| /* |
| * 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 |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "jni.h" |
| #include "classfile/symbolTable.hpp" |
| #include "classfile/systemDictionary.hpp" |
| #include "classfile/vmSymbols.hpp" |
| #include "jfr/jni/jfrJavaSupport.hpp" |
| #include "jfr/recorder/storage/jfrStorage.hpp" |
| #include "jfr/support/jfrThreadId.hpp" |
| #include "jfr/utilities/jfrTypes.hpp" |
| #include "jfr/writers/jfrJavaEventWriter.hpp" |
| #include "oops/instanceKlass.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/fieldDescriptor.inline.hpp" |
| #include "runtime/handles.inline.hpp" |
| #include "runtime/jniHandles.inline.hpp" |
| #include "runtime/thread.inline.hpp" |
| |
| static int start_pos_offset = invalid_offset; |
| static int start_pos_address_offset = invalid_offset; |
| static int current_pos_offset = invalid_offset; |
| static int max_pos_offset = invalid_offset; |
| static int max_event_size_offset = invalid_offset; |
| static int notified_offset = invalid_offset; |
| static int thread_id_offset = invalid_offset; |
| static int valid_offset = invalid_offset; |
| |
| static bool find_field(InstanceKlass* ik, |
| Symbol* name_symbol, |
| Symbol* signature_symbol, |
| fieldDescriptor* fd, |
| bool is_static = false, |
| bool allow_super = false) { |
| if (allow_super || is_static) { |
| return ik->find_field(name_symbol, signature_symbol, is_static, fd) != NULL; |
| } else { |
| return ik->find_local_field(name_symbol, signature_symbol, fd); |
| } |
| } |
| |
| static void compute_offset(int &dest_offset, |
| Klass* klass, |
| Symbol* name_symbol, |
| Symbol* signature_symbol, |
| bool is_static = false, bool allow_super = false) { |
| fieldDescriptor fd; |
| InstanceKlass* ik = InstanceKlass::cast(klass); |
| if (!find_field(ik, name_symbol, signature_symbol, &fd, is_static, allow_super)) { |
| assert(false, "invariant"); |
| } |
| dest_offset = fd.offset(); |
| } |
| |
| static bool setup_event_writer_offsets(TRAPS) { |
| const char class_name[] = "jdk/jfr/internal/EventWriter"; |
| Symbol* const k_sym = SymbolTable::new_symbol(class_name); |
| assert(k_sym != NULL, "invariant"); |
| Klass* klass = SystemDictionary::resolve_or_fail(k_sym, true, CHECK_false); |
| assert(klass != NULL, "invariant"); |
| |
| const char start_pos_name[] = "startPosition"; |
| Symbol* const start_pos_sym = SymbolTable::new_symbol(start_pos_name); |
| assert(start_pos_sym != NULL, "invariant"); |
| assert(invalid_offset == start_pos_offset, "invariant"); |
| compute_offset(start_pos_offset, klass, start_pos_sym, vmSymbols::long_signature()); |
| assert(start_pos_offset != invalid_offset, "invariant"); |
| |
| const char start_pos_address_name[] = "startPositionAddress"; |
| Symbol* const start_pos_address_sym = SymbolTable::new_symbol(start_pos_address_name); |
| assert(start_pos_address_sym != NULL, "invariant"); |
| assert(invalid_offset == start_pos_address_offset, "invariant"); |
| compute_offset(start_pos_address_offset, klass, start_pos_address_sym, vmSymbols::long_signature()); |
| assert(start_pos_address_offset != invalid_offset, "invariant"); |
| |
| const char event_pos_name[] = "currentPosition"; |
| Symbol* const event_pos_sym = SymbolTable::new_symbol(event_pos_name); |
| assert(event_pos_sym != NULL, "invariant"); |
| assert(invalid_offset == current_pos_offset, "invariant"); |
| compute_offset(current_pos_offset, klass, event_pos_sym,vmSymbols::long_signature()); |
| assert(current_pos_offset != invalid_offset, "invariant"); |
| |
| const char max_pos_name[] = "maxPosition"; |
| Symbol* const max_pos_sym = SymbolTable::new_symbol(max_pos_name); |
| assert(max_pos_sym != NULL, "invariant"); |
| assert(invalid_offset == max_pos_offset, "invariant"); |
| compute_offset(max_pos_offset, klass, max_pos_sym, vmSymbols::long_signature()); |
| assert(max_pos_offset != invalid_offset, "invariant"); |
| |
| const char max_event_size_name[] = "maxEventSize"; |
| Symbol* const max_event_size_sym = SymbolTable::new_symbol(max_event_size_name); |
| assert (max_event_size_sym != NULL, "invariant"); |
| assert(invalid_offset == max_event_size_offset, "invariant"); |
| compute_offset(max_event_size_offset, klass, max_event_size_sym, vmSymbols::int_signature()); |
| assert(max_event_size_offset != invalid_offset, "invariant"); |
| |
| const char notified_name[] = "notified"; |
| Symbol* const notified_sym = SymbolTable::new_symbol(notified_name); |
| assert (notified_sym != NULL, "invariant"); |
| assert(invalid_offset == notified_offset, "invariant"); |
| compute_offset(notified_offset, klass, notified_sym, vmSymbols::bool_signature()); |
| assert(notified_offset != invalid_offset, "invariant"); |
| |
| const char valid_name[] = "valid"; |
| Symbol* const valid_sym = SymbolTable::new_symbol(valid_name); |
| assert (valid_sym != NULL, "invariant"); |
