TestOnSpinWaitAArch64.java

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/**
 * @test TestOnSpinWaitAArch64
 * @summary Checks that java.lang.Thread.onSpinWait is intrinsified with instructions specified with '-XX:OnSpinWaitInst' and '-XX:OnSpinWaitInstCount'
 * @bug 8186670
 * @library /test/lib
 *
 * @requires vm.flagless
 * @requires os.arch=="aarch64"
 *
 * @run driver compiler.onSpinWait.TestOnSpinWaitAArch64 c2 nop 7
 * @run driver compiler.onSpinWait.TestOnSpinWaitAArch64 c2 isb 3
 * @run driver compiler.onSpinWait.TestOnSpinWaitAArch64 c2 yield 1
 * @run driver compiler.onSpinWait.TestOnSpinWaitAArch64 c1 nop 7
 * @run driver compiler.onSpinWait.TestOnSpinWaitAArch64 c1 isb 3
 * @run driver compiler.onSpinWait.TestOnSpinWaitAArch64 c1 yield
 */

package compiler.onSpinWait;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.ListIterator;
import jdk.test.lib.process.OutputAnalyzer;
import jdk.test.lib.process.ProcessTools;

public class TestOnSpinWaitAArch64 {
    public static void main(String[] args) throws Exception {
        String compiler = args[0];
        String spinWaitInst = args[1];
        String spinWaitInstCount = (args.length == 3) ? args[2] : "1";
        ArrayList<String> command = new ArrayList<String>();
        command.add("-XX:+IgnoreUnrecognizedVMOptions");
        command.add("-showversion");
        command.add("-XX:-BackgroundCompilation");
        command.add("-XX:+UnlockDiagnosticVMOptions");
        command.add("-XX:+PrintAssembly");
        if (compiler.equals("c2")) {
            command.add("-XX:-TieredCompilation");
        } else if (compiler.equals("c1")) {
            command.add("-XX:+TieredCompilation");
            command.add("-XX:TieredStopAtLevel=1");
        } else {
            throw new RuntimeException("Unknown compiler: " + compiler);
        }
        command.add("-Xbatch");
        command.add("-XX:OnSpinWaitInst=" + spinWaitInst);
        command.add("-XX:OnSpinWaitInstCount=" + spinWaitInstCount);
        command.add("-XX:CompileCommand=compileonly," + Launcher.class.getName() + "::" + "test");
        command.add(Launcher.class.getName());

        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(command);

        OutputAnalyzer analyzer = new OutputAnalyzer(pb.start());

        analyzer.shouldHaveExitValue(0);

        System.out.println(analyzer.getOutput());

        checkOutput(analyzer, spinWaitInst, Integer.parseInt(spinWaitInstCount));
    }

    private static String getSpinWaitInstHex(String spinWaitInst) {
      if ("nop".equals(spinWaitInst)) {
          return "1f20 03d5";
      } else if ("isb".equals(spinWaitInst)) {
          return "df3f 03d5";
      } else if ("yield".equals(spinWaitInst)) {
          return "3f20 03d5";
      } else {
          throw new RuntimeException("Unknown spin wait instruction: " + spinWaitInst);
      }
    }

    private static void addInstrs(String line, ArrayList<String> instrs) {
        for (String instr : line.split("\\|")) {
            instrs.add(instr.trim());
        }
    }

