1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/jfr/recorder/checkpoint/types/jfrThreadGroup.cpp Mon Aug 12 18:30:40 2019 +0300
1.3 @@ -0,0 +1,414 @@
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 "jfr/recorder/checkpoint/jfrCheckpointWriter.hpp"
1.30 +#include "jfr/recorder/checkpoint/types/jfrThreadGroup.hpp"
1.31 +#include "jfr/utilities/jfrResourceManager.hpp"
1.32 +#include "jfr/utilities/jfrTypes.hpp"
1.33 +#include "runtime/handles.inline.hpp"
1.34 +#include "runtime/jniHandles.hpp"
1.35 +#include "runtime/safepoint.hpp"
1.36 +#include "runtime/semaphore.hpp"
1.37 +#include "utilities/growableArray.hpp"
1.38 +
1.39 +class ThreadGroupExclusiveAccess : public StackObj {
1.40 + private:
1.41 + static Semaphore _mutex_semaphore;
1.42 + public:
1.43 + ThreadGroupExclusiveAccess() { _mutex_semaphore.wait(); }
1.44 + ~ThreadGroupExclusiveAccess() { _mutex_semaphore.signal(); }
1.45 +};
1.46 +
1.47 +Semaphore ThreadGroupExclusiveAccess::_mutex_semaphore(1);
1.48 +JfrThreadGroup* JfrThreadGroup::_instance = NULL;
1.49 +
1.50 +class JfrThreadGroupPointers : public ResourceObj {
1.51 + private:
1.52 + const Handle _thread_group_handle;
1.53 + jweak _thread_group_weak_ref;
1.54 + public:
1.55 + JfrThreadGroupPointers(Handle thread_group_handle, jweak thread_group_weak_ref);
1.56 + Handle thread_group_handle() const;
1.57 + jweak thread_group_weak_ref() const;
1.58 + oopDesc* const thread_group_oop() const;
1.59 + jweak transfer_weak_global_handle_ownership();
1.60 + void clear_weak_ref();
1.61 +};
1.62 +
1.63 +JfrThreadGroupPointers::JfrThreadGroupPointers(Handle thread_group_handle, jweak thread_group_weak_ref) :
1.64 + _thread_group_handle(thread_group_handle),
1.65 + _thread_group_weak_ref(thread_group_weak_ref) {}
1.66 +
1.67 +Handle JfrThreadGroupPointers::thread_group_handle() const {
1.68 + return _thread_group_handle;
1.69 +}
1.70 +
1.71 +jweak JfrThreadGroupPointers::thread_group_weak_ref() const {
1.72 + return _thread_group_weak_ref;
1.73 +}
1.74 +
1.75 +oopDesc* const JfrThreadGroupPointers::thread_group_oop() const {
1.76 + assert(_thread_group_weak_ref == NULL ||
1.77 + JNIHandles::resolve_non_null(_thread_group_weak_ref) == _thread_group_handle(), "invariant");
1.78 + return _thread_group_handle();
1.79 +}
1.80 +
1.81 +jweak JfrThreadGroupPointers::transfer_weak_global_handle_ownership() {
1.82 + jweak temp = _thread_group_weak_ref;
1.83 + _thread_group_weak_ref = NULL;
1.84 + return temp;
1.85 +}
1.86 +
1.87 +void JfrThreadGroupPointers::clear_weak_ref() {
1.88 + if (NULL != _thread_group_weak_ref) {
1.89 + JNIHandles::destroy_weak_global(_thread_group_weak_ref);
1.90 + }
1.91 +}
1.92 +
1.93 +class JfrThreadGroupsHelper : public ResourceObj {
1.94 + private:
1.95 + static const int invalid_iterator_pos = -1;
1.96 + GrowableArray<JfrThreadGroupPointers*>* _thread_group_hierarchy;
1.97 + int _current_iterator_pos;
1.98 +
1.99 + int populate_thread_group_hierarchy(const JavaThread* jt, Thread* current);
1.100 + JfrThreadGroupPointers& at(int index);
1.101 +
1.102 + public:
1.103 + JfrThreadGroupsHelper(const JavaThread* jt, Thread* current);
1.104 + ~JfrThreadGroupsHelper();
