1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/jfr/writers/jfrJavaEventWriter.cpp Mon Aug 12 18:30:40 2019 +0300
1.3 @@ -0,0 +1,249 @@
1.4 +/*
1.5 + * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "precompiled.hpp"
1.29 +#include "jni.h"
1.30 +#include "classfile/symbolTable.hpp"
1.31 +#include "classfile/systemDictionary.hpp"
1.32 +#include "classfile/vmSymbols.hpp"
1.33 +#include "jfr/jni/jfrJavaSupport.hpp"
1.34 +#include "jfr/recorder/storage/jfrStorage.hpp"
1.35 +#include "jfr/support/jfrThreadId.hpp"
1.36 +#include "jfr/utilities/jfrTypes.hpp"
1.37 +#include "jfr/writers/jfrJavaEventWriter.hpp"
1.38 +#include "oops/instanceKlass.hpp"
1.39 +#include "oops/oop.inline.hpp"
1.40 +#include "runtime/fieldDescriptor.hpp"
1.41 +#include "runtime/handles.hpp"
1.42 +#include "runtime/jniHandles.hpp"
1.43 +#include "runtime/thread.inline.hpp"
1.44 +
1.45 +static int start_pos_offset = invalid_offset;
1.46 +static int start_pos_address_offset = invalid_offset;
1.47 +static int current_pos_offset = invalid_offset;
1.48 +static int max_pos_offset = invalid_offset;
1.49 +static int max_event_size_offset = invalid_offset;
1.50 +static int notified_offset = invalid_offset;
1.51 +static int thread_id_offset = invalid_offset;
1.52 +static int valid_offset = invalid_offset;
1.53 +
1.54 +static bool find_field(InstanceKlass* ik,
1.55 + Symbol* name_symbol,
1.56 + Symbol* signature_symbol,
1.57 + fieldDescriptor* fd,
1.58 + bool is_static = false,
1.59 + bool allow_super = false) {
1.60 + if (allow_super || is_static) {
1.61 + return ik->find_field(name_symbol, signature_symbol, is_static, fd) != NULL;
1.62 + } else {
1.63 + return ik->find_local_field(name_symbol, signature_symbol, fd);
1.64 + }
1.65 +}
1.66 +
1.67 +static void compute_offset(int &dest_offset,
1.68 + Klass* klass,
1.69 + Symbol* name_symbol,
1.70 + Symbol* signature_symbol,
1.71 + bool is_static = false, bool allow_super = false) {
1.72 + fieldDescriptor fd;
1.73 + InstanceKlass* ik = InstanceKlass::cast(klass);
1.74 + if (!find_field(ik, name_symbol, signature_symbol, &fd, is_static, allow_super)) {
1.75 + assert(false, "invariant");
1.76 + }
1.77 + dest_offset = fd.offset();
1.78 +}
1.79 +
1.80 +static bool setup_event_writer_offsets(TRAPS) {
1.81 + const char class_name[] = "jdk/jfr/internal/EventWriter";
1.82 + Symbol* const k_sym = SymbolTable::lookup(class_name, sizeof class_name - 1, CHECK_false);
1.83 + assert(k_sym != NULL, "invariant");
1.84 + Klass* klass = SystemDictionary::resolve_or_fail(k_sym, true, CHECK_false);
1.85 + assert(klass != NULL, "invariant");
1.86 +
1.87 + const char start_pos_name[] = "startPosition";
1.88 + Symbol* const start_pos_sym = SymbolTable::lookup(start_pos_name, sizeof start_pos_name - 1, CHECK_false);
1.89 + assert(start_pos_sym != NULL, "invariant");
1.90 + assert(invalid_offset == start_pos_offset, "invariant");
1.91 + compute_offset(start_pos_offset, klass, start_pos_sym, vmSymbols::long_signature());
1.92 + assert(start_pos_offset != invalid_offset, "invariant");
1.93 +
1.94 + const char start_pos_address_name[] = "startPositionAddress";
1.95 + Symbol* const start_pos_address_sym = SymbolTable::lookup(start_pos_address_name, sizeof start_pos_address_name - 1, CHECK_false);
1.96 + assert(start_pos_address_sym != NULL, "invariant");
1.97 + assert(invalid_offset == start_pos_address_offset, "invariant");
1.98 + compute_offset(start_pos_address_offset, klass, start_pos_address_sym, vmSymbols::long_signature());
1.99 + assert(start_pos_address_offset != invalid_offset, "invariant");
1.100 +
1.101 + const char event_pos_name[] = "currentPosition";