    // The expected output of PrintAssembly for example for a spin wait with three NOPs:
    //
    // # {method} {0x0000ffff6ac00370} 'test' '()V' in 'compiler/onSpinWait/TestOnSpinWaitAArch64$Launcher'
    // #           [sp+0x40]  (sp of caller)
    // 0x0000ffff9d557680: 1f20 03d5 | e953 40d1 | 3f01 00f9 | ff03 01d1 | fd7b 03a9 | 1f20 03d5 | 1f20 03d5
    //
    // 0x0000ffff9d5576ac: ;*invokestatic onSpinWait {reexecute=0 rethrow=0 return_oop=0}
    //                     ; - compiler.onSpinWait.TestOnSpinWaitAArch64$Launcher::test@0 (line 161)
    // 0x0000ffff9d5576ac: 1f20 03d5 | fd7b 43a9 | ff03 0191
    //
    // The checkOutput method adds hex instructions before 'invokestatic onSpinWait' and from the line after
    // it to a list. The list is traversed from the end to count spin wait instructions.
    //
    // If JVM finds the hsdis library the output is like:
    //
    // # {method} {0x0000ffff63000370} 'test' '()V' in 'compiler/onSpinWait/TestOnSpinWaitAArch64$Launcher'
    // #           [sp+0x20]  (sp of caller)
    // 0x0000ffffa409da80:   nop
    // 0x0000ffffa409da84:   sub sp, sp, #0x20
    // 0x0000ffffa409da88:   stp x29, x30, [sp, #16]         ;*synchronization entry
    //                                                       ; - compiler.onSpinWait.TestOnSpinWaitAArch64$Launcher::test@-1 (line 187)
    // 0x0000ffffa409da8c:   nop
    // 0x0000ffffa409da90:   nop
    // 0x0000ffffa409da94:   nop
    // 0x0000ffffa409da98:   nop
    // 0x0000ffffa409da9c:   nop
    // 0x0000ffffa409daa0:   nop
    // 0x0000ffffa409daa4:   nop                                 ;*invokestatic onSpinWait {reexecute=0 rethrow=0 return_oop=0}
    //                                                           ; - compiler.onSpinWait.TestOnSpinWaitAArch64$Launcher::test@0 (line 187)
    private static void checkOutput(OutputAnalyzer output, String spinWaitInst, int spinWaitInstCount) {
        Iterator<String> iter = output.asLines().listIterator();

        String match = skipTo(iter, "'test' '()V' in 'compiler/onSpinWait/TestOnSpinWaitAArch64$Launcher'");
        if (match == null) {
            throw new RuntimeException("Missing compiler output for the method compiler.onSpinWait.TestOnSpinWaitAArch64$Launcher::test");
        }

        ArrayList<String> instrs = new ArrayList<String>();
        String line = null;
        boolean hasHexInstInOutput = false;
        while (iter.hasNext()) {
            line = iter.next();
            if (line.contains("*invokestatic onSpinWait")) {
                break;
            }
            if (!hasHexInstInOutput) {
                hasHexInstInOutput = line.contains("|");
            }
            if (line.contains("0x") && !line.contains(";")) {
                addInstrs(line, instrs);
            }
        }

        if (!iter.hasNext() || !iter.next().contains("- compiler.onSpinWait.TestOnSpinWaitAArch64$Launcher::test@0") || !iter.hasNext()) {
            throw new RuntimeException("Missing compiler output for Thread.onSpinWait intrinsic");
        }

        String strToSearch = null;
        if (!hasHexInstInOutput) {
            instrs.add(line.split(";")[0].trim());
            strToSearch = spinWaitInst;
        } else {
            line = iter.next();
            if (!line.contains("0x") || line.contains(";")) {
                throw new RuntimeException("Expected hex instructions");
            }

            addInstrs(line, instrs);
            strToSearch = getSpinWaitInstHex(spinWaitInst);
        }

        int foundInstCount = 0;

        ListIterator<String> instrReverseIter = instrs.listIterator(instrs.size());
        while (instrReverseIter.hasPrevious()) {
            if (instrReverseIter.previous().endsWith(strToSearch)) {
                foundInstCount = 1;
                break;
            }
        }

        while (instrReverseIter.hasPrevious()) {
            if (!instrReverseIter.previous().endsWith(strToSearch)) {
                break;
            }
            ++foundInstCount;
        }

        if (foundInstCount != spinWaitInstCount) {
            throw new RuntimeException("Wrong instruction " + strToSearch + " count " + foundInstCount + "!\n  -- expecting " + spinWaitInstCount);
        }
    }

    private static String skipTo(Iterator<String> iter, String substring) {
        while (iter.hasNext()) {
            String nextLine = iter.next();
            if (nextLine.contains(substring)) {
                return nextLine;
            }
        }
        return null;
    }

    static class Launcher {
        public static void main(final String[] args) throws Exception {
            int end = 20_000;

            for (int i=0; i < end; i++) {
                test();
            }
        }
        static void test() {
            java.lang.Thread.onSpinWait();
        }
    }
}