1.105 + JfrThreadGroupPointers& next();
1.106 + bool is_valid() const;
1.107 + bool has_next() const;
1.108 +};
1.109 +
1.110 +JfrThreadGroupsHelper::JfrThreadGroupsHelper(const JavaThread* jt, Thread* current) {
1.111 + _thread_group_hierarchy = new GrowableArray<JfrThreadGroupPointers*>(10, false, mtTracing);
1.112 + _current_iterator_pos = populate_thread_group_hierarchy(jt, current) - 1;
1.113 +}
1.114 +
1.115 +JfrThreadGroupsHelper::~JfrThreadGroupsHelper() {
1.116 + assert(_current_iterator_pos == invalid_iterator_pos, "invariant");
1.117 + for (int i = 0; i < _thread_group_hierarchy->length(); ++i) {
1.118 + _thread_group_hierarchy->at(i)->clear_weak_ref();
1.119 + }
1.120 +}
1.121 +
1.122 +JfrThreadGroupPointers& JfrThreadGroupsHelper::at(int index) {
1.123 + assert(_thread_group_hierarchy != NULL, "invariant");
1.124 + assert(index > invalid_iterator_pos && index < _thread_group_hierarchy->length(), "invariant");
1.125 + return *(_thread_group_hierarchy->at(index));
1.126 +}
1.127 +
1.128 +bool JfrThreadGroupsHelper::has_next() const {
1.129 + return _current_iterator_pos > invalid_iterator_pos;
1.130 +}
1.131 +
1.132 +bool JfrThreadGroupsHelper::is_valid() const {
1.133 + return (_thread_group_hierarchy != NULL && _thread_group_hierarchy->length() > 0);
1.134 +}
1.135 +
1.136 +JfrThreadGroupPointers& JfrThreadGroupsHelper::next() {
1.137 + assert(is_valid(), "invariant");
1.138 + return at(_current_iterator_pos--);
1.139 +}
1.140 +
1.141 +/*
1.142 + * If not at a safepoint, we create global weak references for
1.143 + * all reachable threadgroups for this thread.
1.144 + * If we are at a safepoint, the caller is the VMThread during
1.145 + * JFR checkpointing. It can use naked oops, because nothing
1.146 + * will move before the list of threadgroups is cleared and
1.147 + * mutator threads restarted. The threadgroup list is cleared
1.148 + * later by the VMThread as one of the final steps in JFR checkpointing
1.149 + * (not here).
1.150 + */
1.151 +int JfrThreadGroupsHelper::populate_thread_group_hierarchy(const JavaThread* jt, Thread* current) {
1.152 + assert(jt != NULL && jt->is_Java_thread(), "invariant");
1.153 + assert(current != NULL, "invariant");
1.154 + assert(_thread_group_hierarchy != NULL, "invariant");
1.155 +
1.156 + // immediate thread group
1.157 + Handle thread_group_handle(current, java_lang_Thread::threadGroup(jt->threadObj()));
1.158 + if (thread_group_handle == NULL) {
1.159 + return 0;
1.160 + }
1.161 +
1.162 + const bool use_weak_handles = !SafepointSynchronize::is_at_safepoint();
1.163 + jweak thread_group_weak_ref = use_weak_handles ? JNIHandles::make_weak_global(thread_group_handle) : NULL;
1.164 +
1.165 + JfrThreadGroupPointers* thread_group_pointers = new JfrThreadGroupPointers(thread_group_handle, thread_group_weak_ref);
1.166 + _thread_group_hierarchy->append(thread_group_pointers);
1.167 + // immediate parent thread group
1.168 + oop parent_thread_group_obj = java_lang_ThreadGroup::parent(thread_group_handle());
1.169 + Handle parent_thread_group_handle(current, parent_thread_group_obj);
1.170 +
1.171 + // and check parents parents...
