oracle/graal · error · GraalError

Use of %s is only supported in jargraal

Error message

Use of %s is only supported in jargraal

What it means

GraalError thrown during BenchmarkCounters initialization when -Dgraal.TimedDynamicCounters is set to a positive interval while running inside libgraal (the SVM-compiled in-process compiler library). Timed dumping relies on starting a Java Thread that periodically collects counters; libgraal's image heap/runtime does not support this, and the option is only meaningful in jargraal (JVM-embedded Java-mode Graal).

Source

Thrown at compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/debug/BenchmarkCounters.java:494

                throw new GraalError("invalid arguments to BenchmarkDynamicCounters: (err|out),start,end,(err|out),start,end,... (~ matches multiple digits)");
            }
            for (int i = 0; i < arguments.length; i += 3) {
                if (arguments[i].equals("err")) {
                    System.setErr(new PrintStream(new BenchmarkCountersOutputStream(System.err, arguments[i + 1], arguments[i + 2])));
                } else if (arguments[i].equals("out")) {
                    System.setOut(new PrintStream(new BenchmarkCountersOutputStream(System.out, arguments[i + 1], arguments[i + 2])));
                } else {
                    throw new GraalError("invalid arguments to BenchmarkDynamicCounters: err|out");
                }
            }
            enabled = true;
        }
        if (Options.GenericDynamicCounters.getValue(options)) {
            enabled = true;
        }
        if (Options.TimedDynamicCounters.getValue(options) > 0) {
            if (LibGraalSupport.inLibGraalRuntime()) {
                throw new GraalError("Use of %s is only supported in jargraal", Options.TimedDynamicCounters.getName());
            }
            Thread thread = new Thread(new Runnable() {
                long lastTime = System.nanoTime();

                @Override
                public void run() {
                    try (PrintStreamScope scope = getPrintStream(options)) {
                        while (true) { // TERMINATION ARGUMENT: busy waiting loop
                            try {
                                Thread.sleep(Options.TimedDynamicCounters.getValue(options));
                            } catch (InterruptedException e) {
                            }
                            long time = System.nanoTime();
                            dump(options, scope.out, (time - lastTime) / 1000000000d, jvmciRuntime.collectCounters(), 10);
                            lastTime = time;
                        }
                    }
                }

View on GitHub (pinned to a66e9ccd1d)

Solutions

1. Drop -Dgraal.TimedDynamicCounters when running libgraal.
2. Switch to jargraal mode if you need periodic dumps (run the compiler as Java, e.g. -Dgraal.JVMCILibGraal=false where supported).
3. Use one-shot counter dumps (-Dgraal.BenchmarkDynamicCounters triples or dump-on-exit) instead of timed dumps under libgraal.

Example fix

# before
-XX:+UseJVMCICompiler -Dgraal.TimedDynamicCounters=1000
# GraalError: Use of TimedDynamicCounters is only supported in jargraal

# after
-XX:+UseJVMCICompiler  # timed counters removed under libgraal

// Do not set TimedDynamicCounters when running libgraal
boolean libgraal = Boolean.parseBoolean(System.getProperty("graal.JVMCILibGraal", "true"));
long timed = Long.getLong("graal.TimedDynamicCounters", 0);
if (libgraal && timed > 0) {
    throw new IllegalStateException("graal.TimedDynamicCounters requires jargraal mode; unset it or disable libgraal");
}

When it happens

Trigger: Running with -XX:+UseJVMCICompiler in the default libgraal mode (no -Dgraal.JVMCILibGraal=false or equivalent) together with -Dgraal.TimedDynamicCounters=<ms>>0; LibGraalSupport.inLibGraalRuntime() returns true and the check fires.

Common situations: Reusing a benchmarking flag set that was tuned for jargraal on a JDK that now defaults to libgraal; nightly perf scripts that time-slice counter dumps.

Related errors

• too many counters, reduce number of counters or increase -XX
• invalid arguments to BenchmarkDynamicCounters: (err|out),sta
• invalid arguments to BenchmarkDynamicCounters: err|out
• LogFile substitution %s cannot be combined with any other ch
• Profile file for path %s exists already

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/9ff2aaa056929c77. Report an issue: GitHub.