ClojureRuntimeBenchmark.java

package org.immutant.core;

import org.immutant.runtime.ClojureRuntime;
import org.junit.Test;

import clojure.lang.RT;
import clojure.lang.Var;

public class ClojureRuntimeBenchmark {
    int calls = 1000000;

    @Test
    public void benchmark() {
        //warmup
        direct( false );
        runtime( false );
        
        System.gc();
        direct( true );
        System.gc();
        runtime( true );
    }

    void direct( boolean print ) {
        Var v = RT.var("clojure.core", "str");

        long t1 = System.nanoTime();
        for( int i = 0; i < this.calls; i++ ) {
            v.invoke( "a", "silly", "benchmark" );
        }

        if ( print ) {
            printResults( t1, System.nanoTime(), "RT.var.invoke" );
        }
    }

    void runtime( boolean print ) {
        ClojureRuntime rt = ClojureRuntime.newRuntime( ClojureRuntime.class.getClassLoader(), "foo" );

        long t1 = System.nanoTime();
        for( int i = 0; i < this.calls; i++ ) {
            rt.invoke( "clojure.core/str", "a", "silly", "benchmark" );
        }

        if ( print ) {
            printResults( t1, System.nanoTime(), "ClojureRuntime.invoke" );
        }
    }

    void printResults(long t1, long t2, String label) {
       System.out.println(">>>> " + label + ": Execution time for " + this.calls + " calls: " + 
                          ((t2 - t1) * 1e-6) + "ms (" +
                          ((t2 - t1) / calls) + "ns/call)" );
    }
}