1.172 + while (!(parent_thread_group_handle == NULL)) {
1.173 + const jweak parent_group_weak_ref = use_weak_handles ? JNIHandles::make_weak_global(parent_thread_group_handle) : NULL;
1.174 + thread_group_pointers = new JfrThreadGroupPointers(parent_thread_group_handle, parent_group_weak_ref);
1.175 + _thread_group_hierarchy->append(thread_group_pointers);
1.176 + parent_thread_group_obj = java_lang_ThreadGroup::parent(parent_thread_group_handle());
1.177 + parent_thread_group_handle = Handle(current, parent_thread_group_obj);
1.178 + }
1.179 + return _thread_group_hierarchy->length();
1.180 +}
1.181 +
1.182 +static traceid next_id() {
1.183 + static traceid _current_threadgroup_id = 0;
1.184 + return ++_current_threadgroup_id;
1.185 +}
1.186 +
1.187 +class JfrThreadGroup::JfrThreadGroupEntry : public JfrCHeapObj {
1.188 + friend class JfrThreadGroup;
1.189 + private:
1.190 + traceid _thread_group_id;
1.191 + traceid _parent_group_id;
1.192 + char* _thread_group_name; // utf8 format
1.193 + // If an entry is created during a safepoint, the
1.194 + // _thread_group_oop contains a direct oop to
1.195 + // the java.lang.ThreadGroup object.
1.196 + // If an entry is created on javathread exit time (not at safepoint),
1.197 + // _thread_group_weak_ref contains a JNI weak global handle
1.198 + // indirection to the java.lang.ThreadGroup object.
1.199 + // Note: we cannot use a union here since CHECK_UNHANDLED_OOPS makes oop have
1.200 + // a ctor which isn't allowed in a union by the SunStudio compiler
1.201 + oop _thread_group_oop;
1.202 + jweak _thread_group_weak_ref;
1.203 +
1.204 + JfrThreadGroupEntry(const char* tgstr, JfrThreadGroupPointers& ptrs);
1.205 + ~JfrThreadGroupEntry();
1.206 +
1.207 + traceid thread_group_id() const { return _thread_group_id; }
1.208 + void set_thread_group_id(traceid tgid) { _thread_group_id = tgid; }
1.209 +
1.210 + const char* const thread_group_name() const { return _thread_group_name; }
1.211 + void set_thread_group_name(const char* tgname);
1.212 +
1.213 + traceid parent_group_id() const { return _parent_group_id; }
1.214 + void set_parent_group_id(traceid pgid) { _parent_group_id = pgid; }
1.215 +
1.216 + void set_thread_group(JfrThreadGroupPointers& ptrs);
1.217 + bool is_equal(const JfrThreadGroupPointers& ptrs) const;
1.218 + const oop thread_group() const;
1.219 +};
1.220 +
1.221 +JfrThreadGroup::JfrThreadGroupEntry::JfrThreadGroupEntry(const char* tgname, JfrThreadGroupPointers& ptrs) :
1.222 + _thread_group_id(0),
1.223 + _parent_group_id(0),
1.224 + _thread_group_name(NULL),
1.225 + _thread_group_oop(NULL),
1.226 + _thread_group_weak_ref(NULL) {
1.227 + set_thread_group_name(tgname);
1.228 + set_thread_group(ptrs);
1.229 +}
1.230 +
1.231 +JfrThreadGroup::JfrThreadGroupEntry::~JfrThreadGroupEntry() {
1.232 + if (_thread_group_name != NULL) {
1.233 + JfrCHeapObj::free(_thread_group_name, strlen(_thread_group_name) + 1);
1.234 + }
1.235 + if (_thread_group_weak_ref != NULL) {
1.236 + JNIHandles::destroy_weak_global(_thread_group_weak_ref);
1.237 + }
1.238 +}
1.239 +
1.240 +void JfrThreadGroup::JfrThreadGroupEntry::set_thread_group_name(const char* tgname) {
1.241 + assert(_thread_group_name == NULL, "invariant");
1.242 + if (tgname != NULL) {
1.243 + size_t len = strlen(tgname);
1.244 + _thread_group_name = JfrCHeapObj::new_array<char>(len+1);
1.245 + strncpy(_thread_group_name, tgname, len);
1.246 + _thread_group_name[len] = '\0';
1.247 + }
1.248 +}
1.249 +
