v8/src/zone-inl.h

// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_ZONE_INL_H_
#define V8_ZONE_INL_H_

#include "src/zone.h"

#ifdef V8_USE_ADDRESS_SANITIZER
  #include <sanitizer/asan_interface.h>
#else
  #define ASAN_UNPOISON_MEMORY_REGION(start, size) ((void) 0)
#endif

#include "src/counters.h"
#include "src/isolate.h"
#include "src/utils.h"

namespace v8 {
namespace internal {


static const int kASanRedzoneBytes = 24;  // Must be a multiple of 8.


inline void* Zone::New(int size) {
  // Round up the requested size to fit the alignment.
  size = RoundUp(size, kAlignment);

  // If the allocation size is divisible by 8 then we return an 8-byte aligned
  // address.
  if (kPointerSize == 4 && kAlignment == 4) {
    position_ += ((~size) & 4) & (reinterpret_cast<intptr_t>(position_) & 4);
  } else {
    ASSERT(kAlignment >= kPointerSize);
  }

  // Check if the requested size is available without expanding.
  Address result = position_;

  int size_with_redzone =
#ifdef V8_USE_ADDRESS_SANITIZER
      size + kASanRedzoneBytes;
#else
      size;
#endif

  if (size_with_redzone > limit_ - position_) {
     result = NewExpand(size_with_redzone);
  } else {
     position_ += size_with_redzone;
  }

#ifdef V8_USE_ADDRESS_SANITIZER
  Address redzone_position = result + size;
  ASSERT(redzone_position + kASanRedzoneBytes == position_);
  ASAN_POISON_MEMORY_REGION(redzone_position, kASanRedzoneBytes);
#endif

  // Check that the result has the proper alignment and return it.
  ASSERT(IsAddressAligned(result, kAlignment, 0));
  allocation_size_ += size;
  return reinterpret_cast<void*>(result);
}


template <typename T>
T* Zone::NewArray(int length) {
  CHECK(std::numeric_limits<int>::max() / static_cast<int>(sizeof(T)) > length);
  return static_cast<T*>(New(length * sizeof(T)));
}


bool Zone::excess_allocation() {
  return segment_bytes_allocated_ > kExcessLimit;
}


void Zone::adjust_segment_bytes_allocated(int delta) {
  segment_bytes_allocated_ += delta;
  isolate_->counters()->zone_segment_bytes()->Set(segment_bytes_allocated_);
}


template <typename Config>
ZoneSplayTree<Config>::~ZoneSplayTree() {
  // Reset the root to avoid unneeded iteration over all tree nodes
  // in the destructor.  For a zone-allocated tree, nodes will be
  // freed by the Zone.
  SplayTree<Config, ZoneAllocationPolicy>::ResetRoot();
}


void* ZoneObject::operator new(size_t size, Zone* zone) {
  return zone->New(static_cast<int>(size));
}

inline void* ZoneAllocationPolicy::New(size_t size) {
  ASSERT(zone_);
  return zone_->New(static_cast<int>(size));
}


template <typename T>
void* ZoneList<T>::operator new(size_t size, Zone* zone) {
  return zone->New(static_cast<int>(size));
}


template <typename T>
void* ZoneSplayTree<T>::operator new(size_t size, Zone* zone) {
  return zone->New(static_cast<int>(size));
}


} }  // namespace v8::internal

#endif  // V8_ZONE_INL_H_