1 /* 2 * Copyright (c) 2016, 2019, 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.hpp" 32 #include "runtime/semaphore.hpp" 33 #include "runtime/thread.inline.hpp" 34 #include "trace/traceDataTypes.hpp" 35 36 static jbyteArray _metadata_blob = NULL; 37 static Semaphore metadata_mutex_semaphore(1); 38 39 void JfrMetadataEvent::lock() { 40 metadata_mutex_semaphore.wait(); 41 } 42 43 void JfrMetadataEvent::unlock() { 44 metadata_mutex_semaphore.signal(); 45 } 46 47 static void write_metadata_blob(JfrChunkWriter& chunkwriter, jbyteArray metadata_blob) { 48 if (metadata_blob != NULL) { 49 const typeArrayOop arr = (typeArrayOop)JfrJavaSupport::resolve_non_null(metadata_blob); 50 assert(arr != NULL, "invariant"); 51 const int length = arr->length(); 52 const Klass* k = arr->klass(); 53 assert(k != NULL && k->oop_is_array(), "invariant"); 54 const TypeArrayKlass* const byte_arr_klass = TypeArrayKlass::cast(k); 55 const jbyte* const data_address = arr->byte_at_addr(0); 56 chunkwriter.write_unbuffered(data_address, length); 57 } 58 } 59 60 // the semaphore is assumed to be locked (was locked previous safepoint) 61 size_t JfrMetadataEvent::write(JfrChunkWriter& chunkwriter, jlong metadata_offset) { 62 assert(chunkwriter.is_valid(), "invariant"); 63 assert(chunkwriter.current_offset() == metadata_offset, "invariant"); 64 // header 65 chunkwriter.reserve(sizeof(u4)); 66 chunkwriter.write<u8>(EVENT_METADATA); // ID 0 67 // time data 68 chunkwriter.write(JfrTraceTime::now().value()); 69 chunkwriter.write((u8)0); // duration 70 chunkwriter.write((u8)0); // metadata id 71 write_metadata_blob(chunkwriter, _metadata_blob); // payload 72 unlock(); // open up for java to provide updated metadata 73 // fill in size of metadata descriptor event 74 const jlong size_written = chunkwriter.current_offset() - metadata_offset; 75 chunkwriter.write_padded_at_offset((u4)size_written, metadata_offset); 76 return size_written; 77 } 78 79 void JfrMetadataEvent::update(jbyteArray metadata) { 80 JavaThread* thread = (JavaThread*)Thread::current(); 81 assert(thread->is_Java_thread(), "invariant"); 82 DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(thread)); 83 lock(); 84 if (_metadata_blob != NULL) { 85 JfrJavaSupport::destroy_global_jni_handle(_metadata_blob); 86 } 87 const oop new_desc_oop = JfrJavaSupport::resolve_non_null(metadata); 88 _metadata_blob = new_desc_oop != NULL ? (jbyteArray)JfrJavaSupport::global_jni_handle(new_desc_oop, thread) : NULL; 89 unlock(); 90 }