added VectorSum

cuda-java/VectorSum.java

+//package com.sun.jna.examples;
+
+import com.sun.jna.Library;
+import com.sun.jna.Native;
+import com.sun.jna.Platform;
+
+/** Simple example of JNA interface mapping and usage. */
+public class VectorSum {
+
+    // This is the standard, stable way of mapping, which supports extensive
+    // customization and mapping of Java to native types.
+
+    public interface CLibrary extends Library {
+        CLibrary INSTANCE = (CLibrary)
+            Native.loadLibrary((Platform.isWindows() ? "msvcrt" : "c"),
+                               CLibrary.class);
+
+        void native_vector_sum(Pointer host_a,Pointer host_b, unsigned n_elements);
+    }
+
+    public static void main(String[] args) {
+
+	CLibrary cuda_lib = (CLibrary)Native.loadLibrary("libvectorsum", CLibrary.class);
+	
+	// Memory allocates a contiguous block of memory suitable for sharing with C directly - no copying is necessary
+	Pointer vec_a = new Memory(100 * Native.getNativeSize(Float.TYPE));
+	Pointer vec_b = new Memory(100 * Native.getNativeSize(Float.TYPE));
+
+	// note: Memory instance (and its associated memory allocation) will be freed when ex8p goes out of scope
+	for (int dloop=0; dloop<100; dloop++) {
+	    // populate the array with junk data (just for the sake of the example)
+	    vec_a.setFloat(dloop * Native.getNativeSize(Float.TYPE), 11);
+	    vec_b.setFloat(dloop * Native.getNativeSize(Float.TYPE), 2);
+	}
+	// call the C function
+	double add = clib.native_vector_sum(vec_a,vec_b, 100);
+
+	//check the result
+	Double sum = 0;
+	for (int dloop=0; dloop<100; dloop++) {
+	    sum += vec_a[dloop];
+	}
+
+	System.out.println("sum of 100*13 =  " + sum);
+	
+    }
+}
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