jdk8-mips64-public/hotspot: src/share/vm/jfr/recorder/storage/jfrBuffer.cpp@d2c2cd90513e (annotated)

src/share/vm/jfr/recorder/storage/jfrBuffer.cpp@d2c2cd90513e (annotated)

src/share/vm/jfr/recorder/storage/jfrBuffer.cpp

Wed, 17 Jun 2020 11:43:05 +0300

author: apetushkov
date: Wed, 17 Jun 2020 11:43:05 +0300
changeset 9928: d2c2cd90513e
parent 9858: b985cbb00e68
permissions: -rw-r--r--

8220293: Deadlock in JFR string pool
Reviewed-by: rehn, egahlin

 /*
  * Copyright (c) 2011, 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 "jfr/recorder/storage/jfrBuffer.hpp"
 #include "runtime/atomic.inline.hpp"
 #include "runtime/orderAccess.inline.hpp"
 #include "runtime/thread.inline.hpp"
 #include "jfr/recorder/jfrRecorder.hpp"
 static const u1* const MUTEX_CLAIM = NULL;
 JfrBuffer::JfrBuffer() : _next(NULL),
                          _prev(NULL),
                          _identity(NULL),
                          _pos(NULL),
                          _top(NULL),
                          _flags(0),
                          _header_size(0),
                          _size(0) {}
 bool JfrBuffer::initialize(size_t header_size, size_t size, const void* id /* NULL */) {
   _header_size = (u2)header_size;
   _size = (u4)(size / BytesPerWord);
   assert(_identity == NULL, "invariant");
   _identity = id;
   set_pos(start());
   set_top(start());
   assert(_next == NULL, "invariant");
   assert(free_size() == size, "invariant");
   assert(!transient(), "invariant");
   assert(!lease(), "invariant");
   assert(!retired(), "invariant");
   return true;
 }
 void JfrBuffer::reinitialize() {
   assert(!lease(), "invariant");
   assert(!transient(), "invariant");
   set_pos(start());
   clear_retired();
   set_top(start());
 }
 void JfrBuffer::concurrent_reinitialization() {
   concurrent_top();
   assert(!lease(), "invariant");
   assert(!transient(), "invariant");
   set_pos(start());
   set_concurrent_top(start());
   clear_retired();
 }
 size_t JfrBuffer::discard() {
   size_t discard_size = unflushed_size();
   set_top(pos());
   return discard_size;
 }
 const u1* JfrBuffer::stable_top() const {
   const u1* current_top;
   do {
     current_top = (const u1*)OrderAccess::load_ptr_acquire(&_top);
   } while (MUTEX_CLAIM == current_top);
   return current_top;
 }
 const u1* JfrBuffer::top() const {
   return _top;
 }
 void JfrBuffer::set_top(const u1* new_top) {
   _top = new_top;
 }
 const u1* JfrBuffer::concurrent_top() const {
   do {
     const u1* current_top = stable_top();
     if (Atomic::cmpxchg_ptr((void*)MUTEX_CLAIM, &_top, (void*)current_top) == current_top) {
       return current_top;
     }
   } while (true);
 }
 void JfrBuffer::set_concurrent_top(const u1* new_top) {
   assert(new_top != MUTEX_CLAIM, "invariant");
   assert(new_top <= end(), "invariant");
   assert(new_top >= start(), "invariant");
   assert(top() == MUTEX_CLAIM, "invariant");
   OrderAccess::release_store_ptr(&_top, (void*)new_top);
 }
 size_t JfrBuffer::unflushed_size() const {
   return pos() - stable_top();
 }
 void JfrBuffer::acquire(const void* id) {
   assert(id != NULL, "invariant");
   const void* current_id;
   do {
     current_id = OrderAccess::load_ptr_acquire(&_identity);
   } while (current_id != NULL || Atomic::cmpxchg_ptr((void*)id, &_identity, (void*)current_id) != current_id);
 }
 bool JfrBuffer::try_acquire(const void* id) {
   assert(id != NULL, "invariant");
   const void* const current_id = OrderAccess::load_ptr_acquire(&_identity);
