runtime delegation to JFR streaming APIs via reflection #223
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| @Test | ||
| public void testOpenRepository() { | ||
| assertThat(EventStreams.openRepository()).isPresent(); |
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do we need to close resources here?
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I suppose not, since it's only reading a view of the default repository
| AtomicBoolean seen = new AtomicBoolean(false); | ||
| support.get().onEvent("jdk.ActiveRecording", (_ev) -> seen.compareAndSet(false, true)); | ||
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| support.get().startAsync(); |
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I think we need to terminate this in some way
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| public interface RecordingStreamSupport extends AutoCloseable { |
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I think we should declare @Override void close() to narrow close from AutoCloseable not to throw a checked exception, matching RecordingStream.close.
This makes it easier to do something like the follwoing, since you can't throw checked exceptions within a functional method:
RecordingStreams.newRecordingStream()
.ifPresent(recordingStream -> {
try (recordingStream) {
///etc
}
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Looks like the same applies to EventStream as well
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Released 0.4.0 |
Adds support for accessing JFR streaming APIs at runtime via reflection, while still supporting language levels below Java 14, in a manner similar to the
VirtualThreadsclass from https://github.com/palantir/nylon-threads.This allows consumers to access JFR streaming APIs when running on Java 14 or above, while still targeting language levels below Java 14. The
EventStreamsandRecordingStreamsclasses provide factory methods for creating an object similar in shape tojdk.jfr.consumer.EventStreamorjdk.jfr.consumer.RecordingStreamrespectively, which delegates to an underlying instance at runtime. If JFR streaming is not supported by the runtime, anOptional.empty()is returned instead.Note that
EventStreamsdoes not provide support for theonMetadatamethod ofjdk.jfr.consumer.EventStream, as it depends upon a class added in Java 16. Similarly,RecordingStreamsdoes not provide support forjdk.jfr.consumer.RecordingStream#stop()as it was added in Java 20 and I'm making the assumption that most consumers are still targeting Java 17 or below.