1/*
2 * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25#include "precompiled.hpp"
26#include "jfr/jni/jfrJavaSupport.hpp"
27#include "jfr/recorder/checkpoint/jfrMetadataEvent.hpp"
28#include "jfr/recorder/repository/jfrChunkWriter.hpp"
29#include "oops/klass.inline.hpp"
30#include "oops/oop.inline.hpp"
31#include "oops/typeArrayOop.inline.hpp"
32#include "runtime/semaphore.hpp"
33#include "runtime/thread.inline.hpp"
34
35static jbyteArray _metadata_blob = NULL;
36static Semaphore metadata_mutex_semaphore(1);
37
38void JfrMetadataEvent::lock() {
39 metadata_mutex_semaphore.wait();
40}
41
42void JfrMetadataEvent::unlock() {
43 metadata_mutex_semaphore.signal();
44}
45
46static void write_metadata_blob(JfrChunkWriter& chunkwriter, jbyteArray metadata_blob) {
47 if (metadata_blob != NULL) {
48 const typeArrayOop arr = (typeArrayOop)JfrJavaSupport::resolve_non_null(metadata_blob);
49 assert(arr != NULL, "invariant");
50 const int length = arr->length();
51 const Klass* const k = arr->klass();
52 assert(k != NULL && k->is_array_klass(), "invariant");
53 const TypeArrayKlass* const byte_arr_klass = TypeArrayKlass::cast(k);
54 const jbyte* const data_address = arr->byte_at_addr(0);
55 chunkwriter.write_unbuffered(data_address, length);
56 }
57}
58
59// the semaphore is assumed to be locked (was locked previous safepoint)
60size_t JfrMetadataEvent::write(JfrChunkWriter& chunkwriter, jlong metadata_offset) {
61 assert(chunkwriter.is_valid(), "invariant");
62 assert(chunkwriter.current_offset() == metadata_offset, "invariant");
63 // header
64 chunkwriter.reserve(sizeof(u4));
65 chunkwriter.write<u8>(EVENT_METADATA); // ID 0
66 // time data
67 chunkwriter.write(JfrTicks::now());
68 chunkwriter.write((u8)0); // duration
69 chunkwriter.write((u8)0); // metadata id
70 write_metadata_blob(chunkwriter, _metadata_blob); // payload
71 unlock(); // open up for java to provide updated metadata
72 // fill in size of metadata descriptor event
73 const jlong size_written = chunkwriter.current_offset() - metadata_offset;
74 chunkwriter.write_padded_at_offset((u4)size_written, metadata_offset);
75 return size_written;
76}
77
78void JfrMetadataEvent::update(jbyteArray metadata) {
79 JavaThread* thread = (JavaThread*)Thread::current();
80 assert(thread->is_Java_thread(), "invariant");
81 DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(thread));
82 lock();
83 if (_metadata_blob != NULL) {
84 JfrJavaSupport::destroy_global_jni_handle(_metadata_blob);
85 }
86 const oop new_desc_oop = JfrJavaSupport::resolve_non_null(metadata);
87 _metadata_blob = new_desc_oop != NULL ? (jbyteArray)JfrJavaSupport::global_jni_handle(new_desc_oop, thread) : NULL;
88 unlock();
89}
90