- name: 'Check out repository'
        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
      # When we specify multiple JDKs, the final one becomes the default, which is used to execute Maven itself.
      # Our Maven configuration then specifies different JDKs to use for some of the steps:

        Class<?> optionalClass = Class.forName("java.util.Optional");
        /*
         * We don't *need* to use reflection to access Optional: It's available on all JDKs we
         * support, and Android code won't get this far, anyway, because ProcessHandle is
         * unavailable. But given how much other reflection we're using, we might as well use it

   * of Java 20, it always throws an exception, and as of Java 26, the method does not even exist.
   * For now, we continue using it to clean up under older JDKs.
   *
   * Our usages should at least be *relatively* safe: Typically, threads started by a test are dying
   * at the end of the test, so there is no object state put at risk by stopping the threads

  // Set the Java release version.
  options.release.set(9)

  // Ignore warnings about using 'requires transitive' on automatic modules.
  // not needed when compiling with recent JDKs, e.g. 17
  options.compilerArgs.add("-Xlint:-requires-transitive-automatic")

  // Patch the compileKotlinJvm output classes into the compilation so exporting packages works correctly.
  options.compilerArgs.addAll(

   * of Java 20, it always throws an exception, and as of Java 26, the method does not even exist.
   * For now, we continue using it to clean up under older JDKs.
   *
   * Our usages should at least be *relatively* safe: Typically, threads started by a test are dying
   * at the end of the test, so there is no object state put at risk by stopping the threads

        run: ./gradlew test allTests -Dtest.java.version=21

  testopenjdklatest:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v6

      - name: Configure JDKs
        uses: actions/setup-java@v5
        with:
          distribution: 'zulu'
          java-version: |
            11
            17
            24

      - name: Allow incompatible JVM versions

            <!--
            We can apparently have only one <jdk> per execution: Others are silently ignored :(
            To properly test this, you need to remove existing toolchains:
            rm -rf ~/.m2/jdks/ ~/.m2/toolchains.xml
            (But don't run that if you have put something into ~/.m2/toolchains.xml yourself.)
            -->
            <execution>
              <id>download-25-and-surefire-version</id>

            <!--
            We can apparently have only one <jdk> per execution: Others are silently ignored :(
            To properly test this, you need to remove existing toolchains:
            rm -rf ~/.m2/jdks/ ~/.m2/toolchains.xml
            (But don't run that if you have put something into ~/.m2/toolchains.xml yourself.)
            -->
            <execution>
              <id>download-25-and-surefire-version</id>

    // We can continue if it's 1.8, and we can continue if it's an integer in [9, 20).
    if (javaVersion != null && javaVersion >= 20) {
      // TODO(b/261217224, b/361604053): Make this test work under newer JDKs.
      return;
    }
    TimedWaiterThread thread = new TimedWaiterThread(new AbstractFuture<Object>() {}, 2, SECONDS);
    thread.start();
    thread.awaitWaiting();

    // We can continue if it's 1.8, and we can continue if it's an integer in [9, 20).
    if (javaVersion != null && javaVersion >= 20) {
      // TODO(b/261217224, b/361604053): Make this test work under newer JDKs.
      return;
    }
    TimedWaiterThread thread = new TimedWaiterThread(new AbstractFuture<Object>() {}, 2, SECONDS);
    thread.start();
    thread.awaitWaiting();