1.250 +const oop JfrThreadGroup::JfrThreadGroupEntry::thread_group() const {
1.251 + return _thread_group_weak_ref != NULL ? JNIHandles::resolve(_thread_group_weak_ref) : _thread_group_oop;
1.252 +}
1.253 +
1.254 +void JfrThreadGroup::JfrThreadGroupEntry::set_thread_group(JfrThreadGroupPointers& ptrs) {
1.255 + _thread_group_weak_ref = ptrs.transfer_weak_global_handle_ownership();
1.256 + if (_thread_group_weak_ref == NULL) {
1.257 + _thread_group_oop = ptrs.thread_group_oop();
1.258 + assert(_thread_group_oop != NULL, "invariant");
1.259 + } else {
1.260 + _thread_group_oop = NULL;
1.261 + }
1.262 +}
1.263 +
1.264 +JfrThreadGroup::JfrThreadGroup() : _list(NULL) {
1.265 + _list = new (ResourceObj::C_HEAP, mtTracing) GrowableArray<JfrThreadGroupEntry*>(30, true);
1.266 +}
1.267 +
1.268 +JfrThreadGroup::~JfrThreadGroup() {
1.269 + assert(SafepointSynchronize::is_at_safepoint(), "invariant");
1.270 + if (_list != NULL) {
1.271 + for (int i = 0; i < _list->length(); i++) {
1.272 + JfrThreadGroupEntry* e = _list->at(i);
1.273 + delete e;
1.274 + }
1.275 + delete _list;
1.276 + }
1.277 +}
1.278 +
1.279 +JfrThreadGroup* JfrThreadGroup::instance() {
1.280 + return _instance;
1.281 +}
1.282 +
1.283 +void JfrThreadGroup::set_instance(JfrThreadGroup* new_instance) {
1.284 + _instance = new_instance;
1.285 +}
1.286 +
1.287 +traceid JfrThreadGroup::thread_group_id(const JavaThread* jt, Thread* current) {
1.288 + ResourceMark rm(current);
1.289 + HandleMark hm(current);
1.290 + JfrThreadGroupsHelper helper(jt, current);
1.291 + return helper.is_valid() ? thread_group_id_internal(helper) : 0;
1.292 +}
1.293 +
1.294 +traceid JfrThreadGroup::thread_group_id(JavaThread* jt) {
1.295 + assert(!JfrStream_lock->owned_by_self(), "holding stream lock but should not hold it here");
1.296 + return thread_group_id(jt, jt);
1.297 +}
1.298 +
1.299 +traceid JfrThreadGroup::thread_group_id_internal(JfrThreadGroupsHelper& helper) {
1.300 + ThreadGroupExclusiveAccess lock;
1.301 + JfrThreadGroup* tg_instance = instance();
1.302 + if (tg_instance == NULL) {
1.303 + tg_instance = new JfrThreadGroup();
1.304 + if (tg_instance == NULL) {
1.305 + return 0;
1.306 + }
1.307 + set_instance(tg_instance);
1.308 + }
1.309 +
1.310 + JfrThreadGroupEntry* tge = NULL;
1.311 + int parent_thread_group_id = 0;
1.312 + while (helper.has_next()) {
1.313 + JfrThreadGroupPointers& ptrs = helper.next();
1.314 + tge = tg_instance->find_entry(ptrs);
1.315 + if (NULL == tge) {
1.316 + tge = tg_instance->new_entry(ptrs);
1.317 + assert(tge != NULL, "invariant");
1.318 + tge->set_parent_group_id(parent_thread_group_id);
1.319 + }
1.320 + parent_thread_group_id = tge->thread_group_id();
1.321 + }
1.322 + // the last entry in the hierarchy is the immediate thread group
1.323 + return tge->thread_group_id();
1.324 +}
1.325 +
1.326 +bool JfrThreadGroup::JfrThreadGroupEntry::is_equal(const JfrThreadGroupPointers& ptrs) const {
1.327 + return ptrs.thread_group_oop() == thread_group();
1.328 +}
1.329 +
1.330 +JfrThreadGroup::JfrThreadGroupEntry*
1.331 +JfrThreadGroup::find_entry(const JfrThreadGroupPointers& ptrs) const {
1.332 + for (int index = 0; index < _list->length(); ++index) {
1.333 + JfrThreadGroupEntry* curtge = _list->at(index);
1.334 + if (curtge->is_equal(ptrs)) {
1.335 + return curtge;
1.336 + }
1.337 + }
1.338 + return (JfrThreadGroupEntry*) NULL;
1.339 +}
1.340 +
1.341 +// Assumes you already searched for the existence
1.342 +// of a corresponding entry in find_entry().
