JDK14/Java14源码在线阅读

/*
 * Copyright (c) 2014, 2018, 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/jfrRecorder.hpp"
#include "jfr/utilities/jfrAllocation.hpp"
#include "logging/log.hpp"
#include "memory/allocation.inline.hpp"
#include "runtime/atomic.hpp"
#include "runtime/vm_version.hpp"
#include "utilities/debug.hpp"
#include "utilities/macros.hpp"
#include "utilities/nativeCallStack.hpp"

#ifdef ASSERT
static jlong atomic_add_jlong(jlong value, jlong volatile* const dest) {
  assert(VM_Version::supports_cx8(), "unsupported");
  jlong compare_value;
  jlong exchange_value;
  do {
    compare_value = *dest;
    exchange_value = compare_value + value;
  } while (Atomic::cmpxchg(dest, compare_value, exchange_value) != compare_value);
  return exchange_value;
}

// debug statistics
static volatile jlong _allocated_bytes = 0;
static volatile jlong _deallocated_bytes = 0;
static volatile jlong _live_set_bytes = 0;

static void add(size_t alloc_size) {
  if (!JfrRecorder::is_created()) {
    const jlong total_allocated = atomic_add_jlong((jlong)alloc_size, &_allocated_bytes);
    const jlong current_live_set = atomic_add_jlong((jlong)alloc_size, &_live_set_bytes);
    log_trace(jfr, system)("Allocation: [" SIZE_FORMAT "] bytes", alloc_size);
    log_trace(jfr, system)("Total alloc [" JLONG_FORMAT "] bytes", total_allocated);
    log_trace(jfr, system)("Liveset:    [" JLONG_FORMAT "] bytes", current_live_set);
  }
}

static void subtract(size_t dealloc_size) {
  if (!JfrRecorder::is_created()) {
    const jlong total_deallocated = atomic_add_jlong((jlong)dealloc_size, &_deallocated_bytes);
    const jlong current_live_set = atomic_add_jlong(((jlong)dealloc_size * -1), &_live_set_bytes);
    log_trace(jfr, system)("Deallocation: [" SIZE_FORMAT "] bytes", dealloc_size);
    log_trace(jfr, system)("Total dealloc [" JLONG_FORMAT "] bytes", total_deallocated);
    log_trace(jfr, system)("Liveset:      [" JLONG_FORMAT "] bytes", current_live_set);
  }
}

static void hook_memory_deallocation(size_t dealloc_size) {
  subtract(dealloc_size);
}
#endif // ASSERT

static void hook_memory_allocation(const char* allocation, size_t alloc_size) {
  if (NULL == allocation) {
    if (!JfrRecorder::is_created()) {
      log_warning(jfr, system)("Memory allocation failed for size [" SIZE_FORMAT "] bytes", alloc_size);
      return;
    } else {
      // after critical startup, fail as by default
      vm_exit_out_of_memory(alloc_size, OOM_MALLOC_ERROR, "AllocateHeap");
    }
  }
  debug_only(add(alloc_size));
}

void JfrCHeapObj::on_memory_allocation(const void* allocation, size_t size) {
  hook_memory_allocation((const char*)allocation, size);
}

void* JfrCHeapObj::operator new(size_t size) throw() {
  return operator new(size, std::nothrow);
}

void* JfrCHeapObj::operator new (size_t size, const std::nothrow_t&  nothrow_constant) throw() {
  void* const memory = CHeapObj<mtTracing>::operator new(size, nothrow_constant, CALLER_PC);
  hook_memory_allocation((const char*)memory, size);
  return memory;
}

void* JfrCHeapObj::operator new [](size_t size) throw() {
  return operator new[](size, std::nothrow);
}

void* JfrCHeapObj::operator new [](size_t size, const std::nothrow_t&  nothrow_constant) throw() {
  void* const memory = CHeapObj<mtTracing>::operator new[](size, nothrow_constant, CALLER_PC);
  hook_memory_allocation((const char*)memory, size);
  return memory;
}

void JfrCHeapObj::operator delete(void* p, size_t size) {
  debug_only(hook_memory_deallocation(size);)
  CHeapObj<mtTracing>::operator delete(p);
}

void JfrCHeapObj::operator delete[](void* p, size_t size) {
  debug_only(hook_memory_deallocation(size);)

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