| assert(invalid_offset == valid_offset, "invariant"); |
| compute_offset(valid_offset, klass, valid_sym, vmSymbols::bool_signature()); |
| assert(valid_offset != invalid_offset, "invariant"); |
| return true; |
| } |
| |
| bool JfrJavaEventWriter::initialize() { |
| static bool initialized = false; |
| if (!initialized) { |
| initialized = setup_event_writer_offsets(Thread::current()); |
| } |
| return initialized; |
| } |
| |
| jboolean JfrJavaEventWriter::flush(jobject writer, jint used, jint requested, JavaThread* jt) { |
| DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(jt)); |
| assert(writer != NULL, "invariant"); |
| oop const w = JNIHandles::resolve_non_null(writer); |
| assert(w != NULL, "invariant"); |
| JfrBuffer* const current = jt->jfr_thread_local()->java_buffer(); |
| assert(current != NULL, "invariant"); |
| JfrBuffer* const buffer = JfrStorage::flush(current, used, requested, false, jt); |
| assert(buffer != NULL, "invariant"); |
| // "validity" is contextually defined here to mean |
| // that some memory location was provided that is |
| // large enough to accommodate the "requested size". |
| const bool is_valid = buffer->free_size() >= (size_t)(used + requested); |
| u1* const new_current_position = is_valid ? buffer->pos() + used : buffer->pos(); |
| assert(start_pos_offset != invalid_offset, "invariant"); |
| w->long_field_put(start_pos_offset, (jlong)buffer->pos()); |
| w->long_field_put(current_pos_offset, (jlong)new_current_position); |
| // only update java writer if underlying memory changed |
| if (buffer != current) { |
| w->long_field_put(start_pos_address_offset, (jlong)buffer->pos_address()); |
| w->long_field_put(max_pos_offset, (jlong)buffer->end()); |
| } |
| if (!is_valid) { |
| // mark writer as invalid for this write attempt |
| w->release_bool_field_put(valid_offset, JNI_FALSE); |
| return JNI_FALSE; |
| } |
| // An exclusive use of a leased buffer is treated equivalent to |
| // holding a system resource. As such, it should be released as soon as possible. |
| // Returning true here signals that the thread will need to call flush again |
| // on EventWriter.endEvent() and that flush will return the lease. |
| return buffer->lease() ? JNI_TRUE : JNI_FALSE; |
| } |
| |
| class JfrJavaEventWriterNotificationClosure : public ThreadClosure { |
| public: |
| void do_thread(Thread* t) { |
| if (t->is_Java_thread()) { |
| JfrJavaEventWriter::notify((JavaThread*)t); |
| } |
| } |
| }; |
| |
| void JfrJavaEventWriter::notify() { |
| assert(SafepointSynchronize::is_at_safepoint(), "invariant"); |
| JfrJavaEventWriterNotificationClosure closure; |
| Threads::threads_do(&closure); |
| } |
| |
| void JfrJavaEventWriter::notify(JavaThread* jt) { |
| assert(jt != NULL, "invariant"); |
| assert(SafepointSynchronize::is_at_safepoint(), "invariant"); |
| if (jt->jfr_thread_local()->has_java_event_writer()) { |
| oop buffer_writer = JNIHandles::resolve_non_null(jt->jfr_thread_local()->java_event_writer()); |
| assert(buffer_writer != NULL, "invariant"); |
| buffer_writer->release_bool_field_put(notified_offset, JNI_TRUE); |
| } |
| } |
| |
| static jobject create_new_event_writer(JfrBuffer* buffer, TRAPS) { |
| assert(buffer != NULL, "invariant"); |
| DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(THREAD)); |
| HandleMark hm(THREAD); |
| static const char klass[] = "jdk/jfr/internal/EventWriter"; |
| static const char method[] = "<init>"; |
| static const char signature[] = "(JJJJZ)V"; |
| JavaValue result(T_OBJECT); |
| JfrJavaArguments args(&result, klass, method, signature, CHECK_NULL); |
| // parameters |
| args.push_long((jlong)buffer->pos()); |
| args.push_long((jlong)buffer->end()); |
| args.push_long((jlong)buffer->pos_address()); |
| args.push_long((jlong)JFR_THREAD_ID(THREAD)); |
| args.push_int((int)JNI_TRUE); |
| JfrJavaSupport::new_object_global_ref(&args, CHECK_NULL); |
| return result.get_jobject(); |
| } |
| |
| jobject JfrJavaEventWriter::event_writer(Thread* t) { |
| DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(t)); |
| JfrThreadLocal* const tl = t->jfr_thread_local(); |
| assert(tl->shelved_buffer() == NULL, "invariant"); |
| return tl->java_event_writer(); |
| } |
| |
| jobject JfrJavaEventWriter::new_event_writer(TRAPS) { |
| DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(THREAD)); |
| assert(event_writer(THREAD) == NULL, "invariant"); |
| JfrThreadLocal* const tl = THREAD->jfr_thread_local(); |
| assert(!tl->has_java_buffer(), "invariant"); |
| JfrBuffer* const buffer = tl->java_buffer(); |
| if (buffer == NULL) { |
| JfrJavaSupport::throw_out_of_memory_error("OOME for thread local buffer", THREAD); |
| return NULL; |
| } |
| jobject java_event_writer = create_new_event_writer(buffer, CHECK_NULL); |
| tl->set_java_event_writer(java_event_writer); |
| assert(tl->has_java_event_writer(), "invariant"); |
| return java_event_writer; |
| } |