1.102 + Symbol* const event_pos_sym = SymbolTable::lookup(event_pos_name, sizeof event_pos_name - 1, CHECK_false);
1.103 + assert(event_pos_sym != NULL, "invariant");
1.104 + assert(invalid_offset == current_pos_offset, "invariant");
1.105 + compute_offset(current_pos_offset, klass, event_pos_sym,vmSymbols::long_signature());
1.106 + assert(current_pos_offset != invalid_offset, "invariant");
1.107 +
1.108 + const char max_pos_name[] = "maxPosition";
1.109 + Symbol* const max_pos_sym = SymbolTable::lookup(max_pos_name, sizeof max_pos_name - 1, CHECK_false);
1.110 + assert(max_pos_sym != NULL, "invariant");
1.111 + assert(invalid_offset == max_pos_offset, "invariant");
1.112 + compute_offset(max_pos_offset, klass, max_pos_sym, vmSymbols::long_signature());
1.113 + assert(max_pos_offset != invalid_offset, "invariant");
1.114 +
1.115 + const char max_event_size_name[] = "maxEventSize";
1.116 + Symbol* const max_event_size_sym = SymbolTable::lookup(max_event_size_name, sizeof max_event_size_name - 1, CHECK_false);
1.117 + assert (max_event_size_sym != NULL, "invariant");
1.118 + assert(invalid_offset == max_event_size_offset, "invariant");
1.119 + compute_offset(max_event_size_offset, klass, max_event_size_sym, vmSymbols::int_signature());
1.120 + assert(max_event_size_offset != invalid_offset, "invariant");
1.121 +
1.122 + const char notified_name[] = "notified";
1.123 + Symbol* const notified_sym = SymbolTable::lookup(notified_name, sizeof notified_name - 1, CHECK_false);
1.124 + assert (notified_sym != NULL, "invariant");
1.125 + assert(invalid_offset == notified_offset, "invariant");
1.126 + compute_offset(notified_offset, klass, notified_sym, vmSymbols::bool_signature());
1.127 + assert(notified_offset != invalid_offset, "invariant");
1.128 +
1.129 + const char valid_name[] = "valid";
1.130 + Symbol* const valid_sym = SymbolTable::lookup(valid_name, sizeof valid_name - 1, CHECK_false);
1.131 + assert (valid_sym != NULL, "invariant");
1.132 + assert(invalid_offset == valid_offset, "invariant");
1.133 + compute_offset(valid_offset, klass, valid_sym, vmSymbols::bool_signature());
1.134 + assert(valid_offset != invalid_offset, "invariant");
1.135 + return true;
1.136 +}
1.137 +
1.138 +bool JfrJavaEventWriter::has_required_classes(TRAPS) {
1.139 + const char class_name[] = "jdk/jfr/internal/EventWriter";
1.140 + Symbol* const k_sym = SymbolTable::lookup(class_name, sizeof class_name - 1, CHECK_false);
1.141 + Klass* klass = SystemDictionary::resolve_or_null(k_sym, CHECK_false);
1.142 + return (klass != NULL);
1.143 +}
1.144 +
1.145 +bool JfrJavaEventWriter::initialize() {
1.146 + static bool initialized = false;
1.147 + if (!initialized) {
1.148 + Thread* thread = Thread::current();
1.149 + initialized = setup_event_writer_offsets(thread);
1.150 + }
1.151 + return initialized;
1.152 +}
1.153 +
1.154 +jboolean JfrJavaEventWriter::flush(jobject writer, jint used, jint requested, JavaThread* jt) {
1.155 + DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(jt));
1.156 + assert(writer != NULL, "invariant");
1.157 + oop const w = JNIHandles::resolve_non_null(writer);
1.158 + assert(w != NULL, "invariant");
1.159 + JfrBuffer* const current = jt->jfr_thread_local()->java_buffer();
1.160 + assert(current != NULL, "invariant");
1.161 + JfrBuffer* const buffer = JfrStorage::flush(current, used, requested, false, jt);
1.162 + assert(buffer != NULL, "invariant");
1.163 + // "validity" is contextually defined here to mean
1.164 + // that some memory location was provided that is
1.165 + // large enough to accommodate the "requested size".
