not flush command queue");
+        return this;
+    }
+
     /**
      * Returns true only when {@link Mode#PROFILING_MODE} has been enabled.
      */

src/com/mbien/opencl/CLKernel.java

@@ -82,6 +82,11 @@ public CLKernel putArg(double value) {
         return this;
     }
 
+    public CLKernel putNullArg(int size) {
+        setNullArg(argIndex++, size);
+        return this;
+    }
+
     public CLKernel putArgs(CLMemory<?>... values) {
         setArgs(argIndex, values);
         argIndex += values.length;
@@ -126,6 +131,11 @@ public CLKernel setArg(int argumentIndex, double value) {
         return this;
     }
 
+    public CLKernel setNullArg(int argumentIndex, int size) {
+        setArgument(argumentIndex, size, null);
+        return this;
+    }
+
     public CLKernel setArgs(CLMemory<?>... values) {
         setArgs(0, values);
         return this;

src/com/mbien/opencl/CLMemory.java

@@ -76,7 +76,17 @@ public B getBuffer() {
     }
 
     /**
-     * Returns the size of the wrapped direct buffer in byte.
+     * Returns the capacity of the wrapped direct buffer or 0 if no buffer available.
+     */
+    public int getCapacity() {
+        if(buffer == null) {
+            return 0;
+        }
+        return buffer.capacity();
+    }
+
+    /**
+     * Returns the size of the wrapped direct buffer in byte or 0 if no buffer available.
      */
     public int getSize() {
         if(buffer == null) {