TestOpenCLDataTransfers.java

import com.nativelibs4java.opencl.*;

import org.bridj.*;
import static org.bridj.Pointer.*;

/*
Put these lines in `build.sbt`, and run with `sbt ~run`:

fork := true

libraryDependencies += "com.nativelibs4java" % "javacl" % "1.0.0-RC3"
*/
public class TestOpenCLDataTransfers {
  public static void main(String[] args) {
		int n = args.length == 1 ? Integer.parseInt(args[0]) : 100000;
		for (CLPlatform platform : JavaCL.listPlatforms()) {
		  System.out.println("# Platform " + platform);
		  for (CLDevice device : platform.listAllDevices(true)) {
		    System.out.println("# CLDevice " + device);
        CLContext context = JavaCL.createContext(null, device);
        CLQueue queue = context.createDefaultQueue();
        CLBuffer<Integer> buffer = context.createIntBuffer(CLMem.Usage.InputOutput, n);
        Pointer<Integer> p = allocateInts(n);
        p.set(10);
        
        for (int j = 0; j < 10; j++) {
          int times = 10;
          double timeMap, timeBlockingWrite, timeNonBlockingWrite;
          {
            long start = System.nanoTime();
            for (int i = 0; i < times; i++) {
              Pointer<Integer> pBuffer = buffer.map(queue, CLMem.MapFlags.Write);
              p.copyTo(pBuffer);
              buffer.unmap(queue, pBuffer, (CLEvent[])null);
              queue.finish();
            }
            long time = System.nanoTime() - start;
            timeMap = time / 1000000.0;
          }
          queue.finish();
        
          {
            long start = System.nanoTime();
            for (int i = 0; i < times; i++) {
              buffer.write(queue, p, true, (CLEvent[])null);
              //queue.finish();
            }
            long time = System.nanoTime() - start;
            timeBlockingWrite = time / 1000000.0;
          }
          queue.finish();
        
          {
            long start = System.nanoTime();
            for (int i = 0; i < times; i++) {
              buffer.write(queue, p, false, (CLEvent[])null);
              queue.finish();
            }
            long time = System.nanoTime() - start;
            timeNonBlockingWrite = time / 1000000.0;
          }
          queue.finish();
          
          System.out.println("Time millis [ map / blocking write / non-blocking write ]:");
          System.out.println("\t" + timeMap + " / " + timeBlockingWrite + " / " + timeNonBlockingWrite);
        }
      } 
    }
	}
}