1.343 +JfrThreadGroup::JfrThreadGroupEntry*
1.344 +JfrThreadGroup::new_entry(JfrThreadGroupPointers& ptrs) {
1.345 + typeArrayOop tg_name = java_lang_ThreadGroup::name(ptrs.thread_group_oop());
1.346 + JfrThreadGroupEntry* const tge =
1.347 + new JfrThreadGroupEntry(UNICODE::as_utf8((jchar*) tg_name->base(T_CHAR), tg_name->length()), ptrs);
1.348 + add_entry(tge);
1.349 + return tge;
1.350 +}
1.351 +
1.352 +int JfrThreadGroup::add_entry(JfrThreadGroupEntry* tge) {
1.353 + assert(tge != NULL, "attempting to add a null entry!");
1.354 + assert(0 == tge->thread_group_id(), "id must be unassigned!");
1.355 + tge->set_thread_group_id(next_id());
1.356 + return _list->append(tge);
1.357 +}
1.358 +
1.359 +void JfrThreadGroup::write_thread_group_entries(JfrCheckpointWriter& writer) const {
1.360 + assert(_list != NULL && !_list->is_empty(), "should not need be here!");
1.361 + const int number_of_tg_entries = _list->length();
1.362 + writer.write_count(number_of_tg_entries);
1.363 + for (int index = 0; index < number_of_tg_entries; ++index) {
1.364 + const JfrThreadGroupEntry* const curtge = _list->at(index);
1.365 + writer.write_key(curtge->thread_group_id());
1.366 + writer.write(curtge->parent_group_id());
1.367 + writer.write(curtge->thread_group_name());
1.368 + }
1.369 +}
1.370 +
1.371 +void JfrThreadGroup::write_selective_thread_group(JfrCheckpointWriter* writer, traceid thread_group_id) const {
1.372 + assert(writer != NULL, "invariant");
1.373 + assert(_list != NULL && !_list->is_empty(), "should not need be here!");
1.374 + const int number_of_tg_entries = _list->length();
1.375 +
1.376 + // save context
1.377 + const JfrCheckpointContext ctx = writer->context();
1.378 + writer->write_type(TYPE_THREADGROUP);
1.379 + const jlong count_offset = writer->reserve(sizeof(u4)); // Don't know how many yet
1.380 + int number_of_entries_written = 0;
1.381 + for (int index = number_of_tg_entries - 1; index >= 0; --index) {
1.382 + const JfrThreadGroupEntry* const curtge = _list->at(index);
1.383 + if (thread_group_id == curtge->thread_group_id()) {
1.384 + writer->write_key(curtge->thread_group_id());
1.385 + writer->write(curtge->parent_group_id());
1.386 + writer->write(curtge->thread_group_name());
1.387 + ++number_of_entries_written;
1.388 + thread_group_id = curtge->parent_group_id();
1.389 + }
1.390 + }
1.391 + if (number_of_entries_written == 0) {
1.392 + // nothing to write, restore context
1.393 + writer->set_context(ctx);
1.394 + return;
1.395 + }
1.396 + assert(number_of_entries_written > 0, "invariant");
1.397 + writer->write_count(number_of_entries_written, count_offset);
1.398 +}
1.399 +
1.400 +// Write out JfrThreadGroup instance and then delete it
1.401 +void JfrThreadGroup::serialize(JfrCheckpointWriter& writer) {
1.402 + ThreadGroupExclusiveAccess lock;
1.403 + JfrThreadGroup* tg_instance = instance();
1.404 + assert(tg_instance != NULL, "invariant");
1.405 + ResourceManager<JfrThreadGroup> tg_handle(tg_instance);
1.406 + set_instance(NULL);
1.407 + tg_handle->write_thread_group_entries(writer);
1.408 +}
1.409 +
1.410 +// for writing a particular thread group
1.411 +void JfrThreadGroup::serialize(JfrCheckpointWriter* writer, traceid thread_group_id) {
1.412 + assert(writer != NULL, "invariant");
1.413 + ThreadGroupExclusiveAccess lock;
1.414 + JfrThreadGroup* const tg_instance = instance();
1.415 + assert(tg_instance != NULL, "invariant");
1.416 + tg_instance->write_selective_thread_group(writer, thread_group_id);
1.417 +}