1.166 + const bool is_valid = buffer->free_size() >= (size_t)(used + requested);
1.167 + u1* const new_current_position = is_valid ? buffer->pos() + used : buffer->pos();
1.168 + w->long_field_put(start_pos_offset, (jlong)buffer->pos());
1.169 + w->long_field_put(current_pos_offset, (jlong)new_current_position);
1.170 + // only update java writer if underlying memory changed
1.171 + if (buffer != current) {
1.172 + w->long_field_put(start_pos_address_offset, (jlong)buffer->pos_address());
1.173 + w->long_field_put(max_pos_offset, (jlong)buffer->end());
1.174 + }
1.175 + if (!is_valid) {
1.176 + // mark writer as invalid for this write attempt
1.177 + w->release_bool_field_put(valid_offset, JNI_FALSE);
1.178 + return JNI_FALSE;
1.179 + }
1.180 + // An exclusive use of a leased buffer is treated equivalent to
1.181 + // holding a system resource. As such, it should be released as soon as possible.
1.182 + // Returning true here signals that the thread will need to call flush again
1.183 + // on EventWriter.endEvent() and that flush will return the lease.
1.184 + return buffer->lease() ? JNI_TRUE : JNI_FALSE;
1.185 +}
1.186 +
1.187 +class JfrJavaEventWriterNotificationClosure : public ThreadClosure {
1.188 + public:
1.189 + void do_thread(Thread* t) {
1.190 + if (t->is_Java_thread()) {
1.191 + JfrJavaEventWriter::notify((JavaThread*)t);
1.192 + }
1.193 + }
1.194 +};
1.195 +
1.196 +void JfrJavaEventWriter::notify() {
1.197 + assert(SafepointSynchronize::is_at_safepoint(), "invariant");
1.198 + JfrJavaEventWriterNotificationClosure closure;
1.199 + Threads::threads_do(&closure);
1.200 +}
1.201 +
1.202 +void JfrJavaEventWriter::notify(JavaThread* jt) {
1.203 + assert(jt != NULL, "invariant");
1.204 + assert(SafepointSynchronize::is_at_safepoint(), "invariant");
1.205 + if (jt->jfr_thread_local()->has_java_event_writer()) {
1.206 + oop buffer_writer = JNIHandles::resolve_non_null(jt->jfr_thread_local()->java_event_writer());
1.207 + assert(buffer_writer != NULL, "invariant");
1.208 + buffer_writer->release_bool_field_put(notified_offset, JNI_TRUE);
1.209 + }
1.210 +}
1.211 +
1.212 +static jobject create_new_event_writer(JfrBuffer* buffer, TRAPS) {
1.213 + assert(buffer != NULL, "invariant");
1.214 + DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(THREAD));
1.215 + HandleMark hm(THREAD);
1.216 + static const char klass[] = "jdk/jfr/internal/EventWriter";
1.217 + static const char method[] = "<init>";
1.218 + static const char signature[] = "(JJJJZ)V";
1.219 + JavaValue result(T_OBJECT);
1.220 + JfrJavaArguments args(&result, klass, method, signature, CHECK_NULL);
1.221 + // parameters
1.222 + args.push_long((jlong)buffer->pos());
1.223 + args.push_long((jlong)buffer->end());
1.224 + args.push_long((jlong)buffer->pos_address());
1.225 + args.push_long((jlong)JFR_THREAD_ID(THREAD));
1.226 + args.push_int((int)JNI_TRUE);
1.227 + JfrJavaSupport::new_object_global_ref(&args, CHECK_NULL);
1.228 + return result.get_jobject();
1.229 +}
1.230 +
1.231 +jobject JfrJavaEventWriter::event_writer(Thread* t) {
1.232 + DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(t));
1.233 + JfrThreadLocal* const tl = t->jfr_thread_local();
1.234 + assert(tl->shelved_buffer() == NULL, "invariant");
1.235 + return tl->java_event_writer();
1.236 +}
1.237 +
1.238 +jobject JfrJavaEventWriter::new_event_writer(TRAPS) {
1.239 + DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(THREAD));
1.240 + assert(event_writer(THREAD) == NULL, "invariant");
1.241 + JfrThreadLocal* const tl = THREAD->jfr_thread_local();
1.242 + assert(!tl->has_java_buffer(), "invariant");
1.243 + JfrBuffer* const buffer = tl->java_buffer();
1.244 + if (buffer == NULL) {
1.245 + JfrJavaSupport::throw_out_of_memory_error("OOME for thread local buffer", THREAD);
1.246 + return NULL;
1.247 + }
1.248 + jobject java_event_writer = create_new_event_writer(buffer, CHECK_NULL);
1.249 + tl->set_java_event_writer(java_event_writer);
1.250 + assert(tl->has_java_event_writer(), "invariant");
1.251 + return java_event_writer;
1.252 +}
