--- a/src/hotspot/share/jfr/recorder/checkpoint/jfrMetadataEvent.cpp Fri May 17 15:53:21 2019 +0200
+++ b/src/hotspot/share/jfr/recorder/checkpoint/jfrMetadataEvent.cpp Fri May 17 16:02:27 2019 +0200
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -29,19 +29,11 @@
#include "oops/klass.inline.hpp"
#include "oops/oop.inline.hpp"
#include "oops/typeArrayOop.inline.hpp"
-#include "runtime/semaphore.hpp"
#include "runtime/thread.inline.hpp"
static jbyteArray _metadata_blob = NULL;
-static Semaphore metadata_mutex_semaphore(1);
-
-void JfrMetadataEvent::lock() {
- metadata_mutex_semaphore.wait();
-}
-
-void JfrMetadataEvent::unlock() {
- metadata_mutex_semaphore.signal();
-}
+static u8 metadata_id = 0;
+static u8 last_written_metadata_id = 0;
static void write_metadata_blob(JfrChunkWriter& chunkwriter, jbyteArray metadata_blob) {
if (metadata_blob != NULL) {
@@ -56,34 +48,38 @@
}
}
-// the semaphore is assumed to be locked (was locked previous safepoint)
-size_t JfrMetadataEvent::write(JfrChunkWriter& chunkwriter, jlong metadata_offset) {
+void JfrMetadataEvent::write(JfrChunkWriter& chunkwriter) {
assert(chunkwriter.is_valid(), "invariant");
+ const jlong metadata_offset = chunkwriter.current_offset();
assert(chunkwriter.current_offset() == metadata_offset, "invariant");
+
+ if (last_written_metadata_id == metadata_id && chunkwriter.has_metadata()) {
+ return;
+ }
+
// header
chunkwriter.reserve(sizeof(u4));
chunkwriter.write<u8>(EVENT_METADATA); // ID 0
// time data
chunkwriter.write(JfrTicks::now());
chunkwriter.write((u8)0); // duration
- chunkwriter.write((u8)0); // metadata id
+ chunkwriter.write(metadata_id); // metadata id
write_metadata_blob(chunkwriter, _metadata_blob); // payload
- unlock(); // open up for java to provide updated metadata
+ last_written_metadata_id = metadata_id;
// fill in size of metadata descriptor event
const jlong size_written = chunkwriter.current_offset() - metadata_offset;
chunkwriter.write_padded_at_offset((u4)size_written, metadata_offset);
- return size_written;
+ chunkwriter.set_last_metadata_offset(metadata_offset);
}
void JfrMetadataEvent::update(jbyteArray metadata) {
JavaThread* thread = (JavaThread*)Thread::current();
assert(thread->is_Java_thread(), "invariant");
DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(thread));
- lock();
if (_metadata_blob != NULL) {
JfrJavaSupport::destroy_global_jni_handle(_metadata_blob);
}
const oop new_desc_oop = JfrJavaSupport::resolve_non_null(metadata);
_metadata_blob = new_desc_oop != NULL ? (jbyteArray)JfrJavaSupport::global_jni_handle(new_desc_oop, thread) : NULL;
- unlock();
+ ++metadata_id;
}