   return current_id == NULL && Atomic::cmpxchg_ptr((void*)id, &_identity, (void*)current_id) == current_id;
 }
 void JfrBuffer::release() {
   OrderAccess::release_store_ptr(&_identity, (void*)NULL);
 }
 void JfrBuffer::clear_identity() {
   _identity = NULL;
 }
 bool JfrBuffer::acquired_by(const void* id) const {
   return identity() == id;
 }
 bool JfrBuffer::acquired_by_self() const {
   return acquired_by(Thread::current());
 }
 #ifdef ASSERT
 static bool validate_to(const JfrBuffer* const to, size_t size) {
   assert(to != NULL, "invariant");
   if (!JfrRecorder::is_shutting_down()) assert(to->acquired_by_self(), "invariant");
   assert(to->free_size() >= size, "invariant");
   return true;
 }
 static bool validate_concurrent_this(const JfrBuffer* const t, size_t size) {
   assert(t->top() == MUTEX_CLAIM, "invariant");
   return true;
 }
 static bool validate_this(const JfrBuffer* const t, size_t size) {
   assert(t->top() + size <= t->pos(), "invariant");
   return true;
 }
 #endif // ASSERT
 void JfrBuffer::move(JfrBuffer* const to, size_t size) {
   assert(validate_to(to, size), "invariant");
   assert(validate_this(this, size), "invariant");
   const u1* current_top = top();
   assert(current_top != NULL, "invariant");
   memcpy(to->pos(), current_top, size);
   to->set_pos(size);
   to->release();
   set_top(current_top + size);
 }
 void JfrBuffer::concurrent_move_and_reinitialize(JfrBuffer* const to, size_t size) {
   assert(validate_to(to, size), "invariant");
   const u1* current_top = concurrent_top();
   assert(validate_concurrent_this(this, size), "invariant");
   const size_t actual_size = MIN2(size, (size_t)(pos() - current_top));
   assert(actual_size <= size, "invariant");
   memcpy(to->pos(), current_top, actual_size);
   to->set_pos(actual_size);
   set_pos(start());
   to->release();
   set_concurrent_top(start());
 }
 enum FLAG {
   RETIRED = 1,
   TRANSIENT = 2,
   LEASE = 4
 };
 bool JfrBuffer::transient() const {
   return (u1)TRANSIENT == (_flags & (u1)TRANSIENT);
 }
 void JfrBuffer::set_transient() {
   _flags |= (u1)TRANSIENT;
   assert(transient(), "invariant");
 }
 void JfrBuffer::clear_transient() {
   if (transient()) {
     _flags ^= (u1)TRANSIENT;
   }
   assert(!transient(), "invariant");
 }
 bool JfrBuffer::lease() const {
   return (u1)LEASE == (_flags & (u1)LEASE);
 }
 void JfrBuffer::set_lease() {
   _flags |= (u1)LEASE;
   assert(lease(), "invariant");
 }
 void JfrBuffer::clear_lease() {
   if (lease()) {
     _flags ^= (u1)LEASE;
   }
   assert(!lease(), "invariant");
 }
 static u2 load_acquire_flags(const u2* const flags) {
   return OrderAccess::load_acquire((volatile jushort *)flags);
 }
 static void release_store_flags(u2* const flags, u2 new_flags) {
   OrderAccess::release_store(flags, new_flags);
 }
 bool JfrBuffer::retired() const {
   return (u1)RETIRED == (load_acquire_flags(&_flags) & (u1)RETIRED);
 }
 void JfrBuffer::set_retired() {
   const u2 new_flags = load_acquire_flags(&_flags) | (u1)RETIRED;
   release_store_flags(&_flags, new_flags);
 }
 void JfrBuffer::clear_retired() {
   u2 new_flags = load_acquire_flags(&_flags);
   if ((u1)RETIRED == (new_flags & (u1)RETIRED)) {
     new_flags ^= (u1)RETIRED;
     release_store_flags(&_flags, new_flags);
   }
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/jfr/recorder/storage/jfrBuffer.cpp@d2c2cd90513e (annotated)

src/share/vm/jfr/recorder/storage/jfrBuffer.cpp