SequentialConsistency_StoreBuffer.java

package io.github.lantalex.mm;

import org.openjdk.jcstress.annotations.Actor;
import org.openjdk.jcstress.annotations.JCStressTest;
import org.openjdk.jcstress.annotations.Outcome;
import org.openjdk.jcstress.annotations.State;
import org.openjdk.jcstress.infra.results.II_Result;

import static org.openjdk.jcstress.annotations.Expect.ACCEPTABLE;
import static org.openjdk.jcstress.annotations.Expect.FORBIDDEN;


@JCStressTest
@Outcome(id = "0, 0", expect = FORBIDDEN, desc = "Violation of SC")
@Outcome(expect = ACCEPTABLE, desc = "SC consistent")
@State
public class SequentialConsistency_StoreBuffer {

    /*

        How to run:
        $ ./gradlew clean jcstress --tests  "io.github.lantalex.mm.SequentialConsistency_StoreBuffer"

        Results(x86):
        ----------------------------------------------------------------
          RESULT      SAMPLES     FREQ      EXPECT  DESCRIPTION
            0, 0            0    0.00%   Forbidden  Violation of SC
            0, 1  312,336,405   25.64%  Acceptable  SC consistent
            1, 0  876,763,622   71.98%  Acceptable  SC consistent
            1, 1   28,982,941    2.38%  Acceptable  SC consistent


        Results(arm_v8):
        ----------------------------------------------------------------
          RESULT     SAMPLES     FREQ      EXPECT  DESCRIPTION
            0, 0           0    0.00%   Forbidden  Violation of SC
            0, 1  22,429,382   47.01%  Acceptable  SC consistent
            1, 0  19,432,120   40.73%  Acceptable  SC consistent
            1, 1   5,850,906   12.26%  Acceptable  SC consistent

     */

    volatile int a = 0;
    volatile int b = 0;

    @Actor
    public final void cpu1(II_Result r) {
        a = 1;
        r.r2 = b;
    }

    @Actor
    public final void cpu2(II_Result r) {
        b = 1;
        r.r1 = a;
    }
}