JnaAffinityTest.java

/*
 * Copyright 2016 higherfrequencytrading.com
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package software.chronicle.enterprise.internals;

import net.openhft.affinity.IAffinity;
import net.openhft.affinity.impl.LinuxJNAAffinity;
import net.openhft.affinity.impl.Utilities;
import org.junit.After;
import org.junit.Assume;
import org.junit.BeforeClass;
import org.junit.Test;

import java.util.BitSet;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

/**
 * @author peter.lawrey
 */
public class JnaAffinityTest {
    protected static final int CORES = Runtime.getRuntime().availableProcessors();
    protected static final BitSet CORES_MASK = new BitSet(CORES);

    static {
        CORES_MASK.set(0, CORES, true);
    }

    @BeforeClass
    public static void checkJniLibraryPresent() {
        Assume.assumeTrue(LinuxJNAAffinity.LOADED);
    }

    @Test
    public void getAffinityCompletesGracefully() {
        System.out.println("affinity: " + Utilities.toBinaryString(getImpl().getAffinity()));
    }

    @Test
    public void getAffinityReturnsValidValue() {
        final BitSet affinity = getImpl().getAffinity();
        assertTrue(
                "Affinity mask " + Utilities.toBinaryString(affinity) + " must be non-empty",
                !affinity.isEmpty()
        );
        final int allCoresMask = (1 << CORES) - 1;
        assertTrue(
                "Affinity mask " + Utilities.toBinaryString(affinity) + " must be <=(2^" + CORES + "-1 = " + allCoresMask + ")",
                affinity.length() <= CORES_MASK.length()
        );
    }

    @Test
    public void setAffinityCompletesGracefully() {
        BitSet affinity = new BitSet(1);
        affinity.set(0, true);
        getImpl().setAffinity(affinity);
    }

    @Test
    public void getAffinityReturnsValuePreviouslySet() {
        String osName = System.getProperty("os.name");
        if (!osName.startsWith("Linux")) {
            System.out.println("Skipping Linux tests");
            return;
        }
        final IAffinity impl = LinuxJNAAffinity.INSTANCE;
        final int cores = CORES;
        for (int core = 0; core < cores; core++) {
            final BitSet mask = new BitSet();
            mask.set(core, true);
            getAffinityReturnsValuePreviouslySet(impl, mask);
        }
    }


    @Test
    public void showOtherIds() {
        System.out.println("processId: " + LinuxJNAAffinity.INSTANCE.getProcessId());
        System.out.println("threadId: " + LinuxJNAAffinity.INSTANCE.getThreadId());
        System.out.println("cpu: " + LinuxJNAAffinity.INSTANCE.getCpu());
    }

    private void getAffinityReturnsValuePreviouslySet(final IAffinity impl,
                                                      final BitSet mask) {

        impl.setAffinity(mask);
        final BitSet _mask = impl.getAffinity();
        assertEquals(mask, _mask);
    }

    @After
    public void tearDown() {
        getImpl().setAffinity(CORES_MASK);
    }

    public IAffinity getImpl() {
        return LinuxJNAAffinity.INSTANCE;
    }
}