misappropriate Jfr to log your own logs with unified logging, limited to some tag set though

hacking_jvm_logging.java

import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.util.Arrays;
import java.util.Set;

public class hacking_jvm_logging {
    /**
     * Logging Level
     *
     * public enum LogLevel {
     *    TRACE(1),
     *    DEBUG(2),
     *    INFO(3),
     *    WARN(4),
     *    ERROR(5);
     */
    public static final int LOG_LEVEL_INFO = 3;

    /**
     * Id matching declared tag sets
     *
     * public enum LogTag {
     *     /**
     *      * Covers
     *      * <ul>
     *      * <li>Initialization of Flight Recorder
     *      * <li> recording life cycle (start, stop and dump)
     *      * <li> repository life cycle
     *      * <li>loading of configuration files.
     *      * </ul>
     *      * Target audience: operations
     *      *\/
     *      JFR(0),
     */
    public static final int LOG_TAG_SET_JFR = 0;

    public static void main(String[] args) throws Throwable {
        ProcessHandle.current().info().arguments()
                     .filter(argList -> Arrays.asList(argList).containsAll(Set.of("-Xlog:jfr=info", "--add-opens", "jdk.jfr/jdk.jfr.internal=ALL-UNNAMED")))
                     .orElseThrow(() -> new IllegalArgumentException("not working without JVM arguments"));

        var jvmClass = hacking_jvm_logging.class.getClassLoader().loadClass("jdk.jfr.internal.JVM");
        var lookup = MethodHandles.lookup();
        var privateLookup = MethodHandles.privateLookupIn(jvmClass, lookup);

        var signature = MethodType.methodType(void.class, int.class, int.class, String.class);
        var mh = privateLookup.findStatic(jvmClass, "log", signature);
        // backed by https://github.com/AdoptOpenJDK/openjdk-jdk11u/blob/75e6fdb4dfc5d95674b321e77f42a4097d54c571/src/hotspot/share/jfr/utilities/jfrJavaLog.cpp#L122-L140
        mh.invokeExact(LOG_TAG_SET_JFR, LOG_LEVEL_INFO, "hello jfr");
    }
}

stdout

0.137s][info][jfr] hello jfr